低温碱溶脱除液晶显示器(LCD)玻璃基板粉末中的硅和铝

Desorption of silicon and aluminum in LCD glass powder at low temperature and alkali dissolution

为了提高氯化法回收LCD中铟的效果,降低Si O_2和Al_2O_3对氯化过程的干扰,采用Na OH对液晶显示器玻璃基板粉末中的硅和铝进行了预先溶出规律研究。首先分析了LCD粉末中Si O_2和Al_2O_3的含量、形貌以及铟的浸出变化,然后计算了Si O_2和Al_2O_3的脱除效率。在条件实验基础上通过正交实验设计得出优化实验条件。研究表明,在液固比为90∶2、温度95℃、溶出时间2 h、碱度0.56 g/L的最佳工艺条件下,Si O_2的脱除率为80.88%、Al_2O_3的脱除率为83.30%、二者总的脱除率为81.30%,洗涤液中没有发现铟的溶出,碱溶后的物料表面产生大量均匀的孔状结构。这将对液晶显示器玻璃基板粉末的资源化与铟的富集有重要意义。

Na OH solution was employed to dissolve SiO2 and Al2O3in the glass substrate of liquid crystal display（ LCD） to reduce their interference on chlorination process and improve the recovery rate of indium. The content and morphology of SiO2 and Al2O3as well as the extraction of indium were analyzed and the removal efficiency of SiO2 and Al2O3was calculated. Optimal condition was obtained by condition experiment and orthonormal test. Results indicate that the removal rates of SiO2 and Al2O3are 80. 88% and 83. 30%,respectively and the total removal rate is 81. 30% when liquid-solid ratio is 90 ∶ 2,temperature is 95℃,dissolution time is 2 h and alkalinity is 0. 56 g/L. No indium is found in the washing water. A large number of homogeneous pore structure generate on the surface of the alkali dissolved glass substrate. This is of great significance to the recycling of the LCD glass powder and the enrichment of indium.