(NH_4)_2SO_4-H_2O体系中CaSO_4·2H_2O溶解度的突变现象  

Saltation phenomenon of CaSO_4·2H_2O solubility in (NH_4)_2SO_4-H_2O system

作　　者：刘仕忠[1] 朱家骅[1] 周加贝[1] 夏素兰[1] 许超[1] 宫源 葛敬[1] LIU Shizhong ZHU Jiahua ZHOU Jiabei XIA Sulan XU Chao GONG Yuan GE Jing(School of Chemical Engineering, Sichuan University, Chengdu 610065, China)

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《磷肥与复肥》2017年第4期5-8,共4页Phosphate & Compound Fertilizer

基　　金：国家科技支撑计划课题(2013BAC12B01)

摘　　要：在25℃、搅拌转速180 r/min的条件下,通过实验和理论研究硫酸铵浓度(≤2.50 mol/L)对二水硫酸钙溶解度的影响。结果表明:在同离子效应与盐效应的协同作用下,硫酸铵浓度为0.07 mol/L时,二水硫酸钙的溶解度发生突变。当硫酸铵浓度小于0.07 mol/L时,二水硫酸钙的溶解度随着硫酸铵浓度的增加而减小;而当硫酸铵浓度在0.07~2.50 mol/L时,二水硫酸钙溶解度随着硫酸铵浓度的增加而增加。基于活度积公式和德拜休克尔公式,建立方程预测硫酸铵浓度对二水硫酸钙溶解度的影响,该方程计算值与实验值有很高的吻合度。研究结果为优化磷石膏矿化反应器提供了理论依据。The effect of the concentration （≤2.50 mol/L） of ammonium sulfate on the solubility of calcium sulfate dihydrate is studied experimentally and theoretically under the conditions of 25 ℃ and stirring speed of 180 r/ min. The results show that the solubility of calcium sulfate dihydrate has a sahation when the concentration of ammonium sulfate is 0.07 mol/L under the synergetic effect of the ion-effect and salt effect. When the concentration of ammonium sulfate is less than 0.07 mol/L, the solubility of calcium sulfate dihydrate decreases with the increase of ammonium sulfate concentration, and when the concentration of ammonium sulfate is 0.07-2.50 mol/L, the solubility of calcium sulfate dihydrate increases with the increase of ammonium sulfate concentration. The effect of the concentration of ammonium sulfate on the solubility of calcium sulfate dihydrate can be predicted by the equation based on the activity product formula and the Debye-Huckel formula, the calculated value is in accordance with the experimental value. The results provide the theoretical basis for optimizing the phosphogypsum mineralization reactor.

关 键 词：二水硫酸钙 硫酸铵 同离子效应 盐效应 溶解度 

分 类 号：TQ177.375[化学工程—硅酸盐工业] O614.231[理学—无机化学]