an evaluation cordova mine prop omep81-9-c-78 · presence of 25,580 tons of ore at 0.265 oz/ton...

31C12SEM59 63.4412 MARMORA 010

AN

EVALUATION

CORDOVA MINE PROPERTY

LASIR COLD INC.

March 9, 1981 W. C. WAHL LIMITED

TABLE OF C l31C128EMS9 S3.4*12 MARMORA oioc

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

GEOLOGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

TONNAGE AND GRADE CALCULATIONS . . . . . . . . . . . . . . . . 8

Sample Calculation . . . . . . . . . . . . . . . . . . . . . . . . 9

METALLURGY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 22

COST ESTIMATES . . . . . . . . . . . . . . . . . . . . , . . . . . 23

I Summary - Dewater Cordova Mine . . . . . . . . . . . . . . . . ISII Summary - Portable Test Mill . . . . . . . . . . . . . . . . . . 26III Summary - Underground Mapping 6 Sampling . . . . . . . . . . . 30IV Summary - Diamond Drilling . . . . . . . . . . . . . . . . . . . 33V Summary - Limited Preliminary Stope Development . . . . . . . . 36

APPENDICES . . . . . . . . . . . . . . . . . . . . . . . . . . , . . 37

Appendix i Ore Reserve Calculations by Cominco, Jan. 15, 1939. 38Appendix ii Ore Left in Slopes By Cominco, Feb. 3, 1947. . . . 39Appendix iii Ore Left on upper Levels, Progress Report, 1936 . . 40Appendix iv Ore Left on Upper Levels, Section, Orvana Mines, 41

Feb. 25, 1965. . . . . . . . . . . . . . . . . .Appendix v Ore in Surface Dump, Jan. 1940 . . . . . . . . . . 42Appendix vi Estimate of Surface Materials, Dec. 2, 1980 . . . . . 43Appendix vii Section of Cordova Mines, Satterly's Report, 1942. . 48 Appendix viii Portion of Cominco Assay Plan, 4th Level

Nov. 1, 1938. . . . . . . . . . . . . . . . . . 49Appendix ix Volume per ton of rock . . . . . . . . . . . . . . . 50Appendix X Aurora Quarrying. . . . . . . . . . . . . . . . . . 52

INTRODUCTION

The following evaluation and subsequent report was commissioned by

the President and Directors of Lasir Gold Inc. and was carried out by W. C. Wahl

Limited under the direct supervision of D. C. Wahl P.Eng., Consulting Engineer

assisted by P. R. Rautanen B.Se., Project Geologist. The evaluation 6 report

is based on our examination of all available company data and government

publications. A personal visit to the property was not undertaken at this time,

as it was felt that no advantage would be served by doing so due to the flooded

nature of the old mine workings.

GENERAL

The Cordova Mine is located in south-eastern Ontario near the eastern

boundary of Peterborough County (44O UO 1 north latitude, 77O 50' west longitude).

The site is readily accessible by road, proceeding east from Toronto on High

way # 401 to Belleville and then north on Highway # 14 to Marmora. The mine

is approximately 8 miles beyond Marmora. Total distance from Toronto is

approximately 150 miles.

Lasir Gold Inc. has acquired the mineral rights to the west half of Lot 20

Concession 1, Marmora Township (116 acres), the east half of Lot 20, Concession 1,

Belmont Township (117 acres), and the south-east quarter of Lot 21, Concession 1,

Belmont Township (about 50 acres ), as well as surface rights to the west half

of Lot 20, Concession 1, Belmont Township (116 acres), and the eastern portion

of Lot 19, Concession 1, Belmont Township (about 75 acres). These areas are

indicated on the accompanying map.

-1-

HISTORY

Cold was first discovered on the Cordova property in 1890 by Mr. H.

Strickland who found free gold in an outcrop crossed by a road which was

washed out following a heavy rain. The occurrence went unnoticed until 1891

when the property was bought by Mr. A. W. Carscallen who sank the #1 shaft

to a depth of 60 feet and installed two grinding mills which allowed the recovery

of considerable gold. This work continued until 1893 .

In 1897 a British corporation, the Cordova Exploration Company, bought

the property. Extensive development was undertaken which included the con

struction of a ten stamp mill. During the period 1897 - 1900 there were 4,803

ounces of gold recovered from 15,267 tons of ore. In 1901 the mill was expanded

to 30 stamps and from 1901 to 1903 there were 10,943 ounces of gold recovered

from 41,518 tons of ore. In 1903 two principal owners of the mine died, which

caused the mine to close late in 1903.

In 1911 Cordova Mines Limited bought the property and proceeded to

dewater the mine and sink the #3 shaft to a depth of 500 feet. The mine,

formerly known as the Belmont Mine, was renamed the Cordova Mine. Due to

difficulties with equipment, production was erratic until 1917 when a serious

fire suspended all operations. During this period a total of 10,230 tons of ore

were processed to produce approximately 2,412 ounces of gold.

In 1934, Cominco purchased the property for a sum of $10,000. The #3

shaft was deepened to 1,050 feet and development was mostly confined to the

deeper levels. A 100 ton mill was built in 1939 and during the interval from

October 23, 1939 to July 29, 1940, the mill processed 33,434 tons of ore and

extracted 3,487 ounces of gold. All operations ceased at the end of July, 1940.

During the span of time from 1897 to 1940 the Cordova Mine yielded 21,645 ounces

of gold from 100,449 tons of ore for an average grade bf 0.215 oz/ton.

^ ' ''- ' -? ' h, .L A T* - , -, . .

-3-

At the close of operations in 1940 there were three shafts with depths

of 101,185 and 1,050 feet which gave access to 16,676 feet of drifting, 3,697

feet of cross-cutting, 2,203 feet of sinking and 768 feet of raising. Cominco

conducted 8,029 feet of diamond drilling during its operations. The explored

area of the mine workings is 2,500 feet long, extending to a depth of 1,000 feet.

Ore reserve calculations by Cominco at the^cTosejif) its operations indicate - ~r~ ~" * the presence of 77,130 tons of ore grading^. 1 75j*z7|on with an additional fo~o f f

50,000 tons of probable ore grading 0.175 oz/ton. A total^of-irfiJJt tons of2 ~' ~~~ - - -

ore @ 0.153 oz/ton was left in the stopes by Cominco. There is also the reported t f "0 'r ' '

presence of 25,580 tons of ore at 0.265 oz/ton left in older stopes after the fire ^ - 4 T^

of 1917, but not touched by the Comin

On surface there is an estimated 8,466 .4

rations. This figure is questionable

k.at 0.072 oz/ton adjacent to

No. 3 shaft"1 , as well as an estimated 10,000 tons^at 0.05 oz/ton next to the No. 1

shaft. In addition, there are 600 tons of sand at O^SOoz/ton. These figures

imply that 23,936.7 ounces of gold is still present on thefxoperty, not including

the questionable figure of ore left after the fire of 1917.

The property is presently owned by Lasir Gold Inc., who have been

conducting experimental gold extraction techniques on the surface materials.

, i,-f

f'.'S i 'f, r i ; . , jj 4*

O

Ul

J.

1. letter to S. G. Blaylock; Jan. 15, 1939. (appendix i)

2. memorandum to W. C. Jewitt; Feb. 3, 1947. (appendix i i)

3. progress report for 1936 by C. A. Seaton (appendix Hi) section from Orvana Mines, Feb. 25, 1965 (appendix iv)

4. annual report 1939 and progress reports 1940 by C. A. Seaton (appendix v)

5. personal remarks by Walter Hood, 1981

6. progress report to Lasir Gold Inc.; Dec. 2, 1980. (appendix vi)

-4-

GEOLOGY

The Cordova property of Lasir Gold Inc. is underlain by rocks of Pre

cambrian age. The oldest lithologies are a series of metasediments (including

marble, paragneiss, quartzite, arkose, schist, conglomerate, etc.) and meta-

volcanics (including amphibolite, amphibolite schist, andesite, basalt, pyro

clastics, etc.) which were intensely metamorphosed and deformed during the

Grenville Orogeny approximately 1,100 million years ago. These rocks are cut

by intrusions associated with this orogenic activity.

The oldest intrusives (with associated gold mineralization) are a series

of basic intrusive rocks with compositions ranging from peridotite to quartz

diorite, emplaced early during the Grenville Orogeny. The latest intrusives

are present in the form of granitic domes and pegmatitic dikes intruded towards

the end of the Grenville.

Paleozoic limestones outcrop just to the south of the area and a thin

mantle of glacial debris is widespread throughout the area.9

There would seem to be 2 or 3 ages of basic intrusives based on aero

magnetic evidence. The compositions of the intrusions include quartz diorite,

diorite, gabbro, norite, peridotite, hornblendite, amphibolite, and metagabbro.

The gabbroic intrusives generally form basinal structures with an alteration rim

surrounding the gabbro; and brecciation, iron and sulphide mineralization being

found within the gabbro body.

In Belmont Township, there is a gabbroic complex intruding pre-existing

volcanics and sediments, itself being cut by later felsic dikes. The gabbro is

a medium to coarse grained rock composed of labradorite, hornblende, carbonate,

chlorite, serpentine, sericite, quartz, apatite, pyrite, magnetite and ilmenite.

Local differentiation of the gabbro would appear to have taken place. This gabbro

has a very definite aeromagnetic expression.

-5-

cs-J•Lr*

X. '2' K

QEOLOQX

Legend

6j Peleoioie Sediment!

LF1 Felsic Intrucivei

V [4 i Mafic Intrusive!

~3~j Non-cluttc M*lM*dta*nti

F] Clutic ttaUMdimenti

D UeUvoteMiic*

Shear zones within the gabbro show alteration to biotite and chlorite.

These shear zones are important because all gold mineralization has been found

in vein material within these shears on the western margin of the intrusion.

(Not all shear zones have gold mineralization, however).

Vein material within the shears consists predominantly of carbonate,

feldspar, quartz with pyrite and pyrrhotite. (Gold is associated with the pyrite

only). The vein material is found as (i) replacement of shear zones (i!) series

of stringers and veinlets paralleling the planes of shearing (iii) veinlets in

brecciated replacement zones (iv) lenses of massive material parallel to the shear

planes. Individual shears are quite irregular but usually persist along strike

with widths from 1 to 40 feet.

On the Cordova property there are three shears containing workable

gold-bearing zones. Around the No. 1 shaft we have mineralized zones striking

N60 to 700E and N 80OW dipping 60 to 70OSE. Around the No. 3 shaft the

mineralized zones strike N70 to 85OE and N85OE and N85OW dipping 65OS. These

gold bearing zones appear to coincide with changes in the strike of the

shearing (intersection of shear zones) and also to locations were there is

contortion and variation in the shearing. The major shear zones would seem

to parallel the outer contact of the gabbro. The shear zones may have been

the controlling factor in the direction taken by gold-bearing mineralizing

solutions.

-7-

TONNAGE AND GRADE CALCULATIONS

Data for the tonnage and grade calculations was compiled from all

available sources and evaluated in an attempt to quantify and deliniate blocks of "proven and probable ore" as defined by the Ontario Securities Commission.

"Proven ore" or "measured ore" means that material

for which tonnage is computed from dimensions revealed

in outcrops or trenches or underground workings or

driZZ hoZes and for which the grade is computed from the results of adequate sampling, and for which the

sites for inspection, sampling and measurement are so

spaced and the geological character so well defined that the size, shape and mineral content are established, and

for which the computed tonnage and grade are judged

to be accurate within Zimites which shall be stated and

for which it shaZZ be stated whether the tonnage and

grade of proven ore or measured ore are in situ or

extractable, with dilution factors shown, and reasons

for the use of these dilution factors clearly explained.

"Probable ore" or "indicated ore" means that material

for which tonnage and grade are computed partly from specific measurements, samples or production data, and partly from projection for a reasonable distance on geological evidence, and for which the sites available for inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely or to establish its grade throughout.

-8-

Data for the tonnage and grade calculations, summarized on the

accompanying drawings and charts were compiled from various sources. The

largest single source of data consisted of assay plans, which were prepared by

Cominco during the period from 1934 - 1910. This information provided data

for blocks, A, C, D, E, F, C, J, K, O, P, R, T, U, and V. A Vertical section

from Orvana Mines Ltd. supplied figures for blocks L, M, and N. Progress

reports from the Cominco operations gave overall estimates of material from blocks

Q, Y, and Z. Figures for block W were estimated from values for blocks A, and

Q, the two adjacent blocks. Finally, mineralized zones B, H, l, S, and X also

exist, and are shown on Satterly's map of 1912 (appendix vii), but were not

included on these calculations due to either small size or lack of reliable data.

It should be noted that letters used to designate mineralized zones on

Satterly's report of 1942 have been retained in this report for the sake of

continuity. That is, zone A of Satterly's report corresponds to the calculations

for block 'A 1 of this report. Some additional letters have been added for zones

not covered by Satterly.

