Process for the purification of waste materials or industrial by-products comprising chlorine

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)
• 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) being mixed or blended in the presence of water, with 2-50% by mass, preferably 5-30% by mass, more preferably 10-20% by mass, of water being present in the total composition (C), and
• the ratio of the materials comprising heavy metals (HM) and the waste materials or industrial by-products comprising chlorine (B) is chosen so that the chlorine content of the composition (C) is between 100 and 150%, preferably between 100 and 130%, most preferably between 100 and 110%, of the amount being necessary for a stoichiometric conversion of the heavy metals (HM) in the materials comprising heavy metals (HM) into chlorides, or
• the ratio of the materials comprising heavy metals (HM) and 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%, preferably between 90 and 99%, most preferably between 90 and 95%, of the amount being necessary for a stoichiometric conversion of the zinc in the materials comprising heavy metals (HM) into chlorides.