Experimental study on coal blending coking based on different addition ratios of high sulfur coal

YAN Hui; DENG Shaobo; YANG Bowei; ZHANG Zhikai; SHEN Yanfeng; WANG Meijun

doi:10.3969/j.issn.1007-7677.2023.06.005

Abstract：Rational utilization of different types of high-sulfur coking coal resources and increasing its proportion in coal blending coking is an effective way to reduce cost and increase efficiency in coking process.Based on the indus-trial production of coal blending coking,a kind of high-sulfur coking coal and high-sulfur fat coal was selected re-spectively,and the basic coal quality characteristics of high-sulfur coal and low-sulfur coal in basic coal blending were analyzed by using approximate analysis,caking index,plastic layer index,Gieseler fluidity,and Audibert-Arnu dilatation.X ray photoelectron spectroscopy(XPS),infrared spectroscopy(FTIR)and nuclear magnetic spectroscopy(13 C NMR)were used to determine the sulfur forms and carbon structure parameters of different coking coals.The effects of different proportions of high sulfur coal on the coke quality were compared and analyzed by 40kg coke oven coking test.The results show that the length of aliphatic chain in the carbon structure of high-sulfur coking coal and fat coal is longer,which makes it possible to decompose and produce more hydrogen-containing groups in the coking process,and the plastic layer produced by softening and melting has good fluidity,wide plastic temperature range,and can be better bonded with other coal in coal blend.Sulfides,sulfoxides,sulfones and other forms of sulfur in high-sulfur coking coal and fat coal decompose and combine with hydrogen-containing components to form sulfur-containing gas during the coking process,and the desulfurization rate during individual coking process reaches 32.78%and 42.61%,respectively.In the coal blend,the higher proportion of high-sulfur fat coal with high volatile content and high fluidity leads to much higher expansion pressure,coke shrinkage stress and coke porosity,resulting in the decrease of coke strength.When the ratio of high-sulfur coking coal and fat coal in coal blend is 2%and 3%respectively,the obtained coke mechanical strength is similar to that of basic coke,while the coke strength after reaction increases to 56.0%.