废弃液晶显示器中铟的溴化法浸出研究

Research of leaching indium in waste liquid crystal display by method of bromide

液晶显示器(LCD)是电视、电脑和手机等电子产品的重要部件,资源化回收所含的稀有金属铟具有重要意义。结果表明:(1)采用溴化法浸出LCD中的铟,在采用Br2、溴化钠及硫酸质量浓度分别为20、16、55.2g/L的溴水浸出剂、浸出时间3h、温度50℃的条件下,铟浸出率可达99.2%。(2)采用双极室阴离子膜电解槽电解回收Br2,当电解电压为1.8V、电解时间为300min时,采用四氯化碳对浸出液中未参加反应的Br2进行萃取回收,Br2的回收率为83.5%;电解阴极液中的Fe3+被还原为Fe2+以达到屏蔽目的,电解240min后Fe2+生成量达1 801mg/L,转化率为90.9%。(3)采用氢氧化钠沉淀法粗提取铟,当pH为4.78时,沉淀物的主要成分为In(OH)3,滤渣中In3+占总金属离子质量的47.9%,铟的回收率为94.8%。

Liquid crystal display （LCD） is the important parts of mobile phones,TV,computer and other electronic products. Because of containing rare metal indium, the resource recycling of LCD is of great significance. The results showed that： （1） bromination method was used to leach indium from LCD and indium leaching rate reached 99.2 % under the conditions of 20 g/L of bromide dosage, 16 g/L of sodium bromide dosage,55.2 g/L of sulfuric acid dosage,3 h of leaching time,50℃ of temperature. （2） Electrolytic process was used to recovery bromine from the LCD leaching solution and bromine recovery was 83.5% with carbon tetrachloride extraction; Fe^3＋ was transformed into Fe2＋ by using electrolysis and the concentration of Fe^2＋ was 1 801 mg/L, 90.9% of transformation rate at 240 min of electrolytic time. （3） NaOH precipitation method was used to precipitate indium from leaching solution. The precipitation mainly contains In（OH）3 and 47.9% of In^3＋ quality in total metal ion in residue,the indium recovery of precipitation was 94.8% when pH was 4.78.