▎ 摘　　要

NOVELTY - Preparation of tunnel fireproof coating involves adding 0.8-1.6 pts. wt. base material, 1-4 pts. wt. graphene oxide dispersion and 50-70 pts. wt. filler to a ball mill, sealing, mixing, and grinding for 30-40 minutes. The base material is prepared by adding 10-20 parts mass 3% polyvinyl alcohol aqueous solution to a beaker, adding 2-5 pts. wt. silica sol and 0.02-0.05 part mass polyvinyl alcohol defoamer having pH of 8, stirring for 10-15 minutes, slowly adding 0.1-0.16 part mass 10% borax solution, stirring in a water bath at 80 degrees C for 0.5-1 hour, and adjusting pH to 8-9 with 20 %mass sodium hydroxide solution. The foamed material is prepared by mixing melamine, pentaerythritol, ammonium polyphosphate and vermiculite in a mass ratio of 3:2:2:6. The filler is prepared by adding refractory cement, kaolin, expanded perlite, light calcium carbonate, sepiolite, foamed material, titanium dioxide, magnesium hydroxide and tin oxide to powder mixer, and mixing. USE - Preparation of tunnel fireproof coating. ADVANTAGE - The method enables preparation of coating with improved fire resistance by adding foaming material, filler and additive. DETAILED DESCRIPTION - Preparation of tunnel fireproof coating involves adding 0.8-1.6 pts. wt. base material, 1-4 pts. wt. graphene oxide dispersion and 50-70 pts. wt. filler to a ball mill, sealing, mixing, and grinding for 30-40 minutes. The base material is prepared by adding 10-20 parts mass 3% polyvinyl alcohol aqueous solution to a beaker, adding 2-5 pts. wt. silica sol and 0.02-0.05 part mass polyvinyl alcohol defoamer having pH of 8, stirring for 10-15 minutes, slowly adding 0.1-0.16 part mass 10% borax solution, stirring in a water bath at 80 degrees C for 0.5-1 hour, and adjusting pH to 8-9 with 20 %mass sodium hydroxide solution. The foamed material is prepared by mixing melamine, pentaerythritol, ammonium polyphosphate and vermiculite in a mass ratio of 3:2:2:6. The stable graphene oxide dispersion is prepared by adding 1 g graphite powder to 23 mL 98% sulfuric acid solution, placing obtained mixture in an ice water bath, mixing, slowly adding 2 g potassium permanganate, reacting at 10-15 degrees C for 2 hours, transferring obtained mixture to a constant temperature water bath, stirring at 35 degrees C for 30 minutes, slowly adding 80 mL deionized water to the reaction solution, reacting at 70-80 degrees C for 15 minutes, adding 5 %mass hydrogen peroxide solution until no bubbles are formed in the solution, filtering while hot, washing the filter cake, drying at 60 degrees C for 48 hours, obtaining graphite oxide sample, adding 0.1 g graphite oxide sample to 100 mL aqueous ammonia having pH of 11, stirring for 30 minutes, ultrasonically dispersing at 200-300 W for 45-60 minutes, centrifuging at 10000 rpm for 5 minutes, and removing a small amount of undispersed graphite oxide in the lower portion. The filler is prepared by adding 55-65 pts. wt. refractory cement, 5-15 pts. wt. kaolin, 10-20 pts. wt. expanded perlite, 6-8 pts. wt. light calcium carbonate, 4-6 pts. wt. sepiolite, 6-10 pts. wt. foamed material, 0.2-0.8 pts. wt. titanium dioxide, 6-8 pts. wt. magnesium hydroxide and 2-4 pts. wt. tin oxide to powder mixer, and mixing for 10-20 minutes.