M. Bouchard, S. Rivard, and C.O. Arsenault Corporation Scientifique Claisse, Quebec City, Canada S. Ness Intertek Genalysis, Perth, Australia

Transcription

1 Iron Ore Composition Determination and Total Iron Quantification by Borate fusion and WDXRF A Simplified Analytical Method to the Prevailing ISO M. Bouchard, S. Rivard, and C.O. Arsenault Corporation Scientifique Claisse, Quebec City, Canada S. Ness Intertek Genalysis, Perth, Australia Corporation Scientifique Claisse 2012, All Rights Reserved. Presented at the Norwegian X-ray Conference 2012

2 Current Context in the Iron Mining Industry Production, Production and Production JOHANNESBURG (miningweekly.com) Global iron-ore demand was expected to double to 3.5-billion tons a year by 2030, as China s appetite for the steelmaking commodity continued to drive the market. Estimated Iron Ore Production in Million Metric Tons for Country 2010 According Production to U.S. Geological Country Survey Production China 900* United States 49 Australia 420 Canada 35 Brazil 370 Iran 25 India 260 Sweden 25 Russia 100 Kazakhstan 22 Ukraine 72 Other Countries 88 South Africa 55 Total World 2429 (*The mine production estimates for China are based on crude ore, rather than usable ore, which is reported for the other countries.

3 Iron Ore Producers Needs Productivity Performance h Competitiveness Innovation/Expertise

4 Iron Ore Producers Needs Productivity Tons per year and resources Performance Quality, delivery time and analytical accuracy Competitiveness Price of Iron and delivery time Innovation/Expertise Need to save time and decrease costs

5 Roles of Laboratories Productivity Accurate information and efficiency Performance Delivery time of results and analytical accuracy Competitiveness Faster and more accurate results Innovation/Expertise Need to save time and decrease costs by optimizing analytical methods

6 Scientific Project Standard Methods Available XRF (ISO Iron ores Determination of various elements by X-ray fluorescence spectrometry) Sample Preparation Calibration Spectrometry Quality Control Laboratories Needs Faster, current and upto-date methodologies Specific and simpler methodologies High level of confidence Official Total Iron Methods (ISO and Titrimetric methods)

7 Scientific Project Phase I: Replicate ISO method to get a reference point of comparison for the evaluation of Phase II. Comply with ISO Standard Method analytical targets for both the Total Iron and the rest of the elements of interest Phase II: Develop a commercial-available CRM-based application which would achieve similar accuracy and precision as Phase I, while simplifying the methodology (sample preparation and calibration)

8 The Equipment Used Drying Oven: Muffle Furnace: Automatic Gas Fluxer: Spectrometer: - Fisher Scientific - Fisher Scientific - Claisse M4 TM Fluxer - Bruker S4 Explorer - Max. Temp.: 210 C Isotemp - Propane/Air Heating - WDXRF - Power: 50/60 Hz - Max. Temp.: 1125 C - 3 Positions - Tube: 1000 Watts 110/120 VAC - Power: 50/60 Hz 208/240 VAC

9 Fusion Process - reminder Ground sample is mixed with borate fluxes in a Pt/Au 95%-5% crucible Additives can be added (NWA, solid oxidizers, etc ) Flux is melted at around 1050 o C Sample dissolves in the molted flux Molten flux is poured in a Pt/Au 95%-5% mold and cooled Cold glass disk is ready for XRF analysis AXAA Sydney

10 Sample Preparation Optimization Topic ISO This Project Platinum Ware Pt/Au or Pt/Au/Rh Pt/Au : 95/5 Mold At least 2 mm 1 mm Sample/Flux Ratio 1/10.3 1/10.3 Catch Weight Allowed Allowed Sample State for Weighing Not clearly discussed but seams to point to dried basis (105 C) Allow both as is and dried basis Flux 35 LiT / 65 LiM, NaT or LiT 50 LiT / 50 LiM, Pure Oxidizer NaNO 3 NH 4 NO 3 Non-Wetting Agent NH 4 I when needed (no Br) NH 4 I when needed (no Br) Mixing Spatula and brushing Vortex mixer TM Fusion Apparatus Electric furnace, gas burner (ring and stand) and automated fluxer Claisse M4 TM Fluxer Fusion Time At least 10 minutes (variable) 11 minutes and 20 seconds (fixed) Fusion Temperature In the range of 1000 to 1050 C In the range of 1000 to 1050 C Recast or Refusion Not clearly discussed and/or banned Not allowed for samples

