Abstract: Provided is a coal briquette manufacturing apparatus including a material storage configured to store a plurality of materials for manufacturing coal briquette; a material mixer configured to mix the plurality of materials discharged from the material storage; a coal briquette manufacturer configured to manufacture the coal briquette by press-forming the materials mixed in the material mixer; and a conveyor provided to the material storage, the material mixer or the coal briquette manufacturer, and configured to transport the plurality of materials or the coal briquette, wherein the plurality of materials includes coal ashes, dolomite, and limestone, and a weight of the coal ashes is 70 to 80% of an entire weight of the plurality of materials.

Abstract: An IR supercontinuum source for generating supercontinuum in the MIR or possibly LWIR spectral bands comprises a supercontinuum fiber formed from a heavy metal oxide host glass having low optical loss and high non-linearity over the spectral band that is stable, strong and chemically durable. The supercontinuum fiber is suitably a depressed inner clad fiber configured to support only single transverse spatial mode propagation of the pump signal and supercontinuum. The source suitably includes a tapered depressed inner clad fiber to couple the pump signal into the supercontinuum fiber. The source may be configured as an “all-fiber” source.

Abstract: An optical resonator made from an elongated fiber having a proximal and distal end. A sphere is created on the distal end by locating the distal end in cylindrically symmetrical heating zone along a centerline. For some embodiments, the distal end is rapidly cooled by allowing it to retract away from the heating zone along the centerline during the formation and solidification of the molten microsphere. The resulting optical resonator has an intrinsic quality factor greater than 106 over the 2.0 to 3.2 ?m MIR wavelength range.

Abstract: An IR supercontinuum source for generating supercontinuum in the MIR or possibly LWIR spectral bands comprises a supercontinuum fiber formed from a heavy metal oxide host glass having low optical loss and high non-linearity over the spectral band that is stable, strong and chemically durable. The supercontinuum fiber is suitably a depressed inner clad fiber configured to support only single transverse spatial mode propagation of the pump signal and supercontinuum. The source suitably includes a tapered depressed inner clad fiber to couple the pump signal into the supercontinuum fiber. The source may be configured as an “all-fiber” source.

Abstract: A tellurium oxide glass that is stable, strong and chemically durable exhibits low optical loss from the UV band well into the MIR band. Unwanted absorption mechanisms in the MIR band are removed or reduced so that the glass formulation exhibits optical performance as close as possible to the theoretical limit of a tellurium oxide glass. The glass formulation only includes glass constituents that provide the intermediate, modifiers and any halides (for OH— reduction) whose inherent absorption wavelength is longer than that of Tellurium (IV) oxide. The glass formulation is substantially free of Sodium Oxide and any other passive glass constituent including hydroxyl whose inherent absorption wavelength is shorter than that of Tellurium (IV) oxide. The glass formulation preferably includes only a small residual amount of halide.

Abstract: The invention relates to oil and gas industry, i.e. techniques for making proppants designed to be used as propping agents in oil and gas recovery by the method of formation hydraulic fracturing. A method for the production of a lightweight magnesium silicate proppant, the method comprises heat processing of a magnesium-containing component—a source of magnesium oxide, its co-grinding with a silica-containing component, pelletizing of the batch prepared, sintering and sieving of the pellets prepared, wherein the batch comprises (in terms of calcined substance), in % by weight: SiO2-6 4-72, MgO-11-18, natural impurities—remainder, wherein the heat processing is carried out at temperature not more than 1080 degrees C. A lightweight magnesium silicate proppant is characterized in that the proppant is produced by said method. At least one of the group: serpentine, brucite, caustic magnesite, talc may be used said magnesium-containing component.

Abstract: The specification describes an optical fiber color coding scheme that uses two colors, where each of the two colors constitutes one half of the surface of the optical fiber coating. If a longitudinal portion of the coating is considered a hollow cylinder, then each of the two colors is a hollow hemi-cylinder. To ensure that each of the two colors is always plainly visible to an installer, the two colors are formed with a twist. Using two colors for coding substantially increases the number of available unique color codes. Coloring the entire coating reduces the chances of error in identifying the optical fibers.

Abstract: A process for making a glass product with reduced greenhouse gas emission, comprising: providing a raw material composition comprising at least one silicon dioxide or silicon dioxide-containing compound and at least one pre-reacted compound, wherein the pre-reacted compound comprises an atom of an alkaline earth metal chemically bonded to an oxygen atom, and a silicon atom chemically bonded to the oxygen atom; melting the raw material composition to produce a molten material; and forming the molten material into a glass product.

Abstract: An optical fiber is designed to transmit high-power laser radiation. The optical fiber includes a fiber core, and an inner fiber cladding surrounding the fiber core, where the inner fiber cladding is configured to carry the laser radiation in the fiber core. The optical fiber also includes a first outer fiber cladding surrounding the inner fiber cladding. The first outer fiber cladding has a capillary-free longitudinal section and has a smaller refractive index than the refractive index of the inner fiber cladding. The optical fiber includes an outermost fiber cladding surrounding the first outer fiber cladding. The outermost fiber cladding has scattering centers that surround the capillary-free longitudinal section, where the scattering centers scatter laser radiation emerging from the inner fiber cladding through the first outer fiber cladding along the capillary-free section.

Abstract: A method of forming high strength glass fibers in a continuous system is provided. The method includes supplying a glass batch to a glass melting furnace lined with a material substantially free of noble metals. The glass batch comprises about 50-about 75 weight percent SiO2, about 15-about 30 weight percent Al2O3, about 5-about 20 weight percent MgO, about 0-about 10 weight percent CaO, about 0.25-about 5 weigh percent R2O. The method further includes melting the glass batch in the furnace and forming a pool of molten glass in contact with the furnace glass contact surface, transporting the molten glass from the furnace to the bushing using a forehearth that is at least partially lined with a material substantially free of noble metal materials, discharging the molten glass from the forehearth into the bushing; and forming the molten glass into continuous fibers.

Abstract: A glass composition useful in preparing fiberglass comprises 12 to 25 weight % CaO; 12 to 16 weight % Al2O3; 52 to 62 weight % SiO2; 0.05 to 0.8 Fe2O3; and greater than 2 up to about 8 weight % alkali metal oxide.

Abstract: In a method of producing fibers having property enhancing inclusions, a molten material is supplied to a fiber forming apparatus. A controlled amount of particulate is added to the molten material. The molten material with the added particulate is formed into fibers. An undissolved portion of the added particulate forms inclusions in the fibers, the inclusions having an absorption index in a 2-7 ?m wavelength region that is greater than a corresponding absorption index of the material.

Abstract: A method for manufacturing an optical fiber preform includes the steps of depositing an inner cladding and a central core inside a fluorine doped silica tube and thereafter collapsing the silica tube to form a primary preform. The fluorine doped silica tube has a cross section area that is no more than about 15 percent smaller than the cross section area of the resulting primary preform. The present method facilitates reduced-cost manufacturing of a high-capacity optical fiber preform, which may be drawn to produce an optical fiber having reduced transmission losses.

Abstract: The invention relates to producing continuous organic fibers by stretching from molten minerals. These fibers can be used for producing heat resistant threads, rovings, cut fibers, fabrics, composite materials and products based thereon. The inventive glass has the following chemical composition in mass percentage: 15.9-18.1 Al2O3, 0.75-1.2 TiO2, 7.51-9.53 Fe2O3+FeO, 6.41-8.95 CaO, 2.5-6.4 MgO, 1.6-2.72 K2O, 3.3-4.1 Na2O, 0.23-0.5 P2O5, 0.02-0.15 SO3, 0.12-0.21 MnO, 0.05-0.19 BaO, impurities up to 1.0, the rest being SiO2. The inventive method consists in loading a ground composition in a melting furnace, in melting said composition, in homogenizing a melt, in consequently stabilizing the melt in the melting furnace feeder, in drawing and oiling the fiber and in winding it on a spool. Prior to loading, the composition is held in an alkali solution for 15-20 minutes, and is then washed with flowing water for 20-30 minutes and dried.

