CIESC Journal ›› 2017, Vol. 68 ›› Issue (3): 1155-1162.DOI: 10.11949/j.issn.0438-1157.20161290

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Equilibrium conversion analysis of pressurized carbonation with phosphogypsum

BAO Weijun1,2, ZHAO Hongtao1,3,4, LI Huiquan1,2,4, LI Songgeng3,4, LIN Weigang3,4   

  1. 1 Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    2 National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    3 State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
    4 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2016-09-14 Revised:2016-11-08 Online:2017-03-05 Published:2017-03-05
  • Contact: 10.11949/j.issn.0438-1157.20161290
  • Supported by:

    supported by the National Natural Science Foundation of China (21300212) and the 12th Five-Year Plan of National Science and Technology Support (2013BAC12B02).

磷石膏加压碳酸化转化过程中平衡转化率分析

包炜军1,2, 赵红涛1,3,4, 李会泉1,2,4, 李松庚3,4, 林伟刚3,4   

  1. 1 中国科学院过程工程研究所绿色过程与工程重点实验室, 北京 100190;
    2 中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室, 北京 100190;
    3 中国科学院过程工程研究所多相复杂系统国家重点实验室, 北京 100190;
    4 中国科学院大学, 北京 100049
  • 通讯作者: 李会泉,hqli@ipe.ac.cn;李松庚,sgli@ipe.ac.cn
  • 基金资助:

    国家自然科学基金项目(21300212);国家“十二五”科技支撑计划项目(2013BAC12B02)。

Abstract:

Based on the process of pressurized carbonation with phosphogypsum, the effect of raw material types on carbonation conversion was experimentally studied. In addition, the influence of some operation parameters on the conversion had been analyzed by Aspen plus process simulation software. The results showed that the carbonation reaction can reach equilibrium within 5 minutes under pressured conditions, and it was much more easily for pure anhydrous calcium sulfate to convert completely. However, because of containing crystal water or other impurities, it was difficult for both pure dihydrate calcium sulfate and phosphogypsum to convert completely. Besides, it was found that increasing the initial ammonia concentration, the mole ratio of added ammonia to SO3 in the raw materials, and properly increasing the reaction temperature and system pressure can effectively improve the equilibrium carbonation conversion. Most importantly, the formed ammonium carbonate from the reaction between ammonia and CO2 under high temperature and pressure condition is unstable when pressure decreased. Thus combing the flash operation after pressured carbonation, the formed ammonium carbonate can decompose to release ammonia and CO2, which can further be absorbed and returned to the pressurized carbonation process. This could effectively improve the ammonia utilization rate and reduce the production cost of ammonium sulfate as well.

Key words: phosphogypsum, carbon dioxide, pressurized carbonation, simulation, equilibrium

摘要:

围绕磷石膏加压碳酸化转化过程,首先通过实验研究了原料种类对加压碳酸化转化过程的影响,进一步采用Aspen plus 流程模拟软件深入分析了各工艺参数对磷石膏加压碳酸化过程平衡转化率的影响规律。结果表明,在加压条件下碳酸化反应均可在5 min时达到平衡,其中分析纯无水硫酸钙更容易完全转化,而二水硫酸钙及磷石膏因含有结晶水或其他杂质,使得其难以完全转化。增大初始氨水浓度、N/S(氨和原料中SO3的摩尔比)以及适量提高反应温度与体系压力,均能有效提高磷石膏加压碳酸化反应平衡转化率。特别是在高温和加压条件下,氨与CO2反应生成的碳酸铵盐可以通过降压闪蒸操作实现其自分解,经吸收返回用于加压碳酸化转化过程,可有效提高氨的利用率,降低硫酸铵生产成本。

关键词: 磷石膏, 二氧化碳, 加压碳酸化, 模拟, 平衡

CLC Number: