VERFAHREN ZUR EXTRAKTION VON METALLEN AUS METALLENTHALTENDEN MATERIALIEN DURCH PYROHYDROLYSE

摘要

PCT No. PCT/NL95/00185 Sec. 371 Date Feb. 5, 1997 Sec. 102(e) Date Feb. 5, 1997 PCT Filed Jun. 1, 1995 PCT Pub. No. WO95/33686 PCT Pub. Date Dec. 14, 1995A method for extracting metals from metal-containing materials, especially waste, by pyrohydrolysis. The metal-containing materials which contain at least one or more of the metals from the group consisting of Zn, Cd, Pb, Hg, Cu, Sn (as Sn(0) and Sn(II)), As, Sb, Au, Ag and Bi, are made to react at 700-1100 DEG C., advantageously 800-900 DEG C., with a gas composition which at least comprises 25-45% by volume of water vapor, 0-12% by volume of carbon dioxide, 2-20% by volume of hydrogen chloride, 0-15% by volume of carbon monoxide, the remainder being nitrogen and possibly oxygen. The metals from the above-mentioned group are extracted in the form of volatile metal chlorides. More particularly, metal-containing materials are used which also contain one or more metals from the group consisting of Fe, Cr, Mn, Ni, Mg, Ca, Al, Si, Ti, Co and Zr, this last group of materials being hydrolysed, under the reaction conditions, to give non-volatile metal oxides, or remain, in the oxidic form, or form (2) a non-volatile metal chloride and therefore remain behind in the starting material.