| China is a country which is short of oil and gas but relatively rich in coal resources.Comprehensive consideration of the current situation and future trends of China's energy industry,coal will still occupy the main position in the primary energy structure of our country for a long time.However,the traditional methods of coal utilization are low in energy utilization and seriously polluted.Therefore,promoting the clean and efficient utilization of coal is the key to China's energy reform,the development of clean coal technology is an inevitable choice.Coal slurry technology and coal quality classification technology are important clean coal technology means.Different from other clean and efficient coal utilization methods,coal classification and quality utilization belong to source control,and its low temperature pyrolysis process mainly belongs to physical process.Pyrolysis products are semi coke,gas and tar products.The char yield is 50%-70%of the raw coal,and because of its high ash content,low volatility,high porosity and small packing density,it is difficult to use as direct energy.The structural characteristics of char are studied in this work,and combined with coal water slurry technology,the semi fine pores of Russian fine coal particles were filled and the factors affecting the filling behavior of fine coal particles were investigated.The result shows that the initial concentration of the slurry,the filling time and the material of the coarse powder and the fine powder have little influence on the amount of saturated filling of the semi coke,and the kind of material has a certain influence on the filling process of the semi coke with the dispersant.The particle size of particles plays a decisive role in the filling behavior of char and 5-20?m particles are easier to fill in the half hole,and it is inferred that the kinetic energy of the packed particles is affected by the hole energy.In order to investigate the actual pulping process and slurry properties,through the rheological characteristics of the slurry,it is found that the mixing strength,particle size and thickness ratio have influence on the viscosity of the slurry,which agrees with the experimental results of semi coke filling.High concentration coal water slurry of coal not only should wear to a certain fineness,more important is the size distribution of it should be able to make the size of particles filling,reduce the voids between particles,increase the solid volume share.The different particle size of coarse powder,slurry into fine powder were studied.The concentration of slurry under the same viscosity test,and calculated the rheological analysis and different gradation of particle distance.By adjusting the particle to particle ratio of coal slurry,the performance of CWS can be significantly improved,and the grading particles with different thickness ratio have the best proportion,and the maximum concentration increases with the increase of the thickness ratio.The result shows that when the particle size is greater than four,which can greatly improve the slurry concentration,when the thickness is less than two,gradation are invalid,the gap between the particles cannot be effectively filled,cannot enhance the viscosity of the slurry.fine particles not only to fill the role also can effectively improve the range of interactions between the particles,and play the role of lubrication between the particles.In the best range of the effective distance between fine particles,can not only guarantee the system stability in a certain range,can ensure the system with liquidity when.When the distance between fine particles is too small,the interaction between particles is stronger,and the viscosity of the system increases significantly,resulting in poor fluidity of the slurry. |
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