硫酸渣煤基直接还原焙烧制备直接还原铁

Study on Preparation of Direct Reduction of Iron from Pyrite Cinder by Coal-based Direct Reduction Roasting

摘要: 采用煤基直接还原焙烧—磁选工艺对硫酸渣进行焙烧回收铁的试验研究，考察了还原剂、助熔剂、焙烧温度、焙烧时间等因素对焙烧效果的影响。结果表明：还原剂用量为30%，助熔剂CaO和Na₂SO₄的用量分别为15%和20%，在焙烧温度为950℃条件下焙烧50 min，最终得到直接还原铁的TFe品位为91.89%，TFe的回收率为82.26%，S残余含量0.03%。该直接还原铁可用作电炉炼钢原料。试验工艺对硫酸渣的综合利用和环境保护有着重要的经济和实用价值。

Abstract: In this paper, the process of coal-based direct reduction roasting and magnetic separation was used to recover iron by pyrite cinder roasting. The effects of reducing agent, fluxing agent, temperature and time on the roasting were investigated. The results showed that the iron grade of direct reduced iron of 91.89%, the recovery rate of iron of 82.26%, and the residual content of S of 0.03% were obtained by the amount of reducing agent of 30%, the amount of flux CaO and Na₂SO₄ of 15% and 20%, respectively, and roasting for 50 min at a roasting temperature of 950℃. The direct reduced iron can be used as raw material for electric steelmaking. The experimental results have important economic and practical value for comprehensive utilization of pyrite cinder and environmental protection.