Incombustible material

Method for producing an incombustible material containing at least one mineral substance, said incombustible material comprising a first ingredient including a plurality of pieces comprising fibers of cellulose and/or chips of wood shavings;

• a mass of thermosetting synthetic resin gluing the pieces of said first ingredient together;
• and particles of calcium sulfate, boric acid and an at least partially glass or ceramic forming mineral adhering to said fibers and/or chips, said method comprising:
• (1) forming a mixture containing an at least partially glass or ceramic forming mineral, said step of forming including providing a quantity of the first ingredient having a water content up to about 80 percent by weight and intimately mixing that quantity of the first ingredient with boron minerals which react with sulfuric acid to form calcium sulfate and boric acid;
• (2) adding thereto, while continuing the mixing, concentrated sulfuric acid;
• (3) subjecting the resulting mixture to evaporation;
• and (4) subsequently combining the resulting product with resin and then bonding the product and resin into a solid body by applying pressure and heat to set the resin and obtain said incombustible material with the pieces of cellulose fibers and/or wood shaving chips being in the form of a network.