MERCURY REMOVAL FROM PROCESS SLUDGES VIA HYPOCHLORITE LEACHING

Hypochlorite leaching of two types of chlorine-alkali sludges was stud ied. Experiments were carried out to determine the relevant variables affecting mercury extraction. Ninety seven percent of mercury extracti on was achieved with experimental conditions of 150 g l-1 NaCl, 35-deg rees-C temperature, 0.26% (w/w) active chlorine, a solid/liquid ratio (w/w) of 0.30 and a stirring speed of 1050 rpm. The effects of reactor geometry, type of agitator and consumption of acid and chlorine durin g leaching were analysed. A relationship was established between the m ercury in the leaching solution and in the solid under equilibrium con ditions.