The Effect Of Mineral Matters On Coal Blending With High Ratio Low Rank Coals For Coking

The production capacity of furnace coking industry is much more than the demand in china.The gasification coke produced by low rank coal and middling coal could be used in fixed bed gasification instead of lump coal to save scarce coal resources and enhance the economy.In this work,coking coal,middling coal Shenmu coal from Inner Mongolia coking planet were used.The elemental composition and surface structures were tested using XRF,XRD and SEM,respectively.Minerals phase transformation,pyrolysis and surface characteristics,and CO2 Gasification Reactivity were investigated on different coking conditions and raw material ratio.At the same time,few studies have been made of the relationship between the minerals and coking of bond characteristics.The results showed that the coal ash mainly consisted of silicon,aluminium,iron,and calcium.There are mainly five types of minerals existing in three coal,including kaolinite,quartz,pyrite,gypsum and calcite.The XRD results show that the kaolinite gradually dehydration and decomposed into mullite and sillimanite with the increase of coking temperature.Quartz converted into Si C until the final coking temperature reaches 1100℃.Pyrite converted into Fe S,Fe C and calcite decomposed.Some calcium and sulfur-containing minerals converted into Ca S.When temperature rose,surface oxygen-containing functional groups of coal decreased and then disappearance.Char particle surface cracked and internal holes got larger,and internal surface become flat with the increase of coking temperature.The specific surface area of coke increased and permeability was improved of coke with the increase of mineral content,but total pore volume and porosity decreased.Pore size and the average pore size ranged from 1 to 10 nm and 3 to 9nm,respectively.The carbon crystallite structure of chars gradually developed to sequential direction after carbonization increased.When the ash content of blended coal ranged from 9.35% to 19.97%,the intensity of 002 peak decreased,and the width became larger.At the same time,the width of 100 peak decreased.The order degree of carbon carbon crystallite structure decreased.The minerals changed coking process.The coke gasification reaction index T_0.5 decreased and index R_0.5 increased,and coke reactivity improved.The kinetics of coke-CO₂ reaction zone meet the first order as R=k（1-α）.The value of apparent activation energy and frequency factor increased.The influence of minerals on the pore structure and catalysis combined to affect the coke reactivity.