Coke breeze-less sintering of BOF dust and its capability of dezincing

In order to promote recycling of basic oxygen furnace (BOF) dust, sintering of the dust without coke breeze (fuel) has been researched by pot test met hod and the possibility of dezincing during the sintering has been evaluate d. Typical BOF dust, containing about 20 % of metallic iron (M.Fe), is agglome rated without fuel and dezinced by about 50 % during sintering. The agglome ration is caused by heat generation due to oxidation of the metallic iron. The dezincing takes place by the reaction: ZnO+M.Fe --> Zn(gas)+FeO at elev ated temperature. Secondary dust emitted during sintering mainly consisted of ZnO containing 40 to 50 % of zinc. The ratio of dezincing is improved by blast furnace (BF) dust addition and up-draft sintering method. The carbon in BF dust produces metallic iron and CO gas from "FeO" melt, then they ac celerate ZnO reduction. The up-drafting makes a melt pool in the lower laye r, where the melt remains longer at high temperature, resulting in increase in the ratio of dezincing.