湿法磷酸生产工艺对硫酸钙结晶的影响

Effect of Wet Phosphoric Acid Production Process on Crystallization of Calcium Sulfate

以湿法磷酸连续生产方式,用磷酸二氢钙溶液为原料制备磷酸,对影响硫酸钙结晶及过滤强度的主要工艺条件进行研究。结果表明,磷酸浓度26%P_2O_5、反应温度60℃、反应时间4 h、料浆液固比13∶1、液相SO_3浓度0.035~0.045 g/mL条件下,钙转化率≥98%,滤饼过滤强度≥1 200 kg(干)/(m^2·h),工艺条件完全满足工业生产的要求,工艺简单可行,具有良好的工业应用前景。

Phosphoric acid was prepared from calcium dihydrogen phosphate solution.The main technological conditions affecting the crystallization and filtration strength of calcium sulfate were studied.The results showed that the concentration of phosphate was 26% P2O5,the reaction temperature was 60 ℃,the reaction time was 4 h,the ratio of liquid to solid was 13： 1,the liquid SO3 concentration was 0.035 ~ 0.045 g/mL,the calcium conversion was ≥98%,filter cake filtration strength was ≥1 200 kg（dry）/（m^2·h）,the process conditions fully met the requirements of industrial production.The process is simple and feasible,so it has good industrial application prospect.