Abstract: Fused tuckstone defining lower and upper surfaces. The lower surface includes a support surface to rest on metallic structure of a glass furnace, a tank surface intended to face an upper edge of a tank of the furnace, and a lower transition surface connecting the support and tank surfaces. The upper surface includes a superstructure surface to receive a side wall of a superstructure of the furnace and an upper transition surface connecting the superstructure and lower surfaces. At least a part of the lower transition surface has a crystal density of more than four times the crystal density at a depth of 4 centimeters below the lower transition surface, a crystal density being evaluated by the number of crystals having a surface area of more than 12 ?m2 per mm2 of surface after polishing, the crystal density at the depth being evaluated after cutting of the tuckstone.

Abstract: An insulated tuckstone that includes a basic tuckstone and an insulating layer exhibiting a thermal conductivity lower than 2.0 W·m 1·K?1 between 20° C. and 500° C., exhibiting enough rigidity to be self-supporting and covering an insulated surface of the basic tuckstone. The insulated surface is included in the lower surface of the basic tuckstone, extending into the lower transition surface and representing more than 20% of the lower transition surface. The insulating layer has a chemical composition, as a percentage by mass on the basis of the oxides, such that Al2O3+SiO2+ZrO2+CaO+Na2O+MgO+K2O+TiO2+Fe2O3+HfO2+P2O5+Y2O3>80%.

Abstract: A process for treating a fused refractory product including more than 10% by mass of ZrO2, or “base product.” The process includes heating at least a portion of the surface of the product, so as to melt ZrO2 crystals in a superficial region extending to a depth of less than 2000 ?m. The process includes cooling the molten superficial region obtained in the preceding step so as to obtain a protective layer.

Abstract: A method for producing a glass furnace, including a refractory portion, a waveguide with a measurement portion extending into the refractory portion and an interrogator connected to an input of the waveguide to inject an interrogation signal. The measurement portion incorporating a sensor to send a response signal to the interrogator in response to the injection. The interrogator analyzing the response signal and sending a message. Arranging, inside a mold, a temporary part configured to leave space for a compartment for the measurement portion. Preparing a starting feedstock and introducing the starting feedstock into the mold such that the part is embedded therein to obtain a preform. Hardening the preform to form the refractory portion. Removing the temporary part to make the compartment. Assembling the refractory portion with other constituent elements and introducing the measurement portion into the compartment and connecting the interrogator to the input of the waveguide.

Abstract: A process for the manufacture of a refractory block including more than 80% zirconia, in percentage by weight based on the oxides. The process includes the following successive stages: melting, under reducing conditions, of a charge including more than 50% zircon, in percentage by weight, such as to reduce the zircon and obtain a molten material, application of oxidizing conditions to the molten material, casting of the molten material, and cooling until at least partial solidification of the molten material in the form of a block. Also, the process can include heat treatment of the block.

Abstract: A corner block for a glass furnace tank. The corner block has an outer surface including: upper and lower surfaces delimiting the length of the corner block, right and left surfaces to be in contact with corresponding surfaces of adjacent blocks, a hot face to be in contact with the environment inside the tank, and a cold face, opposite the hot face. A main portion of the corner block extends, over more than 80% of the length of the corner block, between two limiting upper and lower transverse planes. The hot face is edge-free. An edge is a line along which the hot face has a break in slope greater than 25°. The hot face has a profile that is convex in any transverse sectional plane in the main portion.

Abstract: Fused cast refractory product including, as weight percentages on the basis of the oxides and for a total of 100%: ZrO2: balance to 100%, Hf2O: <5%, SiO2: 8.1% to 12.0%, B2O3: 0.20% to 0.90%, Na2O+K2O: 0.40% to 0.80%, Al2O3: 0.3% to 2.0%, Y2O3: <2.0%, Fe2O3+TiO2: <0.6%, and other species: <1.5%.

