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业已发现 ,在矿石浮选过程中 ,细菌的选择性活性也可以由细菌分泌出的外细胞聚合物 (EPS)获得。EPS可由细菌培养液离心分离得到。使用它可显著降低氰化物用量 ,目前选矿作业的氰化物用量大约为 2 0万t/a。所用的细菌是嗜酸的氧化亚铁硫杆菌。为了鉴别细菌的氧化活性范围 ,选择从汉堡大学菌株收集中心得到的 2 0种菌株在特定条件下对硫酸亚铁和黄铁矿进行氧化研究。结果表明 ,所有这些菌株对硫酸亚铁的氧化速度是对黄铁矿氧化速度的 10倍。目前 ,EPS是从 4种菌株中提取的。EPS提取物一般分为亲水部分和疏水部分。亲水部分由岩藻糖、李鼠糖和葡萄糖等糖化合物组成 ,在疏水部分中发现了十二烷基酸、十六烷基酸和十八烷基酸等脂肪酸。分别采用纯矿物和矿物混合物进行浮选试验。与现有了解的情况相反 ,用工业浮选设备获得的结果具有较好的重现性
It has been found that the selective activity of bacteria during ore flotation can also be obtained from exocytose polymers (EPS) secreted by bacteria. EPS can be centrifuged by bacterial culture solution. Using it can significantly reduce the amount of cyanide used, the amount of cyanide used in beneficiation operations is currently about 200,000 t / a. The bacteria used are acidophilic Thiobacillus ferrooxidans. In order to identify the range of bacterial oxidative activity, 20 strains of strains obtained from the Hamburg University Collection Center were selected to oxidize ferrous sulfate and pyrite under specific conditions. The results showed that all of these strains oxidized ferrous sulfate at rates 10 times faster than those of pyrite. Currently, EPS is extracted from 4 strains. EPS extract is generally divided into hydrophilic part and hydrophobic part. The hydrophilic part is composed of sugar compounds such as fucose, plumose and glucose, and fatty acids such as dodecyl acid, hexadecyl acid and stearyl acid are found in the hydrophobic part. Flotation tests were carried out using pure mineral and mineral mixtures respectively. Contrary to what is currently known, the results obtained with industrial flotation equipment show good reproducibility