Fundamental And Industrialization Investigation On Biooxidation Of Arsenic-bearing Refractory Gold Ore

The investigation is made for oxidation mechanism of microbes mainly mesophilic thiobacillus ferrooxidans, thiobacillus thiooxidans and leptospirillum ferrooxidans for sulphide minerals and the function of various factor affected the biooxidation system. According to the growthing characteristics of mesophilic bacteria and physical chemistry characteristics of sulphide minerals, making use of changes of various factor in biooxidation system, and the systematical research and investigation are made for a refractory arsenic-bearing and gold-bearing sulphide ore. The investigation also is made for an industrialized biooxidation plant.The microcosmic mechanism of biooxidation and chemical oxidation for pyrite and arsenopyrite have been investigated and discussed. A selectivity contact biooxidation model is put forward.In the investigation of the four-phase biooxidation system, the factors those closely related to the operation of biooxidation system such as crystal structure of minerals - crystal lattice energy, bond energy et al, and physical and chemical factors - pulp temperature, oxygen content in pulp, carbon dioxide content in pulp, pulp density, particle size in the pulp, shearing strength et al, and electrochemistry factors - content of Fe2+, Fe3+, content of As3+, As5+, the capacity of difference bacteria onFe2+ oxidation et al, are investigated and analysed. Some of new explains and viewpoints also are given by author.Thiobacillus ferrooxidans and Thiobacillus thiooxidans were separated from the test bacterium, but no Leptospirillum ferrooxidans discovered. Leptospirillum ferrooxidans have more high capacity of oxidation for Fe2+ than Thiobacillus ferrooxidans, there is no Leptospirillum ferrooxidans in the test bacterium maybe is the main reason for lower Eh in the pulp.The theoretic analysis for the factors those influence biooxidation system in industrialization plant such as proportion of different minerals in the feed of biooxidation system, mol ratio of iron ions and arsenic ions in the biooxidation system, thermal equilibrium in the biooxidation system, oxygen and carbon dioxide equilibrium in the biooxidation system, solid materials equilibrium in the biooxidation system et al, are\carried out systematically. The cyanide leaching principle and process for biooxidation residue are also analysed and deduced theoretically.The industrialization of biooxidation system is expatiated in the paper. The high-efflcieny and energy-saving biooxidation reactor, multi-holes oxygen-resolving and shear-distributing agitation system, harmful ions separating system after biooxidation, biooxidation waste liquor neutralization system, assistant system for biooxidation system, industrial security of microorganism and environment protection, et al, all those areIVdiscussed in detail in the paper.The problems met in the industrialization biooxidation plant that is set up by Chinese own technology had been solved by the systematically investigation for a variety of factors which effect on biooxidation of arsenic-bearing refractory gold ore. The biooxidation technology is practical and successful in China.