Concentrating challenges of the Zarigan complex Pb-Zn-Fe non-sulfide ore

Abstract

ABSTRACT Zarigan mixed oxide-sulfide complex ore (Yazd province, Iran) contains 6.12% Pb, 0.87% Zn, 47.27% Fe2O3, and 27.18% SiO2. In the present paper, the possibility of lead concentration from the ore was investigated. Process mineralogical studies showed that the lead element has been distributed in the minerals of plumbojarosite, plumbogummite, cerussite, anglesite, and galena, which has made it difficult to concentrate the ore. The main gangue minerals are quartz, goethite, hematite, muscovite-illite, calcite, dolomite, and orthoclase. The results of preliminary experiments showed that using common physical gravity and magnetic separation methods, Zarigan ore cannot be concentrated according to the specifications of the sales market. The results of sulfidation-flotation experiments (–45 μm sample without desliming) showed that the lead grade and recovery in the rougher-scavenger flotation stages reached 8.61 and 54.8%, respectively. With an increase in lead grade up to 52% in the cleaning stages, the overall lead recovery decreased to 11.04%. In the experiments performed by removing the −38 μm fraction, the grade and recovery of lead from the −150 + 38 μm fraction reached 42.25 and 60.21%, respectively. The result of lead leaching with 0.4M HCl + 3.08M NaCl from a −38 μm size fraction showed that lead dissolution is possible. Finally, the Zarigan oxide lead ore processing flowsheet was developed based on the flotation of the +38 μm fraction and the leaching of the −38 μm fraction.