fusion-how to improve throughput by eleminating the loss

FUSIONS – HOW TO IMPROVE THROUGHPUT AND

CONCENTRATION RANGE OF ANALYSIS BY ELIMINATING

THE LOSS ON IGNITION PROCESS STEP, USING DIFFERENT

DILUTION RATIOS AND MAINTAINING ACCURACY AND

PRECISION OF RESULTS

Laura Oelofse (Rigaku Americas) and Yoshijuro Yamada (Rigaku

Corporation )

Abstract

The use of fusions for XRF in industrial process monitoring is common

practice and there are several time consuming steps to complete in

order to render a sample fusion ready.

This paper details a method that would eliminate the need to carry out

the Loss on Ignition, Gain on Ignition step thus eliminating 2 hrs from

the preparation time and it also details the ability to use different

dilution ratios of sample and flux for materials on the same calibration

curve in order to increase the scope of materials that can be included in

a universal calibration curve using both naturally sourced certified

reference materials and synthetic pure chemicals as calibration

standards

Analysis Schemes in Various

Industry Sectors

Product Incoming Raw

Materials

Composition

varies in

narrow range

Widely

varying

composition

XRFs Role in High Throughput

Solutions

Results

Sample Preparation

Sample Loading

Sample Introduction

Analysis

Fusions – Flux + Sample

All compounds changed to oxide form

Eliminate Particle Size Effect

Eliminate Mineralogical Effect

6

Some Typical Fused Glass Beads

7

Why Preparation of Fused Glass Beads

• Particle size and mineralogical effects are removed or diminished by fusion of the sample with a suitable flux to form a glass bead.

• Synthetic calibration standards can be made by mixing pure oxides at concentration levels to suit the analytical range.

• Depending on sample type, fusion can even be quicker than pressed powder procedure.

• Generally accuracies and reproducibility are superior with fusion procedure.

• Only drawback is possible dilution of trace elements and therefore inferior LLD. Low dilution fusions are possible.

8

Preparation of

Fused Glass Beads

9499D00500

To standard holder

Melting method

Weigh outand mix

Flux + Specimen

Heat forMelting

Platinum crucible Remove bubbles

Glass diskspecimen

1000° -1100° C

Cast & Cool

8 - 15 mins

5 mins

3 - 7 mins

9

Preparation of Fused Glass Beads

• Preparation of powder as fused glass bead involves weighing out

sample and flux, placing in Gold/Platinum crucible, heating to 1000

– 1200 degrees and casting as a flat glass bead by pouring melt

into a heated Gold/Platinum mould and cooling under controlled

conditions.

• Newer alternative is moldable where melt remains in crucible and

bead is formed in situ.

• DEPENDING ON NATURE OF SAMPLE – LOSS ON IGNITION

MAY BE NECESSARY. ( CEMENTS, LIMESTONE, DOLEMITE)

In reality there are three types of samples Type 1 – Sample is stable, no loss or gain during fusion process

Type 2 : Sample loses CO2 or Intrinsic Waters during fusion, known as Loss on Ignition

Flux

S F

Sample

LOI

S Replaced with flux

Sample

B

Flux

Flux

LOI

S F

Sample

Type 3: Sample loses CO2 or Intrinsic Waters during fusion, known as LOI and changes oxidation state and pick up oxygen, gaining on ignition, known as GOI

GOI

Analytical Error Factors in Fusion Method The errors can be removed by Rigaku Bead Correction method

Powder Sample

Fusion Bead

Heterogeneity Effect

Grain-size Effect

Mineralogical Effect

Weighing Error

Loss on Ignition

Gain on Ignition

Evaporation of Flux

Error factors

for Bead

Error Factors in Fusion Method

Weighing Fusing

Weighing error

Bead

Sample

Flux(Li2B4O7 etc)

H2O CO2

LOI O2

FeO Fe2O3

GOI Flux evaporation

1000-1200˚ C

Pt crucible

The four error factors can be corrected.

