铝电解槽用干式保温防渗料的研制及应用

Development and application of insulating dry barrier for aluminum electrolytic cell

以优质低高铝为主要原料 ,添加钠长石、石英等外加物 ,制备了干式保温防渗料。随钠长石加入量增加 ,其釉层厚度逐渐增加 ,而热导率先减小 ,再增大 ,钠长石的加入量以 3 %为宜 ;随石英加入量增加 ,防渗料的耐火度由低到高再降低 ,烧结层厚度则由大到小再增大 ,石英的加入量以 9%为宜。制备的干式保温防渗料的理化指标为 :w(Al2 O3 +SiO2 )≥ 94.97% ,耐火度 1 690～ 1 71 0℃ ,80 0℃时的热导率 0 .376W·(m·K) -1 。它能有效地与电解质反应 ,形成一层致密的釉层 ,阻止电解质和铝液继续往下渗透 ,大大减少了冰晶石的消耗 ,且釉层下部材料仍保持疏松 。

The insulating dry barrier was prepared by using high alumina materials with low alumina and impurities as aggregate,and albite and quartz as additives.The results show that: 1)The thickness of glazed layer of the dry barrier after used increases gradually,but it's thermal conductivity initially decreases and then increases with the increase of albite addition,the optimum addition of ablite is 3%; 2)The refractoriness of the barrier changes from low to high and then declines,however,the sintering thickness changes from high to low and increases lastly,9% is the optimum addition of quartz.The chemical composition and physical properties of the prepared barrier are: w (Al 2O 3+SiO 2)≥94.97%,refractoriness 1690～1710 ℃,thermal conductivity at 800 ℃ 0.376 W·(m·K) -1 .The dry barrier can react effectively with the electrolyte forming a dense glazed layer to prevent the further penetration of electrolyte and molten aluminium and thus reducing the consumption of cryolite enormously.And the materials beneath the glazed layer still keeps loose and can be used repeatedly.