Dry mix for treating refractory substrates and process using same

Dry mix for treating refractory substrates, comprising

• combustible particles of at least one oxidizable substance which, in the presence of oxygen, gives rise to an exothermic reaction, and
• particles of at least one other substance,
• wherein these particles together form, during said exothermic reaction, a coherent mass capable of adhering to and/or interacting with a treated substrate,
• this mix comprising, as particles of at least one other substance, particles of at least one expanding substance, the dry mix without the particles of this at least one expanding substance having a first bulk density and the dry mix comprising said at least one expanding substance having a second bulk density lower than said first bulk density,
• characterised in that said mix also comprises, as particles of at least one other substance, particles of at least one siliceous glass, which have a weight fraction greater than any other constituent in the mix, said mix containing:
• a) 45 to 60% by weight of siliceous glass particles;
• b) 20 to 30% by weight of combustible particles;
• c) 5 to 10% by weight of expanded perlite particles;
• and
• d) 10 to 25% by weight of silica particles.