Bioleaching Process Test And Preliminary Study On Leaching Mechanism Of Mixed Uranium Ore From XiangShan Uranium Mine

Compared with the traditional methods,the technology of bioleaching of uranium has the advantages of less investment,low acid consumption,little environmental pollution and simple process,more and more favored by researchers.This paper studied the effect of different factors on uranium ore leaching,from spray intensity,the amount of bacterial inoculation and iron concentration and other aspects analyzed the leaching regularity and leaching effect of uranium ore,discussed the mechanism about the effection of immerse solution with uranium ore.Specific research contents and results were as follows:The spray intensity test showed that,leaching in 108 th days,the cumulative leaching rate of uranium about 5%,10%,15%,20%,25% spray intensity were 80.97%,81.54%,91.40%,89.27%,81.83%,the slag leaching rate were 82.2%?88.5%?90.9%?88.35%?87.55%,the cumulative acid consumption rate were 8.58%?10.42%?11.13%?12.11%?13.27%.Considered the acid leaching cycle,total acid consumption rate and cumulative leaching rate of uranium,the best leaching effect was 15% spray intensity.The amount of bacterial inoculation test showed that,the leaching concentration of uranium and the leaching rate of uranium increased with the increase of the amount of bacterial inoculation,while the increase amplitude of uranium leaching concentration and uranium leaching rate began to decrease in 30% bacterial inoculation.Therefore,it was beneficial to the leaching of uranium to appropriate increase the amount of bacteria inoculation.The iron concentration test showed that the leaching concentration of uranium and uranium leaching rate of 9g/L Fe²⁺ were lower than 5g/L Fe²⁺ and higher than 3g/LFe²⁺,the bacterial activity and leaching effect of 5g/L Fe²⁺ was the best.The leaching concentration of uranium and uranium leaching rate of 9g/L Fe³⁺ had little difference with 5g/L Fe³⁺.The higher the concentration of Fe³⁺ ion,the lower the activity of bacteria,which was not conducive to the interaction between bacteria and minerals,so the concentration of Fe³⁺ ion should not exceed 5g/L.Selected before and after leaching test samples based on the analysis of SEM?EDS and XRD.Studied on the mechanism about the effect of immerse solution with uranium ore showed that,the surface of primary sample was smooth,complete structure,no crack and pit,mainly contained K,Ca,Si,Na,Al,O and other elements,quartz?SiO₂?,albite?NaAlSi3O8?,anorthite?CaAl2Si2O8?,potassium feldspar?KAlSi3O8?,anorthoclase??K,Na?AlSi3O8?and other minerals.With the action of immerse solution,ore surface had different degree of corrosion damage and ore components changed significantly,in addition produced gypsum?CaSO4·2H2O?and jarosite?KFe₃?SO₄?₂?OH?6?which caused the hardened of uranium ore.