METHOD OF ARC-FURNACE DUST RECOVERY Russian patent published in 2013 - IPC C22B7/02 C22B19/30 

FIELD: metallurgy.

SUBSTANCE: arc-furnace dust is agglomerated together with crushed carbon reducing agent and binder material in the form of pellets. The latter are dried, heated and roasted in rotary kiln together with solid reducing agent lumps at temperature of discharged materials of 700-1000°C, gases are cooled and dust bearing zinc and lead sublimates is caught therefrom. Note here that, prior to agglomeration, arc-furnace dust is premixed with lime-bearing material and crushed carbon reducing agent in amount 1.5-2 times higher than stoichiometrically necessary content of carbon for reduction of iron, zinc and lead oxides. Mix is damped to water content of 8-11% and cured for 1-3 hours while obtained pellets are loaded into kiln together with solid carbon reducing agent lumps in amount of 200-500 kg per ton of arc-furnace dust, reducing agent lump size making 20 mm.

EFFECT: higher yield of zinc and iron metallisation.

4 cl, 2 tbl, 1 ex