真空热还原处理铝电解槽废防渗料的研究

Study on disposal process for spent dry barrier of aluminum pots by vacuum thermal reduction

铝电解槽废防渗料中含有大量有害的可溶性氟化物,是一种危险废弃物,急需进行处理。本文对一种真空铝热还原处理废防渗料的工艺进行了研究。通过采用X射线衍射分析对真空热还原后物料的物相进行了分析,研究了还原温度与铝粉配入量对还原过程的影响。结果表明,采用真空热还原处理铝电解槽废防渗料,可实现废防渗料中耐火材料、钠和氟化物电解质三者的分离,在还原温度为1200℃,铝粉配入量为12%时,废防渗料中钠的回收率可达96.95%和氟的回收率可达98.64%,还原后物料的物相主要为氧化铝和钠长石。

The spent dry barrier of aluminum pots contains a large amount of harmful soluble fluorides,which are required to be treated urgently as a kind of hazardous waste.A vacuum aluminothermic reduction process for the treatment of spent dry barrier was studied in laboratory.The phases of the malerials after vacuum thermal reduction were analyzed by X-ray diffraction analysis,and the influence of reduction temperature and addition of aluminum powder on the reduction process was studied.The results showed the refractory material,sodium and fluoride electrolyte in the spent dry barrier can be separated by the vacuum thermal reduction of the spent dry barrier.The recovery rate of sodium was 96.95%and the recovery rate of fluorine was 98.64%under the condition of reduction temperature 1200℃and the addition of aluminum 12%.The phases of the reduced materials were mainly alumina and albite.