| With the development of exploitation for gold ore, the ore which is ease to distill is dring up. Refractory gold ore is the main resource of gold industry at present. Being enwrapped by the arsenopyrite (FeAsS) or pyrite, gold is difficult to be distilled directly by using traditional technology. It is widely accepted that certain bacteria play a mayor role in most leaching operations for metal sulfides. One of the most important bacteria in the sulfide leaching is an acidophilic chemoautotrophic bacterium, Thiobacillus ferrooxidans, which can multiply with mineral sulfide.Three refractory gold-ore which are the refractory mineral of Dongbeizhai, the refractory mineral of metallurgy bureau Xinan and the refractory mineral of Guangxi.were studied. The main element iron, sulfur and arsenic were analyzed for each refractory mineral. Six kinds of Thiobacillus ferrooxindans in lab were used to decompose each refractory gold-ore. GerY was the optimal T. ferrooxindans for refractory mineral of metallurgy bureau Xinan. The inoculated ratio 100% WV and pH = 2.0 were the optimal parameters for the dissolution of Dongbeizhai refractory gold-ore under the conditions of temperature 34℃ and shaking rate 180r/min. The reactor which was an air sparged and stirrer agitated vessel of 6L was designed. The reactor was operated batchwise with respect to the liquid. Technologic parameters which were the stirring rate 650r/min , air flow O.lL/min.L ,pH = 2.0 , solid—liquid ratio W0/V 50g/L were confirmed and the liquid temperature 34℃. Each experimental results were analyzed theoretically and reasonable explanation weregiven.The most important part of this paper is the study for the kinetics of Guangxi refractory gold-ore. The kinetics of the bacterial dissolution of Guangxi refractory gold-ore particles by Thiobacillus ferrooxindans was studied at different particles sizes in a well-mixed batch reactor. Experiment studies were made on the adsorption of bacteria on Guangxi refractory gold-ore particles as well as the bacterial dissolution of the ore. the adsorption data was well fit the Langmuir isotherm equation . The equilibrium constant KA =2.37 X 10~-15m3/cells in the Langmuir equation was independent of the particle size, whereas the maximum adsorption capacity per unit weight of the ore KAm increased with derived, taking into account the effect of initial particle size. Eh, the rate of iron extraction and the growth of T.ferrooxidans in the liquid phase were studied in the fixed condition of pH=2.0, air flow 0.1L/min.L, rotate speed of stirrer 650r/min , solid—liquid ratio Wo/V 50g/L and temperature 34°C The kinetic parameters appearing in the rate equation, the growth yield of Fe2+ YL =3.51 X 1014 cells/kg ,the growth yield of ore YA=1.04X 10~14cells/kg-ore and specific growth rate uA=1.79d~-1of adsorption bacteria, were evaluated by curve-matching, using the experimental data obtained at different initial particle sizes. The constant about the maximum adsorption capacity per unit surface of the ore Xam / =4.32 X 10~8 cells m/kg was acquired. The coefficient of growth K =0.18 X 106D0 is pertinent to the initial particle size. The evaluated kineticparameters were found to be independent to the particle size. Langmuir equation applying Guangxi refractory gold ore:The kinetic model was successfully used to predict the bacterial dissolution behavior for the dissolution rate by using the method of Runge-Kutta..
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