The foaming effects of the LF foaming agents with different carbonate and carbide are investigated. It is shown that, for different foaming agents, the gas quantities generated by the reaction have obvious differences, and it is greater for carbonate than carbon and carbide. The composition of the foaming agent has important effect on the slag foaming. The foaming agent which is composed of SiC, CaC2 and carbonate has the optimal foaming effect. The height of the foaming slag with this foaming agent is twic...