硅热法炼镁还原工序节能减排技术进展

The Progress of Technologies for Energy Saving and Emission Reduction in Reduction Process of Magnesium Production by Silicothermic Reduction

还原工序是硅热法炼镁的最大能耗和排放工序,其主要工艺影响因素包括配料、真空系统、燃烧加热技术、还原罐寿命、还原炉结构以及镁还原渣处理。分别分析了各工艺因素对炼镁能耗和排放的影响机理,重点综述了还原工序节能减排技术的最新研发进展及其应用现状,最后对其发展方向进行了展望:(1)采用微机配料;(2)在机械泵前加水环泵或利用蒸汽射流泵代替机械泵进行抽真空;(3)采用蓄热燃烧技术;(4)开发新的还原罐材质以提高其寿命;(5)调整还原炉结构,延长烟气在炉内停留时间、提高还原罐密集度,或采用竖式炼镁还原炉;(6)机械化出渣、回收渣料热量并对还原渣进行再利用。

The reduction process causes most energy consumption and emission among all the processes of magnesium production by silicothermic reduction; its main influence elements technicaUy are as follows： feed proportioning, vacuum system, combustion heating technology, service life of the reduction pot, structure of the reduction furnace and disposal of the magnesium slag. Then, the elements＇ influence mechanisms on energy consumption and emission in magnesium production are analyzed separately. The new processes of research and development and their application status of energy saving and emission reduction technologies are summarized. Finally, an outlook has been given to the trends of the technologies： （1）The microcomputer proportioning system is adopted. （2）The water ring pump is assigned before the mechanical pump or jet vacuum pump is utilized singly. （3）Regenerative combustion technology is employed. （4）New materials are developed to prolong pots＇ service life. （5）The structure of the reduction furnace is adjusted, in order to prolong the remain time of the flue gas and improve pots＇ distribution density, or vertical magnesium reducing furnace is applied. （6）The magnesium slag is cleared out by mechanical equipments and reutilized after the remaining heat energy is recovered.