Abstract: A process for the manufacture of a refractory block including more than 80% zirconia, in percentage by weight based on the oxides. The process includes the following successive stages: melting, under reducing conditions, of a charge including more than 50% zircon, in percentage by weight, such as to reduce the zircon and obtain a molten material, application of oxidizing conditions to the molten material, casting of the molten material, and cooling until at least partial solidification of the molten material in the form of a block. Also, the process can include heat treatment of the block.

Abstract: A method for producing a glass furnace, including a refractory portion, a waveguide with a measurement portion extending into the refractory portion and an interrogator connected to an input of the waveguide to inject an interrogation signal. The measurement portion incorporating a sensor to send a response signal to the interrogator in response to the injection. The interrogator analyzing the response signal and sending a message. Arranging, inside a mold, a temporary part configured to leave space for a compartment for the measurement portion. Preparing a starting feedstock and introducing the starting feedstock into the mold such that the part is embedded therein to obtain a preform. Hardening the preform to form the refractory portion. Removing the temporary part to make the compartment. Assembling the refractory portion with other constituent elements and introducing the measurement portion into the compartment and connecting the interrogator to the input of the waveguide.

Abstract: A glass furnace including a refractory portion defining a hot face in contact or intended to be in contact with molten glass or with a gaseous environment in contact with molten glass, and a cold face at a distance from the hot face, and a temperature measurement device. The temperature measurement device including a waveguide that includes a measurement portion including at least one temperature measurement sensor configured to send a response signal in response to the injection of an interrogation signal into the waveguide. The temperature measurement device including an interrogator connected to an input of the waveguide and configured to inject the interrogation signal into the input, to receive the response signal returned by the sensor in response to the injection of the interrogation signal, to analyze the response signal received and to transmit a message according to the analysis.

Abstract: A process for treating a fused refractory product including more than 10% by mass of ZrO2, or “base product.” The process includes heating at least a portion of the surface of the product, so as to melt ZrO2 crystals in a superficial region extending to a depth of less than 2000 ?m. The process includes cooling the molten superficial region obtained in the preceding step so as to obtain a protective layer.

Abstract: An unshaped product including, as weight percentages, A) particles (a) of at least one refractory material other than a glass and a glass-ceramic, and the main constituent(s) of which are alumina and/or zirconia and/or silica and/or chromium oxide: B) 2% to 15% of particles (b) of a hot binder chosen from glass-ceramic particles, particles made of a glass, and the mixtures of these particles, a glass being a noncrystalline material exhibiting a glass transition temperature of less than 1100° C., the hot binder not being in the solid state at 1500° C., C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, the particles (a) and (b) being distributed, as weight percentages in the following way: fraction<0.5 ?m: ?1%, fraction<2 ?m: ?4%, fraction<10 ?m: ?13%, fraction<40 ?m: 25%-52%.

Abstract: An insulated tuckstone that includes a basic tuckstone and an insulating layer exhibiting a thermal conductivity lower than 2.0 Wm 1.K?1 between 20° C. and 500° C., exhibiting enough rigidity to be self-supporting and covering an insulated surface of the basic tuckstone. The insulated surface is included in the lower surface of the basic tuckstone, extending into the lower transition surface and representing more than 20% of the lower transition surface. The insulating layer has a chemical composition, as a percentage by mass on the basis of the oxides, such that Al2O3+SiO2+ZrO2+CaO+Na2O+MgO+K2O+TiO2+Fe2O3+HfO2+P2O5+Y2O3>80%.

Abstract: Fused tuckstone defining lower and upper surfaces. The lower surface includes a support surface to rest on metallic structure of a glass furnace, a tank surface intended to face an upper edge of a tank of the furnace, and a lower transition surface connecting the support and tank surfaces. The upper surface includes a superstructure surface to receive a side wall of a superstructure of the furnace and an upper transition surface connecting the superstructure and lower surfaces. At least a part of the lower transition surface has a crystal density of more than four times the crystal density at a depth of 4 centimeters below the lower transition surface, a crystal density being evaluated by the number of crystals having a surface area of more than 12 ?m2 per mm2 of surface after polishing, the crystal density at the depth being evaluated after cutting of the tuckstone.

