Research And Application Of Ultra-fine Tailings Aggregate Content In Mine Filling

Aiming at the actual engineering demand of a lead-zinc mine,a series of research and analysis and practical application of ultrafine grained tailings aggregate filling body are carried out in this paper.In the early stage,through consulting data and field investigation,this paper studies the latest research results of slag powder and superfine tailings at home and abroad,and puts forward the idea of replacing cement with some slag powder.The physicochemical properties of various materials were analyzed,the setting time index of new cementitious materials was tested,and the influence of superfine grained tailings on each component was investigated by high ratio cementitious system.The feasibility of superfine grained tailings cemented by slag powder was preliminarily explored.In the laboratory test,the orthogonal test is carried out by setting different ratios,and according to the requirements of the mine,the parameters that meet the quality requirements of the mine house and the column are selected and have economy.According to ideal parameters and combined with mine filling system,the working performance of new cementitious materials is studied.The feasibility,reliability and economy of the new cementitious material in the process of tailings filling are further verified and optimized by comparing with the indoor test.The details are as follows:(1)According to the research results of previous projects and the experience of traditional industrial filling in mines,the initial setting time,strength and fluidity of on new cementitious materials suitable for ultrafine grained tailings,and the initial setting time,strength and fluidity were observed.and the setting time of the filling body with low sodium sulfate content is shortened with the increase of sodium sulfate concentration,and the effective ratio is 1%?4%,respectively.Finally,the ratio of cementitious material is determined :70%cement,30% slag powder,plus 4% sodium sulfate and 0.1% polycarboxylic acid water reducer.(2)The effects of superfine-grained tailings on the slurry cleaning and filling of new cementitious materials were investigated by using a high ratio cementitious system.When the content of superfine tailings is not more than 20%,the superfine tailings play a nucleation effect,produce a large number of cementitious products and fill them into the pores of the structure.The maximum strength can reach 16.5 MPa;the superfine tailings are added to the filling body,and the particle size gradation of the slurry is optimized.The optimum mixing ratio is 10% and the diffusion degree is 295 mm..Table 2 When the content ratio of superfine grained tailings exceeds 20,the system deviates from the closest accumulation and the strength decreases because of the large increase of ultrafine grained tailings.(3)In view of the actual engineering requirements,the indoor tests were carried out by using pure ultrafine grained tailings aggregate and graded / ultrafine grained mixed tailings respectively to explore the adaptability of new gel materials to different tailings and the strength test of filling body.The scope of the test was expanded.considering the data fluctuation caused by a large number of uncertain factors in the industrial test,a certain diffusivity and strength allowance are retained on the premise that the fluidity,28 d age strength meet the experimental objectives.finally,the filling parameters of new cementitious materials of different tailings types that can be used in industrial tests of different stope are determined.(4)With the help of the mine filling system,the industrial test is carried out according to the parameters determined by the indoor test,and the flow degree and strength of the field test block are tested.During field sampling,the average diffusivity is 306 mm,which meets the requirements of pipeline transportation,and the new cementitious material can adapt to the filling system of mixing building.The average strength of the test group meets the strength requirement of 28 d,and the strength allowance is sufficient.(5)The cost calculation and analysis of new cementitious materials are carried out.By comparing the direct economic benefits of new cementitious materials with cement filling materials,only the cost of filling materials is calculated.Using new cementitious materials can reduce the amount of filling materials by 34% per year,and the cost drop is close to 26%.Can directly save filling cost of more than 936 million yuan per year.