Desulphurisation behaviour of blast furnace slag with high Al₂O₃ content at 1823 K

Abstract

The desulphurisation of blast furnace slag is an important metallurgical function of blast furnace smelting. To elucidate the desulphurisation behaviour of blast furnace slag with high Al 2 O 3 content, the slag-metal equilibrium method was employed to determine the sulfide capacity (C S ) of CaO-SiO 2-Al 2 O 3-MgO melts for blast furnace smelting at 1823 K. When basicity (R w =w(Basic oxide)/w(Acid oxide)) and w(MgO)/w(Al 2 O 3 ) were increased, the intensities of the characteristic peaks of [SiO 4 ] and [AlO 4 ] in Raman spectrum decreased, indicating that the degree of polymerisation had reduced. The cluster structures of [SiO 4 ] and [AlO 4 ] depolymerised and lgC S (i.e. the desulphurisation ability) increased, owing to which the number of free O 2− ions increased. However, when w(Al 2 O 3 ) was increased, the intensities of the characteristic peaks of [SiO 4 ] and [AlO 4 ] in Raman spectrum increased gradually, indicating that the degree of polymerisation had increased, and the simple structures of [SiO 4 ] and [AlO 4 ] were polymerised. As a result, both the number of free O 2− ions and lgC S decreased.

Sulphide capacity of CaO-SiO2-Al2O3-MgO-TiO2-FetO slag with high titanium and high FeO content based on HIsmelt process

“…The coeffcient of determination ( R 2 ), correlation coeffcient (r), root-mean square error (RMSE) of the optimal model reached 0.9763, 0.9881, 0.113, respectively, which outperform the results of the reported models. Zheng et al [5] studied sulphide capacity of CaO-SiO 2 -Al 2 O 3 -MgO slag system by the slag-metal equilibrium method, and analysed the results from the perspective of Raman spectrum. Allertz et al [6] used the copper-slag equilibrium technique to determine the sulphide capacities, which were increased with the increase of oxygen partial pressure at 1873 K, and the effect of changing oxygen partial pressure was much more significant than that of slag composition at a fixed oxygen partial pressure.…”