Abstract: A fused-cast refractory product including, as mass percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+HfO2: remainder to 100%, with HfO2?5%; SiO2: 1.5% to 7.5%; Al2O3: 1.0% to 3.0%; CaO+SrO: 1.2% to 3.0%; Y2O3: 1.5% to 3.0%; Na2O+K2O: <0.15%; B2O3: <1.0%; P2O5: <0.15%; Fe2O3+TiO2: <0.55%; oxide species other than ZrO2, HfO2, SiO2, Al2O3, Na2O, K2O, B2O3, CaO, SrO, Y2O3, P2O5, Fe2O3 and TiO2: <1.5%.

Abstract: An unshaped product including, as weight percentages, A) particles (a) of at least one refractory material other than a glass and a glass-ceramic, and the main constituent(s) of which are alumina and/or zirconia and/or silica and/or chromium oxide: B) 2% to 15% of particles (b) of a hot binder chosen from glass-ceramic particles, particles made of a glass, and the mixtures of these particles, a glass being a noncrystalline material exhibiting a glass transition temperature of less than 1100° C., the hot binder not being in the solid state at 1500° C., C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, the combined particles (a) and (b) being distributed, as weight percentages in the following way: fraction <0.5 ?m: ?1%, fraction <2 ?m: ?4%, fraction <10 ?m: ?13%, fraction <40 ?m: 25%-52%.

Abstract: A fused-cast refractory product including, as mass percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+HfO2: remainder to 100%, with HfO2?5%; SiO2: 1.5% to 7.5%; Al2O3: 1.0% to 3.0%; CaO+SrO: 1.2% to 3.0%; Y2O3: 1.5% to 3.0%; Na2O+K2O: <0.15%; B2O3: <1.0%; P2O5: <0.15%; Fe2O3+TiO2: <0.55%; oxide species other than ZrO2, HfO2, SiO2, Al2O3, Na2O, K2O, B2O3, CaO, SrO, Y2O3, P2O5, Fe2O3 and TiO2: <1.5%.

Abstract: The present invention relates to a fused refractory product having the following average chemical composition, as a percentage by weight on the basis of the oxides and for a total of 100%: ZrO2: 60.0%-80.0%; SiO2: 4.0%-10.0%; Al2O3: balance to 100%; Y2O3?5.0%; Na2O+K2O+B2O3?0.3% and SiO2/(Na2O+K2O+B2O3)?5.0; other oxide species: ?2.0%; the ratio of the ZrO2/Al2O3 weight contents being between 2.0 and 6.0.

Abstract: The present invention relates to a molten, fluid refractory product comprising, in weight percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+Hf2O: remainder to 100% 4.5%<SiO2<6.0% Al2O3<0.80% 0.3%<B2O3<1.0% Ta2O5+Nb2O5<0.15% Na2O+K2O<0.1% K2O<0.04% CaO+SrO+MgO+ZnO+BaO<0.4% P2O6<0.05% Fe2O3+TiO2<0.55% other oxide species, optionally including Y2O3: <1.5%, where Y2O3<0.3%, the “A/B” ratio of Al2O3/B2O3 content by weight being 0.5 to 2.0. The invention can be used in glass melting furnaces.

Abstract: The present invention relates to a molten, fluid refractory product comprising, in weight percentages on the basis of the oxides and for a total of 100% of the oxides: ZrO2+Hf2O: remainder to 100% 4.0%<SiO2<6.5% Al2O3?0.75% 0.2%<B2O3<1.5% 0.3%<Ta2O5 Nb2O5+Ta2O5<1.4% Na2O+K2O<0.2% BaO<0.2% P2O5<0.15% Fe2O3+TiO2<0.55% other oxide species: <1.5% the “A/B” ratio of Al2O3/B2O3 content by weight being no higher than 1.50. The invention can be used in glass melting furnaces.