FREMGANGSMAATE FOR RENSING OG GJENVINNING AV METALLISK KVIKKSOELV FRA ROESTEGASSER SOM INNEHOLDER DETTE

摘要

Method for recovering in metal form, the mercury entrained in roasting gases, containing SO2 so that the cleaned gas has less than 0.1 mg/m<3> of such element. The system is essentially comprised of a conventional device for cooling and washing the gas; two towers sprinkled with an acid solution of Hg(SCN)4<2->, free SCN<-> and activated carbon; two wet electrostatic precipitators one in front of the first tower and the other one between both towers and a reactor for the washing with ammonia of the emulsion (soot) obtained in the condensation. All quicksilver-bearing residues are recycled in the roasting oven, with the appropriate periodicity till hot gases reach, in predetermined conditions, a mercury content higher than 40 mg/m<3>.