Abstract: In order to lower the sulfuric content of the offgas from a smelter reactor in which iron oxide is reduced to molten iron, in the presence of sulfur contaminants, a sufficient amount of a source of zinc is included in the charge to the reactor that the combined weight of the zinc source and the iron oxide source contains at least about 0.6% Zn (calculated as elemental zinc), on a dry weight basis. The temperature of the offgas is maintained at or above approximately 700.degree. C. Vaporized zinc, present in the offgas, binds with sulfur in the offgas to precipitate solid ZnS. After removal of the ZnS, the offgas may have a sulfuric content below 50 ppm by volume of H.sub.2 S equivalent. Suitable sources of zinc include blast furnace dust, electric arc dust, basic oxygen furnace dust, zinc calcine, and zinc sinter.

Abstract: A process for producing a low-sulfur content hot reducing gas stream comprising (a) contacting a sulfur bearing hot reducing gas stream with a desulfurizing agent comprising a desulfurizing fixed bed of solid particles comprising calcium oxide to thereby produce a low-sulfur content hot reducing gas stream and a calcium sulfide composition, then (b) contacting said calcium sulfide composition with an oxidizing gas composed of CO.sub.2, H.sub.2 O and O.sub.

Abstract: A process and apparatus for producing a low sulfur content, hot reducing gas by desulfurizing hot reducing gas by contacting the sulfur-bearing hot reducing gas with a bed of a particulate calcium oxide desulfurizing agent to thereby produce a product gas stream and a byproduct calcium sulfide composition, and then recovering sulfur from the calcium sulfide composition by contacting the calcium sulfide composition with hot liquid water at a temperature and corresponding pressure sufficient to maintain steam in the system and to thereby convert the sulfide to calcium hydroxide and hydrogen sulfide and to produce a liquid water stream containing sulfur, and then combining the sulfur-containing water stream with a fresh water stream and recycling this water stream for contacting the calcium sulfide composition. Preferably water vapor produced in the contacting step is condensed and returned to the system in the final stage of contacting the calcium sulfide composition with hot liquid water.

Abstract: Dolomite which has been used to remove sulfur and/or sulfur-containing compounds from gases by chemical reactions therewith is regenerated by passing through the spent dolomite an oxidizing gas selected from oxygen, CO.sub.2 and H.sub.2 O at temperatures between about 1500.degree. F. and the temperature at which the dolomite becomes unreactive.