▎ 摘　　要

NOVELTY - Manufacturing graphene flakes comprises preparing an iron-intercalated layered graphite by adding molten solution of iron, which is an interlayer exfoliation material into the layered graphite, and introducing it between layers of the layered graphite, pulverizing the prepared iron-intercalated layered graphite with plasma pulverizer to size of 1-10000 nm, adding it in water at 1.5-12.7° C for cooling, so that carbon particles are suspended in water and iron particles are precipitated in water, recovering carbon particles suspended in water to prepare water-dispersed graphene flakes. To pulverize the iron-intercalated layered graphite by generating plasma at 25000-30000° C while supplying compressed air of 1.5-15.5 BAR to the iron-intercalated layered graphite, and pulverized iron-intercalated layered graphite is added into water within 0.0001-0.1 seconds after being pulverized by the compressed air. The prepared water-dispersed graphene flake has solid content of 1.4-7.4 wt.%. USE - The graphene flakes is useful for producing coated steel pipe piles (claim), which is a construction material applied when ground foundation for general civil engineering. ADVANTAGE - The graphene flakes: are easy to recover, and are environmentally friendly; has excellent scratch resistance, adhesiveness, peeling resistance, and construction convenience. The steel pipe piles: has excellent abrasion resistance, surface slipperiness, and durability; and is corrosion resistent. DETAILED DESCRIPTION - An INDEPENDENT CLAIM are also included for: graphene flakes prepared by above mentioned method; manufacturing graphene flakes UV powder resin comprising mixing graphene flakes with an epoxy oligomer emulsion, which is resin for dispersion, drying, preparing graphene dispersion for epoxy powder by pulverizing the dried product, adding 160-320 pts. wt. epoxy oligomer resin, 6.4-12.8 pts. wt. curing agent, and 1.6-3.2 pts. wt. photoinitiator into 100 pts. wt. prepared graphene dispersion for epoxy powder, mixing, injecting the mixed mixture into an extruder, melt-extruding at temperature of 100-110° C, cold-pressing to form flakes, and grinding the prepared mixture of flakes to obtain graphene flakes UV powder resin; and teel pipe pile coated with powder resin and cured by UV.