accuracy evaluation of matrix matching …

•ABRAM L. BODIBA, EZEKIEL D. DIKIO, MICHAEL HORSFALL

• TEST & MEASUREMENT 2016 CONFERENCE & WORKSHOP • 26 - 28 SEPTEMBER 2016

ACCURACY EVALUATION OF MATRIX MATCHING CALIBRATION OF MANGANESE ORE ON X-RAY FLUORESCENCE

Introduction

Sampling process

Sample preparation

Instrumentation

Calibration

Results

Conclusion

26 SEP 2016ACCURACY EVALUATION OF MATRIX MATCHING CALIBRATION OF MANGANESE ORE

ON XRFSLIDE 2

•CONTENTS

•Manganese is the 12th most abundant

element.

•Manganese plays an important role in

Steel production

Battery production

Dietary additives

Chemical production

Aluminum beverages cans


ON XRFSLIDE 3

•INTRODUCTION

•INTRODUCTION

The manganese deposit

in the Kalahari basin is

the biggest mineral

deposit in the world

known to man

The Kalahari situated

60km northwest of

Kuruman in the Northern

Cape Province of South

Africa

Kalahari basin Contains

around 90% of the

world’s manganese ore

reserves

Manganese mining is one of the major

activities taking place within the

Kalahari region.

The lower grade mines are open pit

and high grade mines are underground

A rapid grade analysis is required to

make decision for ore selective mining,

stockpiling, and Rail loading


ON XRFSLIDE 5

•INTRODUCTION


ON XRFSLIDE 6

•SAMPLING


ON XRFSLIDE 7

•SAMPLING

•It is well known that sampling and sample preparation are

the source of errors on XRF analysis

•The errors occur during

Sampling

Sample reduction

Sample mixing

Sample division

Sample preparartion


ON XRFSLIDE 8

•SAMPLING


ON XRFSLIDE 9

•SAMPLE PREPARATION

•All samples were prepared under controlled conditions,

including

The pulverizing

Pulverizing mass and time,

pelletizing pressure and holding time

The samples were pulverized to 100% passing 75 μm

sieves.

•40 samples were collected to be used as secondary

reference standard


ON XRFSLIDE 10


Press pellet must comply with some physical conditions:

Must have a flat surface for analysis

Must be homogenous.

Must be stable under vacuum

Must be infinitely thick for the x-ray wavelength to be measured.

Must have a consistent thickness.


