Preparation And Thermology-mechanics Properties Of Filling Material Based On Mine Tailing With Heat Storage Function

With the continuous development of mining depth from shallow to deep,the problem of high ground stress,high ground heat and heat hazard in deep mining is becoming more and more prominent;at the same time,after a lot of mineral resources were exploited,the abandoned goaf was not filled in time,this results in a series of geological disasters due to the collapse of the goaf.How to develop and utilize abundant geothermal resources in order to alleviate the problem of thermal hazard in deep filling mining,the idea of heat storage and filling mining is put forward in this paper.The paper takes the paraffin as the heat storage material,and takes the filling body with heat storage function as the research object the rheology experiment of filling material based on the tailings,the mechanical and thermal properties experiment of filling body were carried out.The influence of slurry concentration?heat storage material quantity and cement-sand ratio on the mechanical and thermal properties of filling body was analazied by experimental results.The results of the study show that:(1)When the filling slurry concentration is constant,the yield shear stress and viscosity of slurry increase with the increase of heat storage material quantity;The yield shear stress and viscosity of slurry increase with the increase of slurry concentration when the heat storage material quantity is constant.When the heat storage material is not added,the fluid obeys the law of power law.When the rate of heat storage material is less than 10%,the fl uid obeys the Bingham flow pattern.When the rate of heat storage material is more than 10%,the fluid obeys the Hershel-Bulkley model.(2)when the heat storage material quantity is constant,the strength of filling body increases with the increase of filling slurry concentration,and the rate of heat storage material is 5%.As the slurry concentration increases from 68%to 72%,the compressive strength of filling body increases from 0.434MPa to 2.198MPa,which is due to the porosity,and the fractal dimension of porosity decreases gradually with the increase of the slurry concentration.When the slurry concentration is constant,the strength of the filling body decreases with the increase of heat storage material quantity.The concentration of the slurry is 70%,with the rate of heat storage material increasing from 0%to 10%,the compressive strength of filling body decreases from 1.419MPa to 1.089MPa,which is due to the porosity,and the fractal dimension of porosity increases gradually with the increase of heat storage material quantity.(3)When the slurry concentration is constant,the specific enthalpy and specific heat capacity of filling material increase with the increase of heat storage material quantity;the phase change temperature is 30?,the slurry concentration is 70%,when the rate of heat storage material increases from 0%to 10%,the CP of filling material increases from 1.126 J/(g·?)to 1.234 J/(g·?);the slurry concentration is 72%,when the rate of heat storage material increases from 0%to 10%,the melting heat increases from 61.1 J/g to 75.77J/g.When the heat storage material quantity is constant,the specific heat capacity and specific enthalpy of filling material increase with the increase of slurry concentration;when the phase change temperature is 30?,the rate of heat storage material is 5%,when the slurry concentration increases from 68%to 72%,the CP of filling material increases from 1.151 J/(g·?)to 1.193 J/(g·?);the rate of heat storage material is 10%,when the slurry concentration increases from 68%to 72%,the melting heat of filling body increases from 46.36 J/g to 75.77 J/g.Based on the results of this experiment,through the orthogonal test,when the slurry concentration is 72%,the rate of heat storage material is 10%,the cement-sand ratio is 1:6,the filling body with heat storage function has good thermal and mechanical properties,which not only meets the strength requirements of filling body in mining,but also has good thermal storage performance,it lays a good theoretical foundation for cooperative mining of mineral resources and geothermal resources.