二段浸出法提取高炉瓦斯泥中的铟

Extracting of Indium from Blast Furnace Sludge by Two-Stage Leaching

为有效将铟与杂质元素分离,采用先酸性后碱性的二段浸出法提取高炉瓦斯泥中的铟.一段酸性浸出,使瓦斯泥中的金属离子进入液相;二段碱性浸出,利用氢氧化铟两性化合物的性质,使铟留在液相,从而与其他金属离子分离.铟浸出率随硫酸质量浓度、酸浸时间和氢氧化钠体积分数的增加而增加.当硫酸质量浓度达到200 g·L^-1时,铟的浸出率为38%;酸浸2 h后,浸出率的增加速度明显变慢;氢氧化钠体积分数为19%时,浸出率达96%.因此,二段浸出法的最佳工艺条件为:硫酸质量浓度200 g·L^-1,酸浸时间2 h,氢氧化钠体积分数19%.

In order to effectively separate indium from impurity elements, two-stage leaching method was used to extract indium from blast furnace sludge. Metallic ions in the sludge entered into liquid phase by first-stage acid leaching. Indium was separated from other metallic ions owing to amphoteric indium hydroxide, which stayed in liquid phase. Leaching efficiency of indium increased with mass concentration of sulphuric acid, acid leaching time and volume fraction of sodium hydroxide. When the mass concentration of sulfuric acid reached 200 g·L^-1, the leaching efficiency of indium was 38%. After acid leaching for 2 hours, the increase of leaching efficiency slowed down obviously. When the volume fraction of sodium hydroxide reached 19%, the leaching efficiency of indium was 96%. Therefore, the optimum conditions are: the mass concentration of sulfuric acid is 200 g·L^-1, the acid leaching time is 2 h, and the volume fraction of sodium hydroxide is 19%.