(1) (2) (3) (4)

Strategy for the Corrections of LOI, GOI and Dilution Ratio

Model 1 : Use of Ratio of flux to sample weight ( F/S)

Definition of LOI : Imaginary component with no x-ray absorption Correction LOI(GOI) : Concentration is manually input or calculated as balance Dilution ratio : Corrected by manual input of F/S

Model 2 : Use of Ratio of bead to sample weight( B/S)

Flux

LOI

S F

Sample

Definition of LOI : Imaginary component of flux Correction : LOI(GOI) : Concentration is manually input or calculated as balance Dilution ratio : Corrected by manual input of B/S (Note) Flux evaporation can be corrected

LOI

S Replaced with flux

Sample

B

Flux

Analysis in Fused Beads

Use of fusion bead correction

Software generates theoretical alphas for LOI/GOI and dilution ratio

)RαWαWαKC)(1bI(aIWi FFLOILOIjj2

The alphas correct for

LOI/GOI

and Flux evaporation during fusing

Dilution ratio

Calibration equation

The alphas are generated by using a fundamental parameter software and it

generates variety of models.

Dilution ratio models : Flux weight to sample weight(F/S) or bead weight to sample weight(B/S)

LOI/GOI : Loss eliminated or manual input

Rigaku Fusion Bead Correction Software

• Allows for varying flux : sample ratios and the use of

catch weights

• Allows calculation of the Loss on Ignition /Gain on

Ignition and flux loss component by balance or ratio input

Oxides BCS376 LOI 0 LOI 10

SiO2 67.1 67.42 60.68

TiO2 0.02 0.02 0.02

Al2O3 17.7 17.79 16.01

Fe2O3 0.10 0.10 0.09

CaO 0.54 0.54 0.49

MgO 0.03 0.03 0.03

Na2O 2.83 2.84 2.56

K2O 11.2 11.25 10.13

LOI 0.35 0.00 10.00

Total 99.87 99.99 100.01

Sample (g) 0.3000 0.2700

Li2B4O7 ( g) 3.0000 3.0000 -10

0

10

20

30

40

50

60

0 20 40 60

LO

I X

RF

LOI CHEM

LOI CHEM

Lineær (LOI CHEM)

