欢迎访问过程工程学报, 今天是

过程工程学报 ›› 2020, Vol. 20 ›› Issue (5): 609-618.DOI: 10.12034/j.issn.1009-606X.219259

• 过程系统集成与化工安全 • 上一篇    

水氯镁石制备金属镁的过程集成与能量分析

万兆源1,2， 周 桓1*   

  1. 1. 天津科技大学化工与材料学院，天津市卤水化工与资源生态化利用重点实验室，天津 300457 2. 唐山市人民医院，肿瘤研究所中心实验室，河北 唐山 063001
  • 收稿日期:2019-07-19 修回日期:2019-09-18 出版日期:2020-05-22 发布日期:2020-05-18
  • 通讯作者: 周桓 zhouhuan@tust.edu.cn
  • 基金资助:
    典型盐湖卤水环境温度范围稳态相平衡与成盐动态的集成相图及模型化;柴达木盆地盐湖巨化学系统，全组分、全浓度、多温热力学模型构建及模拟预测系统集成

Process integration and energy analysis of bischofite producing metal magnesium

Zhaoyuan WAN1,2, Huan ZHOU1*   

  1. 1. College of Chemical Engineering and Materials Sciences, Tianjin University of Science & Technology, Tianjin Key Lab of Brine Chemical Engineering and Ecological Utilization of Resources, Tianjin 300457, China 2. The Central Laboratory of Cancer Institute, Tangshan People?s Hospital, Tangshan, Hebei 063001, China
  • Received:2019-07-19 Revised:2019-09-18 Online:2020-05-22 Published:2020-05-18
  • Contact: ZHOU Huan zhouhuan@tust.edu.cn
  • Supported by:
    ;国家自然科学基金，盐湖化工联合基金

PDF

摘要： 以无水氯化镁和氧化镁作为中间产物，电解和热还原为两个关键方法，集成各种相关过程，构建了从水氯镁石到金属镁的综合过程网络，其中涉及24个物种、20个化学过程和25个工艺路线；建立了最低能耗分析模型用于简单和复合过程的能量分析；利用物质的标准生成焓和多温等压摩尔热容，计算得出全部反应过程及工艺过程的能量消耗和热量移除。结果表明基于还原法的最优路径是水氯镁石用石灰法转为氢氧化镁，进而煅烧成氧化镁，再铝热还原成金属镁，该过程能耗360.15 kJ/mol，放出热量–315.46 kJ/mol；基于电解法的最优路径是石灰乳法生成氢氧化镁，再煅烧成氧化镁，通过在熔融电解质中电解生成金属镁，该过程能耗738.54 kJ/mol，放出热量–135.42 kJ/mol。无水氯化镁制备耗能高，不在最优路径中。

关键词: 水氯镁石, 金属镁, 热力学, 过程集成, 能量分析

Abstract: Magnesium metal production from bischofite is a process of high energy consumption. It is necessary to explore the process of lowest energy consumption. In this work, with anhydrous magnesium chloride and magnesium oxide as intermediate products, electrolysis and thermal reduction as key methods, a comprehensive process network from bischofite to magnesium metal was constructed, which involved 24 species, 20 chemical processes and 25 process routes. Furthermore, one minimum energy consumption model was proposed to evaluate the thermal effect of multi–chemical process, or multi–process routes. Using the standard enthalpy of formation and temperature-depended isobaric molar heat capacity, the energy consumption and heat removal of all 25 process routes were calculated. The results showed that the optimum path based on thermal reduction method was converting bischofite to magnesium hydroxide by lime method, calcining to obtain magnesium oxide, and further reducing to magnesium metal by aluminum. The energy consumption was 360.15 kJ/mol, and the heat released was –315.46 kJ/mol. Compared with this, the better path of electrolysis was producing magnesium hydroxide by lime method, calcining to get magnesium oxide and further producing magnesium metal by electrolyze in molten electrolyte. The energy consumption of the process was 738.54 kJ/mol, and the heat released was –135.42 kJ/mol. Because of the high energy consumption of anhydrous magnesium chloride preparation, it was not in the optimal path.

Key words: bischofite, metal magnesium, thermodynamics, process integration, energy analysis