Abstract: In order to understand the metallurgical effect of industrial by-product AF3F^TM which can be as the substitute of fluorite in steelmaking process,slag melting characteristics test,hot metal desulphurization and molten steel desulfurization experiments had been done to compare the slagging and desulfurization effect between this AF3F^TM and fluorite slagging agents.Through those experiments it can be concluded that AF3F^TM has better metallurgical effect than fluorite ball and can reduce the lime melting point to lower level. When the ratio of this two slagging agents is 10%,the melting point of lime with AF3F^TM is reduced by 45 ℃.The slag which contains AF3F^TM can achieve slag formation faster and has better desulfurization result.Under the same experiment conditions,AF3F^TM can save at least 20% in terms of usage,and resulted the fluoride waste emissions is reduced by 10% compared with fluorite ball. Therefore,this new slagging agent can find its valuable application in the metallurgical industry,analyzed comprehensively from the perspectives of resources,cost,environmental and metallurgical effect.