Pelletizing steel mill desulfurization slag

Hot metal desulfurization slag is a high-metallic iron content slag produced at a typical steelmaking facility and is currently considered waste. Each year, 50,000 tons of this slag is produced at one particular steelmaking plant. This material can be beneficiated so that it can be utilized as blast furnace feed, but it is necessary to first develop a process for agglomerating it into pellets. A beneficiated slag concentrate was both conventional bentonite binder and a new fly ash-based binder (FBB) that was formulated by the investigators. The FBB used a high-carbon fly ash that is currently landfilled as waste. In addition to fly ash, FBB contained calcium hydroxide as an activator that also acts as flux known to improve the pellet's reducibility characteristics. The desulfurization slag concentrate pellets bonded with the FBB had superior dry compressive strengths compared to the bentonite-bonded pellets.