化工学报 ›› 2016, Vol. 67 ›› Issue (6): 2449-2455.DOI: 10.11949/j.issn.0438-1157.20151942

• 分离工程 • 上一篇    下一篇

反应结晶过程中二水硫酸钙晶粒性能

窦焰1, 刘同海1, 沈浩2, 郑之银2, 刘荣2, 崔鹏1   

  1. 1. 合肥工业大学化学与化工学院, 安徽 合肥 230009;
    2. 安徽六国化工股份有限公司, 安徽 铜陵 244000
  • 收稿日期:2015-12-21 修回日期:2016-03-25 出版日期:2016-06-05 发布日期:2016-06-05
  • 通讯作者: 崔鹏

Characteristic and structure of calcium sulfate dihydrate crystallites in crystallization process during reaction

DOU Yan1, LIU Tonghai1, SHEN Hao2, ZHENG Zhiyin2, LIU Rong2, CUI Peng1   

  1. 1. School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009, Anhui, China;
    2. Anhui Liuguo Chemical Co., Ltd., Tongling 244000, Anhui, China
  • Received:2015-12-21 Revised:2016-03-25 Online:2016-06-05 Published:2016-06-05

摘要:

设计了CaHPO4·2H2O-H2SO4-H3PO4-H2O体系结晶温度、液相SO42-含量、液相P2O5含量、搅拌速率和结晶时间的五因素四水平正交实验,通过测量晶体平均粒径优化出平均粒径最大的工艺参数:结晶温度80℃、液相SO42-含量50g·L-1、液相P2O5含量260g·L-1、搅拌速率50r·min-1和结晶时间2h。在该工艺参数下进行结晶过程研究,通过分析液相SO42-浓度和P2O5浓度,XRD、SEM、EDS和激光粒度分析仪表征晶体,研究发现:0~40min为反应阶段,平均粒径减小;40min之后结晶过程遵从Ostwald递变法则,从CaSO4·0.5H2O过渡到CaSO4·2H2O,平均粒径几乎不变。

关键词: 二水硫酸钙, 反应, 结晶, 制备, 过程

Abstract:

In CaHPO4·2H2O-H2SO4-H3PO4-H2O system, an orthogonal experiment with five factors and four levels, including crystallization temperature, SO42- concentration and P2O5 concentration in liquid phase (solution), stirring rate and crystallization time was designed. Based on the measurement of average particle size, the optimized process parameters for the maximum mean particle size are, 80℃ of crystallization temperature, 50 g·L-1 of SO42- concentration, 260 g·L-1 of P2O5 concentration, 50 r·min-1 of stirring speed, and 2 h of crystallization time. Under the optimum conditions of the crystallization process, by means of analyses on the concentrations of SO42- and P2O5 in solution, and the techniques of XRD, SEM, EDS and laser particle size measurement, it showed that the reaction stage was the first 40 min with a decrease in mean particle size, and after 40 min, the procedure of crystallization follows the Ostwald grading rules, along with the evolution from CaSO4·0.5H2O to CaSO4·2H2O, but with almost identical particle size.

Key words: calcium sulfate dihydrate, reaction, crystallization, preparation, process

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