Research Of The Effect Of Acidification On Tailings And Fluid-solid Coupling Analysis Of Tailings Dam

Whether the tailings dam is safe and stable is directly related to the safe operation of mining enterprises and the safety of life and property of the downstream people.Tailings sand,as the raw material of tailings dam,is oxidized and produced acidic waste water due to the interaction of various complicated factors during storage,tailings of the mineral composition,physical and mechanical properties are corresponding changes,the stress field,seepage field of tailings dam will also change with the tailings acidification.In this paper,the chemical mechanism of tailings acidification and its influence on tailings was analyzed.The dynamic immersion test was used to carry out chemical immersion of tailings sand for 96 h,and the tailings sand after soaking was subjected to the Standard geotechnical tests to study the changes of mineral composition and physical and mechanical properties of tailings sand under different oxidizing degree of tailing(0,25%,50%,75%,100%).The numerical simulation method was used to analyze the fluid-solid coupling deformation of tailings dam under tailing acidification condition.The main research results and conclusions are as follows:(1)Tailings are acidified by the presence of sulfide,and its acidification will cause the chemical and physical movement of tailings such as oxidation-reduction,dissolution,precipitation,ion exchange,adsorption-desorption.These chemical and physical effects will lead to a complex change in mineral composition and physical and mechanical properties of tailings.(2)The dynamic immersion test of hydrogen peroxide for tailings was carried out,mineral composition testing,particle analysis,specific gravity test,maximum dry density test,shear strength test and infiltration test were carried out before and after soaking.(The sulfide),the more insoluble salts are dissolved,the more the fine particles are,the greater the specific gravity,the smaller the maximum dry density,the lower the shear strength,and the smaller the permeability coefficient.(3)GeoStudio numerical simulation software is used to analyze the flow and solid coupling.The simulation results show that the greater the degree of oxidative acidification,the higher the horizontal direction,the vertical direction and the overall deformation,and the lower shear strength.