无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2016, Vol. 48 ›› Issue (9): 51-.

• 论文 • 上一篇    下一篇

结晶法脱除高浓度正磷酸中硫酸根的研究

刘 飞1,李天祥1,2,解 田1,史连军1   

  1. 1.瓮福(集团)有限责任公司,贵州福泉 550501;2.贵州大学化工学院
  • 出版日期:2016-09-10 发布日期:2016-09-18

Removal of SO42- in high concentration orthophosphoric acid by crystallization

Liu Fei1,Li Tianxiang1,2,Xie Tian1,Shi Lianjun1   

  1. 1.Wengfu(Group) Co.,Ltd.,Fuquan 550501,China;2.School of Chemical Engineering,Guizhou University
  • Online:2016-09-10 Published:2016-09-18

摘要: 研究了以工业级湿法磷酸净化酸浓缩生产的质量分数为98%的正磷酸为原料,采用冷却结晶方式脱除正磷酸中的阴离子硫酸根(SO42-)。考察了降温速率、搅拌转速、助长剂用量、养晶时间对正磷酸中硫酸根脱除的影响。确定了最佳工艺条件:搅拌转速为300 r/min,降温速率为每15 min降温1 ℃,助长剂用量为5 g,养晶时间为 1.5 h。在最佳工艺条件下,正磷酸中硫酸根去除率达到82.1%,硫酸根质量分数小于20 mg/kg,达到85%食品级磷酸对硫酸根的质量要求,提高了磷酸产品的附加值。同时,该方法为生产低硫酸根含量的正磷酸提供了一条可行途径。

关键词: 正磷酸, 硫酸根, 结晶, 脱除

Abstract: Anion SO42- in orthophosphoric acid  was removed by cooling crystallization method with the 98%(H3PO4,mass fraction) orthophosphoric acid got from the purification and concentration of industrial grade wet-process phosphoric acid as raw material.The influences of cooling rate,stirring speed,crystal growth substance dosage,and crystal maturing time on the removal effect were investigated.The optimum technological conditions were comfirmed as follows:the stirring speed was 300 r/min,the cooling rate was 1 ℃ per 15 min,the growth substance dosage was 5 g,and the crystal maturing was 1.5 h.Under the best process conditions,SO42- of orthophosphoric acid removal rate reached 82.1%,mass fraction of  SO42- less than 20 mg/kg, meeting the 85% quality requirement for SO42- of food grade phosphoric acid,and improved the added-value of products.At the same time,this method provided a feasible way for the production of orthophosphoric acid with low content of SO42-.

Key words: orthophosphoric acid;SO42-;crystallization, removal

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