Biotreatment of Sulfide Mineral Using Bacteria Associated with the Sulfur Cycle

在这份报告中，我们描述了一种硫化矿物（闪锌矿和黄铜矿）的生物湿法冶金处理，其中硫循环（金属硫化物→硫酸盐→硫化氢→元素硫）是人工构建的，使用与硫循环相关的几种细菌，并利用微生物硫转化从硫化矿物中浸出有价金属和用于生物浸出残渣的后处理。在硫氧化细菌浸出硫化物的实验中，嗜酸嗜热菌Acidianus brierleyi比常见的嗜温浸出细菌氧化亚铁硫杆菌（Thiobacillus ferrooxidans）对硫化物的溶解速度更快。在生物下游处理中，通过使用硫酸盐还原菌如脱硫弧菌（Desulfovibrio desulfovicans）和普通脱硫弧菌（Desulfovibrio vulgaris）将浸出溶液中积累的硫酸盐离子生物还原为硫化氢。在此之后，生物硫化氢被氧化为元素硫， ...更多信息 将所形成的元素硫作为沉淀物回收。在金属回收操作中，海藻酸的凝胶珠可以用作生物聚合物吸附剂，用于收集富集溶液中溶解的金属。由于海藻酸凝胶对重金属离子的吸附强烈依赖于溶液pH，当溶液pH降至1.0时，所有收集在凝胶相中的重金属离子都完全释放到液相中。通过硫化氢将硫酸盐生物转化为元素硫，以及通过生物聚合物珠回收重金属。速率数据表明，生物浸出过程是速率决定步骤（最慢的步骤），在拟议的生物处理过程。在确定为用刺曲霉进行生物浸提的最佳条件下，花费一周时间从闪锌矿和黄铜矿中实现有价值金属的高提取率（大于80%的浸提）。少

In this report we describes a biohydrometallurgical treatment of sulfide minerals (sphalerite and chalcopyrite), in which the sulfur cycle (metal sulfide → sulfate → hydrogen sulfide → elemental sulfur) is artificially constructed using several bacteria associated with the sulfur cycle, and the microbial sulfur transformations are utilized for the leaching of valuable metals from sulfide minerals and for the post-treatments of the bioleaching residue. In the sulfide leaching with sulfur-oxidizing bacteria, the acidophilic thermophile Acidianus brierleyi was found to solubilize the sulfides much faster than the common leaching mesophile Thiobacillus ferrooxidans. In the biological downstream processing, sulfate ions accumulated in the leach solution were biologically reduced to hydrogen sulfide through the use of sulfate-reducing bacteria such as Desulfovibrio desulfuricans and Desulfovibrio vulgaris. After that, the biogenic hydrogen sulfide was oxidized to elemental sulfur using photo … More trophic bacterium Prosthecochloris aestuarii, and the formed elemental sulfur was recovered as a precipitate. In the metal recovery operation, gel beads of alginic acid could be used as a biopolymer sorbent for collecting dissolved metals in the pregnant solution. Because the sorption of heavy metal ions by the alginic acid gels was strongly dependent on the solution pH, all of the heavy metals collected in the gel phase was completely released into the liquid phase when the solution pH was decreased to pH 1.0.Batch tests were conducted to obtain rate data and optimize various process parameters for the individual bioprocesses such as the bioleaching of sulfide mineral, the bioconversion of sulfate to elemental sulfur via hydrogen sulfide, and the recovery of heavy metals by the biopolymer beads. The rate data indicated that the bioleaching process was the rate-determining step (the slowest step) in the proposed biotreatment process. Under the conditions determined as optimum for the bioleaching with A.brierlery, it took a week to achieve high extractions (greater than 80% leaching) of valuable metals from sphalerite and chalcopyrite. Less