(中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 研究了天青石精矿复分解法制备碳酸锶的工艺及溶液化学作用机理。当以Na2CO3为转化剂，SrSO4转化率最高可达97.77%；而用(NH4)2CO3作转化剂时，SrSO4转化率最大仅为78.66%。溶液化学研究结果表明：在复分解反应体系内，反应的实际转化剂为
关键字: 天青石；碳酸锶；复分解；溶液化学
concentrate and its solution chemistry mechanism
（School of Minerals Processing and Bioengineering,Central South University, Changsha 410083, China）
Abstract:The technology and mechanism of solution chemistry of preparation of strontium carbonate by double decomposition from celestite concentrate were investigated. The results indicate that the maximal SrSO4 conversion reaches 97.77% when Na2CO3 is used as the reagent, but the maximal conversion of SrSO4 is only 78.66% when (NH4)2CO3 is used. The investigation results of solution chemistry principles show that CO2-3 ion is the actual conversion agent in this reaction system. CO2-3 irons take up the dominate position when the pH value is greater than 10.3, which benefits to the conversion. However, when the pH value is lowered to 8.5, the CO2-3 molar fraction in liquor almost decreases to zero and SrSO4 conversion reaction therefore nearly ceases. The detected results show that the pH values of (NH4)2CO3 solution in this research are between 8.63~8.79 at 25℃, while the pH value of Na2CO3 solution is greater than 11.0, therefore, the difference of pH values within the reaction systems is the basic reason why the conversion and reaction rate of SrSO4 by Na2CO3 is much higher than that by (NH4)2CO3.
Key words: celestite; strontium carbonate; double decomposition; solution chemistry
