Experimental Study On The Water-Absorbing Process Of Mudstone Containing Clay Minerals Based On Water Chemical Solution

The main environment of coal mining is the sedimentary stratum of many kinds of shale formations.Containing clay minerals argillaceous roadway erosion with highly mineralized mine water leads to the destruction of the supporting structure,and seriously affecting the safety of the mine supporting.So predicting mudstone water absorption dynamic process is fundamental guarantee of safety control of roadway surrounding rock.The typical mudstone water absorption,water absorption model and the gradual characteristic and the effect of clay minerals content,the nature of the solution were studied by XRD test,water absorption experiment,orthogonal experiment and construction of the model and theory analysis.Main conclusions are as follows:（1）The water absorption process of typical mudstone was studied by special sample preparation,XRD analysis and water absorption experiment.Typical mudstone water accords with negative exponential function.Clay minerals type,content,sample size,the natural moisture content,porosity and solution properties are the key factors affecting mudstone water absorbing capacity,moisture content and water absorption rate.（2）The water absorption model and water absorption rate model were constructed by orthogonal experiment,and the water absorption curve is divided into stages.Themudstonewaterabsorbingcapacitymodelis Q（28）Q₀（10）A₁ e^{-t k}1（10）A₂ e^{-t k}2（10）A₃ e^{-t k}3.According to the model parameters（attenuation coefficient）,the curve is divided into four stages:instantaneous water absorption segment,ultra-fast absorption segment,rapid water absorption segment,and slow water absorption section.the mudstone water absorbing rate model is v（28）v₀（10）2M?p′w?é_?4（7）t-t_c（8）²（10）w²ù_?,and divided into four stages according to the trend:the process of sudden increase,the sudden drop,the buffer segment and the stable segment.（3）Through the intuitive analysis,the influence of seven factors and three levels on the water absorption process of the mudstone was analyzed,and the most influential horizontal combination was obtained.Various factors the influence degree of the whole process of mudstone water quantity curve is pH value,clay type,degree of compaction,clay content,cationic,solution concentration and the anion,and the horizontal combination of illite,content of 70%,degree of compaction of 5 MPa,cationic for Na⁺,anionic for CO₃^2-,solution concentration of saturated solution,pH value of 7 has biggest influence on mudstone water quantity.Various factors the influence degree of the whole process of mudstone bibulous rate curve is pH value,clay content and clay types,anionic,degree of compaction,solution concentration and the cation,and the horizontal combination of illite,content of 30%,degree of compaction of 15 MPa,cationic for K⁺,anionic for Cl^-,solution concentration of 0.1mol/L,the pH value of 7 has biggest influence on the rate of mudstone water absorption.（4）Through the real-time monitoring of the sample wave velocity,height and diameter,the pH value and temperature of the solution,the environmental temperature and humidity,the mechanism of the water absorption process of mudstone was revealed.Basic parameter of the curve range and direction information are the keys to the dynamic variation character of mudstone water absorption,are the foundations of analysis of porosity change,particle arrangement,clay minerals content,physical and chemical reaction.