Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied...Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied. The results showed that the time of the bio-oxidation process was decreased obviously and the arsenic leaching rate reached 94.4% after the bioleaching. The bio-oxidation of arsenopyrite and the effective extraction of manganese from pyrolusite were achieved by the bioleaching process. After bioleaching, the leaching rate of gold from the reaction residues reached 95.8% by cyanide leaching. In the bio-oxidation process, pyrolusite increased the redox potential of the solution to accelerate the bioleaching rate. The experiment showed that there were two reaction modes in the bioleaching process.展开更多
To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfac...To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.展开更多
The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching...The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching efficiency by changing valence state of arsenic.The results show that the concentration of As 3+ is larger than that of As 5+ in the lag phase.The concentration of As 3+ decreases in the log phase,and is lower than that of As5 +.HQ-0211 typed bacteria express better resistance for As 3+and As 5+and remain growing when the concentrations of As3 +and As 5+are above 6.0 g/L and 12.0 g/L,respectively.It is found that Fe 3+cannot oxidize As3 +singly as strong oxidant in the leaching system,but can cooperate with pyrite or chalcopyrite to do that.The oxidation of As 3+ is prompted with addition of H2O2.The bacterial activity is improved in favor of bacterial leaching efficiency.NaClO restrains the bacterial growth to depress leaching efficiency because of the chloric compounds affecting bacterial activity.展开更多
基金Project(2015ZX07205-003)supported by the National Water Pollution Control and Treatment Science,ChinaProject(DY125-15-T-08)supported by China Ocean Mineral Resource R&D Association+1 种基金Project(2012BAB07B05)supported by the National Key Technology R&D Program of ChinaProject(2012AA062401)supported by the National High-tech Research and Development Program of China
文摘Pyrolusite was added in the bioleaching process to enhance the bio-oxidation process. Bioleaching tests at different dosages of pyrolusite ore, pH and inoculation amounts of Acidithiobacillus ferrooxidans were studied. The results showed that the time of the bio-oxidation process was decreased obviously and the arsenic leaching rate reached 94.4% after the bioleaching. The bio-oxidation of arsenopyrite and the effective extraction of manganese from pyrolusite were achieved by the bioleaching process. After bioleaching, the leaching rate of gold from the reaction residues reached 95.8% by cyanide leaching. In the bio-oxidation process, pyrolusite increased the redox potential of the solution to accelerate the bioleaching rate. The experiment showed that there were two reaction modes in the bioleaching process.
基金Projects(51104024,51374043)supported by National Natural Science Foundation of ChinaProject(10JJ6019)supported by Hunan Provincial Natural Science Foundation,China+1 种基金Project(10C0399)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(2014SK3182)supported by Hunan Provincial Science&Technology Department,China
文摘To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.
基金Projects(50674029, 50874030) supported by the National Natural Science Foundation of ChinaProject(2006AA06Z127) supported by the National High-tech Research and Development Program of ChinaProject(20060145015) supported by Specialized Research Fund for the Doctoral Program of Higher Education, China
文摘The concentration and variational trend of As3 +and As 5+,the bacterial resistance for the As 3+and As 5+and converting conditions from As3 +to As 5+were analyzed.The additive was used to prompt the bacterial leaching efficiency by changing valence state of arsenic.The results show that the concentration of As 3+ is larger than that of As 5+ in the lag phase.The concentration of As 3+ decreases in the log phase,and is lower than that of As5 +.HQ-0211 typed bacteria express better resistance for As 3+and As 5+and remain growing when the concentrations of As3 +and As 5+are above 6.0 g/L and 12.0 g/L,respectively.It is found that Fe 3+cannot oxidize As3 +singly as strong oxidant in the leaching system,but can cooperate with pyrite or chalcopyrite to do that.The oxidation of As 3+ is prompted with addition of H2O2.The bacterial activity is improved in favor of bacterial leaching efficiency.NaClO restrains the bacterial growth to depress leaching efficiency because of the chloric compounds affecting bacterial activity.
