Sustainable Mining and Metallurgy

The modification of the melt source is an effective approach to reduce the TiO2 content in high-titanium slag and improve its hydration activity, which will enhance its value as an auxiliary cementitious material in cement and concrete. This study proposed the use of steel slag to regulate the slag system's alkalinity and TiO2 content, achieving high-titanium slag melting and melt modification in graphite crucibles. The melt was then rapidly cooled through water quenching to prepare steel slag-modified high-titanium slag. The results indicate that with the addition of steel slag, the alkalinity of the high-titanium slag melt increases, and the iron oxide content in the modified high-titanium slag decreases, suggesting that the melting and modification process can recover metallic iron. The glass content of the modified high-titanium slag is always above 75%, but it decreases as the alkalinity increases. As the alkalinity increases, the TiO2 content in the system decreases, weakening its stabilizing effect on the glass structure, which leads to an improvement in the hydration activity of the modified high-titanium slag micro-powder. The modified high-titanium slag micro-powder with an alkalinity of 1.5 meets the requirements of S75-grade granulated blast furnace slag powder for cement mortar flowability and activity index.