Extraction And Recovery Of Indium In The Blast Furnace Dust

Indium is recovered from the by-products of nonferrous metallurgical factory. In the paper, An indium extracting hydrometallurgical process from the dust of lead smelting is researched.The process consists of four parts: leaching process with sulfuric acid of high concentration at high temperature, separate arsenic process with refrigeration and filtration, recover zinc process by the liquid of leaching slime-washing and extract indium process with D₂EHPA.In the leaching process, the leaching conditions are: the ratio of sulfuric acid and water (volume ratio) 1:2, the ratio of liquid-solid: 4:1, reaction temperature: 112℃, leaching time 2 hours. The leaching rate of indium is up to 80% by 2 recycle leaching.Based on the results of extract indium conditions experiment, the extracting conditions is given as follow: beginning acid concentration of 2mol/L, the phase ratio 0/A =1:4, reaction temperature: 40℃, 2 hours time, the content of D₂EHPA 30%, one stage extraction. The extraction ratio of indium is above 97%.Based on the results of extracting indium conditions experiment, beginning acid concentration is very sensitive to the extraction process, and the extraction process is divided into two parts: one is extraction under high acid concentration of leaching liquid which is up to 5mol/L by one stage current extracting, the other is extraction under lower acid concentration of leaching slime-washing liquid which is up to 2mol/L by three stages current extracting; Other extraction conditions are the same as before. The extraction rate of indium is 74.42% in part one, and 98.55% in the other part.In the process, there are some characteristics as follows:(1)The emulsion does not appear during the extraction process by using the leaching liquid and leaching slag-washing liquid as the liquid of indium.(2)The extraction process is divided into two parts because the beginning acid concentration is very sensitive to the extraction process, and other metals is easy for recovery(3) The process is a hydrometallurgical process, it does not destroy environment and can be applied in industry conveniently and easily.