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Title: Metal recovery from mine tailings using bacteria

Journal Article · · Waste Management
 [1]
  1. Iowa State Univ., Ames, IA (United States). Dept. of Civil and Construction Engineering

Zinc metal and zinc sulfide were recovered by oxidative dissolution using Thiobacillus ferrooxidans, which is aerobic, autotrophic, and acidophilic bacteria. Thiobacillus ferrooxidans derive energy from oxidation of ferrous iron and elemental sulfur using molecular oxygen as an electron acceptor. From the 10,000 mg/L of initial zinc concentration, 97% solubilization of zinc metal was obtained from coarse FeS{sub 2} due to microbial action. Also, about 70% metal solubilization occurred with fine sized materials in 58 days. The general trend observed for the ZnS systems was a decrease in pH with time. The pH drop is an indication that microorganisms are acclimating and producing acidic by-products. The iron oxidation state changes due to substrate containing coarse particle size FeS{sub 2} was shown. The sharp drop of ratio of Fe(II)/Fe(Total) and sharp increase of ratio of Fe(III)/Fe(Total) was observed in 20 days after inoculation. Thus, microbial activity began more rapidly for the coarse particle size substrate than for the fine FeS{sub 2}.

OSTI ID:
31827
Journal Information:
Waste Management, Vol. 14, Issue 8; Other Information: PBD: 1994
Country of Publication:
United States
Language:
English