Determination of Ni, Co and Cu in Laterite-Nickel Ores by Inductively Coupled Plasma-Atomic Emission Spectrometry

A method for the determination of Ni, Co and Cu contents in laterite is presented in this paper. Laterite samples were fused with a mixed flux of Na₂CO₃-Na₂B₄O₇, then the analytes were extracted by HCl acid. The sample solution was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The internal standard method was used to avoid matrix interference based on choosing Y 371.030 nm as the internal calibration line for Cu (324.754 nm) and Y 224.306 nm for Ni (231.604 nm) and Co (228.616 nm). The detection limits for Ni, Co and Cu were 0.5 μg/g, 1.0 μg/g and 1.0 μg/g, respectively. The relative standard deviations (RSD) of the test result were 1.2%-2.0% (n=7), and the recoveries ranged from 95% to 103.6%, which met the requirements of analysis for laterite.