Study On Mixture Ratio Design And Mechanics Performance Test Of Extreme Fine Sand Mine Filling

With the continuous development of national economy and the increase of demand for coal,in order to solve the problem of "three under" pressure coal,coal mining technology has also met with new challenges.Because the traditional coal mining technology has the problem of high cost,low efficiency and severe resource waste,and can not effectively control the surface subsidence,many filling mining technology are developed at home and abroad.Due to coal mine filling using pumping technology,filling material requirements should have good liquidity,initial setting time is not less than 2h,final set time cannot longer than 8h.In order to ensure that filling body effective support to overburden,ensure a safe and effective filling,the compressive strength to meet the requirements.This article use the extreme fine sand,fly ash,425 ordinary Portland cement,and three kinds of additive preparation coal mine filling material meet the requirements of and study the mechanical properties of the filling body.The main content of the experiment includes: Using orthogonal table arrangement experiment.According to the requirements of filling mining technique to fill material,study the influence on filling slump,initial set time,final set time,filling body 28 days compressive strength of cement dosage,fly ash content and quality of slurry concentration,water reducing agent dosage,exciting agent dosage and the coagulant dosage.Through the analysis of the results of the orthogonal experiment,obtain the influence laws of six factors on the filling three indicators,finding out the main factors influencing the test result,and the influence trend of various factors level changes on three test index.Do variance analysis of the test result.The optimal mix proportion is Cement 400 kg/m3,fly ash 400 kg/m3,slurry concentration 80%,water reducing agent 10 kg/m3,and excitation agent dosage 10 kg/m3,dosage of is coagulant 100 kg/m3.Using SPSS software to do regression analysis between slump(x)of filling pulp and slurry consistency(y).It is concluded that the slump of the slurry and slurry consistencyvalue highly positive correlation,and the correlation coefficient is 0.946.Do linear regression analysis,the regression equation between the two variables is y = 0.3x + 2.887,and regression effect is remarkable.Research mechanics performance of filling body include compressive strength,splitting tensile strength,flexural strength and modulus of elasticity.Analysis the correlation of compressive strength and the elastic modulus filling body.It is concluded that there is a highly positive correlation relationship between compressive strength(x)and elastic modulus(y) of the filling body.