Abstract: Magnesium silicate mineral wools having a relatively high liquidus temperature of at least about 1400° C. and to methods for the production thereof are provided. The methods of the present invention comprise melting a magnesium silicate feedstock (e.g., comprising a serpentine or olivine ore) having a liquidus temperature of at least about 1400° C. to form a molten magnesium silicate, and subsequently fiberizing the molten magnesium silicate to produce a magnesium silicate mineral wool. In one embodiment, the magnesium silicate feedstock contains iron oxide (e.g., up to about 12% by weight). Preferably, the melting is performed in the presence of a reducing agent to produce an iron alloy, which can be separated from the molten ore. Useful magnesium silicate feedstocks include, without limitation, serpentine and olivine ores. Optionally, silicon dioxide can be added to the feedstock to lower the liquidus temperature thereof.

Abstract: The method for fabricating an optical fiber comprises the steps of inserting a primary optical fiber preform (11) having a first primary axis (x1) and an outer surface (111) into an overcladding tube (12) having a second primary axis (x2) and an inner surface (120), so that said outer surface and inner surface define an interior space (15); holding the primary preform (11) in a centrally inserted position within the overcladding tube (12) with said first and second primary axes (x1, x2) in substantial alignment with each other; supplying overcladding grain (13) into the interior space (15) that is limited at the lower end of the overcladding tube (12) by means of a closure (125); generating a condition of reduced pressure within the interior space (15) that is limited at the upper end of the overcladding tube (12) by means of an adjoiner (3), which holds the primary optical fiber preform (11) and the overcladding tube (12) in position; and heating the unprocessed secondary preform (1), that consists of the pr

Abstract: Methods for modifying preform core ovality during and subsequent to the formation of an optical fiber preform. After MCVD deposition forms the core rod, but prior to overcladding of the core rod, the code rod may be etched to change its ovality. In order to etch the core rod, the core rod may be mounted to lathe, rotated by at least two rotors, and subjected to a heat source. Additionally, one of the at least two rotors may be phase-shifted from another one of the at least two rotors after the core rod is mounted on the lathe.

Abstract: In an optical fiber (1) for the transmission of high-power laser radiation, with a fiber core (2), with an inner fiber cladding (3) surrounding the fiber core (2) for carrying the laser radiation in the fiber core (2), with a first outer fiber cladding (4) surrounding the inner fiber cladding (3), which has a smaller refractive index than the inner fiber cladding (3) as a result of longitudinally aligned air-filled capillaries (5), and with a second outer fiber cladding (6) surrounding the first outer fiber cladding (4), wherein the first outer fiber cladding (4) has a capillary-free longitudinal section (8), the second outer fiber cladding (6) has according to the invention scattering centers (7) at least in the region of the capillary-free longitudinal section (8) for scattering the laser radiation emerging from the inner fiber cladding (3) along the capillary-free longitudinal section (8).

Abstract: The present invention provides a process for producing a porous quartz glass base, which comprises hydrolyzing a silicon compound in an oxyhydrogen flame in a reaction furnace to generate and deposit fine silica particles on a starting member, thereby forming a porous quartz glass base, wherein a gas discharge pipe for discharging an unnecessary gas from the reaction furnace is heated. According to the present invention, fine silica particles can be prevented from adhering to a gas discharge pipe for discharging the unnecessary hydrogen chloride gas generated in producing a porous quartz glass base.

Abstract: Methods for substantially improving the stability of a melting furnace system including bushings and cooling apparatus for converting molten mineral material to continuous fibers is disclosed. Apparatus and methods for maintaining the molten material throughput and the electrical power load on fiberizing bushings substantially constant are disclosed. The orifice plate, with or without tips or nozzles, is subjected to a more rapid rate of heat removal after the bushing breaks out than it did while the bushing was in a desired fiberizing mode. Apparatus for blowing cooling air upward onto the orifice plate during the time the bushing is breaking out and/or hanging to provide additional cooling is disclosed along with optional additional or alternative apparatus to use for optional additional or alternative cooling is also disclosed.

Abstract: The invention relates to a method of making a mineral melt comprising providing a circulating combustion chamber (1) which comprises an upper zone (2), a lower zone (3) and a base zone (4), injecting particulate fuel, particulate mineral material and primary combustion gas which has optionally an oxygen level of at least 25% by volume into the upper zone of the circulating combustion chamber so that the fuel undergoes pyrolysis in the upper zone to produce char, thereby melting the particulate mineral materials to form a mineral melt and generating exhaust gases, injecting secondary combustion gas which has optionally an Oxygen level of at least 25% by volume into the lower zone of the circulating combustion chamber so that the char combusts, thereby completing combustion of the fuel, and separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass though an outlet in the circulating combustion chamber and the mineral melt collects in the base zone.

