熔盐氯化废渣回收氯化盐及其促进钛铁矿盐酸浸出研究

Preliminary Studies on the Chloride Recycle from Residue of Fused Salt Chlorination and the Effect of Recycled Chloride on Hydrochloric Acid Leaching of Ilmenite

对熔盐氯化废渣进行氯化盐回收,并对回收氯化盐用于钛铁矿盐酸浸出体系作了初步研究。结果表明,水浸可以高效地将熔盐氯化废渣中的可溶氯化盐和不溶氧化物分离。水浸后剩余不溶残渣仅为11%,主要由Fe2O3、(Fe,Mg)2Ti O5和以及(Ca,Al,Mg)Si O3等性质稳定的物质组成,便于堆存,对环境无害。而KCl、Na Cl等废渣中主要氯化物在水浸母液蒸发结晶盐中富集,Cl元素回收率超过95%。回收得到的氯化盐添加到钛铁矿盐酸浸出体系中,可以提高钛铁矿的浸出反应活性。添加氯化盐比例越大,得到的人造金红石产品Ti O2品位越高。添加质量比为50%的氯化盐,可使人造金红石Ti O2品位由80.8%提升至84.5%。

This work preliminarily studied chloride recycle from residue of fused salt chlorination and the effect of recycled chloride on hydrochloric acid leaching of ilmenite. The results show that the soluble chloride and insoluble oxides in residue of fused salt chlorination can be effectively separated by water leaching. The insoluble residue of water leaching that mainly consists of stable oxides such as Fe2O3,（ Fe,Mg）2Ti O5,（ Ca,Al,Mg） Si O3,etc.,is only 11% of mass fraction. It is easy for stockpiling and harmless to the environment. The main chloride in residue of fused salt chlorination,KCl and Na Cl are enriched in the crystalline salts by evaporation of solution of water leaching,and the recovery rate of Cl element exceeds 95%. Adding the recycled chlorides into the system of hydrochloric acid leaching of ilmenite can improve the leaching reactivity. More recycled chlorides are added,synthetic rutile products with higher Ti O2 grade are obtained. The Ti O2 grade of synthetic rutile can increase from 80. 8% to 84.5% by adding recycled chlorides with a mass ratio of 50%.