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过程工程学报 ›› 2019, Vol. 19 ›› Issue (3): 603-608.DOI: 10.12034/j.issn.1009-606X.218291

• 过程与工艺 • 上一篇    下一篇

铁矿烧结烟气半干法脱硫灰亚临界水热非均相氧化

魏汝飞1, 陈龙智3, 龙红明1,2*, 王毅璠1, 李家新1, 李亚飞1, 宣明2   

  1. 1. 安徽工业大学冶金工程学院,安徽 马鞍山 243032 2. 冶金减排与资源综合利用教育部重点实验室(安徽工业大学),安徽 马鞍山 243032 3. 北京科技大学冶金与生态工程学院,北京 100083
  • 收稿日期:2018-09-28 修回日期:2018-11-16 出版日期:2019-06-22 发布日期:2019-06-20
  • 通讯作者: 李家新
  • 基金资助:
    国家自然科学基金项目

Subcritical hydrothermal heterogeneous oxidation of semi-dry desulfurization ash from iron ore sintering flue gas

Rufei WEI1, Longzhi CHEN3, Hongming LONG1,2*, Yifan WANG1, Jiaxin LI1, Yafei LI1, Ming XUAN2   

  1. 1. School of Metallurgical Engineering, Anhui University of Technology, Ma?anshan, Anhui 243032, China 2. Key Laboratory of Metallurgical Emission Reduction & Resources Recycling (Anhui University of Technology), Ministry of Education, Ma?anshan, Anhui 243032, China 3. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
  • Received:2018-09-28 Revised:2018-11-16 Online:2019-06-22 Published:2019-06-20
  • Contact: LI Jia-xin

摘要: 采用亚临界水热氧化法对铁矿烧结烟气半干法脱硫灰进行氧化,采用单因素变量法考察初始压强、温度、固液比、反应时间对脱硫灰中CaSO3氧化的影响。结果表明,适当增加初始压强、提高氧化温度、降低固液比及增加氧化时间可有效改善脱硫灰中CaSO3的氧化效果,温度对CaSO3氧化影响最显著。在初始压强4 MPa、反应温度240℃、反应时间120 min、固液质量比为1:30的条件下,脱硫灰中CaSO4定向析出,呈纤维状,为脱硫灰水热氧化同步合成CaSO4晶须提供了可能。

关键词: 半干法脱硫灰, 综合利用, 氧化改性, 水热合成, 硫酸钙晶须

Abstract: Oxidation modification is an effective way to improve stability of materials. In this work, the semi-dry flue gas desulfurization ash was oxidized by a new method: subcritical hydrothermal heterogeneous oxidation. The effects of reaction temperature, reaction time, initial pressure and mass ratio of solid to liquid on the oxidation of desulphurization ash were studied. The results showed that the desulphurization ash can be oxidized to calcium sulfite by subcritical hydrothermal oxidation, and the oxidation effect was well. The highest oxidation rate reached 99.70%. The oxidation rate of calcium sulfite in desulfurization ash was improved by increasing the initial pressure, reaction temperature, reaction time and decreasing the mass ratio of solid to liquid. When the initial pressure was 4 MPa, the reaction temperature was 240℃, the mass ratio of desulfurization ash to water was 1:20, and the reaction time was 90 min, the oxidation rate of calcium sulfite was 92.26%. In the subcritical hydrothermal system, calcium sulfite was dissolved and ionized to form Ca2+ and SO32? firstly, then SO32? was oxidized by the free oxygen in water, and finally calcium sulfate was formed. Increasing the initial pressure and decreasing the mass ratio of solid to liquid increased the dissolution and ionization quality of calcium sulfite and then increased the oxidation rate of calcium sulfite. With the decrease of mass ratio of solid to liquid, the microstructure of the sample changed obviously from spherical to fibrous. Under the conditions of initial pressure 4 MPa, temperature 240℃, reaction time 120 min and mass ratio of solid to liquid 1:30, calcium sulfite precipitated directionally to form calcium sulfate whisker. It provided the possibility for the simultaneous synthesis of calcium sulfate whiskers by subcritical oxidation of desulfurized ash.

Key words: Semi-dry desulfurization ash, Comprehensive utilization, Oxidation modification, Hydro-thermal synthesis, Calcium sulfate whisker