Abstract: Acetic acid dissolution of limestone for formation of cavity is a kind of environmental approach to fabricating underground storage and preparing precipitated calcium carbonate. This process is an integrated technology consisting of acetic acid dissolution of limestone and CO₂ carbonation of calcium acetate. The kinetics of limestone acidolysis with acetic acid was investigated. Orthogonal experiments were conducted with emphasis on operation conditions (i.e., concentration of calcium acetate, pressure of CO₂, reaction temperature, and reaction time) of the carbonation reaction. The highest conversion of calcium acetate (23.13%) was achieved at the calcium acetate concentration of 0.631mol/L, CO₂ pressure of 5MPa, reaction temperature of 80℃ and reaction for 50 minutes. The product of calcium carbonate was analyzed and could meet the requirements of Chinese national standard.

Key words: limestone, reaction kinetics, calcium acetate, carbon dioxide, optimal design

摘要： 乙酸酸解石灰石造腔是一种建造地下储库同时环保的开采石灰岩制备沉淀碳酸钙的新方法。通过耦合乙酸酸解石灰石及酸解产物乙酸钙CO₂碳酸化的工艺过程，研究了乙酸酸解石灰岩的表面反应动力学和乙酸钙CO₂碳酸化的工艺技术条件。采用正交试验分析法，研究了CO₂碳酸化反应中乙酸钙浓度、反应温度、CO₂压力、反应时间对乙酸钙碳酸化反应制沉淀碳酸钙的影响，并通过正交试验确定了最优化操作条件。实验结果表明，乙酸酸解反应速率主要受乙酸浓度控制，其动力学方程为：CO₂碳酸化反应在当乙酸钙溶液浓度为0.631mol·L^-1，CO₂压力为5.0MPa，温度为80℃，反应时间为50min时CO₂碳酸化效率达到最高（23.13%），生成的沉淀碳酸钙产品各项指标均符合中国国标优级要求。

关键词: 石灰岩, 反应动力学, 乙酸钙, 二氧化碳, 优化设计