| 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>. |
