永平铜矿浸矿细菌最佳生长条件的研究

对从永平铜矿酸性矿坑水中分离出的浸矿细菌进行了最佳生长条件的研究。结果表明,在9K+S培养基中,接种量为20%,pH为1 80,Fe2+浓度为3g/L,总铁为4g/L的条件下,既有利于细菌的生长,又有利于减少铁的沉淀,同时有利于矿物的浸出。     

Bioleaching of chalcopyrite by Acidianus manzaensis under different constant pH

The bioleaching of pure chalcopyrite by thermophilic Archaea strain Acidianus manzaensis YN-25 under different constant pH was first comparatively investigated. Then the relevant sulfur speciation was analyzed by synchrotron radiation based X-ray diffraction (SR-XRD) and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. The acidity of the leaching solution was monitored at 3-h intervals to make it steady at pH 1.25, 1.50, 1.75, 2.00, 2.25 and 2.50, respectively. Leaching results showed that the copper ion extraction increased during chemical leaching but decreased during bioleaching when pH value decreased from 2.50 to 1.25. SR-XRD analysis showed that, during bioleaching, new elemental sulfur (S⁰) phase was detected at all tested pH cases; new jarosite phase was detected at cases of pH 1.50 to 2.50; and jarosite gradually became a major phase when pH value increased. XANES analysis further showed that covellite was detected during bioleaching at cases of pH 1.25 to 2.00 at higher redox potential (ORP) value, while chalcocite and bornite were detected at cases of pH 2.25 and 2.50 at lower ORP value. These results suggested that the formation of S⁰ was mainly accounting for hindering the dissolution of chalcopyrite while the formation of bornite could accelerate the dissolution of chalcopyrite by A. manzaensis.     

Cooperative effect of chalcopyrite and bornite interactions during bioleaching by mixed moderately thermophilic culture

The cooperative interactions between chalcopyrite and bornite during bioleaching by mixed moderately thermophilic culture were investigated mainly by bioleaching experiments and electrochemical experiments. Bioleaching results showed that a cooperative effect existed between chalcopyrite and bornite. When the mass ratio of chalcopyrite to bornite was 3:1, an extremely high copper extraction of more than 88% was achieved after bioleaching for 27 days. One of the major reasons for the cooperative effect was that a certain redox potential range (370–450 mV vs. Ag/AgCl) could be maintained for a long period of time during bioleaching due to the mixture of chalcopyrite and bornite. Electrochemical measurements revealed that chalcopyrite was much easier to be reduced than oxidized, while bornite was prone to be directly oxidized. Hence, galvanic effect between chalcopyrite and bornite enhanced the reduction of chalcopyrite to secondary copper-iron species and promoted the oxidative dissolution of bornite. Therefore, redox potential controlling and galvanic effect both contributed to the cooperative bioleaching of chalcopyrite and bornite.     

Hope for Animals and Their World: How Endangered Species are Being Rescued from the Wild

The presence of heavy metals in mine tailings poses potential threats to environment and human health. The paper reports an investigation of the effects of initial pH on bioleaching of heavy metals (Cu, Zn and Pb) from mine tailings by indigenous sulphur-oxidising bacteria.     

生物浸出磁黄铁矿的研究概况

磁黄铁矿矿物组成复杂,且极易氧化;浮选困难,但易于生物浸出。本文从浸出机理、动力学和强化措施等方面阐述了生物浸出磁黄铁矿的研究现状。指出了该技术存在的问题和应用前景。     

含砷硫化铜精矿的细菌浸出研究

细菌浸出金属因其投资小、成本低、污染轻，适合处理低品位和难处理矿石，已在次生硫化铜矿石提铜中作为首选工艺。介绍了我国某含砷低品位硫化铜矿浮选精矿的细菌浸出试验研究结果，通过选育优良浸矿菌种，可以高效地直接提取某铜精矿中的铜，铜浸出率达到85．52％。     

生物浸出脱除铝土矿选矿尾矿中铁矿物的实验研究

对利用生物技术脱除铝土矿选矿尾矿中的铁矿物进行了实验,研究了各种浸出条件对脱铁效果的影响。结果表明:利用从矿山筛选得到的微生物发酵液对铝土矿尾矿进行浸出除铁,在85℃,液固比为10∶1,反应时间6 h的条件下,可除去尾矿中90%的铁,除铁后的尾矿可作为耐火材料的优质原材料。     

永平低品位原生硫化铜矿石细菌浸出条件研究

为回收利用永平铜矿废矿石中的低品位原生硫化铜矿资源，通过摇瓶实验，研究了接种量、初始Fe^2＋浓度、矿浆酸度、矿石粒度和矿浆浓度等条件对永平低品位原生硫化铜矿石细菌浸出的影响。研究结果表明：有利于铜浸出的条件是接种量20％，初始Fe^2＋浓度0g／L，初始pH值1．2，浸出过程控制pH值小于1．50，矿石粒度5mm，矿浆浓度20％～25％；溶液中三价铁含量过高或产生铁的沉淀都会直接影响细菌的浸矿效果；尽管浸矿细菌能很好地适应浸矿环境，但铜的浸出速度偏慢、浸出率偏低，有待于采取强化浸出措施。     

Effects of quartz addition on chalcopyrite bioleaching in shaking flasks

This paper studies the effects of quartz on bioleaching of chalcopyrite by Acidithiobacillus ferrooxidans, LD-1 through shaking flask experiments. The results showed that quartz concentration can affect the copper extraction. After 32 days, copper extraction of the leaching system at 50 g L⁻¹ quartz concentration increased by about 20%, compared with that of the leaching system without quartz. XRD analysis showed that the amounts of jarosite on the chalcopyrite surface may reduce by the mechanical friction action between fine particles of quartz and chalcopyrite. The analysis of SEM indicated that the surfaces of chalcopyrite particles were eroded by different degrees and the degrees of change were the same as the effects of quartz concentration on copper extraction.     

酸化预处理加快浸铀细菌生长速度

对铀矿石进行酸化预处理,然后菌浸。结合对照试验结果,酸化预处理有利于氧化亚铁硫杆菌和氧化硫硫杆菌对铀矿石的适应,可以加快其生长速度。