RECOVERING METHOD OF Cu, Co, AND Ni FROM LEACHATE OF In CONTAINING DRAINAGE SLUDGE

摘要

PROBLEM TO BE SOLVED: To provide a method which efficiently collects Cu, Co, and Ni which are valuable metals from the leachate of an In containing drainage sludge.SOLUTION: The recovering method of Cu, Co, and Ni from a leachate of an In containing drainage sludge includes: a diluted sulphuric acid-leaching step in which drainage sludge including In, Cu, and Co is leached with diluted sulphuric acid, and is separated to an In containing residue, and a Cu, Co, and Ni-containing leachate; a first neutralization step in which alkali is added to the Cu, Co, and Ni-containing leachate to regulate the pH to 5.0-8.0 and to perform a first neutralization reaction; a rough Cu slag recovery step in which a reaction liquid after the first neutralization step is filtered and is separated to a filtrate and a rough Cu slag, then the rough Cu slag is collected; a second neutralization reaction step in which alkali is added to the filtrate obtained by filtering the reaction liquid after the first neutralization reaction, to regulate the pH to 8.0-12.0 to perform a second neutralization reaction; and a rough Cu and Ni slag recovery step in which the reaction liquid after the second neutralization reaction is filtered and is separated to a filtrate and a rough Co and Ni slag, and then to collect the rough Co and Ni slag.