BLOCK 'V

Sample Calculation

Calculations for block 'V are discussed as they

are typical for all blocks. The assay plan for the 1th level

(dated November 1, 1938, appendix viii) gives 12 assay

values over a distance of 190 feet along drift 402 - A from

cross-cut 430 A to cross-cut 436 A (corresponds to stope

402 - 2). Each assay therefore represents a 4.5 foot length

of drift. The width given with each assay represents the

width in feet across the back of the drift over which the

sample was taken. The assay value is expressed in ounces of

gold per ton of rock. These figures are given in Chart A. With this

-9-

CHART 'A'

SAMPLE CALCULATION : BLOCK *V'

402-A Drift : 430A to 436A Cross-cuts (102-2 Stop*)

Width Assay* Area Area x Assay Total Area TotaKArea x Assay) Total Length Average Width ' Weighted Assay

2.03. S 5.3S.O5.52.55.52.05.53.05.55.05.55.06.05.05.55.55.55.06.06.06.55.05.06.06.05.86.05.25.55.05.56.53.05.56.05.06.04.55.55.0

0.150.42 0.170.030.010.170.250.210.240.130.050.090.160.110.68O.H70.280.320.100.240.130.140.010.070.140.180.040.100.080.270.060.360.080.080.130.300.380.070.090.070.090. 11

9.0015.75 23.85

11.2524.759.00

24.7513.5024.7522.5024.7522.5027.0022.5024.7524.7524.7522.5027.0027.00

22.5022.5027.00

26.1027.0023.4024.7522.5024.7529.2513.5024.7527.0022.5027.0020.2524.7522.50

1.350 |6.615 [ 48.60 12.020 13.5 3.6 0.247 4.055 J

1.9136.1881.8905.9401.7551.2382.0253.9602.470

18.36010.5756.9307.9202.4755.4003.5103.780

378.00 86.33* 76.5 4.9 0.228

1.575 13.150 h 72.00 9.585 13.5 5.3 0.1334.860 J

2.6102.1606.3181.4858.1001.9802.3401.7557.425

10.2601.5752.4301.4182.2282.475

360.00 54.559 67.5 5.3 0.152

Channel Assay: B lock 'V 190 5.1 0.189

* Width and assay data from Cominco Assay Plan dated Nov. 1, 1938 (appendix vlll)

NOTE: 42 data points over a distance of 190 feet (measured from plan view), assuming samples are regularly spaced, then each sample represents 4.5 feet of drift

data it is possible to calculate a weighted mean assay over

an area on the back of the drift. This was done for all

intervals with mineralization greater than 0.05 ounces/ton.

The figures give a weighted assay of 0.189 ounces/ton over

an area of the back measuring 190 feet long by 5.1 feet

wide, refered to as the 'channel assay'. The stope assays

given in Chart B are from samples of trammed material given

in some progress reports from the Cominco operations.

Stope assays are not available for all blocks. Where stope

assays are included, the assay value used in final calcul

ations is the average of the channel and stope assays.

In the past, dilution of ore was a problem at the

Cordova Mine. As mentioned stope assays are from trammed

material which indicates a considerable amount of dilution.

During the final months of operation of the mine, more

concern was placed upon meeting the tonnage requirements

of the mill instead of maintaining ore grade. As a result,

much barren rock was also pulled from the slopes, lowering

ore grades.

Therefore, we have two assay figures, the channel

assays which indicate a highest possible, undiluted ore

grade, and the stope assays which represent an over-

diluted ore grade. The average of the channel and stope

assay should represent a true overall figure of the stope

grade, and were possible this figure has been used. Where

no stope assay is available, the channel assay figure has

been used even though tft is figure is probably slightly higher

than the grade of ore which can realistically be recovered.

The horizontal cross-sectional area of the blocks

was measured on the plan view. The length simply being

-11-

CHART 'B'

Letter,

A

C

D

E

F

C

J

K

L

M

H

O

P

QR

T

U

V

wY

Z

Identification

6 14- 2 Stope

614-3 Stope

654 Raise

614-1 Stope

(12-1 Stope

610-3 Stope

610-2 Stope

610-1 Stope

5th Level

6th Level

6th Level

376 Raise

604-1 Stope

8th Level

912-1 Stope

912-2 Stope

912-3 Stope

402-2 Stope

below 614-2

10th Level W

10th Level E

Cross-section Helghtj Area j

2,500

675

420

600

450

300

500

650-

-

-

500

375

2,500

375

3,000

800

3,800

2,500

625

800

145

150

150

150

ISO

150

140

280-

-

-

175

120

110

110

110

110

160

125

110

110

Volume

362, SOO

101,250

63,000

90,000

67,500

45,000

70,000

182,000-

-

-

87, 500

45,000

275.000

41,250

330, 000

88,000

608. 000

312,500

68, 750

88,000

BLOCK SUMMARY

Volume Volume Tonnage, Removed* Remaining

137,500

7,500

7,680

45,000

29, 2SO

6,000

20,000

91,000-

-

-

21,000

6,000

137,500

7,500

137,500

20,000

150,000-

-

-

225,000

93,750

55.320

45,000

31, 250

39,000

50,000

91,000-

-

-

66. 500

39,000

137,500

33.750

192.500

68, 000

458,000

312.500

61, 7SO

81,000

17,857

7,440

4,390

3,571

3,038

3.095

3, Ml

7.222

2,300

1,500

900

5,271

3,095

10,913

2.679

IS. 271

S, 397

36,149

24,102

5,456

(.914

Channel Assayt

0.222

0.111

0.1S1

0.160

0.352

0.111

0.171

0.254-

-

-

0.151

0.203

0.220

0.167

0.223

0.272

0.119

0.1 M

0.216

0.197

Stop* Assay7

0.129

O.MS-

0.210

0.111

0.040

0.151

0.175-

-

-

-

-

-

0.103

0.141

0.093-

-

-

-

Mean Assay,

0.176

0.092

0.1S1

0.1IS

0.232

0.114

0.117

0.21S

0.150

0.112

0.172

0.151

0.203

0.220

0.135

' 0.112

0.113

0.11*

0.191

0.21C

0.1*7

Tonnage-Grade Product

3,142.1614. S

662.9

MO.i

704.4

352.1

464.3

1,552.7

345.0

273.1

1S4.I

7*7.1

628.3

2.400.*

361.7

2,780.6

917.7

f, 170. fi

4.910.1

1,171.5

1,375.)

NOTES:

1: As in Satterly's report of 1942

2: Square feet, measured on plan view

3: Feet, measured on longitudinal section

4: Cubic feet, estimated from longitudinal section

S: Conversion 12.6 ft'/ton used, see appendix Ix

6: From assay plans

7: Assays performed on trammed material

B: tf 6 and 7 both present, then average value used

the length of the mineralized zone, and the width

estimated from the lateral extent of cross-cuts on either

side of the drift. The cross-sectional area of block 'V

is 3,800 square feet.

The height of the blocks extend half-way to ad

jacent levels (real or imaginary). The height of block

'V is 160 feet. This gives Block 'V 1 a volume of 608,000

cubic feet. From the longitudinal section, it can be

estimated that 150,000 cubic feet of material has been

removed by previous mining, leaving 458,000 cubic feet

of rock in block 'V.

3 Using a figure of 12.6 ft. /ton (see appendix ix),

we therefore have 36,349 tons of material in block 'V

with an average grade of 0.189 ounces per ton. This

implies the presence of 6,870.0 ounces of gold in block 'V.

Calculations for all blocks was carried out in a similar manner. All

tonnages and associated grades for the Cordova Mines are summarized in Chart

C. Broken ore left on surface and underground totals 47,526 tons with an

average grade of O.ISOoz/ton.

Probable ore still in place can be divided into three groups. First, that

zone, here referred to as the 4-6-10 orebody (includes V, A, W, Q, T, Y),

which is estimated to contain 110,655 tons of ore grading 0.192 oz/ton. Second,

that ore left adjacent to the No. 3 shaft (blocks L, M, N) which totals out as

4,700 tons @ 0.164 oz/ton. The remaining blocks of probable ore come to a

total of 56,155 tons @ 0.164 oz/ton.

-13-

CHART -C 1

SUMMARY OF RESERVES CORDOVA MINE

Proven Ore -

Probable Ore

i — Surface Dump -\ : Surf ace ————

1 — Mill Sand* 2

In

(i)

(II)

(Hi)

i —— Pre-Comlnco 3 Stopes ———

1 —— Comlnco ^

TOTAL

D- 6- 10 Orebody Block 'VBlock 'A 1Block 'WBlock 'Q 1Block 'T'Block 'Y 1

TOTAL

13 Shaft Orebody 5 Block 'L 1 Block 'M 1Block 'N 1

TOTAL

Additional Block 'C 1 Probable Ore B |oek , D ,

Block 'E'Block 'F*Block 'C'Block 'J 1Block 'K 1Block 'P 1Block 'U'Block 'R*Block 'O 1Block 'Z'

18,466 tons 0 0.060

600 toni 0 0.300

25,850 tons C 0.265

2,610 tent 0 0.153

117,526 ton* 0 0.1*0 oz./ton

36, 349 ton* t 0. II*17,157 ton* 0 0.17624,102 ton* 0 0.19810,913 ton* 0 0.22015,278 ton* 0 0.182

S, 456 ton* 0 0.216

110,655 ton* 0 0.192 oi./ton

2,300 tons 0 0.150 1,500 tons 0 0.182

900 tons 0 0.172

4,700 tons 0 0.164 oz./ton

7,440 tons 0 0.092 4,390 tons 0 0.1513,571 tons 0 0.1853,036 tons 0 0.2323,095 tons 0 0.1143.968 tons 0 0.1177,222 tons 0 0.2153,095 tons 0 0.2035,397 tons 0 0.1832,679 tons 0 0.1355,278 tons 0 0.1516,984 tons 0 0.197

47,526 ton* 0 t.tfO oi./ton

110,655 tons 0 0.192 oz./ton

4,700 tons 0 0.164 oi./ton

TOTAL 56,155 ton* 0 0.164 oz./ton 56,155 ton* 0 0.164 oz./ton

TOTAL 119,034 ton* 0 0.112 oz./ton

NOTES:

1: Annual report 1939 and progress reports 1940 by C.A. Seaton (appendix v), personal remarks by Walter Hood, 1981

2: Progress report to Lasir Cold Inc., Dec. 2, 1980 (appendix vi)

3: Progress report 1936 by C.A. Seaton (appendix ill); section from Orvana Mines, Feb. 25, 1965 (appendix lv)4: Memorandum to W.C. Jewitt, Feb. 3, 1947 (appendix II)

5: Section from Orvana Mines, July, 1965

The sum total of all materials at Cordova Mine comes to 219,036 tons grading 0.182oz7ton.

An estimate of ore available on January 15, 1939 by Cominco was stated in the following way:

Ore 77,130 tons of 0.175 grade

Probable Ore 50,000 tons of like grade Additional Possible Ore 50,000 to 100,000 tons

These figures are comparable to the figures arrived at in this report.

-15-

METALLURGY

All the previous milling tests carried out on the gold bearing rock from

the old Cordova Mine have shown that this mineralized material is amenable to

gold extraction by cyanidation.

The result of the Ontario Research Foundation Investigation No. 71245

dated May 8, 1980 revealed the following:

11 ... In the case of rock crushed to minus 4", gold extraction appeared to reach a maximum of 58% after 6 weeks. In the case of rock crushed to minus i", Sfft gold extraction was achieved after 2{ weeks, and maximum gold extraction appeared to be 818 after 6 weeks.

In the case of sand, gold dissolution was rapid. Better than 95% gold extraction was achieved in 9 days.

In all cases gold in solution was recovered on activated

charcoal ("coconut shell) with virtually J001 recovery inone pass. ... "

Subsequent studies carried out by the Ontario Research Foundation

investigation No. 71245 dated April 28, 1980 revealed the following:

"... Initial porosity tests on samples of gold-bearing surface rock (said to be development rock) taken from the Cordova Mines property near Havelock, Ontario indicated that on rocks up to 6" in diameter, the.take up of solution was rapid. For example, up to 3 inch penetration appeared to take place within 24 hours.

-16-

Cyamdatton tests using first a 2" diameter column followed by a 1 2" diameter column on minus 2" rock were initiated. In these tests the rock was wetted each day using an alkaline 0,5 g/litre NaCN solution pumped for two hours. The' solution was allowed to penetrate the rock for the bal- Zance of the day. Every seventh day the alkalinity, cyanide strength, and gold content of the solution were measured. The solution was brought back to original lime and NaCN levels and the gold extraction calculated against time. Extraction of gold was approximately 10% a week until it appeared to level off after 8 weeks with over 80% extraction. The lime and NaCN consumption rate was 4.3 and 0. 9 Ibs/ton of rock respectively.

In conjunction with bench-scale tests, a field test was set up at the

Cordova property in the late summer of 1979. Approximately 1500 tons of un

broken development rock (including over 30" diameter boulders) were placed on a

plastic lined pad. Due to freezing temperatures the test was curtailed to about

4 weeks of effective cyanidation. However, due to thawing conditions after shut

down, solution flow continued through the pile. Cold in solution measured several

ppm with gold extraction estimated to be over HOI. The cyanidation of the pad will

restart in the spring with modifications to permit a higher rate of solution flow

through the pad , (at least 20 gpm ).

During the 1980 summer field season Lasir Gold Inc. continued their field

batch test investigations, experimenting with gold extraction by a carbon absorption

technique similar to that used successfully by Cominco during the period from

1939 to 19flO.

The batch test utilized approximately 5 tons of sand which was loaded into

a 7 cubic-feet' cement mixer with water added to make a 601 sand: 401 water

mixture to which was added hydrated lime at a rate of 25 Ibs/ton of sand and the

entire mixture rotated for four hours. After thirty minutes the lime strength was

-17-

Overt!, . * 1/2"

Underflow

activated * charcoal

MINE ORE

iDUMP X GRIZZLEY

PRIMARY JAW CRUSHER

( 15" x 24" )

Belt

SECONDARY CONE CRUSHER ( 3 ft. diameter )

Belt

VIBRATING SCREEN

C 3'x 6')

Belt

BIN

- 1/2"

VIBRATING FEEDER

iBALL MILL

{ S' K 6' )

Pump

HYDROCYCLONE

Ovtrflow

AGITATOR ( 12' x 12' )

j Qyerflow

THICKENER 2O f t. diamttcr)

Pump Underflow

AGITATOR ( 8'x 8' )

f Overflow

SCREEN ( 26 mesh)

Undersiie

TAILINGS PUMP

iTAILINGS POND

DUSTCYCLONE

DUST

ATMOSPHERE

WATER TOWER

iWATER

TANK

4 Urn*

NoCN.

