CPC B09B 3/40 (2022.01) [C01G 9/02 (2013.01); C01G 9/04 (2013.01); C01G 9/08 (2013.01); C04B 7/365 (2013.01); C05D 9/00 (2013.01); C21B 15/006 (2013.01); C21C 5/565 (2013.01); C22B 1/005 (2013.01); C22B 1/08 (2013.01); C22B 7/002 (2013.01); C22B 7/02 (2013.01); C22B 13/025 (2013.01); C22B 19/30 (2013.01); C25C 1/16 (2013.01); C21B 2200/00 (2013.01)] | 18 Claims |
1. A process for the purification of waste materials or industrial by-products comprising chlorine (B), the process comprising the steps of:
a) preparing a composition (C) by blending or mixing waste materials or industrial by-products comprising chlorine (B) with one or more materials comprising heavy metals (HM);
b) reacting (B) and (HM) by thermal treatment of (C);
c) separating evaporated heavy metal chloride compounds (HMCC); and
d) obtaining a solid material after the thermal treatment step, wherein:
the heavy metals (HM) are one or more from the following set of elements: Zn, Pb, Hg, Cu, Cd, Tl, In, Sn, Ni, Co;
the thermal treatment is carried out at a temperature of 500-1200° C. and under a non-oxidizing atmosphere;
the materials comprising heavy metals (HM) and the waste materials or industrial by-products comprising chlorine (B) are mixed or blended in the presence of water, with 2-50% by mass of water being present in the composition (C); and:
a) a ratio of the materials comprising heavy metals (HM) to the waste materials or industrial by-products comprising chlorine (B) is chosen so that a chlorine content of the composition (C) is between 100 and 150% of an amount necessary for a stoichiometric conversion of the heavy metals (HM) in the materials comprising heavy metals (HM) into chlorides; or
b) the ratio of the materials comprising heavy metals (HM) to the waste materials or industrial by-products comprising chlorine (B) is chosen so that the chlorine content of the composition (C) is between 80 and 100% of the amount necessary for a stoichiometric conversion of the zinc in the materials comprising heavy metals (HM) into chlorides.
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