Fusion Bead Correction for LOI in Various Kinds of Materials

SiO2 TiO2 Al2O3 Fe2O3 MnO MgO CaO Na2O K2O P2O5 LOI

BCS393 Chem. 0.70 0.01 0.12 0.05 0.01 0.15 55.46 0.03 0.02 0.01 43.44

(Limestone) XRF 0.77 0.02 0.16 0.03 0.00 0.13 55.78 0.00 0.01 0.00 43.10

Diff. -0.07 0.01 0.04 -0.02 -0.01 -0.02 0.32 -0.03 -0.01 -0.01 -0.34

NBS69b Chem 13.57 1.92 49.29 7.21 0.11 0.09 0.13 0.03 0.07 0.12 27.46

(Bauxite) XRF 13.68 1.92 49.28 7.25 0.11 0.14 0.17 0.00 0.07 0.11 26.99

Diff. 0.11 0.00 -0.01 0.04 0.00 0.05 0.04 -0.03 0.00 -0.01 -0.47

NBS697 Chem 6.84 2.53 45.99 20.09 0.41 0.18 0.71 0.04 0.06 0.97 22.18

(Bauxite) XRF 6.88 2.51 45.98 20.15 0.42 0.25 0.78 0.00 0.06 0.97 22.00

Diff. 0.04 -0.02 -0.01 0.06 0.01 0.07 0.07 -0.04 0.00 0.00 -0.18

NBS97a Chem 44.00 1.91 39.06 0.45 0.00 0.15 0.11 0.04 0.50 0.36 13.42

(Clay) XRF 43.89 1.93 38.72 0.45 0.00 0.09 0.13 0.01 0.58 0.37 13.83

Diff. -0.11 0.02 -0.34 0.00 0.00 -0.06 0.02 -0.03 0.08 0.01 0.41

JDo 1 Chem 0.21 0.00 0.01 0.02 0.01 18.58 33.94 0.01 0.00 0.04 47.18

(Dolomite) XRF 0.28 0.01 0.06 0.01 0.00 18.87 33.95 0.00 0.00 0.03 46.79

Diff. 0.07 0.01 0.05 -0.01 -0.01 0.29 0.01 -0.01 0.00 -0.01 -0.39

BCS375 Chem 67.15 0.38 19.82 0.12 0.00 0.05 0.89 10.41 0.79 0.00 0.39

(Feldspar) XRF 67.80 0.38 20.05 0.10 0.00 0.07 0.87 9.95 0.74 0.01 0.03

Diff. 0.65 0.00 0.23 0.02 0.00 0.02 -0.02 -0.46 -0.05 0.01 -0.36

R801 Chem 78.64 0.10 16.76 0.17 0.00 0.04 0.04 0.22 0.18 0.00 3.86

(Pyrophyllite) XRF 78.62 0.10 16.71 0.17 0.00 0.08 0.08 0.16 0.19 0.02 3.88

Diff. -0.02 0.00 -0.05 0.00 0.00 0.04 0.04 -0.06 0.01 0.02 0.02

BCS314 Chem 96.40 0.19 0.77 0.53 0.01 1.81 1.81 0.05 0.09 0.00 0.10

(Silica brick) XRF 96.47 0.20 0.79 0.49 0.00 1.86 1.86 0.01 0.08 0.01 0.01

Diff. 0.07 0.01 0.02 -0.04 -0.01 0.05 0.05 -0.04 -0.01 0.01 -0.09

Results are obtained by using theoretical alphas and LOIs are

obtained as balance. The accuracy of the calculated LOI across the

range of 0 % - 50% is 0.5%

Quantification and

Correction of Gain

on Ignition

Synthetic mixtures of SiO2 and

FeO were blended to yield

30%, 50% and 70% FeO

During fusion the FeO is

oxidized to Fe2O3 and there is

a weight gain of

(Fe2O3 – 2FeO)/ 2FeO

The mass absorption

coefficient of GOI is set to zero

and the value is considered as

a negative LOI in the FP

calculation.

The WFe2O3 = WFeO + W GOI

SiO2 FeO Fe2O3

calc.

Recalc.

FP value

70.00 30.00

32.27

32.48

calc.

Recalc.

FP value

50.00 50.00

52.64

52.84

calc.

Recalc.

FP value

30.00 70.00

72.17

72.15

Determination of GOI from Standard Iron Ore

Fe2O3 Diff

Chem XRF

JSS 803-2 89.57 89.71 0.14

JSS830-3 84.18 84.16 -0.02

Euro 680-1 86.33 86.31 -0.02

ASCRM 004 89.43 89.51 0.08

• Method applied to iron ore with high Fe content and

shown to be suitable

Dilution Ratio Correction STD

S:F 1:5

JB-2

UNK

S:F 1:10

JG-1

Lit. FP Lit.

SiO2 52.83 73.06 72.75

TiO2 1.18 0.28 0.26

Al2O3 14.57 14.02 14.29

Fe2O3 14.24 2.13 2.21

MnO 0.20 0.06 0.06

MgO 4.63 0.71 0.75

CaO 9.82 2.18 2.19

Na2O 2.02 3.38 3.41

K2O 0.43 4.10 3.97

P2O5 0.10 0.09 0.10

Application of LOI, GOI and dilution ratio correction to

Empirical Calibration Methods

• Matrix correction coefficients were theoretically calculated for LOI,

GOI and dilution ratio correction components

• The matrix correction expression including the dilution ratio

correction is shown on the next slide

• Using the Theoretical Alpha Correction model where the base

component is considered to be the LOI/GOI/D.C then these are

eliminated in the De Jongh calculation and are calculated as a

balance component.

• The accuracy for Fe2O3 in a regression of geological standards for

an uncorrected calibration was 0.161%, for a calibration with

conventional matrix corrections 0.066% and for theoretical matrix

correction coefficients with LOI and GOI correction an improved

accuracy of 0.056%

Rigaku Theoretical Alphas for Fusion Bead

Correction equation of T.Fe

Wi = (aiIi2+biIi +c)*(1+SajWj + aFRF - KF)

Factor Coefficient

K 0.910900

a(T.Fe) 0.002392

a( SiO2) 0.001413

a(Mn) 0.002923

a(CaO) 0.006793

a(MgO) 0.000967

a(Al2O3) 0.001128

a(TiO2) 0.006700

a(P) 0.003929

a(S) 0.004874

a(K) 0.008125

a(FLUX) 0.089130

1. The correction coefficients a j for inter-elements and flux

are calculated theoretically by Rigaku/FP software. These

alphas depend on the optics of spectrometer.