Pump

Proctss Solution

HEAD

TANK

PUMP

Pregnant Solution

HOLDING

TANK

BARREN

TANK

Pump

loaded charcoal

CHARCOAL COLUMNS

Barrtnm 4

Solution

CHARCOAL ASHING

GOLD REFINING

LASIR GOLD INC.CORDOVA MINE PROJECT

GENERAL FLOWSHEET100 T. R D.

PORTABLE TEST MILL

W.G.WAHL LTD. March, 1981

DHAWN *

DGWTRACED *T

ORB

checked for free lime (1 Ib/ton of solution) and if necessary more lime was added.

To this mixture 2.5 Ibs. of hydrogen peroxide was added as an oxidant followed

by NaCN at a rate of 3 Ibs/ton of solution.

After the four hour leach period any remaining clear liquid was decanted

to a holding tank and the remaining load dumped onto a plastic sheet. The solids

were then washed twice with two tons of barren solution and in each case the

pregnant and wash solutions were pumped into a holding tank. After each washing

the leached solids were dumped onto a plastic sheet with any subsequent drainage

being directed to the barren pond. This cycle was repeated each day over the

duration of the test period.

The pregnant solution was pumped in series through three 20 inch diameter

by 10 feet high columns each holding 500 Ibs. of activated charcoal. The effluent

from the charcoal, which assayed less than 2 ppm of gold, went to the barren pond

for recycling as required. In this closed system only water was added to balance

the loss through evaporation.

Approximately 220 tons of sand assaying 0.30 oz.Au7ton were treated

during the test period using a weak alkaline cyanide solution to recover 50 ounces

of gold which were absorbed on activated charcoal. It is expected that the gold

recovery will be over 901 by treatment in a conventional cyanide mill using longer

agitation times. The leached sands from the preliminary testing have therefore

been saved and stock piled on plastic sheets for further gold recovery in a

conventional mill. It is estimated that a further 600 tons (appendix vi) of sand

assaying 0.30 oz. Au/ton is available for leaching in the summer of 1981 using the

same procedure.

The Ontario Research Foundation Studies have shown that during heap

leaching, 751 of gold may be recovered on the -2" rock, of which there is about

18,466 tons on the surface assaying about 0.060 oz/ton (appendix v). Some gold

has been leached from a 1500 ton pad of this material. Larger pumping equipment,

however, would be required to complete this extraction.

The following generalized mill flow sheet has been developed for the

Cordova Mine of Lasir Cold Inc.

-18-

CONCLUSIONS

The results of our evaluation have shown that the gold bearing vein

material mapped underground at the Cordova property of Lasir Gold Inc., is associated with three major shear zones, located within a medium to coarse grained gabbroic complex; and that this vein of material consists predominantly of carbonate, feldspar, quartz, with pyrite and pyrrhotite. (The gold is associated with the pyrite mineralization). The vein material occurs . . .

. . . as a replacement of the shears.

. . . as a series of stringers and veinlets paralleling the planes of

shearing.

. . . as veinlets in brecciated replacement zones.

. . . as lenses of massive material parallel to the shear planes.

The individual shears exhibit strong continuity along strike trending N 70OE to N 85OW and dip moderately to the south at 65 degrees. These shears do however exhibit a somewhat erratic width, ranging from a few feet up to forty feet.

The recently completed tonnage and grade calculations were abie to deliniate and quantify 47,526 tons of proven ore grading 0.180 oz Au /ton and 171,510 tons of probable ore grading 0.182 oz Au/ton. The proven ore consists

of that material stock-piled on surface and broken ore remaining in the slopes. The probable ore consists of insitu material for which tonnage and grade are computed , partly from specific measurements, samples or production data,

and partly from projection for a reasonable distance on geological evidence, and for which the sites available for inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely

or to establish its grade throughout.

-20-

Additional geological and analytical data is needed in order to up

grade the probable ore reserves presently indicated at the Cordova Mine. A

detailed structural analysis of the major shear zones should be undertaken in

order to further define the nature of the gold mineralization.

All previous milling tests carried out by the Ontario Research

Foundation and by Lasir Cold Inc., have shown that the ore from the Cordova

Mine is amenable to gold extraction by cyanidation and that the gold recovery

is expected to be over 901 after treatment in a conventional cyanide mill utilizing

carbon absorption techniques and longer agitation times.

-21-

RECOMMENDATIONS

Based on our evaluation of all the data presently available it is strongly recommended that . . .

. the old Cordova mine be dewatered and that rehabilitation of the underground manways be carried out.

. a 100 t.p.d. portable test mill be acquired and assembled on

site in order to implement and test on a pre-production scale the successful recovery techniques employed by the Ontario

Research Foundation and Lasir Cold Inc., during the 1980 summer field season. The mill flow-sheet will be similar to that used successfully by Cominco in 1938/39.

. an underground geological mapping and sampling program be

carried out in an attempt to extend and further define the major zones of interest and to determine exactly how much material was left in the old slopes.

. an underground diamond drill program be carried out in conjunction with the geological mapping end sampling pro

gram in an attempt to extend known zones on mineralization.

. some of the more promising slopes be developed to provide mill feed for a pre-production run of the 100 t.p.d. portable test mill.

W. C. WAHL LIMITED

P. R. Rautanen, B.Se., Project Geologist

D. G. Wahl, P.Eng., Consulting Engineer

-22-

COST ESTIMATE

- 23 -

SUMMARY

DEWATER CORDOVA MINE

TO FEES:

i) Aurora Quarrying Limited $ 445,000.00

ii) Rehabilitation of Manways etc. 50,000.00

iii) Field Supervision 27,000.00

TOTAL: $ 522,000.00

-24-

TO FEES:

i) Aurora Quarrying Limited(proposal March 21, 1980) $359,000.00

Contingency 36,000.00

SUB TOTAL $395,000.00

Inflation Update(approx. 12Si to March 21, 1981) 50,000.00 $445,000.00

ii) Rehabilitation of Manways etc. $ 50,000.00

iii) Field Supervision (4 months)Senior Project Engineer P.Eng.

BASIC APEO*

MONTHLY PAYROLL COST COST FACTOR

^2,700./month)(2.5)(4 months) S 27,000.00

TOTAL: $522,000.00

NOTE: All of the fees presented in this cost estimate arein accordance to and agreement with those outlined in the "Suggested Schedule of Fees for General Engineer Projects" published by The Association of Professional Engineers of the Province of Ontario dated June, 1979.

-25-

II

SUMMARY

PORTABLE TEST MILL

TO FEES:

i) Pre-Engineering 5 15,000.00

li) Test Mill - Construction 42,900.00

iii) Test Mill - Operational 70,200.00 $128 / 100.00

Contingency 13,000.00 $141,100.00

TO EXPENSES:

i) Mill Equipment $218,000.00

ii) Power 6 Structures 120,000.00

iii) Tailings Pond Preparation 50,000.00

iv) Start-up Supplies 28,000.00 $416,000.00

Contingency 50,000.00 $466,000.00

TOTAL: $607,100.00

-26-

TO FEES:

i) Pre-Engineering $ 15,000.00

ii) Test Mill - Construction Phase

Site Engineer P.Eng.

30 days @ $350./day $ 10,500.00

Labour Force (7 men - 6 weeks)

carpenters (2) $11,040.00

electrician (1) 5,520.00

mechanics (2) 11,040.00

casual labour (2) 4,800.00 32,400.00 $ 42,900.00

iii) Test Mill - Operation {6 month test)

Chief Metallurgist P.Eng.

3 days/month @ $400./day $ 7,200.00

Mill Superintendent, 000. /month) (APEO 2.5) 45,000.00

Mill Assistant, 200. /month) (APEO 2.5) 18,000.00 $ ^0. 200. 00

SUB TOTAL $128,100.00


TOTAL: ?i4i,ioo.oo

-27-

TO EXPENSES:

i) Mill Equipment

Ore Bin $ 6,000.00

Dump/Grizzley 1,000.00

Primary Jaw Crusher 25,000.00

Secondary Cone Crusher 20,000.00

Vibrating Screen 5,000.00

Dust Collector 5,000.00

Vibrating Feeder 3,000.00

Ball Mill 50,000.00

Hydrocyclone 2,000.00

Thickener 25,000.00

Leach Agitators (4) 60,000.00

Solution Tanks (3) 6,000.00

Pulp Pumps (3) 6,000.00

Solution Pumps (3) 3,000.00

Screen 1,000.00 $218,000.00

ii) Power S. Structures

Water Tower $ 10,000.00

Diesel Generator (200kW) 30,000.00

Mill Building (4000ft2 ) 60,000.00Utilities 20,000.00 3120,000.00

-28-

iii) Tailings Pond Preparation $ 50,000.00

iv) Start-up Supplies

Spare Parts $10,000.00

Lime -already boughtNaCN 3,000.00

Activated Charcoal 3,000.00

Diesel Fuel 10,000.00

Grinding Balls 2,000.00 28,000.00

SUB TOTAL $416,O00.00

v) Contingency S Inflation 50,000.00

T Q T A L. $466,000.00

-29-

Ill

SUMMARY

UNDERGROUND MAPPING S SAMPLING

TO FEES:

i) Mapping i Sampling

ii) Model Study

Contingency

$94 / 000.00

30,000.00 $124,000.00

12,400.00 $136,400.00

TO EXPENSES:

i) Mapping S Sampling

Contingency

$64,360.00 $ 64,360.00

6,400.00 $ 70,760.00

TOTAL: 5207,160.00

-30-

TO FEES:

i) Mapping S. Sampling PAYROLL COST APEO___________ COST FACTOR

Project Geologist $2,200.00 2.5 $ 5,500.00

Jr. Geologist 1,600.00 2.5 4,000.00

Jr. Geologist 1,600.00 2.5 4,000.00

Draftsmen 1,300.00 2.5 3,250.00

Cook 1,500.00 2.5 3,750.00

4 month duration (4) 20,500.00 $ 82,000.00

Report Presentation

Project Geologist

20 days @ $250./day 5,000.00

Sr. Project Geologist

20 days @ $350./day 7,000.00

ii) Model Study

Tonnage And Grade Figures 30,000.00

SUB TOTAL 124,000.00


TOTAL: $136,400.00

-31-

TO EXPENSES:

Atco Tractors: Sleep Office Cookery $10,000.00

Camp Equipment

Stove,refrigerator,freezer,bunks etc. 7,500.00

Consumables

{5 men) ^15 ./day/man) (120 days) 9,000.00

Drafting S Office Supplies 5,000.00

Truck Rental

3/4 ton crew cab 4X4$890./month X 4 3,560.00

Gas

$75./month X 4 300.00

50kW Generator

$800./month X 4 3,200.00

Diesel Fuel 800.00

Sample Bags 5,000.00

Assay Cost 20,000.00 $64,360.00


TOTAL: $70,760.00

-32-

IV

SUMMARY

DIAMOND DRILLING

TO FEES:

i) Diamond Drilling

ii) Supervision

iii) Aurora Quarrying

Contingency

$300,000.00

24,000.00

15,000.00 $339,000.00

40,000.00 $379,000.00

TO EXPENSES:

i) Supervision S Aurora Quarrying

Contingency

$ 48,130.00

5,000.00 $ 49,130.00

TOTAL: $428,130.00

-33-

TO FEES:

i) Diamond Drilling 15,000ft,

250'/day X 60 days

15,000 feet @ $20./ft. $300,000.00

ii) Supervision

Project Geologist

60 days @ $250./day

Geological Technician

60 days @ $150./day

$15,000.00

9,000.00 24,000.00

iii) Aurora Quarrying

Hoistman etc.

60 days @ $250./day

SUB TOTAL

Contingency

TOTAL:

15,000.00

339,000.00

40,000.00

S379,000.00

-34-

TO EXPENSES:

Mine on Standby

$10,000./month

Consumables (3 men)

60 days @ $20./day/man

Lodging

60 days @ $20./day/man

Truck Rental (2 months)

3/4 ton crew cab 4X4 $890./month X 2

Gas

$75./month X 2

Generators

$800./month X 2

Diesel Fuel

$200./month

Office S Drafting Supplies

Sample Bags

Assay Costs

Contingency

$20,000.00

3,600.00

3,600.00

1,780.00

150.00

1,600.00

400.00

500.00

2,500.00

10,000.00 $44,130.00

TOTAL:

5,000.00

$49,130.00

-35-

V

SUMMARY

LIMITED PRELIMINARY STOPE DEVELOPMENT

TO FEES:

i) Aurora Quarrying $ 250,000.00

-36-

APPENDICES

-37-

Appendix (i)

Ore Reserve Calculations by Cominco, Jan. 15, 1939

PI tt i * ^^n 4. yro.

I*. )3 *** t

OB Bil ft tt l

W W M f (Ilw* f

Or*

li BOV 15. 19?9)

- ri t\yo tom rf O.IT? c****

- 50,000

JLMltlowl r**iibl* Or* . 90,000 U 100,000 tea**

-38-

Appendix (ii)

Oro Loft in Slopes by Cominco, Feb. 3, 1947

AND BMU.TINO

MEMORANDUM ra. H*.

