Breakthrough Technology for Cobalt Analysis Using pXRF
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The document discusses advancements in portable x-ray fluorescence (pxrf) technology for analyzing cobalt in geological and environmental samples, highlighting its rapid and quantitative capabilities. It addresses challenges posed by elemental interferences from iron and nickel during cobalt detection and presents a new geochem-co method that improves analysis in such scenarios. The results demonstrate the effectiveness of this updated method, achieving high correlation values for cobalt, iron, and nickel measurements.
Breakthrough Technology for Cobalt Analysis Using pXRF
- 1. 1 Breakthrough Technology for Cobalt Analysis Using pXRF TLEM 2018 Simon Bailey & Jake Jarvinen Olympus Australia
- 2. Portable X-ray diffraction (pXRD)—rapid, in-situ, and quantitative mineralogy analysis Field-Portable Solutions for Battery Metals Exploration
- 3. Portable X-ray fluorescence (pXRF)—rapid, in-situ, and multielement geochemistry Field-Portable Solutions for Battery Metals Exploration
- 4. 1. Provides rapid, in-situ elemental measurements for a range of geological and environmental applications 2. Provides decision-quality data faster than traditional XRF 3. Allows for more discriminating laboratory sampling Benefits of pXRF for Exploration
- 5. With sample preparation, pXRF is capable of producing high- quality quantitative data similar to laboratory analysis Benefits of pXRF for Exploration R² = 0.9806 10 100 1000 10 100 1000 LabResults(ppm) Standard Si-Pin Omega (Soil Mode) XRF Results (ppm) Copper(ppm) Log-Log R² = 0.9919 10 100 1000 10 100 1000 LabResults(ppm) Standard Si-Pin Omega (Soil Mode) XRF Results (ppm) Lead (ppm) Log-Log R² = 0.9835 10 100 1000 10000 100000 10 100 1000 10000 100000 LabResults(ppm) Standard Si-Pin Omega (Soil Mode) XRF Results (ppm) Zinc (ppm)Log-Log
- 6. 1. XRF is prone to interelement interferences 2. Common interference is iron (Fe) on cobalt (Co) and nickel (Ni) on Co − When high Fe is present, the ability to see Co at low levels is diminished − When Ni is also present, the ability to see Co has been virtually impossible 3. Co is routinely explored for in the presence of significant Fe and Ni Problems for Cobalt Analysis
- 7. • Energy dispersive X-ray fluorescence (EDXRF) looks for the spectral peaks for each element of interest • Each element is calibrated using only one peak • If another element has a peak that is too close to the element of interest and that element is present in significant concentrations, an interference results Problems for Cobalt Analysis
- 8. • Iron has a peak at 7.06 keV, which is close enough to interfere with cobalt’s primary peak of 6.93 keV • Nickel has a primary peak at 7.48 keV, which is close enough to interfere with cobalt’s secondary peak of 7.65 keV • To date, no brand of pXRF has a reliable way around this Problems for Cobalt Analysis
- 9. Problems for Cobalt Analysis Fe Kβ, Co Kα Ni Kα, Co Kβ
- 10. • When iron and nickel are low, cobalt is easier to detect • When iron and nickel are high: −Soil Mode—false positives for cobalt −GeoChem Mode—cannot see low amounts of cobalt Problems for Cobalt Analysis
- 11. • We need a way of being sure of the cobalt values in all scenarios • We don’t want to have to do too much sample preparation (fused bead, etc) • We don’t want to spend too much time (multiple method analyses) Ultimate Goal of pXRF for Cobalt Exploration
- 12. • Olympus’ updated GeoChem method improves the analysis of cobalt in the presence of iron and nickel • Innovative method of overcoming interferences • Does it work? New GeoChem-Co Method
- 13. • We analyzed 16 samples with high iron • (9% < Fe < 50%, 50 ≤ Co ≤ 6000 ppm, Ni < 500 ppm) • We also analyzed 50 samples with moderate iron • (0.5% < Fe < 15%, 16 < Ni < 8000 ppm, 50 ppm < Co < 2.3%) • The samples were pulps in XRF cups, 60 seconds per beam, no corrections New GeoChem-Co Method
- 15. Results – Cobalt y = 11395x - 220.54 R² = 0.9778 -1000 0 1000 2000 3000 4000 5000 6000 7000 0 0.1 0.2 0.3 0.4 0.5 0.6 LabCoppm Vanta Co %
- 16. Results – Iron y = 1.0047x + 1.8432 R² = 0.9421 0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 0 10 20 30 40 50 60 70 LabFe% Vanta Fe %
- 17. Results – Cobalt y = 1.1861x - 0.0121 R² = 0.9793 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 LabCo% Vanta Co %
- 18. Results – Iron y = 1.025x - 0.0637 R² = 0.9957 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 LabFe% Vanta Fe %
- 19. Results – Nickel y = 1.0419x + 0.0009 R² = 0.9831 0 0.1 0.2 0.3 0.4 0.5 0.6 0 0.1 0.2 0.3 0.4 0.5 0.6 LabNi% Vanta Ni %
- 20. Olympus is a registered trademark, and Vanta is a trademark of Olympus Corporation.