Abstract: For copper recovery from the slag of pyro-metallurgy by reducing the Fe3O4 ，the equilibrium model of reduction of Fe3O4 reduction by diesel oil in the presence of N2 was established based on the Gibbs free energy minimization principle. The effects of reaction temperatures (1220～1280℃)，amount of N2 (480～960m3/d)，ratio of diesel to slag (0.5～2.9 L/t) on Fe3O4 reduction were investigated. Diesel oil was completely cracked under N2 atmosphere，with the main pyrolysis products of C and H2. Meanwhile，the volume of gas during reaction increased. The products of pyrolysis almost remained unchanged with rising reaction temperature and N2 addition. The equilibrium constants of reduction reactions of Fe3O4 by the pyrolysis products of diesel oil were large，and a high degree of reduction reactions was achieved. Fe3O4 in copper slag was reduced to FeO. The reduction degree of Fe3O4 was improved with rising ratio of diesel oil to slag. Pyrolysis of diesel oil and reduction of Fe3O4 by diesel oil in the presence of nitrogen were endothermic.

Key words: copper slag, Fe3O4 reduction, diesel oil, nitrogen, pyrolysis, equilibrium, thermodynamics

摘要： 为降低火法冶金炉渣中磁性铁含量以回收铜，采用柴油在N2存在条件下还原铜渣中Fe3O4；并基于吉布斯自由能最小化原理，建立平衡模型，探讨了反应温度（1220～1280℃）、N2加入量（480～960m3/d）、油渣比（0.5～2.9L/t）对Fe3O4还原反应的影响。结果表明：柴油裂解，主要生成C和H2；同时，反应中气体体积发生膨胀。提高反应温度和N2加入量，裂解产物摩尔分数基本保持不变。Fe3O4与柴油裂解产物的反应平衡常数大，反应程度高，Fe3O4被还原成FeO。油渣比增加，Fe3O4还原率呈线性增加。柴油裂解和柴油在氮气存在条件下还原铜渣中Fe3O4反应都是吸热过程。

关键词: 铜渣, Fe3O4还原, 柴油, 氮气, 热解, 平衡, 热力学