CANADA, UMfTlO

li i loon .

** fcl

M

\

(tot* 401-J•04-1eio-i-t en-)• 14-1-tSI l-lm-i

-i 1*1 n tos-i

Tot* l

1,111 tOMM

*60 Ml I TOM

1(1 lit

11 t

IS

t,110 to**

^gs&^r&L

-39-

Appendix (iii)

Ore Left on Upper Levels, Progress Report, 1936

Po. l fhaftr,/

haport for Xha taar 1986

pa-*atarad to 3rd laval. Attaapt to blook off vatar thlt point waa untuocaaa

. ful. All ra*amr*ayad to 3rd laval. ^' OD thli laval at lent thraa euartart- full brckan auok *bleh aalajrt about .pt-

elao l en lo valua aa vail aa all feoea, which honavar ara in ahaar. LlttH

for furthar

Total AflTuno* to I)eceBb*r Slit, 1?56" " lor 1*?6" * to I*oaber Slit. 1936

M4.B ft. t. fi t. 9EJ495.T *

D * to eoctuvion In of f lea part of monthly raoordt'of toanftf* holatad war* Aaatroyad flurlng tha runner BO th^t no rrcord of vclua can ba reportafl.

DhlLllEO; Two ahlftt ner day wara run flurlnf Auruat anfl aerljr Bep't.

lo. Troa

l1011

HOLS lo.01

00.0 ft.00.000.000.000.000.000. 0

EE.O ft.191.0Io4 .4S65.0152. 6154.049.1

tt. Q ft. flnlahad191.0164.4265.015E.6154.048.1

lotal 992.1

location 601 Drift Keat. Ut. 1449.TD Dap. 6694.64 faarlng l 14 82' Itip -roLan^th U.O ft.

Brlllad lato foot *all and atoppad on account haery flo* of watar.to oaapan It latar. BOM ^uartt *ct eat but tha thraa ataplai takan aaMgrf4ouljr a traea.

(Oil lo**! Location Ml Prlft laat. s—————— Ut. 1469.*1

," Dap. 6&U.OT t - C**rlivg 8 l W l

Dip * tl Lan/tk 191.0 ft.

trill*' l*Vo btAfini wll. ChiafXjr aaphlbollta *hlch la aohlatad la tak*n aaaajad a traea.

-HO-

Ore Left on Upper Levels, Section, Orvana Mines, Feb. 25, 1965

Appendix (v)

Ore in Surface Dump, Jan. 1940

Tojntinr KILUD n miWL1*4 fro* rirat Ci***mi 1*4 fro* coad dm Dump

Total Kill** fro* txiaptIB Duftpa, January let 1940

l,M*•00

fro*

Total Ton* 11111*4

ORE 01

4, tom

ton*

li erom AID orit. 1940

tlO-1 8top* 611-1 Stop* 614-1 Btop* H4-I Stop**ie-i atop*Burf*** Diutp*

Tottl on Rand

Total i.* 11* Holtted

Total rln* Ouao** forwarded to Fojrel Ulnt Total R*itlcln^ In Will PT*** Tallin** Lo**

460 tone E07 tone 614 ton*r. s toot158 ton*

10.818 ton*11.84T tone

4,T*0 toac

3T6.941 Ot* to IT.W) o*140.600 Oz* Au DM.

E5.9BS Oi* Aa

Tour* Yery truXjr,

Total r*winin(! in Mill Prwna ar.oulJ r t To l line* lo** *

C. t . SaatoB*

1E4.V90

0

-42-

Appendix (v) cont'd

Ore removed from Surface Dump, Feb. 1940

f v . * *. A .

llrtk l*t*l * t UK i rt*** M U***VU\K UY*1 * *M i*lft "*rt K

W

I,MI 0.100 ktt.UVi o.OTt Mnt yr

e.MI 0.0*4Or* U Will MB kt tni of i^oaUi tie l MM or* IB ti.O. *wik*tt *t )xi of ^aVk Ut let-*

EIULWtIr l ok fee C *i* jxnired oa UBJT LoA, *Ji4 tantrlo*4i

Oolt - 44T Iroj Oone*t| Tln*um 832. T a* b/ Cordonr* ' 'Hijr Of f le*.

r*port for th* HonVh of A?rlli

Trcrt*4 t,*4l g Tin* ffiilj:

o.io*O.OOU

Ooid •*oov*r/

vcmrp yapof th* 'tin* !

of l^M.I thJftt *ork*4 unA*rcrouBd| on thl* bril* th* foU w*r* kej)dl*0 during th*

l.*t Vat y*t* M tom ^*r unn-khifi *-*r*

Th* fcork, of rcploelag *hrft I*fi6*r* and *i*4*

trori UO-lt Tali ^1*0* ha* b**n f 1 11*4 lo th* t.**i with trek** *r*

lw* Vh* 4 **d

Bo oork *ri don* Kar* during lh*

|to*Uf •Mitlauod kn4 mutce

Atoll t* *twk *M ioM* b*r* AvlKtr th* noatkt

A f** **r* round* **r* tOiM out h*r* Vut M f*r t*

979m tU-*l V* *U*Uf *M i*** k*r* Vvt th* drift *Vor* ^*T*UfnMit)

lini r**ult*i

fe w t

Appendix (v) cont'd

Ore removed from Surface Dump, May, 1940

ft t

itn

fw Kotr t*

CM

ill

*a Orf l

i t**** t*** U rio*** tt** ttrtAm Tr****4 1 F**Pty prt\ ** **U iwrla* **U t*mi 40VI

110-1 1tio-t4M*—1414*1 Z414*1tlft-B 1• 14-1lU-tKaw

tor* |oi*t*4Or* U KillOr* 1* Dnosr

M*,TM

W411*Kt•"!11*l*u

IwT

BU *tfTouat

1,900Mltw.-B

kit

..*

t to4*0— .....—*

47*68

tni of tk* Uonkh^oi^otl *t In*

•f th* Month

4*4480m~m

4MIt*IT48tt104

4—.

s, toe

IBt

Jil'Ml* loll\*4

Or* xm**i tour**

0* I rt* li M*T**

1 T*lli*M

til41*t.in4T4

l,*0tmitiuI,t04

• ,4M toM

t*4 UM11 ioa*

•i oat

UlM* ETiTfDO* IXUQConoKitrtt* 1x109

Total

!H*k lo 4 **i* pour*4 M

Col* -*

4,40* t*aa

T IB* OuntM tllvtr * tt ria*

Tk* folio*!**- *r* fro*

t!**4,*0*.0n.iio.c*t

0.0014

ttkUf l**l* MI V*** lMttll*4 M U* •MTV*' 114. *r tk. **4**1 *JU * tma* WMMt tff -

fr** Ut* iufti*l f*e4. T* U tM **Hjr H M t* lil *ffMtiT*m****

Appendix (v) cont'd

Ore removed from Surface Dump, June, 1940

Ctt'.PfrtA UT ffiCpvntjj Or.ttrit

V

prrp-onpUKOJD

I STAT&riu

(orkl&t1 n*oe

*0*-I40E-8604-1610-1610-t

614-1614-t912-t91E-S916-1916-1903PW

TiWCPT FOR THI UOTTK 07 f

flOffl lil

W.ILLIBOt Hll

rr or BT* r,i:w op.t:t Tom in Stope* i Tont Ore ^roi*n ;1 Tlret of V'onth i ftijrin^ ).'Dnth. . . :

1,795 200?r— - i**r.

1,856 *tl319616

t,12B674

1,908 5C6166 121

149

16

9,604 :,^.r)4

Ton* Ore t7rcrcaed. t

I'l~.70

9?24

..1,408

--1.6T4

Ifcl~.~-—

4,*C7

i Ore Hollted:

Ore inOre ir

WU Pin *t tod cf th* Month:Underground docket! TixJ of 1'onth:

! Ore Willed during Month: ?rrt I'saergrr-undFrca ?-j-f6?e T^-.p

COO t'jr^49 t cai

4,?9t tou*m tom

Tom In Itop+ttt Vonth— to4..

1,6249062

l,?.7f3706117U6746S9106

169

16

C, AM tort

4,407 ton*

U9 to M

4,(J7 ton*

UILIJBOlBrieU Bo 7 or, July

Tonnt^ePercent Operating Tine

The follorlnc l* ttilen frsa reaton'a pr*lialncr/ mill re port for the ttofith of June:

4,627.0 ton* 96.**1. 0.118 oil 0.0094

•BKTFTB

Colfl r.eooTery Percent Cold jToiluotlan, i

I'roduotlon,b04tO OKI

16*0 Ot('

JLTD T055AG1!

it tnd Toroman there *er* On thti bbsii the follot-

of th* r.'lr.se. to**l of 961 ehirti vorkcxl ur.*ercrounfl Ing \9nn*xei v*re hutdled durlne th* month:

4. 68 tom jxtr taan-tMft frre1.81 tony per niiC-ihlft were broken

Vo drilling *BI done tftor the 15th of the month, but fcll drilled *eie bltitedt

i

-45-

Appendix (v) cont'd

Ore removed from Surface Dump, July, 1940

fQT( THI MOITB PT

OD* hoi*

I* t.

*i *bowa b*lo*i

pip T.I*T.

0.00 181. 6 ft. 1934. 07- 6077.46- Tit t 1011.21 tot Hrlft I* t t

littl* pjrrrbotlt* vr.i *etpl*fl *ndTout (*otloo* *hloh oontelnefl• r*t7*a. Thx* w*r* e*Toot*f* 1S4.4 to 136.9 ft. Senpl* ^467 2.6 ft.

* 144.6 to 147.0 n. " 468 E. 6 ft* 161.4 to 153.4 ft. " 469 t.O ft ' 167.4 to 169.9 ft. * 460 E. 6 ft

PT BROtEi ORE:

Tr*e* Tr*o* Tree* .006

yi*.c*: Ton* in Stope* : Ton* -Or* Broken ; Ton* Or* j Ton* lo Stope* : rint of Month : Ixiring I'onth : Tr*-nned 5 at Month-End

402-2402-S604-1610-1610-2612*1614*1614-2

912*2918*1918-2903 C.I.

7 ffi *:

1,824to6~

1,3773706X8723674639105

169

16b, Sil

—--....-...-

Sil

7063014

99747

248669639384C60-

2

3.B9E

1,118-

38380323370

6*136165164#

167

16l, 6 10

fTr*J*)*d tctal 91E-Z l* 154 ton* ^renter than broken, po**lblj ton* 9 ir- 1 or* reported in error *.* coning from 91L-3 Stop*

CM HOIBTPtOr* in Mill Bin at Znd of th* 1/ontbOr* IB TJnflererpund Pooi*ti at th* End of lion t h

Or* Milled th* Month froa W D* * * . Surfeo

TotalDonp

5.9" ton*

Hll K3 tom

4,122 too*

KTUJIgtD. iek Bo.B pourad on l*t.

Th* follovicf li tekaa fro* V*(ton f * prtllminarjr Kill report ntifor th* akonti of /xxlyi*

TJACAf* tr*tt*dr*re*nt Op*r*tl C*l*ulat*d B**diA***,0*1*

ItU.r

T!"*

Ouneai OUB**I

4,171 ton* 88*

.124

.0067

486!00 29.00

-46-

Appendix (vi)

Estimate of Surface Materials, Dec. 2, 1980

PROGRESS REPORT Ko.2

R GOLD INC.

Sampling* of the mill tailings dump wns carried out by V'.H.Hood, P.Eng and P.Kiltby, P. Ens. under my direction. I assisted nnd oversow the prep nr .-.tier. and p-ck^cinj: of the samples vhich were ar.s?yed ?t a connerci-^1 labor F. tor;.*

.and resulted in ny estimate of grade at 0,3 os/ton *.u.

There is an estimated 600 tons of this miteri-il rerisdninj** to be treated.*

Th? portion of these "nill teilings"vjhich was treated this r.nst sunrujr vas only partially leached due to a physical limitation of pilot plant equipment. The nature of ths sands did not lend itself to pond leaching and a. b\tch ojverction in a reversing mixer required akinninc off, at port cycle, of gold laden slines. These slimes are stord for final recovery of gold values i.-, the rill vhen constructed.

703 Ibr of fold l.-'.den charcoal asssyinf 125 os/ton are presently bainr prerircd for shipment to e U.S. smelter from materi-1 treated this surrasr.

i? continuins idth the development of the charcoal stripling pnd electrolytic deposition of the gold adsorbed by the charcorJL and s. cor.tir.uir. report is in progress.

I h-ve psrson?JLly verified thct the estinsted grade of the development ore dunp H Ko.l shaft i*? 0.05 on/ton Au and thnt there is en estimated 20,00? tons of this lov; grade ore in the two nrin durr-s at Ko.1 smd Ko.3 sh?.fts.

Respectfully sub.-nitted

Dec. 2, 1930

-17-

1*r 00

jt&'^J l'//tel/*.V

r--'"" v.i**— ' :

' \' TMkfVlL

ri-. ; ft** 'i*\S -i -i "i *-^-. ["•- v, t............ \ ,j- -

\ 'a-*. , :; li": 1—J"1"1, i |

jm̂5 j! 'li L•i

Jfctfio'L —wore*

'tai?: lv—.n* i K.U J^k

r^i M )) .M lKio, t—LoraiTVMiui VnTtcAt ((erin* ot tint CotKoT* Mm. Biunoirt Tnwmunr. Fmnmnin Cm-im.

