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 ›› 2024, Vol. 56 ›› Issue (5): 101-107.doi: 10.19964/j.issn.1006-4990.2023-0301

• 环境·健康·安全 • 上一篇    下一篇

转晶剂对磷石膏制备无水硫酸钙影响的研究

王明顺(), 敖先权(), 袁兴, 董文燕, 陈前林   

  1. 贵州大学化学与化工学院,贵州 贵阳 550025
  • 收稿日期:2023-06-01 出版日期:2024-05-10 发布日期:2024-05-15
  • 通讯作者: 敖先权,男,教授,博士生导师,研究方向为固体废弃物资源化利用;E-mail:aoxianquan@163.com
  • 作者简介:王明顺(1997— ),男,硕士研究生,主要研究方向为工业固废处理;E-mail:1349490778@qq.com
  • 基金资助:
    国家重点研发计划项目(2018YFC1903500)

Study on effect of crystallizer on preparation of anhydrous calcium sulfate from phosphogypsum

WANG Mingshun(), AO Xianquan(), YUAN Xing, DONG Wenyan, CHEN Qianlin   

  1. College of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China
  • Received:2023-06-01 Published:2024-05-10 Online:2024-05-15

摘要:

磷石膏(PG)产生量大、资源化利用困难,严重影响磷化工行业的发展。为提高PG应用附加值,以除杂后的PG为原料,以NaCl和乙二胺四乙酸二钠(EDTA-2Na)为转晶剂,采用常压盐溶液法制备高白度无水CaSO4。通过SEM、XRD、FT-IR、粒度分析仪等分析方法研究转晶剂对无水CaSO4制备的影响。结果表明:当NaCl质量分数为15%、EDTA-2Na质量分数为0.5%时,PG结晶水脱水时间由120 min缩短至40 min,脱水效果显著;同时,无水CaSO4晶体粒度分布均匀,颗粒表面完整,D50为5.26 μm,白度值为92.5%,P2O5质量分数仅为0.045%。这主要是因为非晶格Na+降低了体系中水的活度,促进PG脱水转晶及杂质脱除;EDTA-2Na中羧基基团与石膏晶体表面的Ca2+发生配位形成的配位离子层可调控无水CaSO4晶体生长,修饰晶面。

关键词: 磷石膏, 转晶剂, 无水CaSO4, 常压盐溶液法

Abstract:

The production of phosphogypsum(PG) is large,and its resource utilization is difficult,which seriously affects the development of phosphorus chemical industry.In order to improve the added value of PG application,anhydrous CaSO4 with high whiteness was prepared by normal pressure salt solution method with PG as raw material,NaCl and EDTA-2Na as crystallization agents.The effect of crystal transition agent on the preparation of anhydrous CaSO4 was studied by SEM,XRD,FT-IR and particle size analyzer.The results showed that when the mass fraction of NaCl was 15% and the mass fraction of EDTA-2Na was 0.5%,the dehydration time of PG crystal water was shortened from 120 min to 40 min,and the dehydration effect was remarkable.At the same time,the particle size distribution of anhydrous CaSO4 crystal was uniform,the particle surface was complete,the D50 was 5.26 μm,the whiteness was 92.5%,and the P2O5 content was only 0.045%.It was mainly because non-lattice Na+ reduced the activity of water in the system,and promoted the dehydration,crystallization and impurity removal of PG.The coordination ion layer formed by the coordination between carboxyl groups in EDTA-2Na and Ca2+on the surface of gypsum crystal could regulate the growth of anhydrous CaSO4 crystal and modify the crystal face.

Key words: phosphogypsum, crystal modifier, anhydrous CaSO4, normal pressure salt solution method

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