11 Sample Preparation Validation (Concentration Ranges of Samples) ISO Phase 1 Phase 2 ISO Phase 1 Phase 2 Fe Cr Si Co Ca Ni Mn Cu Al Zn Ti As Mg Pb P Ba S Na N/A K Sr N/A Sn N/A Zr N/A V RMs from more than 12 organizations plus more than 150 samples from more than 10 mining sites

12 Calibration Standards Optimization Disc Identification ISO Phase 1 Si 100% SiO 2 100% SiO 2 Fe 100% Fe 2 O 3 100% Fe 2 O 3 30 Fe/Si 30% Fe 2 O 3 : 70% SiO 2 30% Fe 2 O 3 : 70% SiO 2 66 Fe/Si 66% Fe 2 O 3 : 33% SiO 2 66% Fe 2 O 3 : 33% SiO 2 30 Al/Fe N/A 30% Al 2 O 3 : 70% Fe 2 O 3 Ca/Si 10% CaO: 90% SiO 2 10% CaO: 90% SiO 2 Ti/Si 10% TiO 2 : 90% SiO 2 10% TiO 2 : 90% SiO 2 V/Si 10% V 2 O 5 : 90% SiO 2 10% V 2 O 5 : 90% SiO 2 Cr/Si 10% Cr 2 O 3 : 90% SiO 2 2% Cr 2 O 3 : 98% SiO 2 Mn/Si 10% Mn 3 O 4 : 90% SiO 2 10% Mn 3 O 4 : 90% SiO 2 Co/Si 10% Co 3 O 4 : 90% SiO 2 10% Co 3 O 4 : 90% SiO 2 Pb/Si 10% PbO: 90% SiO 2 10% PbO: 90% SiO 2 Zn/Si 10% ZnO: 90% SiO 2 2% ZnO: 98% SiO 2 Ba/Si 10% BaO: 90% SiO 2 10% BaO: 90% SiO 2 SynCal Synthetic Calibration Standard Synthetic Calibration Standard 0.6 NaCl/Fe & 1.2 NaCl/Fe N/A Synthetic Calibration Standard for Na

13 Calibration Standards for Phase 2 25 Reference Materials (RM) for calibration 4 RM used as Control / Validation samples 20 Iron Ores and 9 other materials Bureau of Analysed Samples Ltd (BAS) CCRMP, CANMET Mining and Mineral Sciences Laboratories China National Analysis Center for Iron and Steel Dillinger Hütte Laboratory European Committee for Iron and Steel Standardization (ECISS) European Coal and Steel Community (ECSC) Geological Institute for Chemical Minerals Geostats Pty Ltd Institut de Recherche de la Sidérurgie (IRSID) Institute for Geology Ore Deposits, Petrography, Mineralogy and Geochemistry (IGEM) National Institute of Standards & Technology (NIST) Swedish Institute for Metals Research

14 Spectrometry Optimization Element Line Crystal Element Line Crystal Fe Kα LiF220* Cr Kα LiF200 Si Kα PET Co Kα LiF200 Ca Kα LiF200 Ni Kα LiF200 Mn Kα LiF200 Cu Kα LiF200 Al Kα PET Zn Kα LiF200 Ti Kα LiF200 As Kα LiF200 Mg Kα XS-55* Pb Lβ1 LiF200 P Kα Ge Ba Lα LiF200 S Kα Ge Na Kα XS-55 K Kα LiF200 Sr Kα LiF200 Sn Lα LiF200 Zr Kα LiF200 V Kα LiF200 Notes: Line-only measurements is used for phase 1. Other recommendations for the instrument settings were followed. Corrections for line overlaps were made.

