Patent ID: 6379421
Filing Date: 2002-04-30
Classification: C21B,C22B,Y02P

Abstract:
A method for removing one or more undesirable generally toxic metals including at least one of zinc, lead, and cadmium from an iron-containing material, said method comprising:sintering said iron-containing material producing at least one sinter mass and sinter flue gas; crushing such sinter mass into oxidized sinter lumps for handling; preheating said sinter lumps in a non-reducing atmosphere, if needed, to achieve a non-sticking temperature above 650Â° C.; introducing said hot oxidized sinter lumps at such temperature above 650Â° C. into a moving bed reduction reactor; introducing a hot reducing gas at a temperature above about 850Â° C. into said reduction reactor; contacting said hot sinter lumps in said reduction reactor with a stream of said hot reducing gas thereby reducing said sinter lumps and entraining in said stream of reducing gas said undesirable metals in vaporized form and/or in the form of molten aerosols; withdrawing from said reduction reactor the hot reducing gas used to reduce said sinter lumps as an off reducing gas containing and maintaining the vapors and/or aerosols of said undesirable metals; cooling said off reducing gas to a temperature low enough to solidify the vapors and/or aerosols of the undesirable metals contained therein; separating said solidified undesirable metals from said off gas; and withdrawing the resulting reduced iron-containing sinter lumps from said reduction reactor.