▎ 摘　　要

NOVELTY - Preparing graphene nano-powder comprises (i) taking expandable graphite as raw material and placing in a microwave and heating at 1000-1800 degrees C to obtain graphite worms, (ii) mixing graphite worm and swelling solvent, dispersing by vacuum degassing to obtain graphite slurry, then drying at 250-600 degrees C under pressure of 4-50 MPa, (iii) stirring at speed of greater than or equal to 1000 m/seconds, dispersing graphite slurry to obtain graphene suspension, and (iv) spray drying graphene suspension under vacuum to obtain graphene nano powder. USE - The method is useful for preparing graphene nano-powder (claimed). ADVANTAGE - The method has low production cost and is suitable for large-scale production process (claimed). DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing graphene suspension comprising (i) microwave heating expandable graphite raw material at 1000-1800 degrees C to obtain post-expansion graphite worms, (ii) mixed with swelling solvent, degassing by vacuum to obtain graphite dispersed slurry and then drying at 250-600 degrees C under pressure of 4-50 MPa, and (iii) stirring at speed of 1000 m/seconds, dispersing swelling graphite slurry to obtain graphene suspension; and (2) graphene production system comprising a high-temperature microwave oven expansion, the high-temperature microwave oven expansion bottom area provided with a microwave source, a nitrogen glow zone, the nitrogen glow zone bottom is set with a nitrogen inlet, the nitrogen glow zone using resistance wire to pass into nitrogen direct heating, a screw feed conveyor expandable graphite raw materials in the tank passing into a high temperature microwave oven for internal expansion, the high-temperature microwave oven expansion above provided with expanded graphite worms export, the expanded graphite worms outlet through a pipe connected to the expanded graphite worm provided on the autoclave inlet, an electromagnetic autoclave is set with a stirring drive device, bottom of the autoclave provided with graphite slurry outlet, graphite slurry outlet via line is connected to the homogenizer, a pressure relief valve is installed pipeline section, the homogenizer discharge port is connected to a low pressure tank, the low-pressure tank discharges through graphite slurry circulation pump and circulation lines back to the inside of the autoclave.