Ironi i ptan JilH )ra M. l M*, 1*4 r-MMwd irilk Ilw pemM-km d Iht CnwMMdMl Mhihil (.4 ^mllliil Cn*r*ii!t rt Cm**. Umhnl.)

"O•offi D Q.x"

Section of Cordova Mine, Satterly's Report, 1912

! , l 1 l l l M l l l l |1 l l l l l l III Ml l l

T! T3 (Da

Portion of Cominco Assay Plan, 4th Level, Nov. l, 1938

Appendix (ix)

Volume per ton of rock

?gMm?x?mmmmt:-i

: "1

(1) oc urdUu.tr run (rf ri** t b* i* *r* H.1 au. ft.por tea. wi.ll* oa tb* finer *j*k li la BC.* *u. fi. ;^r to*,

\i\ Tb*t OB ria of *l*e *,U* *ol*fir* l* t*k* •toll* MI Ik* rib*r w*U*r m-t*rUl li ve* tn ••tlrntt

(ft) T b* t t*iv (Jo* l l* ec;,*lflcr*ii d*^*bd(.til* wi* Ok

this 'w.*!* of ei J. eu. rt. p*r toc;-F**t Sklj —— - ——— i. 65 tone flrjr ore |*

i,*it 3k^ —————— -V.** toai iry or* ?*

(i) T b', t UB li.* s-.ot* b.*l*, t h. Vont.'.;;* holitvd to daV*

•b* e L* Ter/ closely to t. LV tonn-^.* reported fro* tt* ala*.

'.fta7 pf rfft JfOwj Tt, CO'H3i i-Tn,^

70 coa^'crr t hi ir^ijr T liir o: tt* l itx *ueh

•bl*rijr •••pl*4 from t h* car*, vltb tbe coerce SINK whieh Is met

~ le rt yo, t

T b* fcefl ecmvcyor *-*i •toypvd p^rlodifkllj o**r KM b*ur

•Ad k b* If. /.t *o*b (top or It* t*) t, all of th* jtu*k w** t*k-

•a fro* B ••Ptloa *bo.t *ls^t r**t la l*n*tb. All *f t h* plus ft' MVvrlal *** pU IB oo* *aap)* md th* *l*u* 5* vt*rl*I p**

lato k*oth*)r ***pl*. ;a*af* **rc ria o? *oeh product tad a

•oa\i*rl*ua ard*. FIT* *ucn t**v* w*r* a*** vitta

two autdrvd l M, of m*i*rl*I la *aok t ••t.

-50-

Appendix (ix) con t'd

Table Showing Relatbn between Volumes of Rock, In Place and Broken

Tibia 1. Weifht of Roekt For weifhU of mineral* ud arm, aee See 26, Table 1; Sec 1. Deaeriptr** Table*

Material

Pol Q illite

Granite and porphyry. . . . . .

•Vein quarti, I5% Feflj. . . . .

Wtper

la place

IMlit170 117267It*154itsUllil173UtIMIM

tuft, b

Brokra

M*7

107

H

•4

14n

Da ft]

laplace

12.II.II. 44T!M.13.12.14.13.II.13.12.12.

per ten

Broken

20. t20. tU,720.1

21.3

23.321.1

Ton* pt

In place

.It

.27

.30

.32

.M

.27

.01

.23

.M

.01

.3*

.00

.21

.It

r ra yd

Brokta

1 301 301.31 1.3*

1 30

1.27

I.I*1.21

* Refer* lo pomiUe wt of on*; pur* mineral*, iicuafly weifk man.

SveUiac ia All. On ticaratinf a mixtor* of iclid and loo** rock *ad aartn, l *v yd in plan rnakt* about 1.4 eu yd ia 611. If rock b* Brat (tripped of earth, and thea blactod and dumped by iUelf. tfc* pereentace of void* i* larfer. At Boulder. Colo, I 000 eu yd of *elid rock made a S MO cu yd embankment; a ratio of l : l-S t. la Virginia, iOOOO eu yd of limeatoo* and nue* aehiet. broken and put ia embankment, mad* 00 000 eu yd. an ineraaa* of 10*4. In •ubacjueoue e*ea- xtion. A*hubula Harbor, O, 02 860 cu yd (place meaaur*) gave 109 837 ea yd BMaaurad ia *cow*, an iacreate of tift.

Volume in Place = 571 of Broken Volume

. *. Broken Volume of 22.1 corresponds to In place volume of 12.6

-51-

APPENDIX (X)

AURORA QUARRYING

-52-

flURORflQURRRVinG

March 21, 1980

Mr. Walter H. Hood, P. Eng.PresidentCordova MinesP.O. Box 130Havalock, OntarioKOL !ZO

Subject: Dewater Cordova Mine

Dear Walter:

Enclosed please find our proposal to dewater and examine the Cordova Mine.

We are proposing a Cost Plus contract to complete the project as discussed.

As you are aware there are too many unknowns for a contractor to propose a

firm price without including considerable contingencies to cover these

unknowns.

To provide you with a cost estimate for the project we had to make certain

assumptions as outlined in our proposal. We feel that our target cost will

establish the mine to a position in which you can complete you evaluation

and thus reach your ultimate goal of production.

If you have any other questions or require further information please feel

free to contact us.

Very truly yours,

AURORA QUARRYING LIMITED

E. W. Tutkaluk

cc: Engr. Chron

Aurora Quarrying Limited. Mining Contractors, 220 Wellington St. East. Aurora, Ontario LAG 1J5 (416) 727-4294


PROPOSED WORK PROGRAM AT CORDOVA MINE

Following my initial visit to the Cordova property, discussions with you,

our personel, and examination of sections and plans available, we are

proposing the following procedure:

A) Stage I - During stage one we would dewater the #1 Shaft. Examination

of the ore body would be carried out to determine the availability of

broken ore as shown on one longitudinal drawing. If there is no ore

available then we would proceed to Stage II.

B) Stage II - During this stage we would setup at #3 Shaft, rehabilitate

the Shaft and continue to dewater to the 6th Level.

C) Stage III - During this period we would examine the old workings to the

6th Level from the #3 Shaft.

D) Stage IV - This stage is the continuation of dewatering the mine below

the 6th level, and examination of old workings.

E) Stage V - During this stage the company would determine the final

procedures which would be followed to bring the property into

production.


establish a target cost for the project it was necessary to establish some

paramaters as guidlines. The following items indicate some of the guidelines

used to reach the final target cost:

WATER QUANTITIES

The quantities are based on level drawings and ore mined 200,000 T. Since there

were no volumes of ore indicated in different areas I had to break the water

quantity into groups. Lower at 400,000 gpm (U.S.)

Area

Collar - l Level

1 Level - 2 Level

2 Level - 3 Level

3 Level - 4 Level

4 Level - 5 Level

5 Level - 6 Level

6 Level -10 Level

No. Gals.

1.1 x 1062.5

3.3

3.0

2.1

4.4

3.6

Ace. Gals.

1.1 x 1063.66.99.9

12.016.4

20.00

No. Days

3.0

6.256.257.506.0

11.014.0

Lower at ft/day

33.3

16.0

12.1

13.3

16.6

9.0

Pumping Time = 56 Days

SCHfiDUA OF PRICES

Straight Time Rates

Foreman

Master Mechanic

Mech.-Gen. Opr.

Hoistman

Miner

Surface (Miner)

Overtime Rates

Foreman

Master Mechanic

Mech.-Gen. Opr.

Hoistman

Miner

Surface (Miner)

Base

11.00

10.50

9.80

9.00

B. 70

8.70

16.50

15.75

14.70

13.50

12.60

12.60

t

Bonus Statutory Levies 28.04*

4.00 4.21

4.00 4.07

2.75

2.53

3.50 3.42

2.44

4.00 5.75

4.00 5.54

4.12

3.78

3.50 4.51

3.53

Head Office 6.7*

1.29

1.25

0.84

0.77

1.05

0.75

1.76

1.69

1.26

1.16

1.38

1.08

Profit

2.05

1.98

1.34

1.23

1.67

1.19

2.80

2.70

2.01

1.84

2.20

1.72

t

Total ^ Cost

22.55

21.80

14.73

13.53

18.34

13.08

30.81

29.68

22.09

20.28

24.19

18.93

AURORA QUARRYING LI

IMITED

Notes:

1. Overtime rates will apply after 8 hours per day or 40 hours per week.

2. Statutory Holidays will be paid in the work period - if not worked - 8 hrs. straight time-if worked - 8 hrs. straight time plus all

hrs. worked at O.T. rates

3. There will be an additional charge for the outside crew of #30 per day for travel time, room and board. If more people can be hired locally and some other arrangements made for board this daily cost can be reduced.


:REW SIZE

Day Shift

Foreman 10 Hrs.

Master Mech. 10 Hrs.

Hoistman 8 Hrs.

Miner 8 Hrs.

Miner

Surface

8 Hrs.

8 Hrs l

Regular O.T.

242.02

231.36

108.24

146.72

146.72

104.64

A. Q.

A. Q.

Local

A.Q.

A. Q.

Local

308.70

296.80

162.24

193.52

193.52

151.44

P.M. Shift

Gen. Opr. 8 Hrs. 117.84 Local 176.72

Nite Shift

Gen. Opr. 8 Hrs. 117.84 Local 176.72

Total Cost/Day 1,215.38 1,659.06


IPMENT

Description Source Rental Rate Month

Total

Crew Cab

C

Project iruck Rentals

825 825

600 CFMCompressor

200 KWGenerator

Flygt Pump B22O1

Tugger

Wilden Pump

Duplex Pump

Drills

Welder

Cutting Set

Fan Elect.

Fan Air

Chain Saw

Cap Lamps

Cable 4/4 600'

Phones

Hoist

A. Q. Aurora

Crothers

Flygt

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

A. Q. Aurora

Mine Service

A. Q. Aurora

A. Q. Aurora

1

1

3

1

1

1

5

1

1

1

1

1

6

800

2,079

1,782

125

75

80

60

75

70

100

75

35

6.50

600

50

800

800

2,079

5,346

. 125

75

80

300

75

70

100

75

35

39

600

50

800


fOUIPMENT

Description Source Rental Rate . Month

Total

Transfonner 550/220/110

Hand Held Tools

Auger

Misc.

Testing tt Measuring Apparatus During Project

A.Q. Aurora

l

3

75

35

35

75

35

105

As Required

Notes

1) Rental rates do not include freight costs to site from point of origin

and return at completion of project.

2) The rentals quoted in the above list do not include fuel or lubricants

for the listed equipment. Supply of fuel and lubricants would be treated

as Material Supply.

3) The rental rates quoted are exclusive of all taxes and any taxes

applicable would be paid by Cordova Mines over and above the rental

rates.

4) We believe the above equipment list covers all items necessary to carry

out the Project other than small tools and minor equipment. Snail tools

and minor equipment would be purchased as Material Supply and would be

the property of Cordova Mine. Should Cordova Mine decide to supply any

of the above listed equipment either from their own equipment or through

direct outside rentals by Cordova Mine, the rentals for such equipment

would be deleted from our charges.


t5) All the equipment listed except items (2), (4), (5) A (18) would be

supplied on a usual rental basis which would require Cordova Nines

to supply spare parts as required, fair wear and tear excepted. As

operator, AQL would be responsible for any parts required because of

negligence in operating and/or maintaining the equipment.

3) Material Supply

All material supplied by AQL for the operation including fuels, lubricants,

drill steel, vent tubing, tarps, explosives, small tools, etc. will be

invoiced to Cordova Mines at FOB Site cost, plus 1056 to cover AQL overhead

and profit. There will obviously be no charge for material which Cordova

Mines elects to supply directly. Any minor pieces of equipment not listed

under "Equipment" above, but required to carry out the work will be rented

or purchased by AQL after consultation with Cordova Mines and invoiced to

Cordova Mines at FOB Site cost, plus 1056, unless supplied by Cordova Mines.

Any such small equipment purchased would become the property of Cordova

Mines.

Any used supplies available with AQL such as hose and vent tubing would be

supplied to Cordova Mines {with their permission) at 5056 of current cost,

plus freight charges.

AQL willppurchase any useable common small tools and equipment at the

completion of the job at 5056 of Cordova Mines' cost, excluding the 1056

fee, if Cordova Mines want to sell such tools and equipment.

4) Head Office Visits

During the duration of the proposed program our head office personnel will

make one site visit per month. These visits can be co-ordinated with Cordova

Mines requirements. If problems with our operation require more head office

visits they will be made at our cost, but if Cordova Mines want additional

site consultation with our head office personnel it would be provided on a

per diem cost basis. Our charge for this consultation service, if required,

would be S250.00 per day plus expenses.


SUMMARY OF COST

Stage I (#1 Shaft)

Time: i) Set-Up #1 Shaft 12 Days

ii) De-Water to 4 Level 25 Days

iii) Examine Workings 6 Days

43 Days

Mobilization - Lump Sum 10,453

Wages - 3,215^8 x 1.061 x 43 days 55,449

Small Tools 96.00/day x 43 days 4,128

Board - 4 men x 30 x 43 days 5,160

Equipment - 11.689 x 43 days n25 J-vJO

Equipment Operating - 544 x 31 days 16,864

Repair Shaft Material - 390' x 16.50 6,435

Pipe 2"-4"-18" Vent~ 8 .95 x (390 * 100) 4,385

Surface Plant 15,340*

138,319


OF COSTS (Con 1 1)

Stage II - IV

Stage II Set-Up #3 Shaft 28 days

De-Water to 6 Level 17 days

Stage III Examine Workings 6 days

Stage IV De-Water to 10 Level 14 days

Examine Lower Works 6 days

71 days

Wages - 1215.38 x 1.061 x 71 days 91,555

Small Tools - 96.00 x 71 days 6,816

Board - 4 x 30 x 71 days 8,520

Equipment - 11689 x 71 days25 33,197

Add Pump b Cable - 120 x 57 6,840

Equipment Opr. - 544 x 57 31,008

Repair Shaft Material - 16.50 * 1050 17,325

Pipe - 2"-4"-18" Vent - 8.95 x 750 6,712

Surface 18,900

220,873

TOTAL COST

Phase I 138,000

Phase 2-4 221.000

359,000

A 1096 contingency should be added to total cost to cover some of the

unforeseen conditions which will arise as we progress through the project.