15 Spectrometry Optimization Element Peak ( 2-theta) Time (ISO ) Time (This Project) Element Peak ( 2-theta) Time (ISO ) Time (This Project) Fe Cr* Si Co Ca Ni Mn Cu* Al Zn* Ti As* Mg Pb* P Ba S Na N/A 60 K Sr N/A 40 Sn Zr* N/A 40 V* *: Background were used for the analysis of these elements for phase 2

16 Calculation of Results ISO A software package is given in the standard; Use of background equivalent concentrations (BECs); Use the alpha(i,i) factor and loss eliminated alphas; Intensity-based line overlap corrections are used; Catch weights corrections are used; Use of spectrometer drift monitor is allowed; Alternatively, commercial packages are acceptable under certain restrictions. This project Spectra Plus from Bruker AXS

17 Precision Evaluation (Magnetite) Conc. (%) ISO σ d Limit XRF Phase 1 Phase 2 Conc. (%) ISO σ d Limit XRF Phase 1 Phase 2 Fe Cr SiO Co Al 2 O Ni TiO Cu Mn Zn CaO As <LLD N/A N/A N/A N/A P Sr N/A N/A N/A S <LLD N/A N/A N/A N/A Zr N/A N/A N/A MgO Sn N/A K 2 O Ba Na 2 O N/A Pb V

18 Accuracy Evaluation (JK 42) Certified Values (%) Phase 1 Phase 2 Certified Values (%) Phase 1 Phase 2 Fe Cr SiO Co Al 2 O Ni TiO Cu Mn Zn CaO As N/A N/A N/A P Sr N/A N/A N/A S Zr N/A N/A N/A MgO Sn <LLD <LLD K 2 O Ba N/A N/A N/A Na 2 O Pb N/A N/A N/A V LOI N/A N/A N/A CRM from Swedish Institute for Metals Research

19 Accuracy Evaluation (GIOP-37) Certified Values (%) Phase 1 Phase 2 Certified Values (%) Phase 1 Phase 2 Fe Cr <LLD <LLD SiO Co Al 2 O Ni TiO Cu Mn Zn CaO As P Sr N/A S Zr N/A MgO Sn N/A K 2 O Ba Na 2 O Pb V LOI CRM from GEOSTATS PTY LTD, Mining Industry Consultants

20 Accuracy Evaluation (SRM 692) Certified Values (%) Phase 1 Phase 2 Certified Values (%) Phase 1 Phase 2 Fe Cr N/A N/A N/A SiO Co N/A N/A N/A Al 2 O Ni N/A N/A N/A TiO Cu N/A N/A N/A Mn Zn N/A N/A N/A CaO As N/A N/A N/A P Sr N/A N/A N/A S Zr N/A N/A N/A MgO Sn N/A N/A N/A K 2 O Ba N/A N/A N/A Na 2 O Pb N/A N/A N/A V N/A N/A N/A LOI N/A N/A N/A CRM from National Institute of Standards & Technology

21 Accuracy Evaluation (FER-2) Certified Values (%) Phase 1 Phase 2 Certified Values (%) Phase 1 Phase 2 Fe Cr SiO Co <LLD <LLD Al 2 O Ni TiO Cu Mn Zn CaO As N/A N/A N/A P Sr N/A S Zr N/A MgO Sn N/A N/A N/A K 2 O Ba Na 2 O Pb N/A N/A N/A V N/A N/A N/A LOI N/A N/A N/A CRM from CCRMP, CANMET Mining and Mineral Sciences Laboratories

22 Conclusion A fast, specific and simple methodology (Phase I) was optimized from the ISO Standard Method. Alternative methodology based on commercial CRMs (Phase II) allows for similar results as the official ISO test method while offering a much simpler approach. Borate fusion as a sample preparation method, under controlled parameters, has proven to meet the analytical targets of the ISO Standard Method and gives accurate results even for the Total Iron quantification in Iron Ore materials.

23 Acknowledgments Special Thanks to: Alex Milliard, Chemist for preparing all the disks for this project

24 Questions and Comments If you have questions, please feel free to ask me now or little later at Gammadata s booth.