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通过模拟硫酸型酸雨加速侵蚀石灰岩的室内试验,监测了试验过程中试样的质量变化、Ca~(2+)释放量、酸雨pH值变化、计算了H~+消耗速率及试样的表面硬度变化率,对试样的微观结构进行了观察和测量,对比分析了酸雨的淋蚀作用和浸泡作用,根据试验结果讨论了酸雨溶蚀石灰岩的机理,并分析了孔隙特征对石灰岩溶蚀过程的影响。试验结果表明:酸雨的淋蚀作用会溶解石灰岩中的碳酸盐并剥离岩石表面,造成新鲜岩石继续与酸雨作用,加速了石灰岩的质量损失和Ca~(2+)的释放,同时试样的表面硬度和表层微观结构发生相应的改变,但是,溶蚀产物会部分填充石灰岩内的微孔隙和微裂隙,可以有效减缓小尺寸孔隙(<0.01μm)的破坏;孔隙特征对酸雨侵蚀石灰岩的过程有重要影响,孔隙率越高,酸雨越容易进入岩石内部并造成破坏;孔隙率一定的情况下,孔隙尺寸越大,酸雨作用的时间和程度会越充分,对石灰岩的破坏也越严重;在相同的试验条件下,试验选取的3种石灰岩中南响堂山石窟石灰岩的抗酸雨侵蚀能力最弱。
The indoor test of accelerated limestone erosion by simulating sulfuric acid rain was conducted to monitor the change of mass, Ca2 + release and pH value of acid rain during the test. The H ~ + consumption rate and the surface hardness The microstructure of the sample was observed and measured. The acid rain eroded and soaked effect was analyzed. The mechanism of acid rain dissolution limestone was discussed based on the experimental results, and the influence of pore characteristics on limestone dissolution was analyzed. The results show that acid rain can dissolve the carbonate in limestone and peel off the rock surface, causing the fresh rock to continue to interact with acid rain, accelerating the mass loss of limestone and releasing Ca2 + The surface hardness and surface microstructure change correspondingly. However, the dissolution products will partially fill the micropores and micro-cracks in the limestone, which can effectively reduce the damage of the small-size pores (<0.01μm). Pore characteristics The process of acid rain erosion limestone Importantly, the higher the porosity, the easier the acid rain to enter the interior of the rock and cause damage. With a certain porosity, the larger the pore size, the more time and extent of the acid rain and the more serious damage to the limestone. In the same , The limestone rocks of Zhongnan Xiangtangshan Grottoes selected from the test were the weakest in acid rain erosion resistance.