The effects of introducing M.sedula derivatives having different Cu^2+-resistance on bioleaching capacity of a defined consortium(consisting of A.brierleyi DSM1651 and M.hakonensis HO1-1)were studied in column reactor...The effects of introducing M.sedula derivatives having different Cu^2+-resistance on bioleaching capacity of a defined consortium(consisting of A.brierleyi DSM1651 and M.hakonensis HO1-1)were studied in column reactors at 70℃.Introducing M.sedula copA mutant,a copper sensitive derivative,only had negligible effects on bioleaching.While introducing M.sedula ARS50-2,a Cu^2+resistant strain,substantially consolidated bioleaching process,with 27.77%more copper recovered after 58 d of bioleaching.Addition of M.sedula ARS50-2 likely enhanced the sulfur oxidation capacity of consortium after the 24th day under the Cu^2+stress.The majority of extreme thermoacidophiles were attached on minerals surface as indicated by quantitative PCR(qPCR)data.Successions of microbial community of extremely thermoacidophilic consortia that attached on surface of minerals were different from those in leachate.M.hakonensis HO1-1 was the dominant species attached on minerals surface in each column reactor throughout bioleaching process.The sessile M.sedula ARS50-2 remained as a major species till the 34th day.A.brierleyi DSM1651 was the most abundant planktonic species in leachate of each column reactor.These results highlight that higher Cu^2+-resistance is a beneficial trait for extreme thermoacidophiles to process copper minerals.展开更多
The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated,and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and h...The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated,and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and hand-picked concentrates of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.The experimental results show that the bacteria grow best when the temperature is(30±1) °C and the pH value is 2.0.The bacteria concentration is 2.24×107 mL-1 in this condition.It is found that the copper extraction yield is affected by the inoculum size and the pulp density and the extraction yield increases as the inoculum size grows.The bioleaching rates reach their highest point in sulfide copper and chalcopyrite with a pulp density of 5% and 10%,respectively.Column flotation experiments of low-grade copper sulfide ores show that the bioleaching recovery reaches nearly 45% after 75 days.展开更多
The effects of silver sulfide (Ag 2S) on the bioleaching of chalcopyrite and pyrite were investigated in this paper. It has been shown that Ag 2S enhanced the yields of bioleaching of chalcopyrite but inhibited the bi...The effects of silver sulfide (Ag 2S) on the bioleaching of chalcopyrite and pyrite were investigated in this paper. It has been shown that Ag 2S enhanced the yields of bioleaching of chalcopyrite but inhibited the bio oxidation of pyrite. The addition of Ag 2S selectively increased the copper dissolution from the chalcopyrite containing ores in shake flasks with a recovery of 85.3% compared with 24.3% without Ag 2S, while slightly decreased the iron yields from 51% to 41.8%. The copper extraction of the chalcoopyrite containing waste rock in column leaching charged with 18 kg mass increased up to 21.7% in the presence of Ag 2S, while only 3.4% in the absence of the catalyst. The mechanism of Ag 2S catalysis could be explained well by the "Mixed potential model".展开更多
The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferroox...The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum and Acidithiobacillus thiooxidans)was used to leach three kinds of chalcopyrites with different iron-sulfur ratios.After 36 d of leaching,the chalcopyrite with iron-sulfur ratio of about 1:1 achieved the highest copper extraction(69.62%).In the early stage,iron oxidizing bacteria predominated,and the expression of rus and rio was 8 times higher than that in the late stage.In the late stage,sulfur oxidizing bacteria predominated,and the expression of tetH and HdrAB was 4 times higher than that in the early stage.Furthermore,the three bioleaching systems above were added with elemental sulfur(3 g/L);the chalcopyrite with iron-sulfur ratio of about 2:1 achieved the highest copper extraction(80.63%).The results suggest that the energy metabolism structure of the microbial community could be changed by changing the iron-sulfur ratio during the leaching process for improving the leaching efficiency of chalcopyrite.展开更多
基金Project(207154)supported by the Postdoctoral Research Funding of Central South University,ChinaProjects(31470230,51320105006,51604308)supported by the National Natural Science Foundation of China+2 种基金Project(2017RS3003)supported by the Youth Talent Foundation of Hunan Province,ChinaProject(2018JJ2486)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2018WK2012)supported by the Key Research and Development Projects in Hunan Province,China。
文摘The effects of introducing M.sedula derivatives having different Cu^2+-resistance on bioleaching capacity of a defined consortium(consisting of A.brierleyi DSM1651 and M.hakonensis HO1-1)were studied in column reactors at 70℃.Introducing M.sedula copA mutant,a copper sensitive derivative,only had negligible effects on bioleaching.While introducing M.sedula ARS50-2,a Cu^2+resistant strain,substantially consolidated bioleaching process,with 27.77%more copper recovered after 58 d of bioleaching.Addition of M.sedula ARS50-2 likely enhanced the sulfur oxidation capacity of consortium after the 24th day under the Cu^2+stress.The majority of extreme thermoacidophiles were attached on minerals surface as indicated by quantitative PCR(qPCR)data.Successions of microbial community of extremely thermoacidophilic consortia that attached on surface of minerals were different from those in leachate.M.hakonensis HO1-1 was the dominant species attached on minerals surface in each column reactor throughout bioleaching process.The sessile M.sedula ARS50-2 remained as a major species till the 34th day.A.brierleyi DSM1651 was the most abundant planktonic species in leachate of each column reactor.These results highlight that higher Cu^2+-resistance is a beneficial trait for extreme thermoacidophiles to process copper minerals.
