Study On Microcomponent Properties Of Lignite Used For Blast Furnace Injection

Based on the current tight environment of high-quality coal resources,it is necessary to expand the range of fuel selection for blast furnace injection.This article takes lignite as object of study.Combining the actual coal usage in a steel plant,the grindability and combustion performance of single coals and a certain proportion of mixed coals are studied.First,the feasibility of blast furnace injection of lignite was tested,and it was found that the grindability and combustion performance are the key factors in the use of lignite;then coals were treated with the method of coal petrology,and it was found that the centrifugal effect of the coal completely broken to 160 mesh/200 mesh was the best,any increase or decrease in the particle size will have an adverse effect on the centrifugal effect of the coal;In the process of coal centrifugation,the difficulty of ash content crushing of different coals is unequal;the coal composition with density lower than 1.45g/cm~3 is easier to be broken;when lignite accounts for 30%,the grindability of anthracite vitrinite is improved the most good.Finally,the combustion performance of blended coal was studied.Combustion performance of each composition of lignite:exinite>huminite>inertinite;after mixing the different components of a single coal,lignite and anthracite show better combustion performance,but the combustion performance of bituminous coal is inhibited;The combustion performance of the coal obtained by mixing different coals is improved,but the decrease in burnout temperature is not as large as the decrease in the ignition point;the change in the proportion of single coal in the mixed coal will have an impact,and this effect will alter with the change in the proportion of other coals:When lignite accounts for 0%,bituminous coal:anthracite=4:6 has the best combustion effect;when lignite accounts for 10%,bituminous coal:anthracite=2:7 has the best combustion effect;when lignite accounts for 20%,the addition of bituminous coal will make the combustion performance of the mixed coal worse;when bituminous coal accounts for0%,lignite:anthracite=2:8 has the best combustion effect;when bituminous coal accounts for 10%,lignite:anthracite=2:7 has the best combustion effect;When bituminous coal accounts for 20%,lignite:anthracite 1:7 has the best combustion effect;In this experiment,the addition of lignite more than 20%or the proportion of anthracite less than 70%when using bituminous coal and lignite at the same time will make the combustion performance of the mixed coal worse.