AU

RO

RA

QU

AR

RY

ING

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IT tO

By

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e.

Proj

ect:

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em:

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M5! S

r 2 ff p p

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k

r 3 i d **

5 b l*

f1 *

ro *n - w o*

ffi

y C b M ffiM

lK r 1 m o

l—

0 e5

r o

m r

t*

r

a

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9 "i

\fi

4^

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l B

r **

Jf -1

m IA 0 p

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-"

*6

00

b

o-

JM

0-

ONb

6 O

b b

^ j

0

gO

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(f"

1*

td**

^li

f*

K)

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li^ f\

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5^

-x. i ;,

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iiIIi

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ill

"l

IK .1 P' Jk S

VELLUMS AVAtLtfBL^ Foc ALU

W. G. WA H L LIMITEDCONSULTANTS: GEOLOGY - GEOPHYSICS - 3BO BAY ST. - IOTH FLU. . TORONTO. CANADA MBH M*

TEL. (414) 3094761 . CABLE) WAHLCO - TORONTO

March 9, 1981

if MatortlMr. Walter HoodR. R. #1 RECEIVEDHavelock, Ontario IVCV.1.1**-^KOL1ZO

THEDHECTO*Dear Mr. Hood: HI""* TAWfWI MID

OMEP OFFICESubmited herewith is our report entitled:

AN

EVALUATION

CORDOVA MINE PROPERTY

LASIR COLD INC.

The Cordova Mine is located approximately 150 miles north-east of Toronto, between Havelock and Marmora. Lasir Cold Inc. has acquired the mineral rights to H lots and surface rights to two adjoining parcels of land covering the area known as the Cordova Mine.

Gold was first discovered on the property in J 890 and a number of operators worked on the property, the latest being Cominco which suspended its operations in 1940.

The results of our evaluation have shown that the gold bearing vein material mapped underground at the Cordova property of Lasir Gold Inc., is associated with three major shear zones, located within a medium to coarse grained gabbroic complex; and that this vein of material consists predominantly of carbonate, feldspar, quartz, with pyrite and pyrrhotite. (The gold is associated with the pyrite mineralization). The vein material occurs . . .

. . . as a replacement of the shears.

. . . as a series of stringers and veinlets paralleling the planes of shearing.

. . . as veinlets in brecciated replacement zones.

. . . as lenses of massive material parallel to the shear planes.

The individual shears exhibit strong continuity along strike trending N 7O0E to N 85 W and dip moderately to the south at 65 degrees. These shears do however exhibit a somewhat erratic width,ranging from a few feet up to forty feet.

The recently completed tonnage and grade calculations were able to deliniate and quantify 47,526 tons of proven ore grading 0.180 oz Au/ton and 171,510 tons of probable ore grading 0.182 02 Au/ton. The proven ore consists of that material stock-piled on surface and broken ore remaining in the stopes. The probable ore consists of insitu material for which tonnage and grade are computed, partly from specific measurements, samples or production data, and partly from projection for a reasonable distance on geological evidence, and for which the site available tor inspection, measurement and sampling are too widely or otherwise inappropriately spaced to outline the material completely or to establish its grade throughout.

Additional geological and analytical data is needed in order to up grade the probable ore reserves presently indicated at the Cordova Mine. A detailed structural analysis of the major shear zones should be undertaken in order to further define the nature of the gold mineralization.

All previous milling tests carried out by the Ontario Research Foundation and by Lasir gold Inc., have shown that the ore from the Cordova Mine is amenable to gold extraction by cyanidation and that the gold recovery is expected to be over 901 after treatment in a conventional cyanide mill utilizing carbon absorption techniques and longer agitation times.

It is strongly recommended that the Cordova Mine property of Lasir Gold Inc. be dewatered and a comprehensive underground exploration program consisting of geological mapping, sampling and diamond drilling be carried out.

It is also recommended that a 100 t.p.d. portable test mill be acquired and assembled on site in order to implement and test on a pre-production scale the successful recover techniques employed by the Ontario Research Foundation and Lasir Gold Inc., during the 1980 summer field season. The mill flow-sheet will be similar to that used successfully by Cominco in 1938/39.

Ail of the aforementioned work is estimated to cost $ 2,014,390.00.

All of which is respectfully submitted.

W. G. WAHL LIMITED

D. G. Wahl, P.Eng., Consulting Engineer

DGW/PRR/mlP. R. Rautanen, B.Se., Project Geologist

3IC12SEMS9 63.4*12 MARMORA020

LASIR GOLD INC.

1981 WORK SUMMARY

By;

Peter Maltby, P. Eng. Consultant

LASIR GOLD INC.

1981 PROGRAMME SUMMARY

Work at the Cordova site during the summer of 1981 consisted of developing a system for the batch cyanidation, filtration, and gold recovery by charcoal absorption from the resulting pregnant solution. In order to ensure no environmental dis charge of any low cyanide content barren solution, complete solution recycle was adopted. After considerable trial and error, approximately 300 tons of old tailings sand were leached in 5 ton batches from which about 30 ounces of gold were recovered on charcoal. To date, none of this charcoal has been stripped or ashed for final gold sale. This is planned for 1982.

A schematic flowsheet and equipment used in shown in Figure 1.

The mixer was operated for 6 hours per batch. Overall reagentconsumptions were:

CaO 12 Ibs./ton of sandNaCN 3.5 Ibs./ton of sandHO (oxidant) 0.25 Ibs./ton of sand

Gold recovery was only about 35%. More process air is required and it is intended to use an agitated tank in 1982 for cyanidation using the mixer solely for mixing.

A control laboratory was set up on site to measure lime, cyanide and reducing strengths of solutions.

LABOUR

The personnel on site were trained by management to operate the equipment shown on the flowsheet. It took two men at all times to operate the plant and to run control analyses.

FIGURE l

CORDOVA BATCH CYANIDATION FLOWSHEET FROM OLD TAILINGS DUMP

10 Ib/ton CaO added

lPAD

Moved by Front End Loader

HOPPER

Conveyor belt

Driven by. Tractor

Barren Wash

MIXER

Lead nitrateCaONaCNH202

Barren solution

FILTER PAN VACUUM PUMP

50** Solids by weight

WASHED CAKEPUT ON

PLASTIC SHEETS

Drainage PLASTIC LINED PREGNANT SOLU TION POND

SOLUTION PUMP

PLASTIC LINED BARREN TANK

TWO CHARCOAL COLUMNS_____

TBarren Solution to recycle Makeup in Mixer

Charcoal Storage

31C12SEM59 63.4*12 MARMORA 030

ENVIRONMENT IMPACT ASSESSMENT

AND

DESIGN OF TAILINGS DISPOSAL

FOR

CORDOVA MINE, CORDOVA, ONTARIO

Prepared by: Lasir Gold Inc. P.O. Box 130 Havelock, Ontario KOL 1ZO

Jan. 29, 1982

Distribution: Ministry of Environment (3) Lasir Gold Inc. (2)

31C12SEM58 63.4*12 MARMORA

TABLE OF CONTENTSO3OC

1.0

2.0

3.0

4.0

s: o

6.0

5.1

5.2

5.3

5.4

5.5

5.6

6.1

6.2

6.3

6.4

6.4.1

6.4.2

6.4.3

6.4.4

6.4.5

6.4.6

7.0

INTRODUCTION

SUMMARY

HISTORY

GEOLOGY

ENVIRONMENT

Site Description

Atmospheric

Water Quality

Air Quality

Aquatic Biology and Vegetation

Seismic Zoning

TAILINGS DISPOSAL AREA - DESIGN AND TREATMENT

Method and Location

Tailings Site Design

Dam Construction

Mill Reagents

Sodium Cyanide

Quicklime

Remedial Measures

Neutralizing Agents

Cyanide Removal

Suspended Solids

CONCLUSIONS

LIST OF FIGURES

1. GENERAL LOCATION

2. GEOLOGICAL MAP OF CORDOVA MINES AREA

3. KEY PLAN

4. SIZE GRADATION OF MILL TAILINGS

5. LASIR MILL FLOWSHEET

6. PLAN OF PROPOSED TAILINGS SITE

7. SEISMIC ZONING MAP OF CANADA

LIST OF TABLES

I. PRECIPITATION DATA

II. WIND DATA

III. TEMPERATURE DATA

IV. WATER ANALYSIS #3 SHAFT

1.0 INTRODUCTION

Lasir Gold Inc., Havelock, Ontario is planning to

re-open the former Cordova Mine lcoated in Peter

borough County in Southeastern Ontario. Figure l

illustrates the general location of the mine with

'respect to the major arterial routes.

Lasir Gold Inc. is proposing to construct a 100

ton per day test mill to treat approximately

20,000 tons of gold-bearing ore brought to the

surface by the previous operators of the Cordova

Mine. The company is also proposing to dewater

the old mine workings in order to prove sufficient

underground ore to justify re-opening the mine for

production. Anticipating such new production the

design life expectancy of the operation will be 10

years.

2.0 SUMMARY

Lasir Gold Inc. is planning to re-open the Cordova gold

mine at Cordova Mines, Ontario. Under Section 42 of the

Ontario Water Resources Act for disposal of industrial

waste it is necessary to file Mineral Industries Inform

ation sheets and Application for Approval of Plans for

Tailings Disposal Facilities. These forms are included

in this report.

Approximately 20,000 tons of surface ore is to be

milled at a rate of 100 tons per day in a test mill

to be built at the minesite. At the same time, after

the mine has been de-watered, underground sampling and

diamond drilling will be done to confirm existing ore

reserves and to find more ore to justify construction

of a headframe and installation of a hoist.

A tailings disposal area is available to the south of

the proposed mill site to accommodate up to 300,000

tons of the tailings expected to be produced in a 10

year operating span. Any tailings water will be

retained in a tailings pond before being recycled

back to the mill. Any excess water will be treated

with lime for precipitation of any heavy metals. Due

to the prolonged retention time it is expected that

any free cyanide will have been oxidized.

con'd.....

Summary Page 2

The environmental impact of the tailings water effluent

is expected to be negligible due to the wash treatment,

long retention times, and small outflow due to recircu-

lation.

Impact of base metal arsenic and mercury emissions from

the' milling operations will be negligible due to the

suitable controls available and the absence of heavy

metals in the Cordova ore.

3.0 HISTORY

Gold was first discovered onthe Cordova property in

1890 by Mr. H. Strickland who found free gold in an

outcrop crossed by a road which was washed out follow

ing a heavy rain. The occurrence went unnoticed until

1891 when the property was bought by Mr. A. W. Carscallen

who sank the #1 shaft to a depth of 60 feet and installed

two grinding mills which allowed the recovery of consider

able gold. This work continued until 1893.

In 1897 a British corporation, the Cordova Exploration

Company, bought the property. Extensive development was

undertaken which included the construction of a ten stamp

mill. During the period 1897 - 1900 there were 4,803

ounces of gold recovered from 15,267 tons of ore. In

1901 the mill was expanded to 30 stamps and from 1901 to

1903 there was 10,943 ounces of gold recovered from

41,518 tons of ore. In 1903 two principal owners of the

mine died, which caused the mine to close late in 1903.

In 1911 Cordova Mines Limited Bought the property and

proceeded to dewater the mine and sink the #3 shaft to

a depth of 500 feet. The mine, formerly known as the

Belmont Mine, was renamed the Cordova Mine. Due to

difficulties with equipment, production was erratic

con'd....

History Page 2

until 1917 when a serious fire suspended all operations.

During this period a total of 10,230 tons of ore were

processed to produce approximately 2,412 ounces of gold.

In 1934, Cominco purchased the property for a sum of

$10 / 000. The #3 shaft was deepened to 1,050 feet and

development was mostly confined to the deeper levels.

A 100 ton mill was built in 1939 and during the interval

from October 23, 1939 to July 29, 1940, the mill pro

cessed 33,434 tons of ore and extracted 3,487 ounces of

gold. All operations ceased at the end of July, 1940.

During the span of time from 1897 to 1940 the Cordova

Mine yielded 21,645 ounces of gold from 100,449 tons of

ore for an average grade of 0.215 oz/ton.

4 . O GEOLOGY

The Cordova property of Lasir Gold Inc. is underlain by

rocks of Precambrian age. The oldest lithologics are a

series of metasediments (including marble, parageneiss,

quartzite, arkose, schist, conglomerate, etc.) and meta-

volcanics (including amphibolite, amphibolite schist,

andesite, basalt, pyroclastics, etc.) which were intensely

metamorphosed and deformed during the Grenville Orogeny

approximately 1,100 million years ago. These rocks are

cut by intrusions associated with this orogenic activity.

The oldest intrusives (with associated gold mineralization)

are a series of basic intrusive rocks with compositions

ranging from peridotite to quartz diorite, emplaced early

during the Grenville Orogeny. The latest intrusives are

present in the form of granitic domes and pegmatitic

dikes intruded towards the end of the Grenville.

