Green Green, It’s Green They Say, on the Far Side of the Hill………

Folk Song

UNIVERSITY OF JOHANNESBURG

COLLOCUIUM 2011

THE SOUTH AFRICAN FOUNDRY INDUSTRY

1. NUMBER OF FOUNDRIES

* Includes 4 Investment Casting Foundries

In addition there are 13 Art Foundries and 9 Spin Casters

cf Germany = 900USA = 2000China = 2600

METAL TYPE 2003 2007 2011 %Change 2011/2007

Ferrous 110 110 101* 8

Non Ferrous 103 101 80 21

TOTAL 213 211 181 14

Metal TypeEstimated

Annual Production2003 (tons)

Estimated Annual

Production2007 (tons)

Estimated Annual

Production2011 (tons)

Growth2011 vs.

2007(%)

  2003 2007 2011  

Non-Ferrous 84,000 97,800 91,400 -7%Ferrous 422,000 562,600 479,950 -15%

Total Annual Production 506,000 660,400 571,350 -13%

2. ESTIMATE ANNUAL OUTPUT BY METAL TYPE

cf Germany 2.7m TonsUSA 11.0m TonsChina 39.0m Tons

4. PROCESS TYPES

Process Type No. of Foundries using the Process (%)Sand  Bonded sand 44%Green sand 34%Other 14%

Permanent Mould  Gravity 21%Low Pressure 5%High Pressure Die Casting 7%Other 3%

3. GEOGRAPHICAL LOCATION

ProvinceNo. of

Foundries2003

No. of Foundries

2007

No. of Foundries

2011

Percent of Total2011

Gauteng 110 108 97 54%

Western Cape 26 16 15 8%

Kwa-Zulu Natal 20 26 24 13%

Eastern Cape 16 10 10 6%

Free State 10 7 6 3%

North-West 10 9 5 3%

Northern Cape 6 3 3 2%

Other 15 15 18 10%

NOTE: Other includes Mpumalanga and Vereeniging area

3.1

5. FOUNDRY TYPE

Foundry Type No. of Foundries No. of Foundries(%)

Production 23 24%

Jobbing 50 52%

Production & Jobbing 24 24%

6. AUTOMOTIVE CASTINGS (Est. Production)

METAL TYPE TONS % OF TOTAL / TYPE

Grey Iron 153 072 75

Ductile Iron 78 432 63

Aluminium 66 012 88

Zinc 408 15

Magnesium 240 95

TOTAL 298 164 52

METAL TYPE TONS % OF TOTAL

Ferrous 231 504 48

Non Ferrous 66 660 70

6.1

6.2

7. EMPLOYMENT (Automotive Foundries)

METAL TYPE NO EMPLOYEES % OF TOTAL

Ferrous 2116 22

Non Ferrous 598 34

Total 2714 24

7.2 Automotive Foundries produce 52 percent of the output with 24 percent of the total staff employed in the industry.

7.1

8. FOUNDRY PRODUCING AUTOMOTIVE CASTINGS

• 8 Automotive Iron Foundries generate 48 percent of the total Ferrous tonnage produced

• 16 Non Ferrous Foundries produce 70 percent of the total.

METAL TYPE NO OF FOUNDRIES % OF TOTAL

Ferrous 8 (Est.) 8

Non Ferrous 16 20

Total 24 13

• DEFINITION: Technology that when properly implemented, allows an organisation to meet it’s present needs without compromising it’s future needs.

• Green Technology pervades every aspect of our lives

• Energy reduction is leading the way towards a greener future

• 90 Percent of manufactured goods / products contain cast components

GREEN TECHNOLOGY

Heat Treatment6%

Melting55%

Post Casting7%

Core Mak-ing8%

Other12%

Mold Making12%

ENERGY SAVING OPPUTUNITIES

1. SCRAP SELECTION AND PREPARATION2. CHARGING3. MELTING4. ALLOYING / REFINING / TREATMENT / SAMPLING5. HOLDING6. TAPPING / LADLES7. TRANSPORTING8. POURING9. MAINTENANCE

1. SCRAP SELECTION AND PREPERATION

• Safety• Correct Size• Density• Cleanliness:

Sheared versus Shredded Scrap Rusted Scrap Briquetted Swarf

• Preheating of Scrap?• Induction Melting Limits the Range of Scrap Used

2. CHARGING OF SCRAP

• Prepare the Charge Sequence• Vibrating Systems• Continuous During the Melt• Pre Heat Charge in the Furnace• Focus on Reducing the Duration of Charging to Maximise the

Melting

3. MELTING THE CHARGE

• Mains versus Medium Frequency / cupola• Theoretical Power Versus “Best Practice”• Benefits of Batch Melting

• Efficiency (No Holding) 97 Percent• Max Power• Power Density• Melting Rate• Furnace Size• Production Planning• Less Emmision• Improved Control• Improved Homogeneity

