|
KMID : 0545120160260111871
|
|
Journal of Microbiology and Biotechnology
2016 Volume.26 No. 11 p.1871 ~ p.1880
|
|
|
Two-Step Oxidation of Refractory Gold Concentrates with Different Microbial Communities
|
|
Wang Guo Hua
Xie Jian Ping
Li Shou Peng
Guo Yu Jie
Pan Ying
Wu Hai Yan
Liu Xin Xing
|
|
|
Abstract
|
|
|
|
Bio-oxidation is an effective technology for treatment of refractory gold concentrates. However, the unsatisfactory oxidation rate and long residence time, which cause a lower cyanide leaching rate and gold recovery, are key factors that restrict the application of traditional bio-oxidation technology. In this study, the oxidation rate of refractory gold concentrates and the adaption of microorganisms were analyzed to evaluate a newly developed two-step pretreatment process, which includes a high temperature chemical oxidation step and a subsequent bio-oxidation step. The oxidation rate and recovery rate of gold were improved significantly after the two-step process. The results showed that the highest oxidation rate of sulfide sulfur could reach to 99.01 % with an extreme thermophile microbial community when the pulp density was 5%. Accordingly, the recovery rate of gold was elevated to 92.51%. Meanwhile, the results revealed that moderate thermophiles performed better than acidophilic mesophiles and extreme thermophiles, whose oxidation rates declined drastically when the pulp density was increased to 10% and 15%. The oxidation rates of sulfide sulfur with moderate thermophiles were 93.94% and 65.73% when the pulp density was increased to 10% and 15%, respectively. All these results indicated that the twostep pretreatment increased the oxidation rate of refractory gold concentrates and is a potential technology to pretreat the refractory sample. Meanwhile, owing to the sensitivity of the microbial community under different pulp density levels, the optimization of microbial community in bio-oxidation is necessary in industry.
|
|
|
KEYWORD
|
|
|
Bio-oxidation, mesophiles, moderate thermophiles, extreme thermophiles, two-step process
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|