硫酸钠与氯化钾制备硫酸钾实验研究

为改进硫酸钠与氯化钾复分解法生产硫酸钾工艺,提高硫酸钾产品的纯度和产率,以工业级硫酸钠（纯度≥99.31%）和工业级氯化钾（纯度≥97.42%）为原料,进行了钾芒硝和硫酸钾制备条件的研究。探究了水添加量、反应时间对钾芒硝、硫酸钾的纯度和产率的影响。得到硫酸钠与氯化钾复分解法生产硫酸钾适宜的工艺条件：以100 g氯化钾和106.01 g硫酸钠在298 K条件下反应,制备钾芒硝的较优的水添加量为218.60 g,反应时间为2 h;复分解母液蒸发得到氯化钠的较优蒸发水量为理论蒸发水量的110%;钾芒硝制备硫酸钾的较优的水添加量为322.06 g,较优反应时间为2 h。制备的硫酸钾中水溶性氧化钾的质量分数为52.74%,氯离子质量分数为1.31%,达到GB/T 20406—2017《农业用硫酸钾》中水盐体系粉末结晶状优等品的技术要求。

Experimental study on preparing potassium sulfate by sodium sulfate and potassium chloride

In order to improve the process of producing potassium sulfate with sodium sulfate and potassium chloride by double decomposition method,and increase the purity and yield of potassium sulfate.With industrial grade sodium sulfate（purity≥99.31%） and potassium chloride（purity ≥97.42%） as raw materials,the preparation conditions of glaserite and potassium sulfate were studied.The effects of water addition amount and reaction time on the purity and yield of potassium sulfate and glaserite were investigated.The optimal process conditions for producing potassium sulfate with sodium sulfate and potassium chloride by double decomposition method were obtained as follows：100 g potassium chloride and 106.01 g sodium sulfate reacted at 298 K,the preferred water addition amount was 218.60 g and the reaction time was 2 h.The optimal evaporation amount of sodium chloride obtained by evaporation of metathesis mother liquor was 110% of theoretical evaporation water.The preferred water addition amount of preparing potassium sulfate by glaserite was 322.06 g while the preferred reaction time was 2 h.The mass fraction of K₂O and Cl-in potassium sulfate were 52.74% and 1.31% respectively,which met the technical requirements of premium grade in the standard of Agricultural Potassium Sulfate（GB/T 20406—2017）.