Identification of the significant factors determining extractability of Ni and Cu after sulfation roasting of a PGM-bearing chromitite ore
MetadataShow full item record
Selective sulfation-roast-water leach process of a complex, chromite-rich Cu-Ni-PGM ore to dissolve water-soluble base metal sulfates contained therein was investigated as an alternative process to remove base metals prior to the extraction of precious metals. Ground run-of-mine ore (P80 < 75 µm) was mixed with concentrated H2SO4 (sulfating agent) and Na2SO4 (dual catalyst and sulfating agent) to intensify atmospheric sulfation roast reaction in an unvented electric furnace (static roast under reducing conditions). The acquired calcine was water leached to extract the Ni and Cu sulfates. The roasting conditions were optimized using a Response Surface Methodology which included a Desirability Function Approach in order to maximize Cu and Ni extraction whilst limiting reagent consumption and suppressing Fe and Cr co-dissolution. It was possible to decompose the chromatic-ferritic structure and produce water-soluble metal species by roasting the ore containing 12.80 g/t Pt, 15.20 g/t Pd, 0.0646% Cu, 0.31% Ni, 13.60% Fe and 10.40% Cr. Approximately 90% Ni and 77% Cu were recovered after roasting at 550 °C in closed atmosphere for 2 h with 462 kg/t H2SO4, 76.9 kg/t Na2SO4 and by leaching at 80 °C with 2 wt% solid density for 24 h. The raw ore, roasted mass and water-leach residue were characterized by fire assay and Tescan Integrated Mineral Analysis (TIMA GM Model). Pt + Pd grade has been upgraded from 28 (raw ore) to 32.38 g/t (water-leach residue).
Showing items related by title, author, creator and subject.
Eksteen, Jacques; Mwase, J.; Petersen, J.; Bradshaw, S.; Akdogan, G.; Mpinga, N.; Snyders, C. (2014)The platinum group metals (PGMs) and associated minerals are particularly refractory to most traditional direct leach processes. However, the remoteness of many new ore deposits, socio-political risks, the scarcity of ...
Pyrometallurgical upgrading of PGM-rich leach residues from the Western Platinum base metals refinery through roastingBezuidenhoudt, G.; Eksteen, Jacques; Akdogan, G.; Bradshaw, S.; De Villiers, J. (2013)The production of Platinum Group Metals (PGMs) normally entails the smelting of PGM flotation concentrates, converting of the furnace matte and removal of the bulk of the Ni, Cu, Co, S and Fe through atmospheric and ...
Sinha, M.; Pramanik, S.; Kumari, A.; Sahu, S.; Prasad, L.; Jha, M.; Yoo, Kyoungkeun; Pandey, B. (2017)Recovery of value added products of samarium and cobalt from the waste SmCo magnet was carried out by leaching and solvent extraction. Prior to the leaching the magnet was demagnetized by roasting at 1123 K. Leaching of ...