2. K corresponds to the standard dilution ratio.

3. When the actual dilution ratio “ RF” ( Bead weight/ sample

weight ) is input for the each sample manually, all error

factors are automatically corrected. ( LOI, GOI and Dilution

Correction)

4. Calibration constants (a,b,c) are calculated using the non-

linear regression equation , after standard samples are

measured.

Dilution Ratio Correction

aa

FFF

Ljjjii KRW1cIbW

Calibration equation with dilution ratio correction

FFF RK a

aa FFjjii RW1cIbW

General calibration equation

FFF RRR RF : Difference between the actual

and standard ratio

RF : Actual dilution ratio aFRF + KF is the correction term for

the difference between the actual and standard dilution ratio.

Matrix Correction Model

Correction model Uncorrected component

Notes

Lachance-Traill Analyte Correction by all the components except the analyte. The calibration curve is linear.

de Jongh Base component Correction by all the elements except the base component. The calibration curve is linear.

JIS Base component

and analyte

Correction by all the elements except the base component and the analyte. The calibration curve is linear or quadratic.

When a significant amount of LOI (GOI) is contained, it is advisable to use de Jongh or JIS model.

SiO2 Calibration Curve

Standard value (mass%)

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de Jongh model JIS model

Analysis sample: rock fusion disk (dilution ratio 5:1)

considering self-absorption by the analyte

Accuracy: 0.18 mass%


CaO Calibration Curve


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de Jongh model JIS model

Analysis sample: rock fusion disk (dilution ratio 5:1)

considering self-absorption by the analyte

Accuracy: 0.17 mass% Accuracy: 0.14 mass%

Comparison of Matrix Correction Coefficients between Several Materials by the Fusion Method

— Analysis of Refractories —

Calibration Range of the Major Components and

Dilution Ratio for Each Material

Material Major component (mass%) Dilution ratio

(Flux/Sample) SiO2 Al2O3 Fe2O3 MgO Cr2O3 ZrO2

Clay 37–86 6–49 –5 –1 –1 10

Silica 84–97 –10 10

High alumina –44 47–94 10

Magnesia 81–99 10

Chrome-magnesia –27 10–52 2–53 22.16

Zircon-zirconia –45 48–92 10

Alumina-zirconia-silica –42 10–82 12–48 10

Alumina-magnesia 10–93 3–79 10

The whole range –97 –94 –27 –99 –53 –92 10–22.16

• Wide calibration range • Different dilution ratio

• Flux: Li2B4O7

• LiNO3 was used just for Chrome-magnesia.

Comparison of Matrix Correction Coefficients for Each Material (1)

Clay High alumina Alumina-Zircon-Silica

Analyte SiO2

Correcting comp. Si-Ka

Al2O3 1.38E-03 1.38E-03 1.37E-03

Fe2O3 1.02E-03 1.01E-03 1.02E-03

TiO2 2.44E-04 2.41E-04 2.43E-04

MnO 8.65E-04 8.62E-04

CaO 6.91E-05 6.60E-05 6.81E-05

MgO 1.33E-03 1.33E-03 1.33E-03

Na2O 1.04E-03 1.04E-03 1.04E-03

K2O -5.41E-05 -5.75E-05 -5.49E-05

P2O5 -1.88E-05

Cr2O3 6.06E-04 6.07E-04

ZrO2 8.76E-04 8.68E-04

Correction model: Lachance-Traill

Correction coefficients are almost identical for each material.


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SiO2 Calibration Curve

◆ 10 : 1 ◆ 22.16 : 1

(Chrome-magnesia)


Silica

Clay

AZS

Magnesia

AZS

Chrome-magnesia

AZS: Alumina-zirconia-silica

Magnified

Comparison of Matrix Correction Coefficients for Each Material (2)

Clay High alumina Alumina-Zircon-Silica

Analyte Fe2O3

Correcting comp. Fe-Ka

SiO2 -1.88E-03 -1.87E-03 -2.06E-03

Al2O3 -2.19E-03 -2.18E-03 -2.37E-03

TiO2 3.93E-03 3.95E-03 3.64E-03

MnO -1.94E-04 -1.93E-04

CaO 4.03E-03 4.04E-03 3.72E-03

MgO -2.37E-03 -2.36E-03 -2.54E-03

Na2O -2.62E-03 -2.61E-03 -2.79E-03

K2O 3.94E-03 3.96E-03 3.64E-03

P2O5 -1.65E-03

Cr2O3 7.27E-03 6.91E-03

ZrO2 1.09E-03 1.30E-03

Correction model: Lachance-Traill

Correction coefficients are almost identical for each material.


