Considering the mechanism of a depressant 2-Amino-5-mercapto-1,3,4-thiadiazole in the flotation of chalcopyrite and molybdenite

Abstract

Separating chalcopyrite and molybdenite is difficult owing to their similarly high floatability. Accordingly, this paper considers the depressant 2-Amino-5-mercapto-1,3,4-thiadiazole (AMT), in order to separate chalcopyrite and molybdenite and investigate the relevant mechanism of AMT depression. Single-mineral flotation tests showed that when kerosene was used as the collector and AMT as the depressant, molybdenite showed excellent flotation while chalcopyrite was completely depressed. Mixed mineral flotation tests showed that separation of these two minerals could be achieved when AMT was applied as the depressant. Combining the test results of adsorption, Zeta potential, and XPS, the mechanism of AMT depression is suggested. Therefore, the adsorption mechanism of AMT on the chalcopyrite and molybdenite can be revealed. The adsorption of AMT on the chalcopyrite surface is unquestionably greater than that on the molybdenite surface. The results suggest that AMT is chemisorbed on chalcopyrite surfaces through the Cu-S bonds. By contrast, physisorption on molybdenite surfaces is through electrostatic action. Thus, selective depression of chalcopyrite can be achieved with the use of AMT. This study promises a more environmentally friendly flotation separation process for chalcopyrite and molybdenite.