Study On The Coal Rock Microstructure Separation Of Low-Rank Coal In Enhanced Gravity Field

The coal rock microstructure is the micro component of coal,and the enrichment of coal rock microstructure can improve the conversion efficiency of coal liquefaction effectively,and improve the efficiency of coal coking,and help to produce excellent coal slurry.The paper uses Falcon centrifugal separator to explore the best effect of enrichment of coal rock microstructure in enhanced gravity field.The ash content of raw coal is 9.57%,volatile content is 37.40%,the raw coal belongs long flame coal.The vitrinite content of raw coal is 48.64%,the inertinite content is 44.07%,the exinite content is 0.86%,the Mineral content is 6.43%.The optimal dissociation particle size of coal rock microstructure in the enhanced gravity field was determined to be-0.25 mm by performing screening tests,floating tests and Falcon sorting tests on Shenhua coal sample.The experimental coal samples were dissociated under 0.25 mm,and the optimum operating parameters of the separation of coal rock microstructure were studied.Through the single factor probe tests of rotation frequency and water pressure,obtained the relationship of combustible recovery,ash removal rate,vitrinite recovery and inertinite removal rate with the rotation frequency and water pressure,and determined the test factors and levels of Falcon orthogonal tests.The design and analysis of Falcon orthogonal test were carried out by DesignExpert software.The results were analyzed by using the quadratic model for combustible recovery,ash removal rate,vitrinite recovery and inertinite removal rate.The influence of water pressure on each index is greater than the influence of rotation frequency.Then the orthogonal tests should be optimized,the priority of optimized target is the ash removal rate = inertinite removal rate > combustible recovery = vitrinite recovery,the maximum of combustible recovery and vitrinite recovery were limited.The The minimum value of ash is taken,and the other five evaluation indexes are taken as the maximum.The optimized result is the rotation frequency of 55 Hz and the water pressure of 0.03 Mpa.At this time,the ash content is 4.69%,vitrinite content is 67.50%,combustible recovery is 34.09%,ash removal rate is 82.96%,vitrinite recovery is 40.80%,inertinite removal rate is 76.62%.At this point,in ensuring the vitrinite content in vitrinite enrichment can still guarantee the vitrinite enrichment yield.