Study On Particle Size Evolution And Permeability Of Ore Heap Bulk Under Stress Chemical Coupling

The heap leaching method has the advantages of low cost,small pollution and simple and effective process,and is an effective and economical method for processing poor minerals,tailings,waste rock and other materials to extract useful components.In the process of heap leaching,the migration of the leaching solution and the solid liquid chemical reaction are two important processes,which are the key factors that affect the success or failure of the heap leaching process.The paper is carried out by the National Natural Science Foundation "heap leaching stress path and chemical replacement process granular ore heap mechanical properties Weakening Mechanism of" research of ore heap granular grain size distribution,stress,and chemical exchange reaction under the effect of sample particle level evolution and sample variation law of permeability coefficient,and then reveals the variation law of permeability coefficient in the sample with the action of mechanical chemical coupling.The following conclusions are obtained:(1)Conducted permeability tests of samples of different bulk gradations of ore bodies,by analyzing the change law of the permeability coefficient of the samples in different grading media,the relationship between the permeability coefficient of the media of the ore body and the particle size grading of the sample is obtained.Combining the change law of sample porosity with particle size grading,finally select the appropriate sample grading.(2)Selecting appropriate samples to carry out different axial stress and dead load tests on the samples of the mine bulk materials,the particle size evolution and permeability coefficient change of the granular sample under the action of stress was obtained,and the variation of the particle size and the permeability coefficient of the sample under different stress was compared,and then the relationship between the stress-grain level variation model and the stress-permeability coefficient change model of the ore bulk samples was obtained.(3)In order to study the influence of the chemical exchange process on the permeability of the bulk sample,the leaching tests under the different leaching time of pure water and dilute sulfuric acid were compared.The particle size and the permeability coefficient of the sample under different leaching time were obtained,and then the comparative analysis of the particle size evolution and permeability of the sample under different leaching time gave the model of the effect of chemical exchange on permeability.(4)Based on the relationship between the stress-permeability coefficient change model and the model of chemical exchange effect on the permeability coefficient,a permeability test of the stress-chemical coupling process was carried out,and the permeability coefficients of samples under different stress at different leaching times were obtained,and the change law of the permeability coefficient under coupling was obtained.The mechanism of the change of the permeability coefficient of the sample was described in conjunction with the evolution of the sample size.Finally,the correlation model of the stress-chemical-osmosis coupling process is obtained.