Leaching Settlement And Consolidation Of Tailings And Risk Of Dam Breaking In Tailings Reservoir

The growth of tailings is accompanied by the whole production process of the mine,and the stability of tailings dam is a problem that must be paid attention to in the production process of the mine.After the tailings are discharged in the form of slurry through the ore drawing pipe,they pile up in the tailings dam and deposit and consolidate continuously.In the safety management of the actual tailings reservoir,the stability of the tailings reservoir is usually maintained by adding a certain concentration of flocculant to speed up the settlement and consolidation rate of tailings and rapid drainage.In fact,because of the difference of the tailings' characteristics,the tailings of different grain size show different laws in the process of sedimentation and consolidation,which directly affect the stability of tailings dam.Therefore,the research on the law of sedimentation and consolidation of tailings has important academic value and engineering significance for understanding the dam-break mechanism of tailings dam fundamentally.The paper takes a vanadium-titanium magnetite mine tailings reservoir in Chengde City,Hebei Province as the research object,through the collection of information to obtain the geological environment background,the tailings reservoir evolution history,and the relevant overview of the tailings reservoir engineering.Bring the tailings back to the laboratory,through the particle size distribution test,one-dimensional sedimentation test,field emission electron microscopy scanning test,consolidation test to understand the tailings in the process of sedimentation and consolidation of the relevant characteristics,understand the process of sedimentation and consolidation of tailings dam stability.In order to evaluate the dam-break risk of tailings dam,fuzzy comprehensive evaluation method is selected to evaluate the dam-break risk of tailings dam,and it is found that the relationship between the degree of danger and the degree of vulnerability can not be reflected intuitively.The main research results and conclusions are as follows:(1)By observing the micrographs of different magnification,the shape of the tailings particles,the contact relationship between the particles,the material and structure of the particle surface were observed.From the microscopic point of view,the charge of fine tailings particles attract each other,which is easy to form flocs in the tailings solution,resulting in poor permeability of the whole tailings and strong water retention capacity,which is not conducive to the stability of tailings dam.(2)Through the one-dimensional sedimentation test,it is considered that the main deposition of the tailings with particle size less than 0.075 mm is flocculent net deposition,and the sedimentation curve of the tailings is obtained by using Origin software.Theinfluence of tailings deposition on the stability of tailings dam in the reservoir area is summarized.(3)Through the one-dimensional consolidation test,it is found that the tailings is a medium compressible soil,and the consolidation coefficient of undisturbed tailings increases first and then decreases with the increase of consolidation pressure,and is negatively correlated with water content;The relationship between the compressibility of tailings and particle size shows that the compressibility of tailings with particle size less than 0.075 mm is better than that of the others.Based on the one-dimensional consolidation test results of the tailings sample,some engineering suggestions are put forward to improve the stability of the dam.(4)Using the fuzzy comprehensive evaluation method and the fuzzy coordinate method derived from the fuzzy comprehensive evaluation method,both of the evaluation results are moderate risk,but because the fuzzy coordinate method can highlight the relationship between vulnerability and risk,it is considered more objective.