Determination of S, Ni, and Cu in Copper Nickel Sulfide Ores by Total Reflection X-ray Fluorescence Analysis: Experience of Participation in an Interlaboratory Comparison Program

Abstract

The quality of total reflection X-ray fluorescence (TXRF) analysis data for S, Ni, and Cu in copper nickel sulfide ores has been assessed in the framework of an interlaboratory comparison program, with allowance for requirements that should be met by techniques for determination of the chemical composition of mineral raw materials. Certified techniques for analysis of mineral raw materials by this method are not available, and the results obtained in the interlaboratory comparison program were used to assess and improve TXRF measurement accuracy. Ore samples were prepared in the form of suspensions using wet grinding. The analytical signal used was the intensity ratio of characteristic lines of the elements to be determined and a Ga internal standard. To construct calibration curves, we used reference samples analyzed by certified techniques: Cu and Ni were determined by atomic absorption, and S by gravimetry. The quality of analytical data was assessed using the Z-criterion. The random measurement error did not exceed 5% relative. The relative discrepancies between the TXRF results and interlaboratory comparison test results were within 10%. The described technique can be used for rapid analysis of copper nickel sulfide ore samples.