Experimental investigation on the influence of blast furnace slag basicity and MgO/Al2O3 ratio on flow characteristics using the image measurement method

This study assessed the influence of basicity and the MgO/Al2O3 ratio on the flow characteristics of the CaO-SiO2- Al2O3-MgO blast furnace slag (BFS) system, employing an innovative visualization method. Elevating the basicity from 0.8 to 1.2 increased the critical flow temperature (Tc) from 1286.0 degrees C to 1335.5 degrees C and decreased the critical flow velocity (Vc) from 4.18 mm/min to 3.18 mm/min. Adjusting the MgO/Al2O3 ratio led to fluctuations in Tc and Vc around 1313.0 degrees C and 3.7 mm/min, respectively, demonstrating a negligible impact on BFS flow characteristics. The observed direct correlation between Vc and the temperature range of significant flow characteristic modifications suggests an extended solid-liquid phase transition and a slower discharge of BFS with increasing Vc. Spectroscopic data revealed enhanced flow characteristics by depolymerizing the aluminosilicate structure of BFS with increased basicity. Similarly, an increased MgO/Al2O3 ratio prompted depolymerization but had an insignificant impact on BFS flow characteristics.