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The article investigates dressing of zinc concentrate of Zhezkent processing plant with the purpose of receiving conditioned zinc concentrate and copper product output. The scheme of the zinc concentrate ressing is suggested which includes the following operations: desorption of the initial concentrate by sodium sulfide and activated carbon; preliminary hydraulic classification (washing of thin sludge) complicating the flotation process; comminution of the concentrate in a ball mill up to the size of 96 %, class - 0,044 mm; flotation of copper minerals by reagents: xanthate, Methyl isobutyl ketone blowing agent, and depressors (Na2S, FeSO4, ZnSO4). The proposed dressing scheme provides obtaining conditioned zinc concentrate of grade KC-3 with Zn 47,0 %, and Cu 1,9 %.

The article investigates dressing of zinc concentrate of Zhezkent processing plant with the purpose of receiving conditioned zinc concentrate and copper product output. The scheme of the zinc concentrate ressing is suggested which includes the following operations: desorption of the initial concentrate by sodium sulfide and activated carbon; preliminary hydraulic classification (washing of thin sludge) complicating the flotation process; comminution of the concentrate in a ball mill up to the size of 96 %, class - 0,044 mm; flotation of copper minerals by reagents: xanthate, Methyl isobutyl ketone blowing agent, and depressors (Na2S, FeSO4, ZnSO4). The proposed dressing scheme provides obtaining conditioned zinc concentrate of grade KC-3 with Zn 47,0 %, and Cu 1,9 %. [ABSTRACT FROM AUTHOR]

The recycling of electronic scrap is an important subject not only from an environmental aspect but also for recovering metal resources such as copper. In this work, the microbial extraction of copper and other metals (Cu, Ni, Co, Fe and Al) present in the depopulated and shredded printed circuit board (PCB) is elaborated. Bacterial strains of A. ferrooxidans, A. thiooxidans and a fungal strain, A. niger are used for copper extraction along with other metals from shredded PCBs. An optimum metal recovery of 93% Cu was obtained at 308 K, pH 2 using 8% pulp density in 10 days by a mixed culture of A. ferrooxidans and A. thiooxidans. Whereas using A. niger, a metal recovery of 66% Cu was reported using similar experimental conditions. The results show the higher potential ability of bacteria as compared to fungus to bioleach copper. Additionally, the kinetics and mechanism of copper bioleaching from this e-waste by the chemolithotrophs and heterotrophs were evaluated. The leach liquor obtained from the optimized leaching process was subjected to separation and purification of copper as >99% pure copper sulfate using Acorga M5640 by solvent extraction.