ON XRFSLIDE 11



ON XRFSLIDE 12

•CALIBRATION STANDARD

Name %Mn %Fe %CaO %MgO %SiO2 %Al2O3 %P

BLANK 0.000 0.000 0.000 0.000 0.000 0.000 0.000

ES 5 38.400 5.500 13.938 3.873 4.645 0.230 0.023

ES 4 33.700 4.300 14.921 3.964 5.635 0.236 0.023

ES 33 30.667 4.300 15.239 6.714 4.666 0.296 0.023

ES 32 17.050 6.800 15.750 4.035 4.520 0.246 0.021

ES 31 12.548 7.700 24.657 3.718 6.717 0.291 0.023

ES 30 7.431 10.500 19.769 8.650 4.750 0.351 0.027

ES 3 34.000 4.500 14.541 3.392 4.084 0.272 0.020

ES 29 8.679 8.300 15.695 3.542 2.617 0.285 0.024

ES 28 37.300 4.300 12.301 3.535 4.959 0.262 0.067

ES 20 32.100 4.400 14.628 3.688 4.695 0.252 0.071

ES 19 6.000 12.000 14.979 9.863 3.662 0.261 0.052

ES 15 35.800 6.500 10.366 4.155 3.024 0.540 0.103

ES 13 36.700 10.100 14.669 3.873 4.914 0.268 0.029

ES 10 24.615 8.900 17.438 4.158 5.404 0.250 0.060

EL 9 38.100 4.300 14.537 2.989 4.560 0.174 0.018

EL 8 38.000 4.000 14.655 3.574 4.458 0.186 0.020

EL 6 38.900 2.900 14.938 2.823 3.326 0.181 0.019

Name %Mn %Fe %CaO %MgO %SiO2 %Al2O3 %P

EL 3 38.900 3.900 14.232 3.257 1.246 0.190 0.020

EL 23 37.800 4.400 13.198 3.969 4.526 0.282 0.020

EL 22 37.100 4.000 14.411 4.133 4.696 0.230 0.021

EL 2 40.800 3.800 8.919 1.795 5.678 0.215 0.020

EL 19 35.200 4.200 20.901 3.722 8.532 0.265 0.092

EL 18 36.600 4.000 14.968 5.292 4.508 0.264 0.046

EL 17 21.882 4.500 17.816 4.007 4.776 0.296 0.069

EL 16 26.538 5.200 14.851 3.510 4.738 0.286 0.075

EL 15 20.300 5.300 14.296 4.333 2.388 0.196 0.087

EL 14 39.300 4.400 14.550 5.866 4.540 0.247 0.051

EL 13 38.500 4.400 14.285 3.653 4.562 0.260 0.039

EL 11 38.100 4.600 13.254 2.333 4.724 0.216 0.084

EL 1 39.4 4.1 13.542 4.367 7.894 0.842 0.022

RR1 39.4 4.21 13.24 3.11 4.65 0.22 0.02

EL 5 42.059 4.5 13.206 2.862 6.352 0.172 0.023


ON XRFSLIDE 13

•CALIBRATION STANDARD


ON XRFSLIDE 14

•CALIBRATION

Calibration range

Name Low Max

%Mn 0.00 43.025

%Fe 0.00 12.000

%CaO 0.00 24.657

%MgO 0.00 9.863

%SiO2 0.00 8.532

%Al2O3 0.00 0.842

%P 0.00 0.103

Typical Low grade Manganese

Name Typical value

%Mn 37.000

%Fe 4.000

%CaO 14.000

%MgO 3.000

%SiO2 4.000

%Al2O3 0.200

%P 0.020


ON XRFSLIDE 15

•LOWER GRADE MINERALOGICAL

COMPOSITION OF KALAHARI BASIN Kalahari low grade manganese

Mineral Compositions

Braunite Mn2Mn6SiO12

Kutnohorite Ca(Mn,Mg,Fe++)(CO3)

2

Calcite CaCO3

Hausmannite Mn3O4

Hematite Fe2O3

Bixbyite (Mn,Fe)2O3

Manganite MnO(OH)

Braunite 2 Ca(Mn,Fe)14SiO24

Position [°2θ] (Copper (Cu))

10 20 30 40 50 60 70

Counts

1000

2000

3000

Thorn Inifinity_FY_14_A

Peak List

Bixbyite C; Mn2 O3

Hematite; Fe2 O3

Hausmannite; Mn3 O4

Manganite; Mn O ( O H )

Braunite-1Q; Mn +2 Mn6 +3 Si O12

Braunite-2Q; Ca Mn11.6 Fe2.4 Si O24

Kutnohorite, magnesian; C2 Ca1 Fe0.13 Mg0.23 Mn0.64 O6

Calcite, syn; Ca ( C O3 )


10 20 30 40 50 60 70

Counts

1000

2000

3000

Lab_Std 2_FY_14

Peak List

Bixbyite C; Mn2 O3

Hematite; Fe2 O3

Hausmannite; Mn3 O4







10 20 30 40 50 60 70

Counts

1000

2000

3000

Tripple Star_FY_14_B

Peak List

Bixbyite C; Mn2 O3

Hematite; Fe2 O3

Hausmannite; Mn3 O4






North mine

Central mine

South mine


ON XRFSLIDE 16

•INSTRUMENTATION

XRF generally consist of four basic

components:

• An excitation source - X-ray tube

• A sample

• A detector

• A data collection and analyzing

system.

ElementMono/

GonioCollimator Crystal Detector

Counting

Time (s)Filter

Mn Mono 0.25 LiF200 ExKrBe 30 on

Fe Mono 0.25 LiF200 Sc 30 on

Ca Mono 0.60 LiF200 ExArBe 30 None

Mg Mono 0.60 AX03 FPC 30 None

Si Mono 0.60 PET FPC 30 None

Al Mono 0.60 PET FPC 30 None

P Mono 0.60 Ge111 ExNeBe 30 None


ON XRFSLIDE 17

•INSTRUMENTATION SETUP

• Thermo Fischer scientific advance 9900 series

• QXAS program

• 3.6 kW Rh X-ray tube

• Monochrometer (fixed channel)

• The current 50mA

• Voltage 50kV


ON XRFSLIDE 18

•CALIBRATION LINES

Mn

• A total of four standards were removed from

the calibration as outlier.

• four standards had high percentage

differences.

• Three standards were also removed to

improve the correlation on the graph

• The correlation coefficient is 0.9995 which

indicates a good correlation between the given

concentrations and intensities

Fe

• A total of 36 standards was used, no standard

were removed from the calibration as outlier.

• Six standards were removed to improve the

correlation on the graph.





ON XRFSLIDE 19

•CALIBRATION LINES

CaO

• A total of ten standards were removed from

the calibration as outlier

• The standards had high percentage

differences.

• One standard was also removed to improve

the correlation


indicates a good correlation between the

given concentrations and intensities

SiO2

• Four standards were removed to improve the

correlation on the graph





ON XRFSLIDE 20

•CALIBRATION LINE CONT.

Al2O3

• A total of 36 standards was used, no standard

were removed from the calibration as outlier

• Sixteen standards were removed to improve

the correlation on the graph.




