Practicality of Hand-held XRF Analyzer in Rapid Exploration of Porphyry Copper Deposit

Abstract

BACKGROUND There is a certain deviation between the on-site analysis results of hand-held XRF and the laboratory analysis results due to the unique technical difficulties in field X-ray fluorescence measurement such as roughness effect, uneven effect and humidity effect of samples. OBJECTIVES To seek economic, rapid and practical test conditions of hand-held XRF for rapid exploration of porphyry copper ore in practical work. METHODS Influence of test conditions, such as analytical time, sample content, test distance, sample dry humidity and sample particle size on the analytical results of Niton XL3t GOLDD+ hand-held XRF was quantitatively studied. RESULTS The results showed that, under the best test time of 90s, the determination limits of Cu, Mo, Pb, and Zn were 57μg/g, 14μg/g, 24μg/g, and 38μg/g, respectively, and the calculation formula for the determination limit was given. The field analysis test distance should be less than 5mm and the sample surface should be kept dry. The test method for bulk sample was the simplest but the test results varied the most. When sample was crushed to a particle size of 80 mesh or above, the stability and accuracy of the results were best. Considering that it took a long time to crush sample into 80 mesh, the mixed state of the sample after crushing was better strategy for field testing. CONCLUSIONS The practical application of core scanning in Qulong porphyry copper deposit in Tibet shows that the handheld XRF analyzer is suitable for in-situ analysis and can meet the requirements of rapid exploration and evaluation such as delineation of copper ore bodies in field, which can greatly improve work efficiency and reduce exploration cost.

Keywords

• hand-held xrf analyzer
• in situ analysis
• sample size
• test time
• determination limit of elements
• porphyry copper prospecting