Approximately 2.0–3.0 t of copper slag (CS) containing 35%–45% iron is generated for every ton of copper produced during the pyrometallurgical process from copper concentrate. Therefore, the recovery of iron from CS utilizes a valuable metal and alleviates the environmental stress caused by stockpile. In this paper, a new method has been developed to realize the enrichment of iron in CS through the selective removal of silica. The thermodynamic analyses and experimental results show that the iron in CS can be fully reduced into metallic iron by carbothermic reduction at 1473 K for 60 min. The silica was converted into free quartz solid solution (QSS) and cristobalite solid solution (CSS). QSS and CSS are readily soluble, whereas metallic iron is insoluble, in NaOH solution. Under optimal leaching conditions, a residue containing 87.32% iron is obtained by decreasing the silica content to 6.02% in the reduction roasted product. The zinc content in the residue is less than 0.05%. This study lays the foundation for the development of a new method to comprehensively extract silicon and iron in CS while avoiding the generation of secondary tailing.

在火法冶金过程中，从铜精矿中生产的每吨铜，大约产生2.0-3.0吨含35％-45％铁的铜渣（CS）。因此，从CS中回收铁利用了有价值的金属，并减轻了由储存引起的环境压力。本文开发了一种通过选择性去除二氧化硅来实现CS中铁富集的新方法。热力学分析和实验结果表明，在1473 K下60分钟碳热还原可以将CS中的铁完全还原为金属铁。将二氧化硅转化为游离石英固溶体（QSS）和方石英固溶体（CSS）。QSS和CSS易溶于NaOH溶液，而金属铁不溶于NaOH溶液。在最佳浸出条件下，残留物含有87。通过将还原焙烧产品中的二氧化硅含量降低至6.02％，可获得32％的铁。残留物中的锌含量小于0.05％。这项研究为开发一种在CS中综合提取硅和铁同时避免产生二次尾矿的新方法奠定了基础。