MgO

• Eight standards were also removed to

improve the correlation on the graph





ON XRFSLIDE 21

•CALIBRATION LINE CONT.

30 Yes

Inc.

2

[kcps]

40 66 20 150 2 20 66.16

Threshold Window Start End Inc. Global

ø29 mm Yes Norm

Energy Profile data

PHD Param [Step] Count.Time [s] Count Rate

Ca_m LiF200 ExArBe 80 None

mA PBF/

PBD

Mask Rotatio

n

AGC Type

Energy Profile Parameters

Element/Line Gonio Crystal Detector Collimato

r

kV

Energy Profile

Instrument: ARL 9900

File Information

P

• A total of 36 standards were used,

• five standards were removed from the

calibration as outlier.

• Five standards were removed to improve

the correlation on the graph.




R2 SEE LOD Samples

Mn 0.9995 0.2916 0.001 29

Fe 0.9995 0.0606 0.00121 30

CaO 0.9996 0.0943 - 25

MgO 0.9991 0.0550 0.00418 32

SiO2 0.9993 0.0507 - 28

Al2O3 0.9960 0.0106 - 20

P 0.9980 0.0012 0.0008 26


ON XRFSLIDE 22

•CALIBRATION SUMMARY

Name %Mn %Fe %CaO %SiO2 %MgO %Al2O3 %P

Sarm 138 37.230 5.792 13.230 6.309 3.839 0.197 0.019

Amis 407 36.210 4.160 15.680 5.610 3.220 0.291 0.019

SARM 17 38.661 4.311 14.415 4.637 3.183 0.221 0.019


ON XRFSLIDE 23

•CRM


ON XRFSLIDE 24

•EVALUATION (SARM 138)

Sarm 138 Sarm 138 CRM value

Element Results True value SD Absolute variance % Recovery

%Mn 37.230 37.500 ± 0.64 0.27 99.3%

%Fe 5.792 5.740 ± 0.11 0.05 100.9%

%CaO 13.230 13.010 ± 0.30 0.22 101.7%

%SiO2 6.309 6.060 ± 0.22 0.25 104.1%

%MgO 3.839 3.810 ± 0.08 0.03 100.8%

%Al2O3 0.197 0.198 ± 0.01 0.00 99.5%

%P 0.019 0.018 ± 0.02 0.00 108.6%


ON XRFSLIDE 25

•EVALUATION (AMIS 407)

Amis 407 Amis 407 CRM Value Absolute variance % Recovery

%Mn 36.210 36.25± 0.57 0.04 99.9%

%Fe 4.160 4.22± 0.13 0.06 98.6%

%CaO 15.680 15.81± 0.48 0.13 99.2%

%SiO25.610 5.51± 0.16 0.10 101.8%

%MgO 3.220 3.17± 0.10 0.05 101.6%

%Al2O30.291 0.29± 0.03 0.00 100.3%

%P 0.019 0.02± 0.01 0.00 108.8%


ON XRFSLIDE 26

•EVALUATION (SARM 17)

SARM 17 SARM 17 CRM value Absolute variance % Recovery

%Mn 38.661 38.810 ± 0.300 0.15 99.6%

%Fe 4.311 4.270 ± 0.090 0.04 101.0%

%CaO 14.415 14.400 ± 0.900 0.02 100.1%

%SiO2 4.637 4.690 ± 0.240 0.05 98.9%

%MgO 3.183 3.030 ± 0.180 0.15 105.0%

%Al2O3 0.221 0.240 ± 0.120 0.02 92.1%

%P 0.019 0.018 ± 0.015 0.00 103.3%

Low grade

PP

Consensus

true value

Consensus

Standard

deviation

Relative

percentage

difference

Z-score

%Mn 33.700 33.765 0.143 0.065 -0.456

%Fe 5.260 5.300 0.051 0.040 -0.785

%SiO2 5.410 5.400 0.116 -0.010 0.086

%CaO 18.760 18.280 0.595 -0.481 0.808

%MgO 2.970 2.960 0.094 -0.010 0.106

%Al2O3 0.210 0.219 0.037 0.009 -0.228

%P 0.022 0.019 0.001 -0.003 2.167


ON XRFSLIDE 27

•INTER-LABORATORY COMPARISON

Kalahari Manganese Round Robin Scheme

Advantage of press pellets techniques

•Ease of preparation

•Offer quick turnaround time

•Low cost


ON XRFSLIDE 28

•CONCLUSION

•The results showed good agreement with the certified

value of the CRM’s.

•Inter-laboratory comparison was satisfactory.

•Matrix matching press pellets provide a fast and simple

analysis method.

•Acceptable accuracy level for production


ON XRFSLIDE 29

•CONCLUSION

accuracy evaluation of matrix matching …

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