Utilization of Low-Rank Coal and Zn-Bearing Dusts for Preparation of K, Na-Embedded Porous Carbon Material and Metallized Pellets by Synergistic Activation and Reduction Process

A technology was developed for managing Zn-bearing dust, facilitating the recycling of hazardous solid waste and the production of porous carbon materials. In the one-step process, Zn-bearing dusts were employed not only as raw materials to prepare reduced Zn-bearing dust pellets but also as activators to prepare K, Na-embedded activated carbon. In the process, the Fe, C, Zn, K, and Na in the dusts were rationally utilized. Under optimal conditions, the reduced pellets and porous carbon materials were simultaneously produced and characterized using XRD, SEM/EDS, FTIR, and adsorption of nitrogen techniques. The results indicated that the reduced pellets, with low levels of harmful elements and high iron grade and strength, could be directly used as burden for enhancing blast furnace operation without additional agglomeration. Meanwhile, the K and Na-embedded porous carbon material demonstrated superior SO₂ and NO adsorption capacities compared to the commercial activated carbon, making it suitable for purifying SO₂ and NO-bearing flue gas. The hazardous solid wastes were effectively used to treat flue gases through this technology. The mechanism in the synergistic reduction and activation process was elucidated. The coupling effect between the reduction reactions of Fe₂O₃, Fe₃O₄, FeO, MgFe₂O₄, CaFe₂O₄, ZnFe₂O₄, KFeO₂, and NaFeO₂ in the dusts and activation reaction of C in the coal promoted the synchronous reduction and activation process.