Coal-based cryptocrystalline
graphite is an intermediate phase
formed during the transformation of highly metamorphic anthracite
into crystalline graphite. In order to explore the relationship between
the graphitization degree of coal-based cryptocrystalline graphite
and its physical properties from macromolecular structure to provide
a theoretical basis for industrial application, samples were tested
by X-ray diffraction, electrochemistry, and thermal conductivity and
compared with standard graphite (SG) and artificial thermal simulation
graphitized samples. The results show that with the increase of graphitization
degree and the growth of microcrystalline structure, the electrical
impedance of cryptocrystalline graphite decreases, the conductivity
increases, the specific capacity of initial discharge increases, and
the thermal conductivity increases, which gradually approach the electrical
and thermal properties of crystalline graphite. The linear equations
between impedance and La and Lc are y = −0.42x + 70.44 and y = −1.87x +
70.62, and the correlation coefficients are 0.93 and 0.88. The linear
equations between thermal conductivity and the horizontal extension
length (La) and vertical stacking thickness
(Lc) are y = 0.09x + 1.36 and y = 0.4x +
0.76, the correlation coefficients are 0.82 and 0.84., and the reduction
of microcrystalline parameters d002 and
the increase of La and Lc lead to a direct improvement of physical properties.
Artificial thermal simulation samples also show the same regularity,
but their physical properties are lower than those of natural evolution
samples. Short-term high-temperature simulation is different from
long-term magma heat and pressure, and the growth of graphite microcrystals
is more complete under long-term geological conditions, resulting
in better physical properties.