不同pH值水溶液对石灰岩溶蚀影响的模拟研究

The simulation study of the effect of liquid with different pH value on corrosion for limestone

选择含云灰岩和云灰岩两种石灰岩样片,采用不同pH值水溶液和不同浸泡时间研究其对溶蚀的影响,结果表明:1)在3～30h的短时间尺度,pH值为6.0和3.0时均会增加含云灰岩的溶蚀量,而云灰岩在pH值为6.0的微酸环境中溶蚀量增加,在自然石灰岩环境中的积水(pH值为7.7)中溶蚀量会随着浸泡时间延长而稳定增加;2)在1～30d的长时间尺度,含云灰岩和云灰岩在不同pH值溶液中的溶蚀量显现出波状减少的趋势。在pH值为3.0溶液中两种石灰岩溶蚀样片的溶蚀量在1～5d都远大于其他溶液,含云灰岩和云灰岩在浸泡1、5d的溶蚀量分别是pH值为7.7溶液中溶蚀量的106、11.4和30.5、47.4倍。pH值为6.0的微酸溶液在溶蚀1～5d内也能增加云灰岩的溶蚀量。两种石灰岩样片在浸泡10d后溶蚀量都大幅降低,最终出现沉积现象;3)含云灰岩在由小到大6个不同pH值溶液中的溶蚀速率分别是0.139、0.042、0.029、0.015、0.013和0.005mm/(cm2.a)。在溶蚀初期1～5d的时间里,pH值降低会使含云灰岩溶蚀速率成倍增加,云灰岩在不同pH值溶液中的溶蚀速率除pH值为6.0和7.0的增加外,其他与含云灰岩的趋势一致,10d后所有溶液的溶蚀速率迅速减少并接近一致。云灰岩在pH值为3.0、6.0、4.0、5.0、7.0、7.7溶液中的最大溶蚀速率分别是0.196、0.114、0.062、0.026、0.059和0.006mm/(cm2.a)。在相同pH值与相同的溶蚀时间下,云灰岩的溶蚀速率大于含云灰岩。

Two kind of sample wafer of limestone containing dolomite and dolomitization limestone were selected to study the corrosion effects of liquid with different pH value and different soak time, the results showed： 1） Within the time scale of 3-30 h, Solution amount of limestone containing dolomite in the liquid pH 3. 0 and pH 6. 0 were much more than others. Solution amount of dolomitization limestone in the liquid pH 6.0 were much more than others, in contrast, the Solution amount of two kind of limestone in the liquid pH 6.0 were steadily increased over time;2） Within the time scale of 1-30 d, the solution amount of two kind of limestone in the different liquid shows a tendency of wavelike decreased, in primary time of corrosion 1-5 d, the dissolution amounts of two kinds of limestone samples in the liquid pH 3.0 were much larger than others, and the dissolution amounts of the containing dolomite limestone and dolomitization limestone were 106 times, 11.4 times and 30.5 times, 47.4 times as much as that of it in the liquid pH 7. 7 after soaked 1 d and 5 d, respectively. At the same time, the dissolution amount of dolomitization limestone in the liquid pH 6.0 was also increased. 10 d later, the dissolution amounts of two kinds of limestone were significantly reduced, and culminating in deposition phenomenon. 3） The maximum dissolution rate of the containing dolomite limestone in different pH （3. 0,4.0, 5.0, 6.0,7.0-7.7）liquid were 0. 139, 0. 042,0. 029, 0. 015,0. 013, and 0. 005 mm/（cm^2·a）. In the initial dissolution time of 1-5 d, the reduced pH value made with the dissolution amount of the containing dolomite limestone rated multiply, except the increasing in liquids of pH 6.0 and pH 7. 0,there are the similar tendency of the dissolution rate of the dolomitization limestone in other liquids. 10 d later, the dissolution rate of all to quickly reduced and nearly identical. The maximum dissolution rate of the dolomitization limestone in the pH 3.0,6.0,4.0,5.0,7.0 and 7.7 were 0. 196,0. 114,0.0G2,0. 026,0, 059 and 0. 006 mm/（cm^2·a）. With the same pH and dissolution time, the dissolution rate of the dolomitization limestone was much more than that of containing dolomite limestone.