Palezoic limestones outcrop just to the south of the

area and a thin mantle of glacial debris is widespread

throughout the area.

There would seem to be 2 or 3 ages of basic intrusives

based on aeromagnetic evidence. The compositions of

the intrusions include quartz diorite, diorite, gabbro,

norite, peridotite, hornblendite, amphibolite, and

con'd.....

Geology Page 2

metagabbro. The gabbroic intrusives generally form basinal

structures with an alteration rim surrounding the gabbro;

and brecciation, iron and sulphide mineralization being

found within the gabbro body.

In Belmont Township, there is a gabbrioc complex intruding

pre-existing volcanics and sediments, itself being cut by

later felsic dikes. The gabbro is a medium to coarse grained

rock composed of labradorite, hornblende, carbonate, chlorite,

serpentine, sericite, quartz, apatite, pyrite, magnetite and

ilmenite. Local differentiation of the gabbro would appear

to have taken place. This gabbro has a very definite aero

magnetic expression.

Shear zones within the gabbro show alteration to biotite

and chlorite. These shear zones are important because all

gold mineralization has been found in vein material within

these shears on the western margin of the intrusion. {Not

all shear zones have gold mineralization, however.)

Vein material within the shears consists predominantly of

carbonate, feldspar, quartz and pyrite and pyrrhotite.

(Gold is associated with the pyrite only.) The vein

material is found as (i) replacement of shear zones

(ii) series of stringers and veinlets paralleling the

planes of shearing (iii) veinlets in brecciated replace

ment zones (iv) lenses of massive material parallel to

con'd.....

Geology Page 3

the shear planes. Individual shears are quite irregular

but usually persistent along strike with widths from l

to 40 feet but averaging 6 feet.

On the Cordova property there are three shears containing

workable gold-bearing zones. Around the No. l shaft we

have mineralized zones striking N60 to 70OE and N80OW

dipping 60 to 70OSE. Around the No. 3 shaft the mineral

ized zones strike N70 to 85OE and N85OE and N85OW dipping

65OS. These gold bearing zones appear to coincide with

changes in the strike of the shearing (intersection of shear

zones) and also to locations where there is contortion and

variation in the shearing. The major shear zones would

seem to parallel the outer contact of the gabbro. The

shear zones may have been the controlling factor in the

direction taken by gold-bearing mineralizing solutions.

A geological plan is shown on Figure 2.

5.0 ENVIRONMENT

5.l Site Description

The Cordova mine is located in Southeastern Ontario

near the eastern boundary of Peterborough County

{440 40' north latitude, 77O 50' west longitude).

The site is readily accessible by road proceeding

east from Toronto on Highway #401 to Belleville and

then north on Highway #14 to Marmora. The mine is

8 miles beyond Marmora. Total distance from Toronto

is approximately 150 miles.

Lasir Gold Inc. has acquired the mineral rights to the

west half of Lot 20 Concession l Marmora Township

{116 acres) the east half of Lot 20, Concession l,

Belmont Township (117 acres) and the southeast quarter

of Lot 21, Concession l, Belmont Township (about 50

acres) as well as surface rights to the west half of

Lot 20, Concession l, Belmont Township. These areas

are shown in the Key Plan, Figure 3.

5.2 Atmospheric

Data on the climate for the Peterborough area is

enclosed in the form of Tables at the end of this

section. These tables include the precipitation

and temperature records for the Peterborough area

together with the meteorological data. The precipita

tion and temperature data has been measured by

con'd...,

Environment Page 2

Environment Canada over a study period between 1941

and 1970. Peterborough was chosen since it was the

closest place to Cordova Mines where such data had

been collected.

From these tables it can be seen that the average

annual mean precipitation that could be expected

at the mine site would be in the order of 734 mm

with approximately 201 as snowfall. The maximum mean

daily temperature averaged over a year would be 11.7 Co

with a minimum mean daily temperature of 11 C. The

mean daily temperature would be 6.4OC. Wind speed

and frequency information for Stirling, Ontario is

reproduced on Table III. The maximum observed hourly

spped was 50 m.p.h. and the average yearly speed from

all directions was 7.1 m.p.h. The major wind directions

appear to be from the west.

5.3 Water Quality

Water analyses have been done on #3 shaft mine water

shown in Table IV. The heavy metal content of this

water is well below M.O.E. guidelines of l mg/litre.

All of the other parameters are also well below M.O.E.

guidelines.

con'd.....

environment Page 3

The significance of opening a mill on the water

quality has been discussed elsewhere in this report.

5.4 Air Quality

Operation of the mine and mill is not expected to have

a significant effect on the atmosphere. Background

information could be established prior to the mill

going on stream by using a simple system of dust fall

jars. These dust fall jars would be monitored for 4

months prior to milling and then for an additional 6

months after milling commenced.

5.5 Aquatic Biology and Vegetation

There appears to be no published data on the above for

the area. From a recent as yet unpublished study data

is still being collected.

5.6 Seismic Zoning

The location of the property is shown in the Seismic

Zoning map, Figure 7. No effect is expected from seismic

activity on the tailings area since the tailings will be

placed on bedrock and the material used in the dam will

not be subject to liquefaction.

6.0 TAILINGS DISPOSAL AREA - DESIGN AND TREATMENT

6.1 Method and Location

A conventional tailings disposal area usually consists

of a natural ground depression ideally bottoming on

bedrock with impermeable dams constructed to retain

tailings water. In the case of cyanide solutions, any

excess tailings overflow not required in the milling

process is flowed to a polishing cell where sufficient

.retention time is present to allow for destruction of

free CN ions by natural oxidation.

The anticipated tailings size gradation is shown in

Figure 4. The proposed mill flowsheet is shown in

Figure 5.

At the Cordova site a natural ground depression exists

adjacent to the proposed test mill site in the form of

a valley bounded on three sides by high rock outcrop.

There appears to be little surface overburden. A survey

plan of this area is shown in Figure 6. The area was

surveyed in 1981.

It is planned to pump mill tailings at 55% solids to

the tailings area. An impermeable dam of crushed waste

rock and clay will be built to retain the tailings.

Clear solution will be decanted from a decant tower

con'd.....

railings Disposal Area - Design and Treatment Page 2

for re-use in the mill. Any surplus mill solution will

be decanted to a polishing cell for natural destruction

of free CN ions. Retention time of up to 100 days of

such solution will be provided.

In summary, the reasons for choosing the proposed tail

ings site are:

1."The area is a natural ravine.

2. The area can incorporate both solids and a polishing

cell for solution treatment if required.

3. It is believed that on bulldozing the existing topsoil,

rock outcrops will be exposed on which a dam can be

built thus avoiding any chance of seepage.

4. Sufficient area exists for the deposition of tailings

during the life of the mine which can be enlarged by x

100% if required for a longer mine life than presently

envisaged.

5. Natural slope of land allows for easy control of

effluent flow being directed back to the mine for

recirculation.

6. Minimizes the environmental impact on the surrounding

environment.

It is assumed that the tailings will have a unit weight

of 130 Ib/cu.ft.

con'd....

Tailings Disposal Area - Design and Treatment Page 3

6.2 Tailings Site Design

The proposed layout for the tailings system is shown

in Figure 6. This layout shows the proposed discharge

system in plan view. The solids will be retained in

the natural depression with a low perimeter dyke con

structed to control the outflow of tailings water.

The water will be held behind this dyke to allow for

any chemical reactions to take place, sludge settle-

'ment, and for process water recirculation as required.

6.3 Dam Construction

It is suggested that sand or gravel and/or mine rock

waste could be used as core material for the dam.

The dam could then be covered with clay material to

render it impermeable. Monitoring of the tailings

water solution would be done to ensure that it could

be discharged into the natural environment in cases of

heavy precipitation.

6.4 Mill Reagents

The following reagents are proposed to be used within

the milling circuit for gold recovery.

con'd.....


6.4.1 Sodium Cyanide (NaCN)

To be used in the direct dissolution of gold as

governed by the reaction below:

2 Au 4- 4 NaCN + 2 HjO 4- O2 -* 2 NaAu(CN) 2 * H2O2 * NaOH

The quantities of NaCN reported to be used in the

milling circuit are comparable to other gold milling

operations in Ontario. It is expected that the

amount of cyanide reporting to the tailings will

be low due to recirculation of barren solution and

destruction by natural oxidation. The main

threat of NaCN is that low concentrations of this

chemical in surface waters can prove to be fatal

for fish species such as trout. The degree of

recirculation will govern the type of remedial

reasures such as lime dosage that will be required

to allow for the proper breakdown of cyanide to

provide a clean discharge water.

6.4.2 Quick Lime (CaO)

In the milling circuit CaO will be used as a

depressant for the iron sulphides (pyrite) to

ensure oxidation of pyrite does not form acid

which could destroy the sodium cyanide in the

gold circuit. This protective alkali causes

con'd.


an increase in the pH of the effluent. Final

pH of the effluent will be Ph9.

6.4.3 Remedial Measures

The degree of remedial measures will depend on

the percentage of recirculation of tailings water

returned to the mill. The following remedial

measures are listed:

1. Neutralizing agents

2. Cyanide removal

3. Suspended solids control

These measures are presented in the view that

IQQ* recirculation will be incorporated at the

minesite. A total recirculation of mill effluent

will dictate that minimal amounts of overflow

seepage will occur.

6.4.4 Neutralizing Agents

Generally gold mines using alkaline cyanidation

stabilize the pH around 10. Neutralizing the

pH at site will not therefore be a major require

ment. If pHs should become depressed, lime treat

ment facilities could be incorporated into the

tailings design similar to that shown in Figure 5.

Such a system would also cause precipitation of

any heavy metals by the following reaction:

M"1"* 4 2(OH~) -*M()H) 2

con'd..


Based on the solubility constant of individual

reactons, theoretical pH values can be calculated

where optimum removal of metal cations by precipi

tation of hydroxide compounds can occur. By holding

the pH at 9 good copper and zinc precipitation and

fair removal of iron would be achieved.

The effectiveness of this system has been recorded

at many Northern Ontario base metal mines. For

example, at Mattabi Mines a base metal operation

north of Ignace, lime treatment is used to control

the trace heavy metals in the mill effluent. Mill

water before treatment generally contains in the

order of 5 ppm zinc and copper. After treatment

with lime, the concentrations of zinc and copper

are decreased to l ppm. The design removal pH is

.in the order of 9.0. Although the proposed project

is not a base metal mine, the same general character

istics for treatment would apply to this gold operation.

6.4.5 Cyanide Removal

As a closed circuit with final washing of the filter will

be incorporated into the milling operation, the expected

cyanide concentration in the effluent will be limited.

con'd.....


It is expected that retention times within the

tailings area will be sufficient to cause the total

chemical breakdown of any residual cyanide.

6.4.6 Suspended Solids

The use of quicklime within the milling process will

probably increase the suspended solids in the tail

ings water. If the concentration of suspended

solids should exceed M.O.E. guidelines at any time

a flocculent could be used to settle out solid

particles.

7.0 CONCLUSIONS

The following conclusions are presented:

1. Discharge of mill tailings pulp at 55% solids by

weight to a tailings area adjacent to the mill site

is proposed. The tailings will be dumped on bedrock

and retained behind an impermeable dam.

2. Precipitation falling on the tailings will be stored

behind a dam constructed of local sand and stone and

based on bedrock. Such water will be analysed at

regular intervals and returned to the mill as process

water as required. Any surplus will be discharged to

the natural watercourse after natural oxidation in a

polishing cell.

3. Based on a milling rate of 100 tons per day the total

volume annually will be 800,000 cu.ft. The tailings

area will have an original design capacity of 8 mm cu.ft.

or 10 years storage.

4. Since the heavy metal content of the ore is low and all

but a trace of cyanide will be removed by oxidation, the

overall impact of the mining operation on the surround

ing environment will be minimal.

Cordovo L Mines

GEOLOGY

Legend

Palwnole Sediment!

S F*Ufc Intrusive*

4J Hcfle IntnuhrM

j"j Non-cUitfc MetuMUooiU

a~| CUsUe

71 HeUvolcuiiei

S MI of opening (in) U.S. Standard s ieve s ize

100A" l" W" l" i" i"-l6 3 * '3 '4 i a

100 60 20 10 6 l .6 .2 .1 .06

Grain size (mm).01 .002 .001

M. l. T. CLASSIFICATION

TYPICAL GRADATION ENVELOPE FOR TAILINGS

t

.0001

COBBLE coarse medium fineGRAVEL

coarse medium fineSAND

SILT CLAYFINE GRAINED

O2J >ZwN m

g w

CDC-H

6z

(rkCC

MILL FLOWSHEET

lGRIZZLEY

Truck Ramp

FIGURE 5.

