An Innovative Technique for Comprehensive Utilization of High Aluminum Iron Ore via Pre-Reduced-Smelting Separation-Alkaline Leaching Process: Part I: Pre-Reduced-Smelting Separation to Recover Iron

• Main Authors: Siwei Li, Jian Pan, Deqing Zhu, Zhengqi Guo, Yue Shi, Jianlei Chou, Jiwei Xu
• Format: Article
• Language: English
• Published: MDPI AG 2019-12-01
• Series: Metals
• Subjects: high-aluminum iron ore; smelting separation; modification; alkaline leaching
• Online Access: https://www.mdpi.com/2075-4701/10/1/57

In this study, a novel process was established for extraction of Fe and Al from a complex high aluminum iron ore (33.43% Fe_total and 19.09% Al₂O₃). The main steps in the proposed process included pre-reducing high alumina iron ore and subsequent smelting to produce pig iron and rich-alumina slag, followed by alkaline leaching of the slag to obtain sodium aluminate solution and a clean slag. When smelting the pre-reduced high alumina iron ore pellets at 1625 °C for 30 min with a slag basicity of 0.40, the pig iron yielded 97.08% Fe and extracted 0.13% Al₂O_3, together with an iron recovery of 94.54%. In addition, more than 68.93% Al₂O₃ was recovered by leaching the slag, which was achieved by firstly roasted the slag at 900 °C for 2 h and then alkaline leaching at 95 °C for 2 h with a liquid-to-solid ratio of 10 mL/g. In addition, the alkaline leaching slag could potentially be used as raw material for construction purpose, which mainly consisted of SiO₂ and CaO.