Verfahren und Vorrichtung zur Immobilisierung und Rückgewinnung von Schwermetallen

摘要

A process for permanent immobilisation of heavy metal-contg. pollutants and for heavy recovery, using a glass melt, involves (i) feeding mixed and crushed glass and pollutants to a melting reactor; (ii) heating at up to 1500 deg.C to cause melting and high temp. reaction of the mixt.; (iii) supplying reactant and/or catalyst to the reactor to control the chemical reaction; (iv) continuously and/or discontinuously tapping molten heavy metal through a taphole; and (v) continuously withdrawing heavy metal-enriched molten glass over a weir. Appts. for carrying out the above process is also claimed. A closed melting reactor, having a charging opening above the glass melt surface and an overflow opening below the glass melt surface, is provided with (a) two or more nozzles (3), in the bottom (4), side walls and/or end walls, for introducing reactant and/or catalyst below the glass melt surface; and (b) one or more heavy metal tapholes (5) in the bottom (4) of the reactor (1). The wt. ratio of glass (esp. scrap glass) to pollutants (esp. sludge, dust, ash and/or slag) is 1:0.1-4. The reactor temp. is produced by combustion of fossil fuel, e.g. waste oil. Dust-laden gaseous reaction prods. are subjected to waste gas cleaning to remove pollutants for return to the reactor. USE/ADVANTAGE - For processing electroplating sludge, paint and lacquer sludges, clarification sludge, filter dust and ash, incinerator sludge, lead dross, salt slags, throat gas dust, tin ash, lead ash, calcium phosphate sludge, anode mud, browning salt waste, etc.. The process provides effective and inexpensive permanent immobilisation of a wide range of pollutants, prodn. of reusable prods. (e.g., glass for construction or insulating material mfr.) and recovery of heavy metals.