从催化剂厂废渣回收稀土的综合利用

Comprehensive Utilization of Rare Earths Recovered from Waste Slag from Catalyst Factory

根据废渣矿物的物理和化学性质,对组份(％)为5.04Re_2O_3、21.70Al_2O_3、45.35SiO_2的废渣,提出回收稀土副产硫酸铝及水玻璃的综合利用三段浸出方案。首先以0.5mol/1的稀盐酸从废渣中抽出稀土,用草酸将稀土沉析;抽出稀土后的滤渣,继以1.5—2mol/1的稀硫酸浸出,所得硫酸铝溶液,配加石灰去除游离酸;酸浸过的滤渣,最后以10％的NaOH溶液浸出,常压下便能得到模数2.5—3.0的水玻璃。

Based on the physical and chemical properties of a slag which is composed of 5.04% Re_2O_3, 21.70% Al_2O_3 and 45.35% SiO_2, a scheme for the recovery of rare earths with aluminium sulphate and water glass as by products by the comprehensive utilization three-stage leaching process is proposed. Rare earths are first leached out with 0.5mol/l HCl and precipitated with oxalic acid.The filter cake is further leached with 1.5—2mol/l sulphuric acid. The free acid in the aluminium sulphate solution thus obtained is neutralized and removed by the addition of lime. Finally the residue is treated with 10&% NaOH solution under atmospheric pressure to give water glass of modulus of 2.5—3.0.