Study On The Change Of Functional Groups And Pore Structure During Coke Coking

Coke,as an indispensable raw material in the iron and steel smelting process,plays a very important role in the smelting process.However,the development of new technologies such as blast furnace coke oven gas and full-oxygen blast furnace ironmaking has led to a significant reduction in the coke ratio in the blast furnace,resulting in increased coke chemical performance and mechanical load,and higher requirements for coke performance.At the same time,the world’s coking coal storage is also decreasing,and the weathering of a large number of coking coals has further increased the reduction of high-quality coking coal storage.At present,China’s system with coal as the main energy structure has not changed significantly.Therefore,the effective utilization of high-quality coal and the change of coal char at the micro level in the coking process are very important.How to effectively use the existing highquality coke resources and optimize the coking process has become a key issue in the current coke smelting technology.In this paper,three coking coals were used to prepare different microstructures of coke.The pressurized micro-coke furnace was used to simulate blast furnace coking,and the macroscopic changes of coke in the coking process were followed up.The FTIR characterization of the obtained semi-coke and coke products was carried out.The composition of the chemical structure of the colloid during the coking process was studied by combining the temperature field changes caused by the properties of the colloid.The development of the pore structure of the coal coke during the coking process was obtained by the low temperature adsorption method and the mercury intrusion method,and finally passed the constant temperature reactivity test and The compressive strength test comprehensively analyzes the influence of the pore structure on the overall performance of the coke,revealing the reason for the pore structure development.The experimental results show that the peak pore structure of the micropores from the raw coal to the coke stage changes from 3.4 nm to 3.4 and 5 nm bimodal pore structure.It is known that the 3.4 nm diameter pore structure is the congenital pore structure exhibited by the carbon charcoal itself,and 5 nm.The diameter pore structure is the structure of the acquired pore formed by the plastic mass after adsorption and solidification of a part of the volatile matter.The oxidation of coal samples leads to a gentle distribution of coke pore size,no obvious pore size,and a uniformly distributed pore structure is beneficial to increase the compressive strength of coke.The FTIR measurement results were quantitatively analyzed by the method of peak-matching.The results showed that the chemical structure of the plastic mass structure contained less functional groups than coal and coke,mainly guided by the amino-hydroxy group to the aromatic ring and the aliphatic side chain.Large chemical structures that integrate large amounts of free radicals.The aminocarboxy group guides the formation of a liquid phase substance,and the macromolecular compound(aliphatic,aromatic structure)is responsible for integrating the free radicals and ensuring that the plastic mass has good thermal stability,and the plastic mass inhibits the passage of the gaseous substance.The expansion pressure further enhances the overall cohesiveness of the coal char.Oxidation leads to a decrease in the content of the liquid phase during the coking process of coking coal,a change in the properties of the plastic mass,a shorter residence time of the heat stability,a decrease in the fluidity and expansion of the liquid phase,and an increase in the gas permeability.