Bioleaching of Marmatite with Various Mixed Cultures of Microorganisms
Bioleaching of marmatite with various mixed cultures of microorganisms was investigated. The experiments were carried out in shaking flasks with iron-free nutrient and the pulp density of 10% wt/vol at the temperature of 30℃. The results show that zinc is preferentially leached before iron.The leaching rate of zinc with the mixed culture of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillumferrooxidans is 62% in 18 days. The leaching rate of zinc with the mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans is nearly the same as that with the mixed culture of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans (45% versus 50%). SEM and EDX analysis of the leaching residues indicate that a solid product layer composed of iron sulfide, elemental sulfur and jarosite accumulates in the mineral surface and becomes a barrier to the dissolution of marmatite. The bioleaching of mannatite follows the shrinking core product layer model. When the product layer increases and becomes insoluble, the leaching rate is controlled by the diffusion through the product layer and slows down. When the product layer decreases or becomes a porous layer, the leaching rate is controlled by chemical reaction and enhanced dramatically.
Bioleaching Marmatite Microorganisms Reaction kinetics Hydrometallurgy
Z. Y. Lan Y. H. Hu
Faculty of Land Resource Engineering, Kunming University of Science and Technology, Kunming, China School of Minerals Processing & Bioengineering, Central South University, Changsha, China
国际会议
XXIV International Mineral Processing Congress(第24届国际矿物加工大会)
北京
英文
2816-2821
2008-09-24（万方平台首次上网日期，不代表论文的发表时间）