Abstract: (CaOA12O3)slag and(CaOSiO2A12O3)slag were synthesized with CaO， SiO2 and A12O3 as main raw materials. The occurrence form of the sulfur in the slag under different cooling methods such as watercooling and furnacecooling was investigated. The results showed that 11CaO·7A12O3·CaS solid solution is the main occurrence form of sulfur in the CaOA12O3 slag with the substrate of 12CaO·7A12O3. However，in the CaOSiO2A12O3 slag， when the A12O3 content was low， sulfur existed in the form of CaS single phase in both water and furnace cooling processes， while the A12O3 content was high， sulfur existed in the form of CaS single phase when the slag was watercooled， while when the slag was furnace cooled， the sulfur existed in the form of 11CaO·7A12O3·CaS solid solution. The occurrence form of sulfur in LF refining slags can be controlled by changing the cooling method and the composition of the slag.

Key words: refining slag, sulfur, occurrence form, solid solution, watercooling, furnacecooling