酸性水化学溶液侵蚀下不同矿物成分含量灰岩溶解特性及力学特性研究
Dissolution characteristics and mechanical properties of limestone with different mineral composition contents eroded by acid chemical solution
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摘要: 以灰岩、方解石为研究对象,配置不同酸性水化学溶液,对酸性水化学溶液侵蚀下灰岩、方解石试件进行溶解动力学试验及力学试验,获得水化学溶液侵蚀过程中灰岩、方解石试件溶解行为及抗压强度的变化规律,研究不同矿物成分含量对灰岩溶解特性及强度损伤特性的影响。试验结果表明:①浸泡灰岩、方解石试件水化学溶液中离子浓度随着浸泡时间的增加呈幂函数上升趋势,试件在酸性水化学溶液中的溶解过程分为酸岩反应、水解反应两个阶段;②在酸性水化学溶液侵蚀过程中,灰岩试件酸岩反应速率小于方解石试件,但其水解反应速率大于方解石试件,最终灰岩溶蚀破坏程度大于方解石;③酸性水化学溶液侵蚀下灰岩、方解石试件的力学损伤规律与其溶解动力学行为之间呈现良好的相关性,灰岩、方解石试件单轴抗压强度随着浸泡时间的增加呈幂函数下降趋势,酸岩反应阶段,灰岩强度损伤程度低于方解石,水解反应阶段,其强度损伤程度高于方解石。Abstract: In order to investigate the effects of different mineral composition contents on the dissolution characteristics and strength damage characteristics of limestone, the dissolution kinetics and mechanical tests of limestone and calcite specimens eroded by acidic aqueous chemical solution are carried out to obtain the variation laws of dissolution characteristics and strength damage characteristics of limestone and calcite specimens during the erosion process of acidic aqueous chemical solution. The test results show that: (1) The ion concentration in the chemical solution exhibits an increasing of power function trend with the increase of immersion time, and the dissolution process of limestone and calcite specimens in acidic aqueous chemical solution is divided into acid rock reaction and hydrolysis reaction. (2) In the erosion process of acidic aqueous chemical solution, the acid rock reaction rate of limestone specimens is lower than that of calcite ones, while the hydrolysis reaction rate is higher than that of calcite ones, and finally the limestone dissolution damage degree is greater than that of calcite specimens. (3) The mechanical damage laws of limestone and calcite specimens eroded by acidic chemical solution show a good correlation with their dissolution kinetics behavior. The uniaxial compressive strength of limestone and calcite specimens shows a decreasing trend of power function with the increase of immersion time. The strength damage degree of limestone is lower than that of calcite at the acid rock reaction stage, while the strength damage degree of limestone is higher than that of calcite at the hydrolysis reaction stage.