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Fe2O3 Calibration Curve

◆ 10 : 1 ◆ 22.16 : 1

(Chrome-magnesia)

Accuracy: 0.029

mass%

Zircon-zirconia

Magnesia

Chrome-magnesia

AZS: Alumina-zirconia-silica

Chrome-magnesia

Magnified

Dilution Ratio Correction + Matrix Correction

Rock sample : dilution ratio 10:1 and 5:1

Analyte : SiO2

Analysis sample CCRMP: SY-2, SY-3

GSJ: JA1, JA2, JA3, JB2, JB3, JG1a, JG2, JG3, JGb1, JR1, JR2, JLs1, JCp1


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Dilution Ratio Correction Rock sample : dilution ratio 10:1 and 5:1

Analyte : SiO2

●：5:1 ●：10:1

Accuracy: 11 mass%

No correction

Accuracy: 3.6 mass%

Dilution ratio correction

●：5:1 ●：10:1

The dilution ratio correction improves the accuracy; however, the fitting is

still not excellent due to matrix effect.


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Dilution Ratio Correction + Matrix Correction

Rock sample : dilution ratio 10:1 and 5:1

Analyte : SiO2

● 5:1 ● 10:1


Dilution ratio cor.

+ Matrix cor. Accuracy: 3.6 mass%

Dilution ratio correction

● 5:1 ● 10:1

The combination of the dilution ratio and matrix corrections enables

an excellent fitting.

LOI Correction (1)

• Test sample: rock sample with 50 mass% LOI

(the bead was made with the dilution ratio 10:1, and then treated as the dilution ratio 5:1, which results in the sample with 50 mass% LOI.)

• Analyte: SiO2

LOI Correction and Matrix Correction Coefficients

Without LOI cor. With LOI cor.

Base component SiO2 LOI

Na2O -4.79E-04 5.15E-03

MgO -6.32E-05 5.81E-03

Al2O3 5.91E-03

SiO2 -1.97E-03 2.78E-03

P2O5 -1.99E-03 2.74E-03

K2O -2.03E-03 2.67E-03

CaO -1.87E-03 2.94E-03

TiO2 -1.61E-03 3.35E-03

MnO -7.21E-04 4.76E-03

Fe2O3 5.03E-04 5.11E-03

Correction model: de Jongh Element line: Si-Ka


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Matrix Correction (without LOI Correction)

Analyte : SiO2

● w/o LOI ● with LOI

Accuracy: 3.5 mass%

Matrix correction

Accuracy: 2.5 mass%

No correction



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LOI Correction and Matrix Correction

Analyte : SiO2


Accuracy: 3.5 mass%

Matrix correction


LOI correction + Matrix cor.


Wide Analysis Range in XRF

Analysis of Diverse Natural

Minerals

by the Fusion Method

(Synthetic Fusion Bead Added)

Purpose of This Test Analysis

• To obtain a good fitting for calibration curves with wide concentration range of diverse natural minerals by the fusion method

• To obtain a good fitting for calibration curves with synthetic

standard fused beads

Reference Materials for Calibration (1) Sample Material Dil. ratio Sample Material Dil. ratio

