复分解法硫酸钾生产工艺中硫酸钾和硫酸铵的三元相图研究

摘要

为了研究复分解法硫酸钾生产工艺的反应原理,建立了相图测试平台,确定了体系平衡时间,标定了平台测试精度.基于测试平台,测试和绘制了30 ℃和60 ℃下硫酸钾和硫酸铵的三元体系相图,并对饱和液相线进行拟合计算.确定硫酸钾与硫酸铵在相图中不存在三相点和单盐结晶区,而是形成了组分连续的硫酸钾铵固溶体结晶区,从理论上揭示了复分解法硫酸钾生产工艺不能在一步反应过程中生成完全纯净的硫酸钾产品.%In order to study the reaction mechanism of production of K2SO4 by double decomposition process, a phase diagram test system is established and its equilibrium time and measuring accuracy are determined.By this system, ternary phase diagram of K2SO4 and (NH4)2SO4 at temperatures of 30 ℃ and 60 ℃ are measured and completed, and saturated liquid phase lines and their fitting calculation are figured out.It is found that K2SO4 and (NH4)2SO4 do not have triple-point and crystalline region of pure salt in their ternary phase diagram, there is only a component-continuous solid solution crystalline region formed.It has revealed theoretically that pure K2SO4 cannot be produced in one-step reaction by double decomposition process.