Abstract

Bauxites and red mud (RM) from alumina production facilities are distinguished by high contents of iron compounds and can be regarded a promising feedstock for magnetite production. The hydrothermal treatment of bauxites from the Severouralsk Bauxite Mine (SBM), red mud (RM), and hematite in an alkaline medium in the presence of FeSO₄ or metal (Al, Fe, Ca, Mg, or 0.25Mg–0.25Al–0.5Fe) powders promotes the formation of magnetite in the products. The hydrothermal treatment parameters were dictated by bauxite leaching parameters at the production facility to provide high aluminum recovery. X-ray diffraction analysis, scanning electron microscopy, and magnetic measurements showed that the treatment of red mud in the presence of FeSO₄ or metallic Al yielded highly disperse materials containing 32.4% or 23.7% Fe₃O₄, respectively. The presence of Fe or 0.25Mg–0.25Al–0.5Fe mixed powders in bauxite leaching provided for 40.8 or 67.9% Fe₃O₄, respectively, in the form of crystalline particles of sizes up to 5 μm. The higher magnetization values of the products owing to the formation of magnetic phases will ensure their efficient magnetic separation.

中文翻译：

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赤泥和铝土矿水热处理产物中氧化铁的组成及性质

摘要

来自氧化铝生产设施的铝土矿和赤泥 (RM) 的特点是铁化合物含量高，可被视为磁铁矿生产的有前景的原料。在 FeSO ₄或金属（Al、Fe、Ca、Mg 或 0.25Mg–0.25Al– 0.5Fe) 粉末促进产品中磁铁矿的形成。水热处理参数由生产设施中的铝土矿浸出参数决定，以提供高铝回收率。X 射线衍射分析、扫描电子显微镜和磁测量表明，在 FeSO _{4存在下处理赤泥}或金属 Al 产生的高分散材料分别含有 32.4% 或 23.7% Fe ₃ O ₄。Fe 或 0.25Mg–0.25Al–0.5Fe 混合粉末在铝土矿浸出中的存在分别提供了 40.8 或 67.9% 的 Fe ₃ O ₄，以尺寸达 5 μm 的结晶颗粒的形式存在。由于磁相的形成，产品的较高磁化值将确保它们有效的磁分离。