BAS203a Talc 10 NBS688 Basalt rock 10

BCS313-1 High purity silica 10 SRM 1c Limestone 10

BCS314 Silica brick 10 SRM 69b-1 Bauxite 10

BCS315 Fire brick 10 SRM 696 Bauxite Surinam 10

BCS319 Magnesite 10 SRM 697 Bauxite Dominican 10

BCS368 Dolomite 10 SRM 698 Bauxite Jamaican 10

BCS369 Magnesite-Chrome 22.167 SRM 70a Potash feldspar 10

BCS370 Magnesite-chrome 22.167 SRM 99a Soda feldspar 10

BCS375 Soda feldspar 10 R-603 Clay 10

BCS376_1 Potash feldspar 10 R-701 Feldspar 10

BCS358 Zirconia 10 R-801 Pyrophyllite 10

BCS388 Zircon 10 JSS009-2 Pure iron oxide 10

BCS389 High purity magnesium 10 JRRM511 Chrome-magnesia 22.167

BCS393 Limestone 10 JRRM602 Zirconia 10

BCS394 Calcined bauxite 10 JRRM701 AZS 10

BCS395 Bauxite 10 RM-611 Portland cement 10

NBS98a Plastic clay 10 RM-612 Portland cement 10

NBS120c Florida phosphate rock 10 RM-613 Portland cement 10

Reference Materials for Calibration (2) Sample Material Dil. ratio Notes

ECISS782-1 Dolomite 10

ECISS776-1 Fire brick 10

BCS348 Ball clay 10

NIST 81a Glass sand 10

NIST 278_1 Obsidian rock 10

NIST 1413 Glass sand 10

NBS694 Phosphate rock 10

BAS 683-1-(1) Iron ore sinter 10.13

BAS 683-1-(2) Iron ore sinter 10.13

BCS315_Co1 Fire brick with Co AA standard sol. 10 For analysis of Co from the WC container

BCS315_W1 Fire brick with W AA standard sol. 10 For analysis of W from the WC container

NIST278_1_Co05 Obsidian rock with Co AA standard sol. 10 For analysis of Co from the WC container

NIST278_1_W05 Obsidian rock with W AA standard sol. 10 For analysis of W from the WC container

TiO2_10 TiO2 reagent 10 To extend TiO2 calibration range

P2O5_25 LiPO3 reagent 10 To extend P2O5 calibration range

K2O_50 K2CO3 reagent 10 To extend K2O calibration range

CaO_100 CaCO3 reagent 10 To extend CaO calibration range

Na2O_25 Na2CO3 reagent 10 To extend Na2O calibration range

Calibration Range

Analyte Calibration range Analyte Calibration range

Na2O 0 – 25 Fe2O3 0 – 99.84

MgO 0 – 96.7 Cr2O3 0 – 52.51

Al2O3 0 – 88.8 ZrO2 0 – 92.7

SiO2 0 – 99.78 HfO2 0 – 1.63

P2O5 0 – 33.34 SO3 0 – 6.07

K2O 0 – 50 SrO 0 – 0.28

CaO 0 – 100 Co2O3 0 – 1.407

TiO2 0 – 10 WO3 0 – 1.261

MnO 0 – 0.596 Li2B4O7 10 – 22.167 Dilution ratio (flux/sample)

Unit: mass%


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Na2O calibration



MgO calibration

Na2CO3

Synthetic bead

BCS370 Mg-Cr

BCS369 Mg-Cr


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Al2O3 calibration


SiO2 calibration


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P2O5 calibration


SO3 calibration

LiPO3

Synthetic bead

Portland cement

Phosphate rock


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K2O calibration


CaO calibration

K2CO3

Synthetic bead CaCO3

Synthetic bead


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TiO2 calibration


Fe2O3 calibration

TiO2

Synthetic bead Fe2O3

Synthetic bead

Iron ore

Summary • By applying the dilution ratio correction, LOI correction and matrix

correction (theoretical alphas), it is possible to obtain a good fitting for calibration curves with wide concentration range for diverse natural rocks and minerals by the fusion method.

• With a few calibration standards, it is necessary to use the de Jongh or Lachance-Traill models, where calibration curves are linear in theory. In this test, de Jongh model was used because some samples contain significant LOI content.

• With a large number of calibration standards, it is possible to use the JIS model, where calibration curves can be quadratic.

• With synthetic fused beads to extend the calibration range, it is possible to obtain a good fitting for calibration curves.

Conclusion • The fusion bead method is useful sample preparation for eliminating

hetrogeneity effects, particle size effects, however chemical

reactions can cause the sample weight to decrease or/and increase

during fusion because of volatilization of H2O, CO2 and oxidation.

• It is possible to correct error factors in fusion for either the FP

method or the Empirical Calibration method.

• It is possible to skip the lengthy independent LOI step in preparing

the samples for fusion, by incorporating the step into the fusion

process and correcting for the associated losses and/or gains via

the correction methods just detailed

• It is possible to weigh catch weights and have them recorded in the

dilution correction.

• The time savings realized by eliminating the LOI step and supporting

varying dilution ratios improves throughput and cuts the analysis

cost per sample

• Thank you for your attention

fusion-how to improve throughput by eleminating the loss

Documents

sample fusion ready

nature of sample loss

ignition flux s f sample

fusion method

fusion procedure

fusion process type

flat glass bead

suitable flux