Study on Hematite Reduction via Wheat Bran Alkaline Thermal and Its Application Potential in the Bayer Process

作者：Xin He, Guozhi Lv, Qingdong Li, Xiaolei Zhang, Zhisheng Yun, Ting‐an Zhang · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2025 · DOI：10.1021/acssuschemeng.5c03069 · 被引用次数：6 · 研究领域：Bauxite Residue and Utilization、Extraction and Separation Processes、Phosphorus and nutrient management

The Bayer process primarily focuses on the extraction of alumina, yet it insufficiently addresses the comprehensive recovery of other valuable elements, resulting in significant environmental threats due to the discharge of large quantities of red mud. By converting iron-bearing phases such as aluminum goethite, andradite, and hematite into magnetite, the dissolution efficiency of alumina can be significantly enhanced, while also achieving an efficient recovery of iron-containing resources. This study employs the theory of mineral phase reconstruction to achieve the directional transformation of hematite into magnetite by utilizing the reducing properties of wheat bran under alkaline thermal conditions. A systematic investigation was conducted to evaluate the effects of various parameters on the conversion efficiency during the alkaline thermal reduction of hematite with wheat bran, utilizing X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and chemical analysis for assessment. Furthermore, the surface characteristics of hematite, magnetite, and desilication product (DSP) were characterized in conjunction with Zeta potential, wettability, and solvation trends. The findings indicate that the conversion efficiency of hematite significantly improves with increasing temperature, wheat bran dosage, and sodium oxide concentration. Under simulated Bayer process dissolution conditions, with a sodium oxide concentration of 240 g/L, a molecular rat...