Abstract: In an optical fibre (1) for the transmission of high-power laser radiation, with a fibre core (2), with an inner fibre cladding (3) surrounding the fibre core (2) for carrying the laser radiation in the fibre core (2), with a first outer fibre cladding (4) surrounding the inner fibre cladding (3), which has a smaller refractive index than the inner fibre cladding (3) as a result of longitudinally aligned air-filled capillaries (5), and with a second outer fibre cladding (6) surrounding the first outer fibre cladding (4), wherein the first outer fibre cladding (4) has a capillary-free longitudinal section (8), the second outer fibre cladding (6) has according to the invention scattering centres (7) at least in the region of the capillary-free longitudinal section (8) for scattering the laser radiation emerging from the inner fibre cladding (3) along the capillary-free longitudinal section (8).

Abstract: A process for making a glass product with reduced greenhouse gas emission, comprising: providing a raw material composition comprising at least one silicon dioxide or silicon dioxide-containing compound and at least one pre-reacted compound, wherein the pre-reacted compound comprises an atom of an alkaline earth metal chemically bonded to an oxygen atom, and a silicon atom chemically bonded to the oxygen atom; melting the raw material composition to produce a molten material; and forming the molten material into a glass product.

Abstract: A method for manufacturing a single mode optical fiber with a reduced PMD (Polarization Mode Dispersion), by drawing an optical fiber preform composed of a core and a clad surrounding the core, includes (a) heating the optical fiber preform to a high temperature using a furnace, and drawing an optical fiber from an outlet of the furnace at a linear velocity (Vf) of 500 mpm or above by means of neck-down drawing; and (b) impressing a spin on the optical fiber by means of a spin impressing device provided on a drawing path of the optical fiber, wherein a maximum spatial frequency of spin (y) impressed on the optical fiber satisfies the following equations Exp ? ( 24 ? t - 12 ) ? y ? - 20 × log ( V f 500 ) + 25 and t=(0.21×CladOval)+(0.04×CoreOval)+(0.17×ECC), where y is a maximum spatial frequency of spin [turns/m], Vf is a drawing velocity [mpm], CladOval is a clad ovality [%], CoreOval is a core ovality [%], and ECC is an eccentricity [?m].

Abstract: A neutralization system for controlling the pH of the washwater used to clean and maintain polyacrylic bound glass forming equipment. The neutralization system introduces a base solution to a washwater solution when the pH of the washwater solution contained in a closed loop washwater recovery system falls below about 8.5, thereby substantially reducing the corrosion rate of the components of the equipment associated with acidic polyacrylic acid binder, maleic acid cobinder or maleic anhydride cobinder and washwater solution. A closed-loop hoodwall washwater recovery system may also be introduced in addition to the neutralization system that allows for the recovery and reuse of polyacrylic acid binder and maleic acid cobinder or maleic anhydride cobinder with a minimal amount of base solution, thereby minimizing degradation of insulation properties of polyacylic acid bound glass fiber products.

Abstract: The invention relates to a sample cell with a glass body comprising a gas inlet and a gas outlet and at least one orifice, a plane glass window is fused into the orifice, the shape and size of the window corresponds to the shape and size of the orifice, the orifice is limited by a rim, the rim is wider than the thickness of the window, the rim of the window is fused with the rim of the orifice. The invention further relates to a method of producing the sample cell. The window is inserted into the orifice. The rim of the orifice is heated several times from the exterior in such a way that the glass melts and a fused joint is formed between the window and the rim of the orifice. The sample cell produced by the method has a particularly rigid joint between the window and the glass body. Therefore, this glass cell is able to withstand pressures above 10 bar and allows the passage of light without lens effects owing to its plane-parallel windows. The sample cell is used in a polarizer for inert gas.

Abstract: An optical fiber that contains a core of polycarbonate and a coating is disclosed. The coating is a polymer that contains structural units conforming to specified formulae. Also disclosed is a method for preparing the inventive fibers and the use thereof for transmitting signals.

