Abstract
Pyrite tailings from operating industrial facilities, beyond their primary component, frequently contain valuable base metal minerals (e.g., Co, Ni, Cu) that are in constant demand and are critical for 'green energy' technologies. Despite the comparatively low concentration of Ni and Co in these tailings, their overall reserves are potentially significant. The objective of this study was to investigate the recovery of nickel, cobalt, and copper from leach sulfuric solutions derived from nickel-cobalt-bearing pyrite concentrate using solvent extraction. It was established that selective metal recovery necessitates the preliminary precipitation of iron as jarosite at a controlled pH. From the resultant iron-free solution, selective copper extraction was achieved using Acorga 5640 in kerosine at a pH range of 2.8�3.0. This was followed by the co-extraction of Ni and Co using Cyanex 272 combined with TBP at a pH of 5.0. To obtain high-purity cobalt and nickel sulfate, the optimal solvent extraction scheme was determined to be 2E+1Sc+1S (2 Extraction stages + 1 scrabbing stage + 1 Stripping stage). As a result of this research, pure iron hydroxide, along with marketable nickel, cobalt, and copper sulfates, were successfully recovered. Further concentration of the final cobalt sulfate solution requires a subsequent sorption process.