SURGE BIN

APRON FEEDER

To Process

PUMP

Gao -PbNQ- NaCN-

oversize

GaoNaCN

grinding solution

GRINDING MILL

lVIBRATING SCREEN

undersize

PUMP

THICKENERoverflow- IPREG. TANK

underflow

PUMP

AGITATORS filtrate

PUMP

DRUM FILTER wash

cake

REPULPER

\ f

PUMP

BARREN TANK

tPPTN.UNIT

Au PPTEto

Refining

TAILINGS

FIGURE 6.

lOUNOAIIi! OF THl ZONl INDICATING OROUND ACCUSATIONS

AS A MACTION OF O IAVITAT IONA l ACCEIUA T10 N

SHOWN THUS

SEISMIC ZONING MAP OF CANADA

TABLE I

Mean

Rainfall

Snowfall

Total

No. of days with precipitation

No. of days with rainfall

No. of days with snowfall

Greatest pptn. in 24 hours

PRECIPITATION DATA* FOR PETERBOROUGH 1941 to 1970

Millimeters

Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Year

12.4 12.4 25.9 53.8 75.7 64.3 68.8 60.2 67.8

39.9 37.3 21.1 6.6 T O O O O

52.1 49.8 47.8 61.5 75.9 64.3 68.8 60.2 67.8

11 10 9

214

10 8 6

9

8

2

10

9

1

8

8

0

8

8

0

8

8

0

7

7

0

66.0 44.5 57.9 65.3 66.8 83.6 77.7 87.1 81.3 Years 93 95 94 96 97 97 96 97 96

Greatest snowfall in 24 hours 66.0 40.6 55.9 23.4 15.2 O O O 2.5

Greatest rainfallin 24 hours 33.0 44.5 50.8 57.7 66.8 83.6 77.7 87.1 81.3

61.5 52.6 22.6 578.3

0.5 13.5 34.0 152.9

62.0 66.8 56.6 733.6

8 10 11 109

8 7 3 73

O 3 8 37

62.2 61.5 43.2 87.197 96 92

15.2 27.9 30.5 66.0

62.2 57.2 39.4 87.1

* From Canadian Normals, Downsview, Ontario Environment Canada

TABLE II

TEMPERATURE DATA* FOR PETERBOROUGH 1941- 1970

0C

Mean Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. Year

Daily Temp. -8.6 -7.5 -2.0 6.0 12.1 17.7 20.0 19.1 14.8 9.1 2.3 -5.7 6.4

Daily Max. Temp. -3.7 -2.4 2.9 11.6 17.9 23.5 25.8 25.1 20.6 14.7 6.3 -1.6 11.7

Daily Min. Temp. -13.4 -12.6 -6.9 0.4 6.2 11.8 14.1 13.1 9.0 3.4 -1.8 -9.9 1.1

Extreme Max. Temp. 14.4 13.9 25.0 30.0 35.0 36.7 38.9 37.2 37.2 30.6 23.9 15.0 38.9

Years 83 86 85 85 85 85 84 86 84 86 86 83

Extreme Min. Temp. -37.8 -38.9 -31.1 -20.0 -7.2 -1.7 2.2 -2.8 -7.8 -14.4 -23.9 -39.4 -39.4

No. of days withfrost 30 27 28 15 3 O O O l 8 20 29 161

* From Canadian Normals, Downsivew, Ontario Environmen^ Canada

TABLE III

WIND DATA

closest place

STIRLING, ONT.PERIOD W5S-

JAJI JAHV

PEICENTAGE

1 •mnratS3SIssrESSVsv vsvVvwav IWCala

7 5

10

5li

2 22

558 9

12

9 •9

1.6

•f* PERIODE

resrev

MAX API MARS An

MATMAI

HEIGHT OF

JOTjun

JUL.run.

ANEMOMETER

AUG AOUT

at

FREQUENCY

6k 95i

2k27

15 10 8k6

7 5 967

2k28

12

97 65

AVERAGE WIND SPEED IN

US BraiISl

SIS3SSSVEVvsvVvwwmAll

7-9 8.6 8.9 6.56.66.08.06.87-97-6

10. J8.2

10.18.17-7

8.7 7-28-77.27-k7-17-77-29-29. li

11.98.78.6

9.". 7-99-""6-77-96.17-k7-89-89-3

11.68-59-2

7

755

i5k9

11

8 5k

MILES P

8.7 8.1

10.29-19-67-38-58.68.9

10.011.78.69-7

7

53k

375

13

11

k6

6

623

Z

87

15

12

310

E* HOUR7-6 6.1

7-7 6.57-77-*8.16.97.97-*8.68.3

10.77-97.8

6.6 5-96.56.16.76.16.76.56.77.29-16.77-5

7

522

22

77

15

13

312

5.6

5-16.66.17-16.06. k6.15-96.98.27-16. k

e

62

3

2

76

15

10

k12

VITESSE

5.65 B

5.16. k5-36.86.67-05-95.86.28.16.56.5

7

B23

k76

12

9

311

kfi* HAUTEUR Of I'ANEMC

OCI Ml DK TIMOCT MOT D8C ABIBL

FREQUENCE

6667

7897k k 6 k* * S *

332277565535

12 10 9 11

10 11 12 12

k k k k8 6 78

MAETU

IN t*

I

Bno

i

BfB

aao10

on0

OK)B

BOCal*

MOYENNI DES VENTS EN MJILES/HEURE

6.1 6.J 6.8 74 6.8 i

5.06.35.77.*6.67.26.k6-37.0e.k6.76.1

Directions7-8 8.2

Ma

8.2

hxlraMaxlanx

8.7

Oba erredObeerved

Probable Maxisma M- .M—.- Hourly fi]

7.". 6.1

Hourly SpeedOustOust md

Speedfor

5-6

SOW-

70

5-5

TlteaseTlteeseRafale

5.8

6.1 6.2 6.3 6.36.8 7-2 6.* 7-*7-7 6.7 6.* 6.7B.k 9-3 8.5 7.97-0 7-9 6.7 6.87.5 8.0 7-2 7-56.6 8.3 7.2 7-17.0 10.} 8.8 8.17.1 9-1 8.0 8.19.1 10.2 9-6 9.9

7-1 8.7 7-7 7-78.2 8.} 8.5 7-9

ftm

B Bf

IIBB

SBt

BOto

060

0MO

B?

BOleat** directions

6.6 7-8 7.3 7.1

boralre maHaale observe*•axil

••JOB

sale oba*rv*e des rafale*al* en rapport are* Ylteax w*nta horalraa

STATION I NFORMATIONLooted Uj Bllet v*tt nortbvtit of Stirling, ft eo&aeftsloD road approxlBftteljr 3/8 all* aortto of alia road. Rolllnc eouDtry surrouBda tb* nw In all dtnetiona. Hldft of Mill north of iltc. Sam* obstruction by tmi 150 r**t viat of am. Expoaurc jood In all other •.uadranta.

DONNfES HELATIVES A LA STATION Bltui-a kj Btlln l 1'ouaat-nord-oojit ta Btiflihi, aar une rout* a* eoocniton altu** a ainliuu 3/8 d* mille au nord d* l* rout* prtnclpale. U r**4on enrlroDnante eat accldentee. Mat ehtne da eolUnaa a'awod au nerd, a 150 pleda i I'oueat, dn artrea fonent IB obatacla. Mil 1'exyoaltlon aat aoau dana lea autrea fua4nata.

TABLE IV

MAY 1981 ANALYSIS OF CORDOVA #3 SHAFT

MINE WATER

Element

Mn

Fe

Co

Ni

Cu

Zn

Mo

Ag

Cd

Pb

Content mg/litre

1

1

1

1

1

2

2

1

1

6

Detection limit was l mg/litre for all elements except Pb which was 2.5 mg/litre. Mine water pH 6.8

REPt . it i2 REF. FILE 7001-G4

l SOLUTION

WAS ANALYSED AS FOLLOWS:

UNITS METHOD . DETECTION LIMIT MN PP8 DCP 10.000 FE PPB OCP 10.000 CO PP6 OCP 10.000 NI PPB DCP 10.000 CU PPB DCP 10.000 ZN PPB DCP 10.000 MO PPB DCP 50.000 AG PPB DCP 10.000 CO PPB DCP 10.000 PB PPB DCP 25.000

X-RAY ASSAY LAB

DATE 29-MAY-81 ' CERTIFIED BY

*** UNLESS INSTRUCTED OTHERWISE WE WILL DISCARD REJECTS 30 DAYS AND PULPS 180 DAYS FROM DATE OF THIS REPORT

CORRECTED REPORTX-RM^ASSAY LABORATORIES 29-MAY-81 REPORT 11212 REF. FILE 7001-G* PAGE l

SAMPLE MN PPB F6 PPB CO PPB Nl PP8 CU PPB

COROOVA MINE ^0 *C10 <10 <10 <10

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LASIR GOLD INC.Cordova Mine, Cordova Mines, Ont.,

P. O. Box l 30, Havelock, Ontario, KOL l ZO

SUMMARY OF WORK INITIATED 1979 BY THE CORDOVA GOLD SYNDICATE AND CONTINUED THROUGH 1980 AND 1981 BY LASIR GOLD INC.

During 1979 summer season a 1500 ton pile of ore from the approximately 20, 000 ton pile of development ore immediately north of No* 3 shaft was constructed on a reinforced plasic sheet underlain by a 2 foot sand layer and covered with a 6 inch layer of sand on top of which the ore pile was built. The pad was built so that the centre was sloped in from the edges and longitudinally inclined to drain into a collector box at one end. Pad dimensions were 40 feet wide and 100 feet long and the pile made 10 feet high with side slope of 80 degrees.

A series of 40 sprays fed by 4 Jabsco pumps were used to impregnate the pile with a weak cyanide solution at a rate of 0. 5 gal7min/spray head. A make-up pond was filled with 60, 000 gals of water taken from No2 mine shaft to which lime was added to provide a PH of 10 and then NaCN was added to produce a l^o cyanide solution in a 6 foot diameter by 6 foot high head tank which provided a positive head to the 4 Jabsco pumps feeding the 40 spray heads on the ore pile.

The pile was thoroughly soaked with the CN solution and the drained solution was collected in a box at the low end of the pile. The collected solution was then pumped through a charcoal column 2 feet in diameter and l O feet high. The overflow from the column was returned to the make-up pond.

After the leaching circuit had proceeded for 400 hrs., the daily cycle being to spray for 16 hrs and oxydise-drain for 8 hrs. , the spray cycle was stopped. The charcoal, 800 Ibs., was assayed and reported to contain 131 oz/ton Au.

Attempts were made to strip the charcoal and deposit the gold from the strip solution in an electrolytic cell which had been successfully done on test ore at the Ontario Research Foundation. This did network out satisfactorily, primarily due to the inability to carry out adequate analytical analysis on site. The lag in getting results back from the commercial laboratory made the development of this part of the project impractical. Gold was deposited in the cell but the solution was not adequately stripped and the parameters became too numerous to adequately monitor with the limited facilities on location.

An attempt was then made to burn the charcoal and collect the gold from the ash. Propane burners with added air enabled the charcoal to be burned but an inability to control the removed air properly resulted in an excessive loss of ash with the contained gold values.

Due to the limited financial resources of the company it was then decided to ship the gold laden charcoal to the ASARCO smelter at Hellena, Mo. This turned out to a task of major proportions and less than satisfactory in all respects. The contract arrangements were done through New York and it took almost three months before the charcoal could be shipped. Sampling was systematically done by ASARCO with inspection of all Batn.ple preparation

witnessed by Lasir Gold Inc. Two quarters of the final assay sample were kept by ASAR CO and two brought back by Lasir Gold. The Lasir Gold Inc sample was assayed at Lakefield Research Ltd. and these assays were consistantly higher than ASAR CO1 s assays and the arbitration a s sayer was used. These assays were even worse than those which ASAR CO did frond - the Lakefield Research results. Payment was finally effected when the time limitation stipulated in the contract became effective at the ASARCO assay value which was consistently 20 oz/tcnless than the Lakefield Research assays. The company suffered in three major ways from this operation. The Canadian dollar dropped to a point lowest at the time shipment was made so that trans portation costs and inspection costs were highest, payment was held up for almost six months and was finally made when gold price had dropped over $110 from the time the charcoal was originally shipped.

During the 1980 summer work program at the Cordova Mine site the old mill tailings area was investigated. Samples taken at random from various spots over the dump area resulted in an average gold value of 0. 33 oz/ton. Systematic sampling of the estimated 1200 tons of these tailings has confirmed these values.

A pile of these tailings was made on a pad similar to the original 1500 ton ore pile to accomodate 50 tons. The fineness of the tailings however did not allow the solution to drain through the pile and an enclosure had to be provided. This also proved inadequate in that the colloidal properties of the mixed tailings with CN solution did not permit a clean solution to be fed through the charcoal columns.

The results of this trial and error approach to the physical treatment of these relatively high grade tailings is approximately 300 tons of partially treated materials which warrants retreating through proper facilities. The company's metallurgical consultant, Mr Peter Maltby, has prepared a flo-eheet to process these old mill tailings on an economical basis and this is shown in his covering report which summarized the work covered by the period of this OMEP application.

A separate report by W. G. Wahl Limited dated March 9, 1981, prior to making an application for an OMEP grant, was "An Evaluation, Cordova Mine Property, Lasir Gold Inc. " This is a comprehensive report which reviewed all of the available data from previous operators, most notably COMINCO which held the property from 1935 until 1940 and tr* recoveredS, 487 oz gold.

The Wahl report quantifies 47, 52k,171, 510 tons probable ore grading 0.182A copy of the Environmental Impact Assessment fe Design of Tailings Disposal for Cordova Mine, prepared by the company, is attached.

June 18, 1982, Lasir Gold Inc.

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NOTE: The central portion of each ore block

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SCALE l in. * 40 ft.

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LASIR GOLD INC.CORDOVA MINES PROJECT

CROSS SECTION

LINE 4800LOOKING EAST

MARCH, 1981 /UGI j SCALE l in * 40ft

DRAWN BY

PRTRACED BY

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APPROVED

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DWG. NO.

an evaluation cordova mine prop omep81-9-c-78 · presence of 25,580 tons of ore at 0.265 oz/ton...

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