CIESC Journal ›› 2025, Vol. 76 ›› Issue (1): 81-92.DOI: 10.11949/0438-1157.20240417

• Thermodynamics • Previous Articles     Next Articles

Prediction and verification of calcium sulfate scaling trend in hydrothermal desalination process of high salinity mine

Yuanhui TANG1,2,3(), Yuanji BAI2,3, Qiang GUO1, Xiaolei HE4, Lixin YU3, Yakai LIN3(), Xiaolin WANG3   

  1. 1.State Key Laboratory of Water Resource Protection and Utilization in Coal Mining, National Institute of Clean-and-Low-Carbon Energy, Beijing 102209, China
    2.College of Chemistry and Environmental Engineering, China University of Mining and Technology, Beijing 100083, China
    3.Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
    4.China Huaneng Clean Energy Research Institute Co. , Ltd. , Beijing 102209, China
  • Received:2024-04-16 Revised:2024-08-18 Online:2025-02-08 Published:2025-01-25
  • Contact: Yakai LIN

高矿化度矿井水热法脱盐过程中硫酸钙的结垢趋势预测及验证

唐元晖1,2,3(), 柏元吉2,3, 郭强1, 何晓磊4, 余立新3, 林亚凯3(), 王晓琳3   

  1. 1.北京低碳清洁能源研究院,煤炭开采水资源保护与利用全国重点实验室,北京 102209
    2.中国矿业大学(北京) 化学与环境工程学院,北京 100083
    3.清华大学化学工程系,膜材料与工程北京市重点实验室,北京 100084
    4.中国华能清洁能源研究院有限公司,北京 102209
  • 通讯作者: 林亚凯
  • 作者简介:唐元晖(1986—),女,博士,副教授,tyh@cumtb.edu.cn
  • 基金资助:
    煤炭开采水资源保护与利用国家重点实验室2020年开放基金课题项目(GJNY-20-113-09);中央高校基本科研业务费专项资金项目(2022YQHH04);北京市自然科学基金项目(2232018);国家自然科学基金面上项目(22378225);国家重点研发计划项目(2022YFC2105103)

Abstract:

The highly mineralized mine water is characterized by its complex composition, high salinity, and significant hardness, which leads to the formation of inorganic scales during thermal desalination processes, primarily composed of CaSO₄. Based on the typical composition of highly mineralized mine water, a simulated feed solution containing Ca²⁺, Mg²⁺, Na⁺, Cl⁻, and SO42- was prepared. The solubility of CaSO₄ in the Ca²⁺-Mg²⁺-Na⁺-Cl⁻-SO42- system was then investigated using an isothermal dissolution method at temperatures of 40, 50, 60, and 70℃. The results indicate that within the temperature range of 40℃ to 70℃, the solubility of CaSO₄ decreases with increasing temperature, increases with higher MgCl2 concentration, and decreases with higher Na2SO₄ concentration. The Oddo-Tomson saturation index method was used to predict the scaling trend of CaSO4 in the thermal desalination process, and the modified saturation index (SI) equation was obtained. The prediction results of this equation are consistent with the scaling experiment of CaSO4 on the surface of stainless steel pipe at 65℃. When the saturation index exceeded 0.2, CaSO₄ crystals began to precipitate on the surface of stainless steel tubes in the Ca²⁺-Mg²⁺-Na⁺-Cl⁻-SO42- system. Finally, scaling experiments using simulated high-mineralized mine water SA and SB were employed to demonstrate the feasibility and limitations of this method in practical mine water applications.

Key words: highly mineralized mine water, calcium sulfate, saturation index, scaling, thermal desalination

摘要:

高矿化度矿井水具有成分复杂、含盐量高、硬度大的特点,在热法脱盐过程中会产生以CaSO4为主的无机垢。根据高矿化度矿井水的典型组成,配制含有Ca2+-Mg2+-Na+-Cl--SO42 -的模拟原料液,首先采用恒温溶解法,考察温度为40、50、60、70℃时CaSO4在Ca2+-Mg2+-Na+-Cl--SO42 -体系的溶解度。结果表明:在40~70℃的范围内,CaSO4的溶解度随温度的升高而减小,随MgCl2浓度的增加而增大,随Na2SO4浓度的增加而减小。采用Oddo-Tomson饱和指数法,对CaSO4在热法脱盐过程的结垢趋势进行预测,得到修正的饱和指数(SI)方程,该方程预测结果与65℃下CaSO4在不锈钢管表面的结垢实验相吻合。且当饱和指数大于0.2时,Ca2+-Mg2+-Na+-Cl--SO42 -体系中的CaSO4晶体开始在不锈钢管表面析出,最后采用模拟高矿化度矿井水SA和SB的结垢实验说明本方法在实际矿井水应用的可行性和局限性。

关键词: 高矿化度矿井水, CaSO4, 饱和指数, 结垢, 热法脱盐

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