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 L_a and L_c 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 (L_a) and vertical stacking thickness (L_c) 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 L_a and L_c 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.

Lithium (Li) is an important strategic resource, and with the increasing demand for Li, there are some limitations in the exploitation and utilization of conventional deposits such as the pegmatite-type and brine-type Li deposits. Therefore, it has become imperative to search for Li from other sources. Li in coal is thought to be one of the candidates. In this study, the petrology, mineralogy, and geochemistry of No. 2₁ coal from the Hebi No. 6 mine, Anhe Coalfield, China, was reported, with an emphasis on the distribution, modes of occurrence, and origin of Li. The results show that Li is enriched in the No. 2₁ coal, and its concentration coefficient (CC) value is 6.6 on average in comparison with common world coals. Lithium in the studied coal is mainly present in aluminosilicates, mainly clay minerals, some of which contain a significant amount of Ti. The Li enrichment in the No. 2₁ coal is mainly controlled by the terrigenous materials and sourced from the moyite of the Yinshan Upland. Furthermore, Li in the No. 2₁ coal is more enriched in coals formed in acidic and humid conditions and coals influenced by fresh water during peat accumulation.

Pulverized coal is one of the main controlling factors constraining the capacity of coal-bed methane wells during CBM drainage. The characteristics of pulverized coal can be used to identify the sources of the pulverized coal particles and to develop reasonable means of controlling pulverized coal output. Using light transmission microscopy, laser particle size testing, X-ray diffraction, reflection polarized optical microscopy, and scanning electron microscopy with energy dispersive X, the characteristics of pulverized coal collected during CBM drainage in the Hancheng block were analyzed for concentration, particle size, composition, and morphology. These traits were used to identify the sources of pulverized coal. The results showed that coal body structure (structural damage) was a primary control factor of pulverized coal output. The sizes of the pulverized coal particles tended to be around 100 μm. The main components of pulverized coal were vitrinite and clay minerals. The pulverized coals were divided into groups based on their columnar, flaky, or granular morphology. Columnar pulverized coal may involve the formation of the native structure coal or the fragmented coal that later sustains erosive damage. Flaky pulverized coal may be produced by the flaking of scaled coal or leaf coal. In this way, granular pulverized coal may be produced from granulated coal. Therefore, the morphology of the pulverized coal was found to be related to its coal body structure and to late mechanical destruction.