In light of the steel industry's rapid advancements, the availability of high-quality mineral resources is diminishing. Therefore, the recovery of iron from BOF slag is of great significance to the sustainability development. Considering the compositional characteristics of BOF slag, the transformation of the iron-containing phase into (Mn,Mg)yFe3-yO4 is the key step. Thus, a novel process for recovering iron resources by synergistic treatment of blast furnace slag (BFS) and BOF slag was proposed. This research employed FactSage thermodynamic simulation, XRD, SEM-EDS, XPS, and EPMA to analysis the impact of BFS addition (10–50 %), cooling methods (from water-cooling to furnace-cooling), and temperature (1400–1600 °C) on phase transformation and the RO oxidation mechanism, and the conditions of (Mn,Mg)yFe3-yO4 generation and enrichment was obtained. The results show that at BFS addition of 30 %, reaction temperature 1400 °C and furnace-cooling, the iron-containing phase (Ca2Fe2O5 and RO) was almost completely transformed into (Mn,Mg)yFe3-yO4. The oxidation mechanism of RO was formation of (Mn,Mg)yFe3-yO4 by cation diffusion. Under optimal conditions, the iron recovery rate and the grade reached 65.74 % and 32.07 %, respectively, which can be used as raw material for ironmaking. Meanwhile, the main phase of the tailing slag was β-Ca2SiO4, without f-CaO, which has the potential to be used in the cement and concrete industries with the advantages of both low cost and eco-friendly. Therefore, the process with green, efficient and low cost was provided, which is a feasible idea for the comprehensive utilization of industrial solid waste.

中文翻译：

---

协同处理高炉矿渣和转氧转炉矿渣以高效回收铁：相变和氧化机制


随着钢铁工业的快速发展，优质矿产资源的供应量正在减少。因此，从转炉渣中回收铁对于可持续发展具有重要意义。考虑到转炉渣的成分特征，含铁相向(Mn,Mg)yFe3-yO4的转变是关键步骤。因此，提出了一种通过高炉渣（BFS）和转炉渣协同处理来回收铁资源的新工艺。本研究采用 FactSage 热力学模拟、XRD、SEM-EDS、XPS 和 EPMA 来分析 BFS 添加量 (10-50%)、冷却方法（从水冷到炉冷）和温度（1400-1600℃）的影响。 °C)对相变和RO氧化机理的影响，得到了(Mn,Mg)yFe3-yO4生成和富集的条件。结果表明，当BFS添加量为30%、反应温度为1400℃、炉冷时，含铁相（Ca2Fe2O5和RO）几乎完全转变为(Mn,Mg)yFe3-yO4。 RO的氧化机理是通过阳离子扩散形成(Mn,Mg)yFe3-yO4。在最佳条件下，铁的回收率和品位分别达到65.74%和32.07%，可作为炼铁原料。同时，尾矿渣的主相为β-Ca2SiO4，不含f-CaO，具有成本低、环境友好等优点，在水泥和混凝土行业具有应用潜力。因此，提供了一种绿色、高效、低成本的工艺，为工业固废综合利用提供了一种可行的思路。