Abstract: A glass fiber containing a fiber processing agent for increasing the surface strength of a rubber product, such as a rubber belt or a tire, and a rubber product containing the glass fiber. The fiber processing agent is comprised of a dispersion solution having a 2-component dispersoid including a rubber latex and an epoxy resin. By using the 2-component dispersoid solution comprised of the epoxy resin, which has excellent strength and also has excellent heat resistance and water resistance, and the rubber latex, which is flexible, a glass fiber and a rubber product can be obtained having greatly increased durability, without bringing about a drop in quality, even under a poor environment.

Abstract: The invention relates to a coating for tools that are used to process heat treated glass, e.g., molten glass or the like, to reduce the adhesion of said glass. The coating consists at least partially of a system of carbon-based layers and/or hard materials containing carbon.

Abstract: Rock fibres are made from a melt formed from a blend of low and high halogen waste materials. 80 to 98% are low halogen materials (containing less than 0.5 wt. % halogen) and 2 to 20% are high halogen materials (containing at least 1 wt. % halogen).

Abstract: A method and system for feeding and burning pulverized fuel, such as petroleum coke, in a glass melting furnace, which includes a glass melting and a plurality of burners associated with a pair of sealed regenerative chambers disposed side-by-side which act as heat exchangers, the burners are arranged in a series of ports that are associated with the glass melting region of the furnace. The system includes means for supplying the pulverized fuel by each one of the burners for melting glass raw materials. The emissions of flue gases produced by the combustion process of the fuel in the furnace are controlled in order to maintain clean the flue gases and for reducing the emission of impurities from the fuel such as SOx, NOx and particulates.

Abstract: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change.

Abstract: Disclosed is a method of protecting glass optical fiber preforms and glass precursor elements for making optical fiber preforms, wherein the preform or glass precursor element is stored within a protective bag. The protective bag preferably has anti-static agents incorporated therein. The protective bags can be employed to protect any glass precursor element used in making optical fiber preforms, for example, glass core canes, glass tubes, or the optical fiber preforms themselves.

Abstract: Provided are glass compositions uniquely applicable for the preparation of ultrafine fibers for filtration and separation applications. The glasses meet all physical and chemical criteria, including that for biodissolution rate.

Abstract: The present invention relates to resorbable glass scaffolds for use in biological applications and methods for making same. Specifically, these scaffolds are composed of phosphate glass fibers, where the rate of dissolution into biological fluids is controlled by the length of time the glass is held above its melt temperature prior to spinning the fiber.

Abstract: A method for processing a glass fiber material, wherein the glass fiber material has been heat treated at a temperature less than or equal to the annealing temperature of the glass for a length of time effective to prevent separation and fraying of the edges of the material upon cutting.

Abstract: A preliminary member of an optical device component with optical fiber comprises a long capillary tube made of glass or crystallized glass and an optical fiber which is fixed in the inner hole of the long capillary tube with adhesive. The overall length of the preliminary member is a plurality of times that of the optical device component or more. A plurality of short capillary tubes with optical fibers are formed by cutting the preliminary member. Thereafter, by polishing both end faces of the short capillary tube with optical fiber, an optical device component can be obtained.

Abstract: To increase the strength of the glass panel, for example of a CRT, the surface temperature of the glass panel at the inner surface of the corners is reduced, during press-forming, to a value below the surface temperature at the inner surface at the centre, the difference being preferably 50° C.-150° C. The forced cooling at the corners compensates for the larger reheating effect in the corners than at the centre that occurs after formation. As a consequence of this compensating effect, a more homogeneous distribution of surface stresses is obtained, increasing the strength of the glass panel.

Abstract: A repellent thread for rodents is described comprising a multifilament thread of glass impregnated with a solution of quinine and/or a derivative thereof in admixture with a textile size.

Abstract: A method and apparatus for controlling the shape and position of a deformable object are described. At least a portion of an object is heated to a temperature sufficient to render the heated portion deformable by a force. An image profile of the heated portion of the object is obtained. A controller compares the image profile to a reference profile and produces an error image signal. Based on the error image signal, an instruction signal is generated. A force applicator responsive to the instruction signal applies a radial force to at least one distinct predetermined location on the heated portion of the object in response to the instruction signal to cause the heated portion of the object to conform to the reference profile. The invention is particularly useful in controlling the shape of an optical fiber preform.

