▎ 摘　　要

NOVELTY - Preparation of graphene additive includes feeding 100-120 pts. wt. biomass carbon source and 3-5 pts. wt. pore-forming agent in single-screw extruder, mixing, carbonizing, mixing carbon source precursor with modified chitosan solution, sending to microfluidizer, homogenizing, heating 150-200 pts. wt. base, adding 10-20 pts. wt. borate ester, mixing, placing graphene slurry and phosphorus-containing additive in water bath, dispersing graphene slurry and phosphorus-containing additive in base oil, adding dispersant and antioxidant, mixing and dissolving dispersant and antioxidant in base oil. USE - Method of preparing graphene additive used for mineral coating. ADVANTAGE - The method reduces structural defects of graphene surface, improves dispersibility and lubricity of graphene and enhances the strength and water resistance of coating. DETAILED DESCRIPTION - Preparation of graphene additive comprises feeding 100-120 pts. wt. biomass carbon source and 3-5 pts. wt. pore-forming agent in single-screw extruder, mixing for 30-50 minutes, carbonizing at 350-450 degrees C to obtain carbon source precursor having porous structure, mixing carbon source precursor with modified chitosan solution at 60-80 degrees C for 35-45 minutes at 2000-4000 revolutions per minute to obtain chitosan modified carbon source dispersion slurry, sending chitosan modified carbon source dispersion slurry to microfluidizer, homogenizing to obtain high-pressure fluid, homogenizing under 110-120 MPa to obtain graphene slurry, heating 150-200 pts. wt. base at 70-90 degrees C, adding 10-20 pts. wt. borate ester, mixing for 20-40 minutes, placing graphene slurry and phosphorus-containing additive in water bath, dispersing graphene slurry and phosphorus-containing additive in base oil at 70-90 degrees C, adding dispersant and antioxidant, mixing for 30-50 minutes and dissolving dispersant and antioxidant in base oil.