• Furnace Lids / Covers

Best Tactic BestTheoretical Industry % Practice % Practice

Selected Processes Minimum Average Difference Minimum Difference MinimumIron Induction Melting 351.5 796.3 56% 538.1 35% 1,689.50

Iron Cupola Melting 351.5 1,413.60 75% 1,002.50 65% 1,124.50

Aluminum Reverberatory 288.7 1,399.80 79% 510.5 43% 523.2Melt Furnaces

Comparison of Practical Minimum, Theoretical Minimum and Best Practice Minimums for Selected Processes

Estimated Iron Induction Melting Energy Usage

Per Ton MeltGross Melt Tacit Tacit Tacit

Item KWh/Ton Loss KWh/Ton KWh/Ton 10 Btu / Ton 10 Btu / Ton 10 Btu / Ton**

Heel Melting Calculated 800 1.5% 812 2550 2.77 8.71 14.52

Heel Melting and Holding Estimated 954 1.5% 969 3041 3.31 10.39 17.31

Modern Batch Melter Caclulated 500 1.5% 508 1594 1.73 5.44 9.07

Batch Melter and Holding Estimated 530 1.5% 538% 1690 1.84 5.77 9.62Includes Hold Power for 8 Hours per day and preheat gas at 74 kWh/ton melt for heel melterShip tons consider 60% yuekd

Induction and Cupola Melting Energy Comparison 10' Btu / Ton

Melt Tacit Melt Tacit Ship

Item Energy Energy Energy

Induction Heel Melting 3.31 10.39 17.31

Modern Induction Batch Melting 1.84 5.77 9.62

Low Efficiency Cupola 4.92 5.76 9.6

High Efficiency Cupola 3.25 3.84 6%

1950 - 1960's 1960 - 1970's 1970 - 1980's 1990's0%

10%

20%

30%

40%

50%

60%

70%

80%

Energy EfficiencyTacit Energy Efficiency

Iron Induction Melting Energy Efficiency

1950 - 1960's 1960 - 1970's 1970 - 1980's 1990's0

100

200

300

400

500

600

700

800

900

kWh/ton

Historical Induction Melting Furnace Energy* (Delivered)

Electricity

5.7 10’ Btu

(Power Plant)

Power Supply Losses

Cable Losses

Coil Losses

Refractory and CoverLosses

Iron Melting

3.89Losses

1.711.81 1.73 1.45 1.16

0.020.08 0.290.26

Modern Induction Melting Process

4. ALLOYING / REFINING / DE - SLAGGING / SAMPLING

• Ferro – Alloy Additions• Sampling – Floor Controls• Sampling – Spectrometer Analysis• Slag Removal – Tools, Efficiency• Slag Wall, Slag Build – Up – Use of Fluxes• Treatment of Metal

5. HOLDING

• Avoid Holding Metal in Batch Furnaces• Melt Cold – Pour Hot

6. TAPPING / LADLES

• Melt Cold – Pour Hot• Refractories• Pre Heating Using Oxy – Fuel to Improve Efficiency• Management

7. TRANSFER OF MOLTEN IRON

• Preparation• Speed and Accuracy of the Operation• Temperature Control• Skimming

8. POURING

• High Power Thermal Plasma Heating Efficient Heating Fast Offers Metallurgical Benefits

• Existing Systems = Cold Ladles & Auto Pouring UnitsBoth have Disadvantages

• HPTP Offers a Cost Effective Solution• Improved Temperature Control to +- 5 C• Energy Efficiency Improvement of 20%

9. MAINTENANCE

• Refractories: Replacement Schedule – Push Out Type of Refractory Campaign Life On Going Repairs – Chemical Erosion Leading to

Failure Measurement

• Furnace: Regular Coil Inspection Water System Quality Harmonious Controls Short Main Power Cable Supply

CONCLUSION

• There is no “One Size Fits All” Solution• There are no Immediate Technological Innovation in the melting of Iron

(No Magic Wand)

• Retrofitting Technology is Available• The Approach Recommended is Continuous Improvement in Small

Increments• Opportunities for Energy Saving EXITS

ACKNOWLEDGEMENTS

• Advanced Melting Technologies “BCS Inc Nov 2005”• Theoretical / Best Practice Energy Use in Metal Casting Operations “JF Suhfo, JT Radia –

May 2004”• Improvement in Energy Efficiency of a Melting furnace “Dr DS Padan, Tata Motors Limited”• High Power thermal Plasma Heating in Automotive Casting Units: Tomorrow’s Technology

Applied to Today’s Casting “Luis Cobos Enal 2010”• Casting Directory 2011 “Crawford Publications”• How to Become a Practical Green Foundry Indsustry? “G Gigante, Thyssen Krupp –

Wupaca, WI USA 2010