A mineral wool panel, intended to be used as an acoustic panel, has a surface density of greater than or equal to 3.2 kg/m.sup.2, an air flow resistivity of between 30 and 120 kPa.Math.s/m.sup.2, and a Young's modulus of between 0.5 and 4 MPa.

A mineral wool panel, intended to be used as an acoustic panel, has a surface density of greater than or equal to 3.2 kg/m.sup.2, an air flow resistivity of between 30 and 120 kPa.Math.s/m.sup.2, and a Young's modulus of between 0.5 and 4 MPa.

An article for the conversion of glass, the article being made of an alloy that contains the following elements, the proportions being indicated as percentage by weight of the alloy (limit values included): Cr 20 to 35%, Fe 1 to 6%, W 3 to 8%, Nb 0.5 to 3%, Ti 0 to 1%, C 0.4 to 1%, Co 0 to 3%, Si 0.1 to 1.5%, Mn 0.1 to 1%, the remainder being nickel and unavoidable impurities.

A ceramic spinner and a method of making the same is provided. The ceramic spinner includes: a top portion with a first opening, the first opening having a first diameter; a base portion with a second opening, the second opening having a second diameter smaller than the first diameter; a cylindrical portion extending between the top portion and the base portion, the cylindrical portion including a peripheral outer wall, a peripheral inner wall, and a plurality of through holes extending between the peripheral outer wall and the peripheral inner wall. The cylindrical portion may include a material having a module of rupture (MOR) exceeding 100 MPa, a Mohs hardness exceeding 8, or a Young's Modulus exceeding 250 GPa, or any combinations thereof.

An alloy contains the following elements, the proportions being indicated as percentage by weight of the alloy (limit values included) Cr 20 to 35%, Fe 1 to 6%, W 3 to 8%, Nb 0.5 to 3%, Ti 0 to 1%, C 0.4 to 1%, Co 0 to 3%, Si 0.1 to 1.5%, Mn 0.1 to 1%, the remainder consisting of nickel and unavoidable impurities, wherein a (Nb+Ti)/C weight ratio is between 1 to 2.4.

A process for forming mineral fibers by internal centrifugation using a device including a basket and a fiberizing spinner suitable for rotating jointly about an axis of rotation, the basket including an annular wall pierced by orifices and the fiberizing spinner including an annular wall pierced by orifices, the process including feeding the basket with material to be fiberized at a temperature T.sub.a; centrifuging the material to be fiberized by joint rotation of the basket and of the fiberizing spinner. The factor F is greater than 2000, the factor F being defined by F=μ.sub.adN/Q; wherein μ.sub.a is the viscosity of the material to be fiberized at the temperature T.sub.a; d is the distance between the annular walls of the basket and of the fiberizing spinner; N is the number of orifices of the basket; and Q is the feed flow rate of the material to be fiberized.

A method of and an arrangement for recycling mineral wool waste to mineral wool production includes at least one melting furnace for melting virgin mineral wool raw material, the melting furnace including an inlet for virgin mineral wool raw material and an outlet for molten mineral wool material, a production line connected to the outlet for molten mineral wool material for producing a mineral wool product from the molten mineral wool material. The production line includes a curing oven, a fluidized bed reactor including an exhaust gas duct, an inlet for predetermined primary fuel, an inlet for predetermined bed material, and an outlet for an ash material, the ash material including bottom ash discharged via a bottom outlet from the fluidized bed reactor or fly ash separated by a particle separator from exhaust gas in the exhaust gas duct or a mixture of the bottom ash and the fly ash.

A method of and an arrangement for recycling mineral wool waste to mineral wool production includes at least one melting furnace for melting virgin mineral wool raw material, the melting furnace including an inlet for virgin mineral wool raw material and an outlet for molten mineral wool material, a production line connected to the outlet for molten mineral wool material for producing a mineral wool product from the molten mineral wool material. The production line includes a curing oven, a fluidized bed reactor including an exhaust gas duct, an inlet for predetermined primary fuel, an inlet for predetermined bed material, and an outlet for an ash material, the ash material including bottom ash discharged via a bottom outlet from the fluidized bed reactor or fly ash separated by a particle separator from exhaust gas in the exhaust gas duct or a mixture of the bottom ash and the fly ash.

The present invention relates to a metal alloy, characterized in that it comprises, in percent by weight on the total weight of the alloy, 1-4% of niobium (Nb), 0-0.5% of hafnium (Hf), 27-29% of chromium, 1-5% of nickel (Ni), 0.3-0.45% of carbon (C), 0-2% of tantalum (Ta), 0-2% of titanium, 1-3% of iron, less than 0.5% of manganese (Mn), less than 0.3% of silicon (Si), less than 0.2% of zirconium (Zr), the remainder being cobalt (Co) and unavoidable impurities. This metal alloy has superior mechanical strength characteristics at high temperature which make it suitable for the manufacture of a manufactured article, in particular a spinner, for the production of mineral fibers, such as glass fiber, rock fiber and the like.

The invention relates to an uncured thermal and/or sound insulation product, based on mineral wool, advantageously on glass wool, that is in the form of a ply comprising a mineral wool layer sized by at least one binder, said sized layer having: a surface density, or basis weight, of less than or equal to 350 g/m.sup.2, preferably less than or equal to 300 g/m.sup.2, or less than or equal to 250 g/m.sup.2, and, optionally, greater than or equal to 200 g/m.sup.2, a micronaire of at most 3 under 5 grams, preferably of at most 15 l/min, better still of at most 12 l/min, and of at least 9 l/min, and the ply having a thickness of greater than 10 mm, or greater than or equal to 15 mm, or even greater than or equal to 25 mm. The invention makes it possible to propose a thermal and/or sound insulation product that is lighter while retaining satisfactory thermal and/or sound insulation properties and a good mechanical strength.