Article ID Journal Published Year Pages File Type
6672356 Minerals Engineering 2018 8 Pages PDF
Abstract
The depression performance and mechanism of the zinc sulfate (ZnSO4) and sodium dimethyl dithiocarbamate (SDD) combined depressant with butyl xanthate (BX) as collector in a mixed Cu-Zn sulfide floation system were fully investigated using micro-flotation experiments, zeta-potential determination, and local electrochemical impedance spectroscopy (LEIS) analysis. The micro-flotation experimental results indicated that the combined depressant has a significant selective depression effect on sphalerite but has slight effect on chalcopyrite. The depression performance of the combined depressant strictly depends on the dosage of ZnSO4 + SDD and flotation pH. However, excessive SDD is detrimental to chalcopyrite flotation. The optimum conditions for flotation separation of chalcopyrite from the Cu-Zn sulfide were as follows: combined depressant dosage of 10−4 mol/L (ZnSO4: SDD = 3:1), BX dosage of 10−5 mol/L, and flotation pH of 10. Under such conditions, a copper concentrate assaying 30.21% Cu with 86.79% recovery was achieved from the Cu-Zn sulfide flotation system, and this concentrate had a very low Zn grade of 4.20% with 5.48% recovery. Both the zeta-potential and LEIS results confirmed that the presence of the combined depressant can significantly prevent the adsorption of BX onto the sphalerite surface, especially for an alkaline pH range of 9-12; however, the adsorption of BX onto the chalcopyrite surface is not affected. The LEIS provides a powerful tool for observing the adsorption of flotation reagents on mineral surface.
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Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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