Effect of Additives on Melting Point of LATS Refining Ladle Slag

To avoid slag sticking on the ladle immersion cover during the LATS refining and alloying process, the effect of Al2O3 on the melting point of the ladle slag was studied and the additives including CaF2, B2 O3, Li2 O, and CaO were used to decrease the melting point of the ladle slag. The melting point was measured using the hemisphere method. The results show that the addition of Al2 O3 to the ladle slag increases the melting point. The fluxing action is not remarkable if only CaF2 or CaO is used as the additive. The fluxing action of the composite additive obtained by the mixing of CaO and CaF2 in the mass proportion of ΩCaO: ΩCaF2 = 2:1 is preferred. The fluxing action of B2 O3 is also notable. When the B2 O3 content in mass percent is in the range from 2% to 10%, the corresponding melting point is 1 380 °C to 1 290 °C. The fluxing action of Li2O is the most remarkable. When the Li2 O content is up to 5%, the melting point of the slag is lower than 1 300 °C.