褚学伟, 付海, 王中美,等.灰质白云岩可溶性影响研究[J].河南理工大学学报（自然科学版）,2024,43(3):60-69.

CHU X W, FU H , WANG Z M, et al. Study on the solubility of gray dolomite[J]. Journal of Henan Polytechnic University(Natural Science), 2024, 43(3): 60-69.

灰质白云岩可溶性影响研究

褚学伟, 付海, 王中美, 张佳欣, 张启林

贵州大学 资源与环境工程学院，贵州 贵阳 550025

摘要: 目的 常温常压条件下方解石与白云石含量组成相近的碳酸盐岩溶蚀研究较少，为揭示此类岩石溶蚀特性， 方法 选取灰质白云岩作为试验对象，开展常温常压下不同酸性与流态条件下的溶蚀模拟试验，通过分析酸液pH、试样质量与孔隙变化、钙镁离子释放量等碳酸盐岩溶蚀参量，探讨影响灰质白云岩溶蚀速率的因素。  结果 结果表明：（1）pH≤3时，H+消耗量大于钙镁离子生成量，电导率值呈快速降低趋势；pH＞3时，H+消耗量略大于钙镁离子生成量，电导率呈缓慢降低趋势，pH=3是电导率值由大变小转折的关键点，突出体现了H+消耗量与钙镁离子生成量的关系。（2）灰质白云岩方解石溶解速度与溶蚀量均远大于白云石的，初始酸液摩尔浓度较高条件下溶蚀效果更明显。（3）孔隙数量增加会加大岩石与酸溶液接触面积，进而加快岩石溶蚀速度。（4）杂质充填岩石孔隙减小了酸液对岩石的破坏。（5）高摩尔浓度酸液（pH≤3）与较强流态环境下溶蚀速率更大，岩石表面可溶物质溶出能力更强，酸液摩尔浓度较低时（pH≥4），流态变化对溶蚀速率影响较小。  结论 研究结果可为碳酸盐岩溶蚀研究、溶蚀程度评价与工程建设提供参考。

关键词:碳酸盐岩;化学溶蚀;矿物组分;水动力条件;溶解差异

doi:10.16186/j.cnki.1673-9787.2022050026

基金项目:国家自然科学基金资助项目（42062016）；国家自然科学基金委员会-贵州喀斯特科学研究中心联合项目（U16612442）；贵州大学引进人才科研项目（贵大人基合字［2019］36号）

收稿日期:2022/05/10

修回日期:2022/07/05

出版日期:2024/05/15

Study on the solubility of gray dolomite

CHU Xuewei, FU Hai, WANG Zhongmei, ZHANG Jiaxin, ZHANG Qilin

College of Resources and Environmental Engineering, Guizhou University, Guiyang 550025, Guizhou, China

Abstract:  Objectives Since there are fewer studies on the dissolution of carbonate rocks with similar calcite and dolomite content under normal temperature and pressure, this study aims to reveal the dissolution characteristics of such rocks. Methods Gray dolomite was selected as the test object to conduct dissolution simulation tests under different acidic and flow conditions at normal temperature and pressure. The study explores the factors influencing the dissolution rate of gray dolomite by analyzing the dissolution parameters of carbonate rocks, including the pH of the acid solution, the mass of the specimen, changes in the pore space, and the amount of calcium and magnesium ions released. Results The results show that: (1) When the acid pH ≤ 3, H⁺ consumption is larger than the generation of calcium and magnesium ions, and the conductivity value shows a rapid decreasing trend; when the acid pH > 3, H⁺ consumption is slightly larger than the generation of calcium and magnesium ions, and the conductivity shows a slow decreasing trend. The point where the acid pH = 3 is a key turning point for the conductivity value from large to small, highlighting the relationship between H⁺ consumption and the generation of calcium and magnesium ions. (2) The dissolution rate and amount of calcite in gray dolomite are much higher than that of dolomite, and the dissolution effect is more pronounced under higher initial acid molar concentration conditions. (3) An increase in the number of pores enhances the contact area between the rock and the acid solution, thereby accelerating the dissolution rate of the rock. (4) Filling of rock pores with impurities reduces acid damage to the rock. (5) High molar concentration acid (pH ≤ 3) has a higher dissolution rate in a stronger flow state environment and a greater ability to dissolve soluble substances on the rock surface. When the molar concentration of acid is lower (pH ≥ 4), the change of flow state has less effect on the dissolution rate. Conclusions The results of the study can provide a reference for carbonate rock dissolution research, evaluation of dissolution degree, and engineering construction.

Key words:carbonate rock; chemical dissolution; mineral composition; hydrodynamic conditions; dissolution difference