SO₂ and NO_x emissions from iron and steel production pollute the atmosphere. With the implementation of ultra-low emission standards, the requirements for flue gas purification have become more stringent. Activated carbon, due to its rich surface chemistry, stable physical structure, and excellent adsorption and renewability, has a significant effect on the synergistic removal of multiple pollutants from industrial flue gas, and its industrial application has achieved a SO₂ removal rate of ≥98% and a NO_x removal rate of ≥83%. Firstly, we analyze the structure of activated carbon and the adsorption principle, discuss the mechanism of desulfurization and denitrification, and explore the shortcomings of the technology; then, we summarize the modification methods of activated carbon, determine the impregnation method of loading non-precious metal oxides as the optimal solution, and elucidate the loading conditions, process, and reaction mechanism; finally, we discuss the current status of the research, analyze the process deficiencies and the direction of optimization, and look forward to the prospect of development.

The implementation of ultra-low emission standards in the steel industry imposes higher demands on flue gas purification. Carbon-based materials, leveraging their porous structure and surface activity, demonstrate high adsorption potential for treating heavy metal ions, sulfur- and nitrogen-containing compounds, and volatile organic pollutants. However, their application is constrained by a limited selective adsorption capacity. This paper systematically analyzes the mechanisms by which carbon-based materials treat water, air, and soil pollutants; investigates their physical and chemical degradation patterns; and summarizes practical physicochemical modification pathways. Research indicates that modification techniques can effectively overcome performance limitations of carbon-based materials, enhance pollutant adsorption efficiency, and provide new insights for the engineering application of multi-media pollution synergistic control and environmental remediation technologies.

To investigate the influences of quasi-particles structure in the sintering bed on combustion behaviors and CO and NO emission, the non-isothermal combustion experiments and gas analysis were carried out by using coke breeze and sintering raw materials to prepare different types of quasi-particles. The results show that the four types of quasi-particles combustion processes were consistent with the unreacted nuclei model. The adhering layer had positive catalytic effects on coke breeze combustion and the reduction of NO by CO. Compared with S´-0.25, the apparent activation energies of the C71% and P15%(2) combustion decreased by 1.85 kJ/mol and 27.34 kJ/mol, the CO emission reductions were 47.75% and 50.07%, and the NO emissions were reduced by 67.50% and 6.95%, respectively. Compared with S´2~3, the apparent activation energies of the S33%(2~3) decreased by 18.66 kJ/mol, and the emissions of CO and NO were decreased by 87.99% and 75.29%, respectively. Additionally, the structural changes of the four types of quasi-particles significantly affected the combustion and emission behaviors. The adhering fines of S-type, C-type and P-type had abundant porous structure, which provided active sites for the adsorption of CO and NO, promoted the reduction of NO by CO. In contrast, the emissions of S´-type gases were higher, and the emissions increased with increasing of size. Therefore, increasing the S-type content and reducing the S´-type content in the sintering bed will not only effectively improve the solid fuel combustion efficiency, ensure sufficient combustion zone temperature, but also greatly reduce emissions in the sintering flue gas.

Microwave irradiation activated carbon desulfurization technology has broad prospects for its high efficiency and environmental protection advantages, but the generation of CO by-products affects the industrial application of this technology. In this paper, the formation characteristics of CO in microwave carbon thermal desulfurization reaction were analyzed by thermodynamic calculation. Combined with Langmuir-Hinshelwood (L-H) theory, the hyperbolic intrinsic kinetic rate equation was established by using three mechanism models of SO ₂ adsorption, surface reaction and CO desorption as control steps. Finally, the parameters of the model were estimated. The results show that the microwave irradiation activated carbon desulfurization process is consistent with the L−H model, and the rate equation with the irreversible surface reaction (SO ₂ *+2C → 2CO ^* +S _(g) ) as the control step is consistent with the actual situation. In addition, the activation energy of desulfurization reaction is 32.53 kJ · mol ⁻¹ , and the results show that microwave has a catalytic effect on the carbothermal desulfurization reaction, which provides an important theoretical support for the treatment of SO ₂ in sintering flue gas by microwave method.