Research And Application Of Super-clean Coal Produced From Ningxia Anthracite

China is the major steel producer and coke producer in the world.Although coal resources in China is rich,most of them are non-coking coal.The coal directly used for coking production are fewer.The utilization value of weak cohesive and non-cohesive coals in coking industry can be effectively improved by preparation of super-clean coal through thermal solvent extraction technology.Anthracite is a typical non-stick coal with the highest degree of coalification.There are many macromolecular substances in the Anthracite.The carbon chain of molecular in the Anthracite is long,and the aromatic ring structure is larger,this leads to the decrease of thermal extraction rate.In this paper,the preparation of super-clean coal form Ningxia anthracite by thermal solvent extraction was mainly studied.The pretreatment of anthracite using different solvents were performed and the results showed that the KOH has the best effect.The influence of different pretreatment process conditions on the thermal extraction rate of anthracite were investigated.The optimal process conditions were: the concentration of KOH solvent was 1mol/L,the ratio of solvent and coal mass was 10:1,reflux condensation time was 2h,and the thermal extraction rate was 35.2%.The thermal solvent extraction of anthracite using different metal oxides as catalysts showed that MgO had the best catalytic effect.The effects of MgO obtained from different preparation methods and process conditions on the thermal extraction rate of anthracite were studied.The results showed that the thermal extraction rate reached 41.7% using the MgO prepared by direct precipitation method.The obtained MgO had a cubic lattice structure with an average particle size of 500-600 nm after drying for 4 hours,and then roasted at 800℃ for 5 hours.The characteristics of super-clean coal prepared from anthracite were studied.The results showed that super-clean coal had excellent cohesiveness,thermoplasticity,meltability,fluidity and coking property.By comparing the cold strength of coke produced by 40 kg industrial test coke oven,it was proved that adding a small amount of super-clean coal can significantly reduce the consumption of main coking coal,greatly increase the proportion of weak and non-cohesive coal,and expand the coking coal resources.