Abstract: A glass composition includes greater than or equal to 45 mol % to less than or equal to 60 mol % SiO2; greater than or equal to 15 mol % to less than or equal to 25 mol % Al2O3; greater than or equal to 10 mol % to less than or equal to 20 mol % Li2O; greater than or equal to 0 mol % to less than or equal to 7.5 mol % Na2O; greater than or equal to 0 mol % to less than or equal to 5 mol % K2O; greater than or equal to 7 mol % to less than or equal to 13 mol % P2O5, and greater than or equal to 0 mol % to less than or equal to 4 mol % TiO2. The glass composition may have a liquidus temperature of less than or equal to 1300° C. and an inter-diffusion coefficient greater than or equal to 4000 ?m2/hour. The glass composition is chemically strengthenable. The glass composition may be used in a glass-based article or a consumer electronic product.

Abstract: An optical glass has a refractive index (nd) of 1.55 or more. A difference (Tf?Tg) between a fictive temperature (Tf) and a glass transition temperature (Tg) of the optical glass is 0° C. or more. The optical glass may have a crack initiation load L of 350 mN or more.

Abstract: The present application provides a double-beam laser polishing device and a double-beam laser polishing method for an aluminum alloy, which includes a frame; a rotary workbench and an optical path system, which are arranged on the frame. The optical path system includes: a first fiber laser, a second fiber laser, a first three-dimensional galvanometer, and a second three-dimensional galvanometer. The first three-dimensional galvanometer is connected with the first fiber laser through an optical fiber, and the second three-dimensional galvanometer is connected with the second fiber laser through an optical fiber. The first three-dimensional galvanometer and the second three-dimensional galvanometer are arranged side by side above the rotary workbench in a horizontal direction.

Abstract: Described herein are organosilicon modification layers and associated deposition methods and inert gas treatments that may be applied on a sheet, a carrier, or both, to control van der Waals, hydrogen and covalent bonding between a sheet and carrier. The modification layers bond the sheet and carrier together such that a permanent bond is prevented at high temperature processing as well as maintaining a sufficient bond to prevent delamination during high temperature processing.

Abstract: A vacuum insulated glass product and the method for making the same, wherein the vacuum insulated glass comprises: a first glass substrate; a second glass substrate disposed facing the first glass substrate; a sealing structure provided between the first glass substrate and the second glass substrate and used for airtight binding of the first glass substrate and the second glass substrate to form a vacuum cavity; and a plurality of supports provided inside the vacuum cavity for bearing pressure from the first glass substrate and the second glass substrate. The sealing structure comprises: metal layers which are fixedly formed on facing surfaces of the first glass substrate and the second glass substrate, and an intermediate solder layer which is disposed between and connects the metal layers. The sealing structure has arc-shaped transition structures at the corner areas of the glass substrates.

Abstract: Optical glass that has an Abbe number (Vd) of less than 23 and is suitable for use as a single-lens material constituting a photographic-imaging lens; an optical element including the optical glass; and an imaging lens containing a lens including the optical glass. Optical glass that has an Abbe number (Vd) of less than 23, wherein a flat plate of said optical glass with a thickness of 10 mm exhibits an ISO color contribution index (ISO/CCI) of 0 for blue (B), up to 9 for green (G), and up to 9 for red (R).

Abstract: An optical glass may be a phosphate based glass containing at least any one of oxides selected from TiO2, Nb2O5, WO3, and Bi2O2. The total content (HR) of the TiO2, Nb2O5, WO3, and Bi2O2 may be 35 mol % or above, the noble metal content may be less than 2.0 ppm, and the ?OH value, given by the following general formula, may be 0.1 mm-1 or above: ?OH=?[ln(B/A)]/t.

Abstract: An apparatus and method are provided for sintering a hollow cylindrical body of porous synthetic silica. The apparatus comprises a hollow mandrel for supporting the body in a horizontal position, and the mandrel is housed within a vacuum furnace having heating elements arranged to surround the body circumferentially along its entire length. The method includes supporting the body on a hollow horizontally-oriented mandrel in a vacuum furnace in which heating elements are disposed surrounding the body, and heating the body by means of the elements to a sintering temperature.

