Abstract: The sustainable development of environment was affected by high energy consumption, high pollution steel enterprises.The development of clean energy and the promotion of green economy were the road to the development of the metallurgical industry. Based on its own hot metal conditions, Nanjing Steel has developed manganese-based high-efficiency composite slagging materials to achieve clean production. It was found that when the ratio of manganese to silicon was 0.8-1.0, the dephosphorization rate of the converter reache over 90 %, and the dephosphorization stability was the best. When the Mn mass fraction in the slag reached 3.5 %, the slag had the best melting property and the lowest oxygen supply. When the final slag (FeO) mass fraction was 20 %-22 % and the final slag (MnO) mass fraction was 3.0 %-3.5 %, the slag dephosphorization efficiency was the best. The average mass fraction of residual manganese in the end point molten steel could be increased from 0.050 % to 0.092 % by using manganese-based high-efficiency composite slagging material. The use of high-efficiency composite metallurgical materials improves the stability of converter smelting, reduces soot emissions, reduces smelting production costs, and improves the overall competitiveness of enterprises.

Key words: environmental protection, converter, composite material, metallurgical applications