三种硫化铁单矿物的细菌氧化过程研究

Study on the Bio-oxidation Process of Three Single Iron Sulfide Minerals

载金的硫化铁矿物成分主要是黄铁矿,其次是磁黄铁矿和镍黄铁矿.三种单矿物分布在金矿石中的含量不同,细菌氧化周期也随之改变.试验表明,三种矿物氧化过程均产酸,黄铁矿被细菌直接氧化,溶液中细菌浓度较小;磁黄铁矿和镍黄铁矿除受细菌直接氧化,被Fe3+间接氧化也很显著.黄铁矿氧化时间大致是其他两种矿物的3倍,因而工业配矿可酌量降低富含黄铁矿之金精矿用量.本试验通过研究三种单矿物各自的细菌氧化过程,为成分复杂金精矿的细菌浸出工业实践提供了重要理论依据.

There are three iron sulfide minerals involving in gold-bearing ore, which take part in the process of microbial leaching, i.e. pyrite, pyrrhotite and pentlandite in order of gold content. And their bio-oxidation durations are therefore different because of their different distributions in gold-bearing ores. Experimental results showed that all of three minerals produced acidic substance, such as H2SO4. Pyrite is direct oxidized by bacteria and the cell content in solution is less than the other two minerals. Both pyrrhotite and pentlandite are also oxidized by Fe^3＋ besides direct bio-oxidation. Pyrite is more resistant to oxidation than the other two and its durability for oxidation is 3 times as long as that of the other two under the same conditions. It follows that the pyrite-rich gold concentrate should be less used in industrial applications. The bio-oxidation processes of the three single minerals were individually observed and analyzed, and their results can provide important data for reference to microbial leaching practice of complex gold concentrates.