Thermal treatments of industrial wastes in controlled atmospheres for the elimination of As, Hg, Cd, Se and the concentration of Pb, Cu and Zn

Thermal treatments of five different types of non-ferrous metallurgical was tes, under a controlled atmosphere, were carried out at temperatures lower than 800 degrees C for the separation of their toxic compounds and the conc entration of valuable metals in the treatments residues. The best results w ere obtained by the treatments in air or hydrogen, or both successively. Si mple treatments, using air or hydrogen, of three samples allowed the elimin ation of more than 95% of their toxic elements and almost doubled their val uable metals concentration. For the rest of the samples, a combined treatme nt was necessary for their efficient decontamination. In this case, the val uable metals content in the treatment's residue was increased to a reasonab le value. Most of the solids issuing from these treatments can be recycled in current non-ferrous metallurgical processes. (C) 1999 Elsevier Science B .V. All rights reserved.