铁矿烧结烟气半干法脱硫灰亚临界水热非均相氧化  

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

作　　者：魏汝飞 陈龙智 龙红明 王毅璠[1] 李家新 李亚飞 宣明 Rufei WEI;Longzhi CHEN;Hongming LONG;Yifan WANG;Jiaxin LI;Yafei LI;Ming XUAN(School of Metallurgical Engineering, Anhui University of Technology, Ma'anshan, Anhui 243032, China;Key Laboratory of Metallurgical Emission Reduction & Resources Recycling (Anhui University of Technology), Ministry of Education, Ma'anshan, Anhui 243032, China;School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China)

机构地区：[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

出　　处：《过程工程学报》2019年第3期603-608,F0001,共7页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:51704004);安徽省自然科学基金资助项目(编号:1808085QE133)

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Ca SO3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Ca SO3的氧化效果,温度对Ca SO3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Ca SO4定向析出,呈纤维状,为脱硫灰水热氧化同步合成Ca SO4晶须提供了可能。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.

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 

分 类 号：TF09[冶金工程—冶金物理化学]