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 ›› 2025, Vol. 57 ›› Issue (9): 30-36.doi: 10.19964/j.issn.1006-4990.2024-0507

• 研究与开发 • 上一篇    下一篇

二水法湿法磷酸体系降低磷石膏中共晶磷损失的工艺研究

何琳(), 杨光宏, 李军()   

  1. 四川大学化学工程学院,四川 成都 610065
  • 收稿日期:2024-09-25 出版日期:2025-09-10 发布日期:2025-05-27
  • 通讯作者: 李军,男,博士,教授,研究方向为结晶与萃取分离技术;E-mail:lijun@scu.edu.cn
  • 作者简介:何琳(1999— ),男,硕士,研究方向为磷化工工艺研究;E-mail:18281586261@163.com

Study on process of reducing loss of eutectic phosphorus in phosphogypsum by dihydrate wet-process phosphoric acid system

HE Lin(), YANG Guanghong, LI Jun()   

  1. School of Chemical Engineering,Sichuan University,Chengdu 610065,China
  • Received:2024-09-25 Published:2025-09-10 Online:2025-05-27

摘要:

在湿法磷酸生产过程中,磷石膏中的共晶磷是导致磷资源浪费的关键因素,解决共晶磷损失问题对磷酸生产具有重要意义。为了降低二水法湿法磷酸工艺的共晶磷损失、提高经济效益,设计在Ca(H2PO42-H3PO4-H2SO4体系下模拟无固相的二水法湿法磷酸生产过程,考察反应温度、液相P2O5质量分数、陈化时间和液相SO3浓度对磷石膏中共晶磷含量的影响。结果表明,当反应温度为75 ℃、液相P2O5质量分数为26%、陈化时间为3.0 h、返酸中添加过量3.0%的硫酸(液相SO3质量浓度为41.19 g/L)时,磷石膏中的共晶磷含量显著降低至0.21%(质量分数);对比不同反应条件下生成的二水硫酸钙晶体形貌差异,观察到该反应体系生成的二水硫酸钙晶体以板状和棒状晶形为主,其中长棒状晶体在轴向方向的优势生长有利于减少磷石膏中共晶磷的含量。实验对磷石膏中共晶磷含量的变化及其结晶形貌进行了研究,有利于更加全面的认识共晶磷的形成机理,同时对二水法湿法磷酸实际生产选择合适的工艺参数具有参考价值。

关键词: 湿法磷酸, 磷石膏, 共晶磷, 磷损失

Abstract:

In the process of wet-process phosphoric acid production,eutectic phosphorus in phosphogypsum is the key factor leading to the waste of phosphorus resources.Solving the problem of eutectic phosphorus loss is of great significance to phosphoric acid production.In order to reduce the loss of eutectic phosphorus in dihydrate wet-process phosphoric acid process and improve economic efficiency,the production process of wet-process phosphoric acid by dihydrate method without solid phase was simulated in Ca(H2PO42-H3PO4-H2SO4 system.The effects of reaction temperature,liquid P2O5 concentration,aging time and liquid SO3 concentration on the eutectic phosphorus content of phosphogypsum were investigated.The results showed that when the reaction temperature was 75 ℃,the mass fraction of liquid-phase P2O5 was 26%,the aging time was 3.0 h,and the excess of 3.0% sulfuric acid(the concentration of SO3 in liquid phase was 41.19 g/L) was added to the return acid,the eutectic phosphorus content in phosphogypsum was significantly reduced to 0.21%.Comparing the differences in the morphology of calcium sulfate dihydrate crystals formed under different reaction conditions,it was observed that the calcium sulfate dihydrate crystals formed by the reaction system are mainly plate-like and rod-like crystals,and the dominant growth of the long rod-like crystal in the radial direction was beneficial to reduce the content of eutectic phosphorus in phosphogypsum.In this experiment,the change of eutectic phosphorus content and its crystal morphology in phosphogypsum were studied,which was conducive to a more comprehensive understanding of the formation mechanism of eutectic phosphorus.At the same time,it provided reference value for the actual production of dihydrate wet-process phosphoric acid to select appropriate process parameters.

Key words: wet process phosphoric acid, phosphogypsum, eutectic phosphorus, phosphorus loss

中图分类号: