LAUSR

During the steelmaking process, the generation of steelmaking slag is inevitable, and large quantities of steelmaking slag has been produced annually. Generally, steelmaking slag is used as a raw material for road construction and civil works. In Japan, approximately 14 million tons of steelmaking slag is generated annually, and more than 60% of it is used for road and civil constructions.1) Because of the high basicity (mass% CaO/mass% SiO2), alkaline elution is the most serious environmental issue when steelmaking slag is used near coastal areas or rivers. Therefore, treatments to suppress alkaline elution becomes necessary before slag utilization. Among the slag treatment methods, slag aging can suppress the volume expansion of slag;2) however, this treatment cannot prevent alkaline elution as it changes free CaO (MgO) to Ca(OH)2 (Mg(OH)2). Slag carbonation has also been proposed3–5) to change the free CaO that is exposed at the surface of the slag particle into CaCO3. This method can suppress the alkaline elution from the surface of the slag particle, but the industrial operation is still limited. In addiContribution of Mineralogical Phases on Alkaline Dissolution Behavior of Steelmaking Slag