软钾镁矾和氯化钾转化硫酸钾结晶粒度研究  

Crystal size of K_2SO_4 crystallizing from K_2SO_4·MgSO_4·6H_2O and KCl

作　　者：胡天琦 张志宏[1] 王健康[1,2] 马艳芳[1] 赵冬梅[1] 王婧[1] 张永明[1] Hu Tianqi Zhang Zhihong Wang Jiankang Ma Yanfang Zhao Dongmei Wang Jing Zhang Yongming(Qinghai Institute of Salt Lakes, Chinese Academy of Sciences ,Xining 810008, China University of Chinese Academy of Sciences)

机构地区：[1]中国科学院青海盐湖研究所,青海西宁810008 [2]中国科学院大学

出　　处：《无机盐工业》2017年第3期14-18,共5页Inorganic Chemicals Industry

基　　金：高新技术研究与发展计划(2012-G-212A);青海省科技支撑项目(2013-G-139A)

摘　　要：以前期实验结论为指导,结合相图、溶解结晶理论设计实验方案,探究了温度、加料方式、晶种、过饱和度对软钾镁矾(K2SO4·Mg SO4·6H2O)和氯化钾转化硫酸钾结晶粒度的影响。实验结果表明:在25~55℃范围内,随着温度升高,硫酸钾晶体平均粒径增大;分时变温,在55℃转化60 min,然后在25℃降温60 min,可以使反应较为快速地达到平衡,减少溶解转化的时间,同时提高了硫酸钾的收率,改善了硫酸钾晶体的粒度分布;改变加料方式,先加入氯化钾,30 min后加入软钾镁矾,在25℃条件下转化结晶120 min,所得硫酸钾晶体的平均粒径比混合加料方式增大约1.9倍;选择特定时间添加晶种和缓慢加入原料,所得硫酸钾晶体的平均粒径显著增大。此研究结果对实际生产中的工艺优化、产品控制具有一定的指导意义。Guided by the preliminary experiment conclusion,an experiment plan was designed with combinations of phase diagram theory and dissolving crystallization theory,to investigate the effects of temperature,feeding way,seed crystal,and degree of supersaturation on the granule size of K_2SO_4,which crystallized from K_2SO_4·MgSO_4·6H_2O and KCl.Results showed that the average particle size（D50） increased with the increase of the temperature at the range of 25~55 ℃.Changing the temperature at each stage,crystal transforming at 55 ℃ for 60 min and then cooling at 25 ℃ for 60 min,it would actualize fastbalancing,reduce dissolving time,improve the yield and the crystal size distribution of K_2SO_4.If adding KCl first at the beginning of the reaction,and then adding K_2SO_4·MgSO_4·6H_2O after 30 min,the D50 increased by 1.9 times than the previous crystals prepared by mixing adding way.Adding seed crystal at a specific period and adding raw materials in a slow way,the D50 increased observably.These results can provide the basis for process improvement and product control in actual production process.

关 键 词：硫酸钾 结晶 粒径分布 

分 类 号：TQ131.13[化学工程—无机化工]