▎ 摘　　要

NOVELTY - A coated sand comprises 75-80 pts. wt. quartz sand, 8-10 pts. wt. aluminum powder, 4-6 pts. wt. thermoplastic phenolic resin, 3-5 pts. wt. graphene, 1-2 pts. wt. calcium peroxide, 4-6 pts. wt. plant ash, 8-10 pts. wt. titanium dioxide, 6-8 pts. wt. river sand, 0.8-1.2 pt. wt. hexamethylenetetramine, water, calcium stearate and synergistic agent. The synergistic agent is obtained by mixing plant ash, boron nitride, carbon fiber, pottery clay, ferrous sulfate, talc, zircon powder, silicone oil, ethyl acetate, furan resin, urea and benzenesulfonic acid, and crushing. USE - Coated sand is used for manufacturing thin-walled sand core. ADVANTAGE - The coated sand having excellent thermal stability, fluidity, strength, heat dissipation characteristics, and suppressed generation of defects with respect to metal casting surface, and is economically prepared by simple method. DETAILED DESCRIPTION - A coated sand comprises 75-80 pts. wt. quartz sand, 8-10 pts. wt. aluminum powder, 4-6 pts. wt. thermoplastic phenolic resin, 3-5 pts. wt. graphene, 1-2 pts. wt. calcium peroxide, 4-6 pts. wt. plant ash, 8-10 pts. wt. titanium dioxide, 6-8 pts. wt. river sand, 0.8-1.2 pt. wt. hexamethylenetetramine, 2.4-3 pts. wt. water, 0.25-0.35 pt. wt. calcium stearate and 5-7 pts. wt. synergistic agent. The synergistic agent is obtained by soaking 5-7 pts. wt. plant ash in water for 1-1.5 hours, mixing 4-5 pts. wt. boron nitride, 3-4 pts. wt. carbon fiber, 19-23 pts. wt. pottery clay, 2-3 pts. wt. ferrous sulfate, 2-3 pts. wt. talc and 10-13 pts. wt. zircon powder for 30-40 minutes, adding 3-4 pts. wt. silicone oil and 2.5-3.5 pts. wt. ethyl acetate to wet-mixer for 40-60 seconds, heating to 120-140 degrees C, adding 4-5 pts. wt. furan resin, 1-1.5 pts. wt. urea and 0.1-0.3 pt. wt. benzenesulfonic acid, grinding for 60-80 seconds, drying and crushing to 200-250 mesh. An INDEPENDENT CLAIM is included for preparation of coated sand.