▎ 摘　　要

NOVELTY - Application of limestone comprises mixing and grinding mixed powder of calcium carbonate and metal magnesium powder at mass ratio of 100:48-55 for 10-40 minutes, putting powder in high temperature furnace under protection of argon gas protection device at 60-65 ml/minute for 4-6 hours at 800-1100 degrees C, reacting for 30-60 minutes at 800-1100 degrees C, and cooling into room temperature under protection of argon gas to obtain grey powder; and putting grey powder with hydrogen ion concentration of 2-6/L of acid solution to react for 20-40 minutes, and washing to neutral with distilled water. USE - Method of application of limestone used to prepare graphene (claimed). ADVANTAGE - The method is simple, utilizes wide raw material source, has low cost, and is safe, green and environment-friendly.