Comparison of ultrafine-grain isotropic graphite prepared from microcrystalline graphite and pitch coke

摘要: Abstract As a metamorphic product of coal, microcrystalline graphite is ultrafine polycrystalline structure with near-isotropic and highly graphitized characteristics, which endows itself great potential as filler for ultrafine-grain isotropic (UGIG). In this work, two kinds based UGIG, MGG12 MGG8, are prepared by liquid mixing process from an average particle size 12 8 μm, respectively. For comparison, pitch coke PCG8, control sample 8 μm using the same binder preparation method. Compared MGG8 exhibit many property advantages such higher density, graphitization degree, thermal conductivity, isotropy, lower coefficient expansion, smaller median pore diameter, porosity better barrier to molten fluoride salt. Notably, due smallest diameter (0.431 μm) among these three salt weight gain ratio only 0.13 wt% under 5 atm, much than 16.1 wt% 15.1 wt% PCG8 4 atm, These indicate that may have over UGIG applications reactor. addition, relevant mechanisms analyzed discussed comparison structural characteristics coke.