Study On Acid Leaching Performance Of A Sandstone Uranium Deposit By Final Residual Liquid

After the extraction of uranium resources in part of the mining area of the acid in-situ leaching mine,a large amount of acidic uranium-containing residual liquid in the mining area,and because the sediment cannot be repaired immediately,the high-contamination concentration residual liquid may spread to the surrounding area.Therefore,in this study,the main leaching performance of the residual liquid was studied,the residual value of the residual liquid residue was investigated,and the effective components were used for leaching.The article focuses on the leaching performance of residual liquid and groundwater to minerals under different process parameters such as acid concentration,oxidant,solid-liquid ratio,and leaching time,and studies the repeated leaching performance of residual liquid.By analyzing the mineralogical characteristics and leaching kinetic characteristics before and after leaching,the leaching mechanism is eliminated,and the theoretical basis is provided for the reuse of in-situ leaching uranium by acid method.The main research is as follows:The experimental results of the static leaching of uranium by the leaching solution of the residual liquid and groundwater showed that the optimal leaching rates of uranium by the residual liquid group and the groundwater group were 77.36%and 74.97%,respectively.Residual liquid reuse experiment results show that 1.0g/L H₂O₂ was added to the uranium ore during the first leaching.The leaching solution produced after leaching still has a good leaching effect on the uranium ore,and can be repeated 1-2 times without the need to repeat add H₂O₂ reagent.After repeated leaching of the residual liquid,the uranium concentration of the solution is increased,which is beneficial to the uranium extraction.The results of leaching kinetics of residual liquid and groundwater show that the leaching rate of uranium increases gradually with the increase of leaching temperature and leaching time.The shrinkage nucleus model was used to analyze the leaching kinetics.The results show that the residual liquid and groundwater are leached during the leaching process,that is,the leaching is controlled by both the chemical reaction and the diffusion control,and the apparent activation energy is 27.519 kJ/mol and Ea=21.649kJ/mol.The mineralogical characteristics before and after the leaching of the residual liquid and groundwater showed that there was no obvious sign of damage to the surface of the ore during the leaching of the residual liquid and groundwater.The single leaching of the ore had a low consumption of the components of the residual liquid.The ore is mainly composed of quartz,kaolin and feldspar gangue minerals with Si as the main element,and the structural form before and after the reaction hardly changes.The iron in the mineral is in the form of Fe₂O₃ as the main oxide,and generally the uranium-bearing ore in the ore is UO₂,and the residual liquid has the possibility of secondary leaching of the mineral.The above experimental research results show that the leaching of uranium ore by acid method still has a good leaching effect on uranium ore.Using the leaching solution to prepare leaching solution for uranium extraction in the nearby mining area can not only reduce the cost of leaching Moreover,it can reduce the risk of contaminated groundwater diffusion in decommissioned mining areas and the cost of groundwater remediation at a later stage,and has high practical application value.