Abstract:
In this paper, mineral processing study was carried out on a silver-bearing low-grade lead & zinc ore. The two processes of Ag and Pb bulk flotation (regrinding of Ag and Pb rough concentrate)—Zn flotation and Ag and Pb bulk flotation (regrinding of Ag and Pb middlings)—Zn flotation were proposed based on the characteristics of the ore property, firstly, the selective combination collector BK906 and BK903G was adopted to collect silver and lead sulfides from the alkali-free pulp close to neutral pH value with the bulk flotation process flowsheet and the Ag and Pb bulk concentrate was obtained, and then the zinc sulfides were recovered by flotation separation from the flotation tailings of Ag and Pb by the conventional lime+copper sulfate+xanthate method and the Zn concentrate was obtained. The comparison tests were conducted by adopting two technological processes of Ag and Pb bulk flotation (regrinding of Ag and Pb rough concentrate)—Zn flotation and Ag and Pb bulk flotation (regrinding of Ag and Pb middlings)—Zn flotation. Finally the flowsheet of Ag and Pb bulk flotation (regrinding of Ag and Pb rough concentrate)—Zn flotation was determined, and the results of closed-circuit test were obtained the silver and lead concentrate with grading 5252.5 g/t Ag, 27.54% Pb, 3.87% Zn and recovery rate of 73.03% Ag and 76.47% Pb, and the zinc concentrate with grading 359.6 g/t Ag, 0.37% Pb, 54.96% Zn and Zn recovery of 71.00%. It can be achieved high-capacity recovering valuable metals silver, lead and zinc associated in the ore.