Product containing chromium 3 oxide for glass furnace

A method for the manufacture of an additive-containing product for a glass furnace comprising, exclusively at the surface, an additive selected from:

• phosphorus compounds other than glasses and vitroceramics,
• WC, MoO3,
• silicon carbide,
• boron carbide,
• silicon nitride,
• boron nitride,
• glasses comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• vitroceramics comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• and their mixtures,
• said additive-containing product, without taking into account said additive,
• having the following chemical analysis, as a percentage by weight on the basis of the oxides:
• Cr2O3≥2%, and
• Cr2O3+Al2O3+CaO+ZrO2+MgO+Fe2O3+SiO2+TiO2≥90%, and
• Cr2O3+Al2O3+MgO≥60%,
• the content by weight of additive being in the range 0.01% to 6% on the basis of the additive-containing product,
• said method comprising the following steps in succession:
• A) preparing a feedstock comprising a particulate mixture and water;
• B) shaping said feedstock in a manner such as to form a preform;
• C) optionally, sintering said preform in a manner such as to obtain a sintered product,
• a precursor of said additive being applied to the surface of the preform and/or applied to the surface of the sintered product.

A glass furnace comprising an additive-containing product comprising, at the surface and/or in the core, an additive selected from:

• phosphorus compounds other than glasses and vitroceramics,
• WC, MoO3,
• silicon carbide,
• boron carbide,
• silicon nitride,
• boron nitride,
• glasses comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• vitroceramics comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• and their mixtures,
• said additive-containing product, without taking into account said additive, having the following chemical analysis, as a percentage by weight on the basis of the oxides:
• Cr2O3≥2%, and
• Cr2O3+Al2O3+CaO+ZrO2+MgO+Fe2O3+SiO2+TiO2≥90%, and
• Cr2O3+Al2O3+MgO≥60%,
• the content by weight of additive being in the range 0.01% to 6% on the basis of the additive-containing product,
• the additive-containing product being obtained by a method comprising the following steps in succession:
• A) preparing a feedstock comprising a particulate mixture and water;
• B) shaping said feedstock in a manner such as to form a preform;
• C) optionally, sintering said preform in a manner such as to obtain a sintered product,
• a precursor of said additive being added to the feedstock and/or applied to the surface of the preform and/or applied to the surface of the sintered product, wherein said additive precursor is selected from FePO4, MgPO4, ZnPO4, CuPO4, H3PO4, WO3, WC, MoO3, Si, Al, Fe, SiAl, FeSi, SiC, B4C, Si3N4, a glass comprising iron, and their mixtures.

A glass furnace comprising an additive-containing product comprising, at the surface and/or in the core, an additive selected from:

• phosphorus compounds other than glasses and vitroceramics,
• WC, MoO3,
• silicon carbide,
• boron carbide,
• silicon nitride,
• boron nitride,
• glasses comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• vitroceramics comprising elemental phosphorus and/or iron and/or tungsten and/or molybdenum,
• and their mixtures,
• said additive-containing product, without taking into account said additive, having the following chemical analysis, as a percentage by weight on the basis of the oxides:
• Cr2O3≥2%, and
• Cr2O3+Al2O3+CaO+ZrO2+MgO+Fe2O3+SiO2+TiO2≥90%, and
• Cr2O3+Al2O3+MgO≥60%,
• the content by weight of additive being in the range 0.01% to 6% on the basis of the additive-containing product,
• wherein the additive-containing product is in the form of a hardened concrete or a sintered concrete.