氟化盐母液综合利用及效益分析

以湿法生产氟化盐工艺过程中所排放的母液为原料,利用母液中的氟、铝和硅等资源,采用化工同元溶解的原理,其工艺路线为氯化钠脱硅—脱硅后的母液合成冰晶石—加石灰中和除氟、除酸。其关键技术为氯化钠脱硅:投入过量氯化钠,使母液中氟硅酸根转化成副产品氟硅酸钠,母液被精制;再加入精制氢氟酸与各形态铝合成冰晶石副产品,从而有效地提高了氟、铝和硅的收率。半工业化实验结果表明:计算年产4 000 t氟化铝产品的母液,企业可回收产品氟化铝140 t,生产副产品氟硅酸钠238 t、冰晶石206 t、中和残渣375 t,每年可获效益140万元人民币。

Comprehensive utilization and economic benefits of fluoride salt mother liquor

Using fluorin,aluminum and silicon of fluoride salt mother liquor in the wet process as the materials,the process i.e.sodium chloride desilication-compound cryolite-lime addition and fluorin and acid removal was employed by the chemical industry principle.Sodium chloride desilication was considered as the key technology.Silicofluoride acid radical of the mother liquor will be transformed into sodium silicofluoride if excess sodium chloride was added,and the mother liquor was refined.The refined hydrofluoric acid and various aluminum can compose the by-product-cryolite,which can improve the collection rate of fluorin,aluminum and silicon.The results indicate that aluminum fluoride product will be returned about 140 t,sodium silicofluoride and cryolite are 238 t and 206 t,and neutralization residue is 375 t,if the mother liquor output of aluminum fluoride product is 4000 t per year.The annual economic benefit will reach 1,400,000 yuan RMB.