Abstract: A method capable of forming a sufficiently thick low alkali concentration region without heating glass to a high temperature and even in an atmosphere which is not an atmosphere of plasma formation gas such as helium and argon, is provided. A glass substrate having a pair of main surfaces and being made of glass containing an alkali oxide in its composition, is disposed between a first electrode and a second electrode so that one main surface is separated from the first electrode and the other main surface is brought into contact with the second electrode, and a corona discharge is generated by applying a direct-current voltage to the first electrode as a positive electrode and the second electrode as a negative electrode, in a positive-electrode-side surface layer portion of the glass substrate, at least one positive ion including an alkali ion migrate toward the negative-electrode-side.

Abstract: Ion transport membranes are integrated with a glass melting furnace and a float glass bath. Only feeds of air, steam and hydrocarbon are necessary for producing hot oxygen for the melting furnace and a mixture of nitrogen, carbon dioxide, and hydrogen for the float glass bath.

Abstract: A method of annealing at least one sapphire lamina is disclosed. The method comprises at least two different heating steps and produces an annealed sapphire lamina having improved optical properties that can be used for fabricating a cover plate of an electronic device. The cover plate and electronic device comprising the annealed sapphire lamina are also disclosed.

Abstract: A method of making a shaped glass article includes placing a glass sheet on top of a mold. A heat exchanger is arranged relative to the mold such that a heat exchange surface of the heat exchanger is in opposing relation to a back surface of the mold and separated from the back surface of the mold by a gap containing a layer of gas. The height of the gap is selected such that the dominant heat transfer between the heat exchange surface and the back surface of the mold is by conduction through the layer of gas. The glass sheet is heated and formed into a shaped glass article with the mold. The heat exchanger is operated to remove heat from at least part of the mold during at least one of heating the glass sheet, forming the shaped glass article, and cooling the shaped glass article.

Abstract: Boron-containing network sulfide glass which may be useful in IR transmitting applications, such as IR optics, laser or fiber amplifiers doped with rare earths with emission in the near IR, and methods of making the same.

Abstract: A rare earth ion doped silicate luminescence glass and preparation method thereof are provided. The luminescence glass is the material with the following formula: aM2O.bM?2O3.cSiO2.dRE2O3, wherein M is at least one of Na, K and Li, M? is at least one of Y, Gd, La, Sc and Lu, RE is at least one of Ce, Tm, Tb, Ho, Dy, Er, Nd, Sm, Eu and Pr. The preparation method is: grinding the raw material until mixed uniformly, calcining the raw material at 1200-1500° C. for 1-5 h, cooling to room temperature, annealing at 600-1100° C. for 0.5-24 h, cooling to room temperature again, molding then getting the product. The performance of the product is stable. The product is homogenous, and the luminescence performance is good. The light transmittance is high. The process of the preparation method is simple and with low cost.

Abstract: A fused silica glass article having greater resistance to damage induced by exposure to laser radiation such as laser induced wavefront distortion at deep ultraviolet (DUV) wavelengths, and behaviors such as fluence dependent transmission, which are related to intrinsic defects in the glass. The improved resistance to laser damage may be achieved in some embodiments by loading the glass article with molecular hydrogen (H2) at temperatures of about 400° C. or less, or 350° C. or less. The combined OH and deuteroxyl (OD) concentration may be less than 10 ppm by weight. In other embodiments, the improved resistance may be achieved by providing the glass with 10 to 60 ppm deuteroxyl (OD) species by weight. In still other embodiments, improved resistance to such laser damage may be achieved by both loading the glass article with molecular hydrogen at temperatures of about 350° C. or less and providing the glass with less than 10 ppm combined OH and OD, or 10 to 60 ppm OD by weight.

Abstract: An apparatus for manufacturing a glass optical element includes: a heating unit that heats a glass material; a pressurizing unit that pressurizes the glass material; a cooling unit that cools the glass material; a molding room in which the heating unit, the pressurizing unit, and the cooling unit are located; an inert-gas supplying unit that forms a plurality of flows of an inert gas within the molding room by blowing the inert gas in a plurality of directions crossing each other; and an inert-gas emitting unit that emits, from within the molding room, the inert gas supplied into the molding room by the inert-gas supplying unit.

Abstract: A method for producing a polarizing element includes: forming particulate materials of a metal halide on a glass substrate; forming a protective film that covers the particulate materials in a non-plasma environment; stretching the particulate materials by heating and stretching the glass substrate; and forming acicular metal particles by reducing the metal halide constituting the stretched particulate materials.

