(中南大學 資源加工與生物工程學院，長沙 410083)
摘 要: 研究了天青石精礦復(fù)分解法制備碳酸鍶的工藝及溶液化學作用機理。當以Na2CO3為轉(zhuǎn)化劑，SrSO4轉(zhuǎn)化率最高可達97.77%；而用(NH4)2CO3作轉(zhuǎn)化劑時，SrSO4轉(zhuǎn)化率最大僅為78.66%。溶液化學研究結(jié)果表明：在復(fù)分解反應(yīng)體系內(nèi)，反應(yīng)的實際轉(zhuǎn)化劑為
關(guān)鍵字: 天青石；碳酸鍶；復(fù)分解；溶液化學
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