Abstract: Novel boron-free glass compositions are described which are particularly suited for making fine diameter glass fibers for HEPA electronic clean-room filtration media using flame-attenuation or rotary glass processing.

Abstract: A process for the preparation of molten mineral compositions wherein organic impurities are removed by reaction with oxygen introduced via the decomposition of calcium peroxide.

Abstract: The glass compositions of the present invention contain at least 2.0 wt % Al.sub.2 O.sub.3 to give resulting glass fiber an acceptable chemical durability for product performance, but no more than 3.0 wt % to ensure the fiber maintains a relatively high biosolubility. The compositions further include relatively high amount of Na.sub.2 O+K.sub.2 O+MgO+CaO, which tends to increase fiber biosolubility and allows for the use of reduced amounts of B.sub.2 O.sub.3 in the composition. The glass compositions have KI values that generally equal or exceed a KI value of 40 and are suitable for rotary processing. The compositions have liquidus temperatures below about 1800.degree. F. and viscosities above 300 Poise at the liquidus temperature. For higher B.sub.2 O.sub.3 compositions the liquidus temperatures are below 1650.degree. F., and the viscosities are above 1,000 Poises at the liquidus temperatures.

Abstract: Fused biconical tapered couplers formed from the pulling of heated optical fibers have controllable coupling ratios by dynamically adjusting the heat intensity and pull speed during fabrication. Fiber coupler fabrication begins by arranging two optical fibers, heating the optical fibers using a heat source a predetermined distance from the optical fibers, and pulling the optical fibers at an initial pulling velocity as the heated optical fibers soften. The heat source is moved away from the optical fibers and the pulling velocity is selectively reduced in response to a substantial change in the detected coupling ratio. Changes in the coupling ratio are controlled by selectively reducing the pulling speed and the heat intensity to a point where the pulling of the optical fibers may be halted, and the heat removed, without a substantial change in the detected coupling ratio. The coupling ratio may be monitored at different wavelengths for fabrication of wideband couplers and wavelength division multiplexers.

Abstract: An insulation panel is formed comprising a binderless, heat bonded glass fiber insulation board encapsulated within a partially evacuated, gas-tight envelope. The insulation board is formed by laying down discrete length glass fibers into a thin glass fiber mat with the glass fibers lying predominately in and randomly oriented in planes extending substantially parallel to the major surfaces of the thin glass fiber mat. The thin glass fiber mat is layered to form an uncompressed thick glass fiber blanket. The thick glass fiber blanket is heated to a temperature between about 25.degree. C. below and about 20.degree. C. above the strain temperature of the glass fibers; compressed to its final thickness and density; and cooled to form the binderless, heat bonded glass fiber insulation board having glass fibers lying predominately in planes which extend parallel to the major surfaces of the insulation board. The insulation board is encapsulated within the gas-tight envelope to form the insulation panel.

Abstract: The mineral fiber forming apparatus having electrodes for heating heat softenable mineral material to form a molten mineral mass is disclosed. Organically-coated glass fiber scrap and cullet are supplied to the vessel providing the heat softenable mineral material. An impeller turbulently mixes the molten mineral mass dispersing batch into the molten mineral mass and converting water in the molten mineral bath to steam. Molten mineral material formed by the apparatus includes small seeds and gaseous occlusions. The molten mineral material is fed from an outlet port in the vessel to a rotary spinner which forms hollow mineral fibers having gaseous occlusions of between 1% and 10% by volume by centrifuging the molten mineral material through a rotary bushing.

Abstract: The invention provides a process which makes it possible to regulate the degree of oxidation-reduction of a glass during its production.According to the invention, which relates to glasses intended to be transformed into continuous or staple fibers containing at most about 1% by weight of Fe.sub.2 O.sub.3, the degree of oxidation of the glass is obtained by incorporating in the mixture of vitrifiable products at least two oxidizing agents, one of them being an inorganic nitrate, the other being, according to preference, an oxidized compound of manganese in which the oxidation state of the manganese is greater than 2, potassium dichromate and/or ceric oxide.The invention particularly favors the recycling of waste from products with a glass fiber base in the vitrifiable mixture.