METHOD OF PROCESSING NONFERROUS METALLURGY WASTES CONTAINING ARSENIC AND SULPHUR

摘要

FIELD: chemistry.;SUBSTANCE: invention can be used when recycling cakes, sludge and dust formed when processing nonferrous metal ore containing arsenic and sulphur. The method of processing nonferrous metallurgy wastes involves loading a mixture, firing said mixture and crystallisation of arsenic trioxide. Before loading into a furnace, the mixture is prepared by loosening, mixing with a soda or lime additive, drying at temperature of 160-200°C to moisture content of not more than 4% of the mass of the mixture. The mixture is fired in two steps. At the first step, the mixture is subjected to weakly oxidative firing in a horizontal revolving tube furnace at initial temperature in the region of loading the mixture of 300°C and final temperature in the region of discharging cinder of 900°C. At the second step, gases coming out of the firing furnace are subjected to post-oxidation with oxygen in a post-oxidation chamber at temperature of 600-630°C. Gases coming out of the chamber are cleaned from cinder dust in a hot electrostatic filter. Arsenic trioxide is crystallised in a settling chamber which consists of series-arranged pre-chamber, crystalliser and tail chamber. Gases coming out of the settling chamber are cleaned from arsenic trioxide particles in a cold electrostatic filter. The cleaned gases are fed to a sulphuric acid production line.;EFFECT: invention increases the degree of extraction of arsenic and sulphur, purity of arsenic trioxide and environmental safety of the waste treatment process.;2 dwg, 1 ex