Patent ID: 7435281
Filing Date: 2008-10-14
Classification: C22B,Y02P

Abstract:
1. A pyromettallurgic process for the treatment of post-steelwork residues of a Waelz process in the form of melted slag, comprising the steps of: providing: preparing the residues from the Waelz process together with other post-steelworks residues, in a hopper and optionally adding additives and reaction elements; starting the pyrometallurgic treatment in pyrometallurgic treatment section (D) with a metal bath ( introducing the residues from the Waelz process together with other post-steelworks residues, together with suitable additives including at least one carbon and chemical reagents, into the furnace ( introducing directly into the slag ( reacting the residues with the slag ( a) separation of the liquid metallic phases which are added to the metal bath ( b) separation of the metallic volatile elements in vapour phase which, when transferred to the free zone of the furnace ( c) separation of the stable ceramic and/or silicate phases which form the inert phase of the slag ( d) (separation and neutralization of other elements risky for the environment that are present in the residues to provides inert slag ( supplying energy by means of an electrode column ( extracting the metallic bath ( extracting the powders leaving the pyrometallurgic treatment section (D), collecting and sending the powders to the hydrometallurgic treatment section (C) together with the powder coming from the rotating furnace (B); and obtaining zinc and lead from hydrometallurgic treatment section (C).