Partial Extraction —Determination of Nickel, Cobalt, Manganese and Other Elements in the Lateritic Nickel Ore by Inductively Coupled Plasma Optical Emission Spectrometry

Objective To address the limitation of existing chemical analysis methods in evaluating the enrichment of valuable elements such as iron, nickel, and cobalt in oxidized and silicate minerals of laterite nickel ores, Method certified reference materials of lateritic nickel ores as research subjects and simulated a hydrometallurgical process were used. The tests focused on key factors, including the type and ratio of selective extractants, extraction temperature, and roasting pretreatment. The optimal extraction parameters were identified as follows: a mixed extractant composed of 1.5 mol/L hydrochloric acid and 1 mol/L ammonium fluoride, with extraction performed at 135 ℃ using 25 mL of extractant and no pre-roasting. Result The impact of the extractant on the matrix and the instrumental parameters for ICP-OES determination were investigated. Method validation results showed that the precision (RSD, n=12) was≤5.79%. The detection limits for MgO, CaO, total iron (TFe), cobalt (Co), nickel (Ni), alumina (Al₂O₃), manganese (Mn), and chromium (Cr) were≤0.007 7%, For limonite-type samples, the leaching rates of nickel and cobalt reached 99% and 91.67%, respectively. For serpentine-type samples, the leaching rates were 97.6% and 91.3%. Conclusion These values are consistent with the recovery rates of nickel and cobalt in industrial hydrometallurgical processes, indicating that this method is highly effective for analyzing and testing available metal elements in oxidized and silicate minerals of laterite nickel ores.