As the hazardous solid waste from alumina production, red mud (RM) is often used in the preparation of slurry or catalyst, but rarely considered for in-situ desulfurization of fluidized bed. In this paper, an experimental study was conducted on a lab-scale circulating fluidized bed (CFB) combustor to explore the feasibility of RM replacing limestone for in-situ desulfurization, from the perspectives of efficiency, combustion stability, CaO activity, deposition, NO_x emission and operation cost. Although the adopted limestone showed better performance under most working conditions, the highest RM desulfurization efficiency still reached over 94% at 900 °C bed temperature and 20% blending ratio. Better combustion stability could be achieved at 900 °C and no more than 6.11% RM blending. The increase of RM addition had opposite effect on carbon content in bottom ash and fly ash, as well as the SO₂ and NO_x emissions whatever the bed temperature was. Compared with Zhundong coal, no severe ash deposition was observed at cyclone outlet, but the ash sintering got much worse at the upper furnace. The results demonstrated the feasibility to adopt RM directly as SO₂ sorbents during CFB combustion, and achieved the dual effects of SO₂ reduction and resource recovery of RM.

作为氧化铝生产过程中产生的有害固体废物，赤泥（RM）常用于制备浆料或催化剂，但很少考虑用于流化床原位脱硫。本文在实验室规模的循环流化床（CFB）燃烧器上进行了实验研究，从效率、燃烧稳定性、CaO活性、沉积、NO _X排放和运营成本。尽管采用的石灰石在大多数工况下表现出较好的性能，但在900℃床温和20%掺混比下，最高RM脱硫效率仍达到94%以上。在 900 °C 和不超过 6.11% 的 RM 混合下可以获得更好的燃烧稳定性。无论床温如何，RM 添加量的增加对底灰和飞灰中的碳含量以及 SO ₂和 NO _x排放都有相反的影响。与准东煤相比，旋风出口处没有观察到严重的灰沉积，但在上部炉子的灰烧结情况要差得多。结果证明了直接采用 RM 作为 SO ₂的可行性CFB 燃烧过程中吸附剂，实现了 SO ₂还原和 RM 资源回收的双重效果。