TREATMENT OF WASTE LIQUID CONTAINING COPPER HAVING HIGH CONCENTRATION BY IRON POWDER

摘要

PURPOSE:To treat efficiently waste liquid contg. copper having a high concn., by mixing acidic waste liquid and alkaline waste liquid to requlate pH to =3.5, mixing specific acidic waste liquid, water and iron powder with the liquid mixture, and subjecting the mixture to oxidation and reduction. CONSTITUTION:Waste acidic etching liquid A contg. Cu and waste alkaline etching liquid B contg. Cu are mixed and stirred for 20hr in a mixing tank, and waste ferric chloride soln. and water are charged under stirring in a reaction vessel, whereby the waste liquid mixture is obtd. Iron powder is charged into the waste liquid mixture in the reaction vessel. The concn. of Cu therein determined by an analysis after stirring for 30min decreases to 200ppm and the concn. of Cu determined by the analysis again after charging of the iron of the amt. conforming to the amt. of copper and stirring for 30min is 4ppm. The pH in the stage of oxidation and reduction reaction is kept at 3.2. The liquid is then transferred through a relay tank into a flocculation tank, where an anionic flocculating agent is added to the liquid and the treated liquid is fed to a settling and concentrating device, so that the sludge thereof is treated in a concentrating tank.