Study On Strength Characteristics And Mechanism Of Improving Tin Ore Tailings Silt By Curing Agent

With the gradual increase in the mining volume of minerals,more and more tailings are discarded in the process of beneficiation.However,the tailings are mostly stored in the form of tailings silt dams,which not only causes a waste of resources,but also buried them.The hidden dangers of safe production and ecological environment caused by the dam break.Therefore,improving the strength of the tailing silt sand by the curing agent is not only beneficial to improve the stability of the tailing silt dam,but also can use the improved tail silt sand in other fields,thereby turning waste into treasure,in terms of safety and environmental protection.All have very important theoretical value and engineering significance.In this paper,through the unconfined compressive strength test,direct shear test,and variable head penetration test,the strength characteristics of inorganic composite curing agent,epoxy resin curing agent,and SCA curing agent modified tail silt sand are obtained,combined with X-ray diffraction(XRD)and X-ray fluorescence spectroscopy(XRF)methods to obtain sample chemical elements and compound types,and then use scanning electron microscope(SEM)and energy spectrum analysis(EDS)to explore the sample's microstructure and typical positions The content of chemical elements leads to the mechanism of different curing agents to improve tailing silt.The main research work and achievements of this paper are as follows:(1)For the modified tail silt samples of inorganic composite curing agent,epoxy resin curing agent,and SCA curing agent,the unconfined compressive strength test and direct shearing under the conditions of different curing time and curing agent mixing ratio were carried out.Tests and permeation tests with variable heads showed that: with the increase of curing time,the compressive strength,shear strength,and impermeability of the three curing agents improved tailing silt sand have all increased,but the increase in the strength of the sample is lower.There are differences in the required curing time;with the increase in the mixing ratio of the three curing agents,the compressive strength,shear strength,and impermeability properties of the samples are also improved to varying degrees.Among them,the slag and cement in the inorganic composite curing agent increase The influence of the strength characteristics of tailing silt is more significant.(2)Analyze the chemical element content and compound types of the modified tail silt sand by XRD and XRF,observe its microstructure characteristics with SEM,and use EDS to analyze the element content in the typical positions of the sample,so as to explore the mechanism of the curing agent to improve the tail silt sand The results show that the three curing agents can obviously improve the integrity of the internal structure of the tailing silt sand and fill the pores between the tailing silt particles.But the curing mechanism and effect are not the same.The inorganic composite curing agent can generate a large amount of gel and mineral crystals through the hydration reaction of cement,slag powder,slaked lime,etc.The epoxy resin curing agent can directly adhere to the tailing silt particles,and SCA curing The agent mainly relies on the hydration reaction of cement and slaked lime,and it can only promote the reaction by ion replacement.