A novel technology, modified roasting in CO–CO₂ mixed gas and magnetic separation, was presented to recover iron from copper slag. The effects of various parameters such as dosage of flux (CaO), gas flowrate of CO and CO₂, roasting temperature, roasting time, particle size of modified slag and magnetic flux density on the oxidized modification and magnetic separation were investigated by comparison of the X-ray diffraction patterns and iron recovery ratio. The optimum conditions for recovering iron by oxidizing roasting and magnetic separation are as follows: calcium oxide content of 25 wt.%, mixed gas flow rates of CO₂ and CO of 180 and 20 mL/min, oxidizing roasting at 1323 K for 2 h, grinding the modified slag to 38.5–25.0 μm and magnetic separation at 170 mT. The mineralogical and microstructural characteristics of modified slag revealed that the iron-bearing minerals in the copper slag were oxidized, the generated magnetite grew into large particles, and the silicate in copper slag was combined with calcium oxide to form calcium silicate. Finally, the iron-bearing concentrate with an iron grade of 54.79% and iron recovery ratio of 80.14% was effectively obtained.

提出了一种新技术，即在CO-CO ₂混合气体中进行改进的焙烧和磁选，以从铜渣中回收铁。通过对比考察了助熔剂（CaO）的用量，CO和CO _2的气体流量，焙烧温度，焙烧时间，改性渣的粒径和磁通量密度等参数对氧化改性和磁选的影响。 X射线衍射图和铁的回收率。通过氧化焙烧和磁分离回收铁的最佳条件如下：氧化钙含量为25 wt。％，混合气体流量为CO ₂CO的浓度为180和20 mL / min，在1323 K氧化焙烧2 h，将改性炉渣研磨至38.5–25.0μm，并在170 mT进行磁选。改性渣的矿物学和微观结构特征表明，铜渣中的含铁矿物被氧化，生成的磁铁矿长成大颗粒，铜渣中的硅酸盐与氧化钙结合形成硅酸钙。最终，有效地得到了铁品位为54.79％，铁回收率为80.14％的含铁精矿。