Recovery of valuable metals from manganese purification sludge (SPS) containing Mn-Ni-Co sulfide and preparation of battery-grade Ni-Co-Mn sulfate solution

• Published in: Hydrometallurgy 2024-08, Vol.227, p.106331, Article 106331
• Main Authors: Yue, Leiting, Wang, Mingyu, Li, Jia, Guan, Wenjuan, Li, Qinggang, Cao, Zuoying, Wu, Shengxi, Zhang, Guiqing
• Format: Article
• Language: English
• Subjects: Battery-grade Ni-Co-Mn sulfate solution; SPS; Valuable metals
• ISSN: 0304-386X; 1879-1158
• DOI: 10.1016/j.hydromet.2024.106331

The manganese production industry produces a large amount of sulfide purification sludge (SPS) every year, representing a hazardous solid waste but also a valuable secondary resource for Ni, Co, and Mn. In this paper, the recovery of Ni, Co, and Mn from the SPS was achieved by (i) leaching with a solution of hydrogen peroxide, (ii) selectively extracting nickel, cobalt and manganese, (iii) solvent extraction for zinc removal, and finally obtained the battery-grade Ni-Co-Mn sulfate solution. During the hydrogen peroxide solution leaching stage, the leaching efficiency of Co, Mn, and Ni reached 98.5%, 98.6%, and 95.6%, respectively. A synergistic extraction system (SES) consisting of decyl 4-picolinate and dinonylnaphthalene sulfonic acid was used to selectively extract Ni, Co, and part of Mn, and the extraction of Ni and Co was >99.8% and 95.5%, respectively. The loaded organic was subjected to four-stage countercurrent scrubbing using a 5 g/L H2SO4 solution, resulting in nearly 100% removal of Ca and Mg. After that, 150 g/L H2SO4 was used to strip Ni, Co, and Mn from the loaded organic to obtain a crude Ni-Co-Mn sulfate solution. Finally, D2EHPA was utilized for the extraction of impurity Zn from the stripping solution to obtain a battery-grade Ni-Co-Mn sulfate solution with