INFLUENCE OF COKING COAL PROPERTIES AND PROPORTION OF LOW-RANK COAL ON THE COKING PERFORMANCE OF HIGH-PRESSURE BRIQUETTE
The use of low-rank coal to prepare metallurgical coke is an important way to alleviate the shortage of coking coal resources and optimize the utilization of coal resources.Briquette coking is an important method for preparing metallurgical coke from low-rank coal with a high ratio.In order to explore the application of low-rank coal in high-pressure briquette coking,the compressive strength,pore structure,optical structure,surface morphology and other characteristics of coke after high-pressure forming and high-temperature distillation of coking coal and 1/3 coking coal with different ratios of low-rank coal were studied.The results show that with the increase of the ratio of low-rank coal,the compressive strength of briquette coke first increases and then decreases,and the maximum can reach more than 6 kN,exceeding the standard of 2.5 kN for first-class metallurgical pellets.Different from the traditional coking method,in high-pressure briquette coking,the interaction between low-rank coal and coking coal can promote the formation of inlay structure in coke,and the inlay structure plays the role of connecting the microstructure of coke fragmentation and reducing the number of pores and cracks on the surface of colloids.Adding a certain ratio of low-rank coal can increase the gas permeability of briquette colloids,reduce the structural defects formed by the obstruction of volatilization analysis in the high-pressure briquette dry distillation process,and improve the strength of the coke.However,after the ratio of low-rank coal is too high,the adhesion of the colloidal body of the briquette will be reduced,and the strength of the coke will be reduced.The optimal addition ratio of low-grade coal varies depending on the nature of the coking coal.Under the forming pressure of 150 MPa,the optimal matching ratio of low-rank coal to main coking coal is 50％,and the optimal matching ratio with 1/3 coking coal is 30％.
万方数据
维普
