金矿的细菌浸出处理研究

Bacterial leaching of refractory gold ore

利用细菌对难处理金矿进行浸出处理,具有成本低廉、环境污染小、处理效率高等突出优点,已成为非常有前途的难处理金矿的预处理方法。笔者以河北遵化滑石峪金矿(含金黄铁矿)样品为例,在几种氧化亚铁硫杆菌中发现D3菌种处理此类难浸金矿有显著的增大提金率的效果。在200目粒度条件下,氰化提金率从单纯氰化的63.9%提高到细菌预处理后再氰化的88.2%,而且对100目以下的大粒度金矿,提金率也普遍提高10%以上;此外,还进行了该菌种处理金矿过程的条件实验,如粒度影响、pH值变化和物理方法强化的研究,得出了金矿在细菌氧化过程中的一些规律和在实际操作时的最优化控制条件。

The leaching pretreatment of refractory gold ores by bacteria has advantages of lower operating costs, less environmental pollution and higher efficiency of treatment. So it is considered to be a promising effective method for pretreatment of refractory gold ores. In this study, samples were taken from the Huashiyou gold deposit, Zunhua, Hebei. The samples are refractory ore, a kind of pyrite containing gold. Several strains of Thiobacillus ferrooxidans were used in pretreatment of the samples. Among those, D3 strain was found to decompose sulfide ores effectively. If the size of the ore is 200-mesh, the cyanidation rate of gold rises from 63.9 （without biooxidation ） to 88.2% （after biooxidation）. For gold ore with a grain size 〈 100 mesh, the cyanidation rate of gold may also generally rises 〉10%. In addition, some conditional experiments for the process of treatment of gold ore by this strain were also performed; for example, the size influence, pH change and strengthening of the physical method were studied. Some rules in the biooxidation process of gold ore and the optimum controlling conditions during practical operations were obtained from the experimental results.