To study the effect of high temperature heating on the physical properties of benton-ite,MX-80 bentonite powder was subjected to 4 different temperatures(25,100,150,200 ℃)under heating for 30 days.The variations of physical properties such as specific gravity,limit water content and swell index of MX-80 bentonite were studied.On this basis,thermogravimetric analysis(TGA)test and X-ray diffraction(XRD)test were carried out to reveal the changes of physical properties and the microscopic mechanism of the MX-80 bentonite after being heated at high temperature.The experiment results show that the physical indicators(specific gravi-ty,limit water content,swell index)of MX-80 bentonite decreases with the increase of heating temperature.The temperature below 100 ℃ has little effect on the physical properties of ben-tonite,while the temperature at 150 ℃ and above has greater effects on the physical proper-ties.After being heated for 30 days,the montmorillonite content of MX-80 bentonite decreases,and a new mineral paragonite appears after being heated at 150 ℃ and 200 ℃ respectively,indi-cating the transformation of montmorillonite to paragonite in the soil after reaching a heating temperature of 150 ℃.After heating,the content of weakly bound water and strongly bound water absorbed by MX-80 bentonite decreases.The changes in the physical properties of MX-80 bentonite can be attributed to the transformation of montmorillonite to paragonite and the desorption of bound water in MX-80 bentonite after different temperature treatments.
维普
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