Experimental Study of Coal Sample Damage in Acidic Water Environments

Abstract We investigated the effects of acidic and circumneutral water on coal samples by uniaxial compression, acoustic emission, a series physical tests. In water, were damaged, their ultrasonic velocities decreased, as minerals such kaolinite calcite underwent dissolution. When pH was < 7, compressive strength elastic modulus while duration residual stage tended to increase. The reactions stronger at higher H + concentrations number large pores increased; there significant increase in accumulated emission counts maximum average energy near unstable crack growth stage. post-peak characterized different waters failure modes identified spectrum analysis. Acidic damaged weak areas complex chemical reactions, which made direct tensile more likely when loaded.