A qualitative study on the retention of mercury from SO2-containing process gases on copper smelter dusts

Mercury present in process gases can to some extent be removed in dust filt ers such as textile bag house filters. The removal efficiency in such filte rs is dependent on gas composition, gas temperature and properties of dust particles collected in the filter. In the present study, laboratory scale e xperiments were conducted to study qualitatively the influence of different types of dusts on the retention of mercury in SO2-containing gases. A gas mixture composed of N-2, SO2, O-2 and Hg was passed through a textile filte r covered with dust, Two different types of dust were used in the experimen ts: one dust containing mainly Cu- and Fe-sulphides and Fe-oxides and one c ontaining mainly Cu-, Fe, and Zn-oxides and -sulphates, The dusts were stud ied using microprobe equipment after exposure to the mercury-containing gas , Thermodynamic calculations were carried out for comparison with the exper imental results. The study shows that mercury is mainly associated with par tially roasted chalcopyrite particles.