Method for protecting a porous carbon-containing material from oxidation, and material obtained thereby

A process for the protection of a porous carbon-containing material against oxidation and catalytic oxidation of carbon, comprising the steps consisting of:

• preparing an aqueous solution containing the precursors of a glass-containing phosphate base modified at least by the presence of zinc oxide;
• impregnating the porous material with the aqueous solution such that it penetrates the accessible pore space of the material;
• drying the impregnated material;
• and
• carrying out heat treatment to form an internal coating which protects against oxidation, constituted by said modified phosphate glass-containing base,
• characterized in that:
• the precursors are introduced into the aqueous solution so as to allow the formation of a glass-containing base in which the molar ratio between the glass modifying oxides, comprising zinc oxide, and the glass forming oxides, principally comprising or consisting of phosphoric anhydride, is sufficiently high to confer a resistance to corrosion by moisture on the glass-containing phosphate base, and
• the solution is formed by firstly dissolving in water, a polyphosphate which can then allow the required quantity of precursor salts of the modifying oxides comprising at least one zinc salt to dissolve to form a stable solution without the formation of a precipitate.