合浦珠母贝壳制备碳酸钙、丙酸钙的工艺研究

Study on the technology of preparation of calcium carbonate and calcium propionate from Pinctada martensii shell

以合浦珠母贝开珠后的贝壳为原料,研究制备碳酸钙、丙酸钙的工艺技术。通过分析贝壳粉颗粒大小和酸的品种、浓度及用量对酸溶率的影响,结果表明:100目的贝壳粉与4mol/L的盐酸,按固液比为1∶20,在40℃酸溶处理2h,酸溶率可达到99%,该酸溶液与Na2CO3溶液的体积比为9∶5时,碳酸钙得率最高;利用L9(34)正交实验优化丙酸钙工艺,结果表明,最佳工艺条件为碳酸钙与水的比例1∶40(W/V),碳酸钙与丙酸比例1∶3(W/V),反应温度60℃,反应时间0.5h,丙酸钙产率为86%,产品纯度为83.4%。

The technology of the preparation of calcium carbonate and calcium propionate from Pinctada martensfi shell was studied.The particle size of Pinctada martensfi shell power and acid varieties, concentrations,volume to dissolve acid were discussed.The results showed that dissolve acid rate can reached 99% with the proportion of 1：20（W/V） for the shell power of 100 mesh to 4mol/L hydrochloric acid in 2h at 40℃.The yield of calcium carbonate was the highest with a proportion of 9：5 （V/V）for hydrochloric acid solution to sodium carbonate solution.Using the orthogonal test L9 （3^4 ） calcium propionate optimization technique, the results showed that the best technological conditions for the proportion of 1：40（W/V） for calcium carbonate to water,the proportion of 1：3 （W/V） for calcium carbonate to propionate acid by stirring for 0.5h at 60℃,the rate of calcium propionate were 86% and its purity achieved 83.4%.