Abstract: A method for recycling processing of dust generated in a converter furnace, includes: crushing and drying a cake formed by adding a binder to a slurry containing iron powder-containing dust that is generated at the time of converter blowing and wet-collected to produce a mixed slurry and subjecting the produced mixed slurry to a dehydration treatment in a filter press; accumulating the cake in an accumulation tank; and charging the cake into a converter furnace 10, the crushed product in the accumulation tank 25 is kept at a temperature of less than 90° C. by forcibly passing air into the accumulation tank 25 and charged into a converter furnace according to the converter operation.

Abstract: Method for recovering etchant from etching waste liquid 11 containing iron chloride is disclosed, wherein iron powder is mixed with iron chloride waste solution containing metal ions having a lesser ionization tendency than iron ion in an mixing vessel so as to cause a reaction between the iron powder and the metal ions and remove the precipitated metal from the iron chloride waste solution.