Core grade graphite with a purity higher than 5 parts per million boron and a density greater than 1.50g/cm3; Artificial fine-grained solid graphite with special requirements for density, tensile fracture strain, and thermal expansion coefficient at 20 ℃; Artificial graphite with high purity (>99.9%), high strength (flexural strength>30M? Pa), and high density (>1.73? G/cubic centimeter)