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研究了一种从某种稀土光学玻璃中回收稀土和铌、锆的湿法工艺。此工艺首先采用盐酸酸浸出稀土,然后加入一定量的碱保持微沸30 min,过滤后得到稀土滤液和铌锆的水解固体。研究了影响稀土浸出的条件,盐酸浓度、温度、浸出时间、液固比和搅拌速率,通过酸浸正交实验得出了这些影响因素的优组合,在优组合的条件下,Y、La、Gd的浸取率分别为100.00%、99.98%、99.96%;盐酸滤液经草酸沉淀、过滤、洗涤、灼烧获得稀土混合氧化物纯度为99.80%,总回收率高达99.6%。水解获得的铌、锆混合物经过草酸溶解、加Na_2CO_3沉淀铌,使铌、锆得到了分离;铌、锆的回收率分别到达91.68%、99.47%。
A kind of rare earth optical glass from rare earth and niobium, zirconium wet process. In this process, hydrochloric acid is firstly used to leach the rare earth, and then a certain amount of alkali is added to keep the solution boiled for 30 min. After filtration, the rare earth filtrate and the niobium zirconium hydrolyzed solid are obtained. The conditions affecting the rare earth leaching, the concentration of hydrochloric acid, the temperature, the leaching time, the liquid to solid ratio and the stirring rate were studied. The optimal combination of these factors was obtained by orthogonal test of acid leaching. Under the optimum conditions, The leaching rates of Gd were 100.00%, 99.98% and 99.96%, respectively. The hydrochloric acid filtrate was precipitated by oxalic acid, filtered, washed and calcined to obtain a rare earth mixed oxide with a purity of 99.80% and a total recovery of 99.6%. The mixture of niobium and zirconium obtained by hydrolysis was dissolved in oxalic acid and niobium was precipitated by adding Na_2CO_3. The recovery of niobium and zirconium reached 91.68% and 99.47% respectively.