Analysis of Bioleaching Characteristics and Multi-Element Dissolution Behavior of Complex Zinc Ores

Abstract In order to recover low-grade complex zinc ore in a reasonable way, this study adopts bioleaching method to study it. The ore samples contain 1.52%, 2.03% and 14.4% zinc, respectively, which occurs in the form of sphalerite. Other major minerals include pyrite, galena, quartz and mica. The inoculation of the domesticated strain was basically free of adaptation period, and the cell concentration could be rapidly increased after a short decrease. The leaching extent of zinc increased continuously, while the leaching rate decreased gradually. After the bioleaching process, sliver, lead and iron were mainly present in the residue phase. X-ray diffraction spectroscopy analysis showed that sphalerite, galena and pyrite were dissolved, and the latter two further precipitated to produce PbSO4 and jarosite. In addition, the dissolution of calcium compounds can lead to the formation of gypsum precipitation. These precipitates covered the fresh ore surface may hinder the further bioleaching process. The Exponential model was used to simulate the bioleaching process, and it was found that the fit coefficients were all greater than 0.98, and a reasonable leaching cycle was further discussed. The results provide a good basis for the economic and environmentally friendly recovery of low-grade complex zinc ores.