基金Project(2012AA061501)supported by the National High-tech Research and Development Program of ChinaProject(20120162120010)supported by the Research Fund for the Doctoral Program of Higher Education of China+2 种基金Project(NCET-13-0595)supported by the program for New Century Excellent Talents in University of ChinaProject(51374248)supported by the National Natural Science Foundation of ChinaProject(2010CB630905)supported by the National Key Basic Research Program of China
文摘The grown conditions of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were investigated,and then experiments were conducted to research the bioleaching behaviors of crude ore of copper sulfide and hand-picked concentrates of chalcopyrite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.The experimental results show that the bacteria grow best when the temperature is(30±1) °C and the pH value is 2.0.The bacteria concentration is 2.24×107 mL-1 in this condition.It is found that the copper extraction yield is affected by the inoculum size and the pulp density and the extraction yield increases as the inoculum size grows.The bioleaching rates reach their highest point in sulfide copper and chalcopyrite with a pulp density of 5% and 10%,respectively.Column flotation experiments of low-grade copper sulfide ores show that the bioleaching recovery reaches nearly 45% after 75 days.
文摘The effects of silver sulfide (Ag 2S) on the bioleaching of chalcopyrite and pyrite were investigated in this paper. It has been shown that Ag 2S enhanced the yields of bioleaching of chalcopyrite but inhibited the bio oxidation of pyrite. The addition of Ag 2S selectively increased the copper dissolution from the chalcopyrite containing ores in shake flasks with a recovery of 85.3% compared with 24.3% without Ag 2S, while slightly decreased the iron yields from 51% to 41.8%. The copper extraction of the chalcoopyrite containing waste rock in column leaching charged with 18 kg mass increased up to 21.7% in the presence of Ag 2S, while only 3.4% in the absence of the catalyst. The mechanism of Ag 2S catalysis could be explained well by the "Mixed potential model".
基金Project(2017zzts382)supported by Central South University Postgraduate Independent Exploration and Innovation,ChinaProject(2014jpkc003)supported by Central South University Graduate Excellent Course,China+1 种基金Project(2015JJ2165)supported by Hunan Provincial Natural Science Foundation of ChinaProject(165611031)supported by Central South University Fundamental Research Funds Special Funding,China。
文摘The energy metabolism structure of microbial community plays an important role in the process of biohydrometallurgy.In this article,an artificial microbial community composed of three strains(Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum and Acidithiobacillus thiooxidans)was used to leach three kinds of chalcopyrites with different iron-sulfur ratios.After 36 d of leaching,the chalcopyrite with iron-sulfur ratio of about 1:1 achieved the highest copper extraction(69.62%).In the early stage,iron oxidizing bacteria predominated,and the expression of rus and rio was 8 times higher than that in the late stage.In the late stage,sulfur oxidizing bacteria predominated,and the expression of tetH and HdrAB was 4 times higher than that in the early stage.Furthermore,the three bioleaching systems above were added with elemental sulfur(3 g/L);the chalcopyrite with iron-sulfur ratio of about 2:1 achieved the highest copper extraction(80.63%).The results suggest that the energy metabolism structure of the microbial community could be changed by changing the iron-sulfur ratio during the leaching process for improving the leaching efficiency of chalcopyrite.
