Scholarlink

<p>The accumulation of red mud, a byproduct of alumina production, poses significant environmental and resource challenges due to its high alkalinity and large volume. This study addresses the urgent need for sustainable disposal methods by proposing an innovative approach that substitutes traditional fossil fuel coke with renewable straw biomass for iron extraction from high-iron red mud. The reduced slag generated from this process is further utilized to synthesize sulfoaluminate cement clinker, thereby achieving complete utilization of red mud. Thermodynamic analysis indicates that iron oxide and sodium oxide in red mud are relatively easy to reduce, while oxides such as SiO<sub>2</sub>, TiO<sub>2</sub>, and Al<sub>2</sub>O<sub>3</sub> present greater challenges. Experimental results demonstrate that under optimal conditions (alkalinity 0.8, reaction time of 25&#xa0;min, carbon ratio of 1.1, temperature of 1400&#xa0;°C, and 4% CaF<sub>2</sub> addition), the iron recovery rate reaches 99.7%, with the reduced metal containing 92.9% iron and minimal impurities, rendering it suitable for steelmaking. The conditioned reduced slag can be utilized to produce sulfoaluminate cement clinker with excellent performance under sintering conditions of 1300&#xa0;°C, a holding time of 1.0&#xa0;h, and air cooling. The hydration products of the cement clinker primarily consist of AFt, calcium sulfoaluminate, AFm, calcium silicate, and calcium sulfate, demonstrating rapid hardening properties and high early strength. Notably, the entire process generates no additional waste emissions, underscoring its potential for industrial application and supporting sustainable waste management and resource efficiency.</p> Graphical Abstract <p></p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Green Process for Red Mud Utilization: Iron Recovery and Cement Precursor Synthesis

  • 期刊论文

  • 发表日期：

    2025年8月8日

查看全文
  • Xin He,
  • Guo-zhi Lv,
  • Zhi-gang Jiang,
  • Song Wang,
  • Xiao-fei Li,
  • Qing-dong Li,
  • Zhuang-zhuang Yun,
  • Ting-an Zhang

摘要

The accumulation of red mud, a byproduct of alumina production, poses significant environmental and resource challenges due to its high alkalinity and large volume. This study addresses the urgent need for sustainable disposal methods by proposing an innovative approach that substitutes traditional fossil fuel coke with renewable straw biomass for iron extraction from high-iron red mud. The reduced slag generated from this process is further utilized to synthesize sulfoaluminate cement clinker, thereby achieving complete utilization of red mud. Thermodynamic analysis indicates that iron oxide and sodium oxide in red mud are relatively easy to reduce, while oxides such as SiO2, TiO2, and Al2O3 present greater challenges. Experimental results demonstrate that under optimal conditions (alkalinity 0.8, reaction time of 25 min, carbon ratio of 1.1, temperature of 1400 °C, and 4% CaF2 addition), the iron recovery rate reaches 99.7%, with the reduced metal containing 92.9% iron and minimal impurities, rendering it suitable for steelmaking. The conditioned reduced slag can be utilized to produce sulfoaluminate cement clinker with excellent performance under sintering conditions of 1300 °C, a holding time of 1.0 h, and air cooling. The hydration products of the cement clinker primarily consist of AFt, calcium sulfoaluminate, AFm, calcium silicate, and calcium sulfate, demonstrating rapid hardening properties and high early strength. Notably, the entire process generates no additional waste emissions, underscoring its potential for industrial application and supporting sustainable waste management and resource efficiency.

Graphical Abstract