Abstract: Surface modification layers and associated heat treatments, that may be provided on a sheet, a carrier, or both, to control both room-temperature van der Waals (and/or hydrogen) bonding and high temperature covalent bonding between the thin sheet and carrier. The room-temperature bonding is controlled so as to be sufficient to hold the thin sheet and carrier together during vacuum processing, wet processing, and/or ultrasonic cleaning processing, for example. And at the same time, the high temperature covalent bonding is controlled so as to prevent a permanent bond between the thin sheet and carrier during high temperature processing, as well as maintain a sufficient bond to prevent delamination during high temperature processing.

Abstract: Corrosion of the inner surface of the crown of a glassmelting furnace is reduced or avoided by directing at low velocity along that surface a gaseous stream comprising water vapor, or comprising the combustion products of an oxy-fuel burner operated at a stoichiometric ratio of at least 1.0, or the combustion products of a burner operated at a stoichiometric ratio less than 1.0, or by injecting into the furnace interior a gaseous reactant which reacts with alkali species in said space.

Abstract: It is an object of the present invention to provide a copper-containing silica glass which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength of 400 nm or less, and which is excellent in long term stability even in the high output use. The copper-containing silica glass is made to have copper of from 5 wtppm to 200 wtppm, which emits fluorescence having a peak in a wavelength range of from 520 nm to 580 nm under irradiation of ultraviolet light with a wavelength ranging from 160 nm to 400 nm, and in which an internal transmittance per 2.5 mm thickness at a wavelength of 530 nm is 95% or more.

Abstract: A device for making a window includes a main body defining a first space and a second space, a first shaft provided in the first space and connected to the main body, a first die provided in the first space and connected to the first shaft, a second shaft connected to the main body, movable relative to the first shaft and extending to the first space from the second space, and a second die provided in the first space and connected to the second shaft.. The device further includes an air-tight chamber surrounding the first and second dies, a gas supply conduit and a gas discharge conduit connected to the chamber, and an actuator connected to the second shaft and configured to move the second shaft relative to the first shaft. At least one of the first and second dies has a flat area and a curved area.

Abstract: A green light-emitting glass and the method of preparing the same are provided. The components with parts by mole of the green light-emitting glass are alkali oxide 25-40, Y2O3 0.01-15, SiO2 40-70, Tb2O3 0.01-15. The method of preparing the glass includes mixing alkali salt with Y2O3, SiO2 and Tb4O7, firing the mixture at 1200° C.-1500° C. for 1-5 hours, cooling the precursor to the room temperature and annealing the precursor in a reducing atmosphere at 600° C.-1200° C. for 1-20 hours. A green light-emitting glass with good transparence, high uniformity, easily being made into big bulk and high stability is provided. The process of capsulation of parts by using the glass is simple. And a method of preparing the glass with simple process and low cost is provided.

Abstract: A method for producing a polarizing element includes the steps of: forming an island-shaped film of a metal halide on a glass substrate; forming needle-shaped particles of the metal halide by stretching the glass substrate through heating to elongate the island-shaped film; and forming needle-shaped metal particles composed of a metal by reducing the metal halide of the needle-shaped particles, wherein the metal halide is deposited on the glass substrate by a reactive physical vapor deposition method.

Abstract: A method for producing a polarizing element includes the steps of: forming a coating film of a metal on a glass substrate; forming an island-shaped film composed of a metal halide on the glass substrate by partially removing the coating film and also halogenating the metal; forming needle-shaped particles of the metal halide by stretching the glass substrate through heating to elongate the island-shaped film; and forming needle-shaped metal particles composed of a metal by reducing the metal halide of the needle-shaped particles.

Abstract: A white light emitting glass-ceramic. The chemical formula of the glass-ceramic is aSiO2.bAl2O3.cNaF.dCeF3.nDyF3.mAg, wherein a, b, c, d, n and m are, by mol part, 25-50, 15-30, 10-30, 10-25, 0.01-1 and 0.01-1, respectively, and a+b+c+d-100. A method for producing said glass-ceramic is also provided. Silver ion is doped in the glass-ceramic in the form of silver particles by means of sintering and reduction annealing treatment, and thus the luminescence properties of rare earth ion is improved.

Abstract: A sealing apparatus for use in conveying molten glass from a first vessel to a second vessel, wherein at least a portion of the first vessel is nested within the second vessel without contact between the first and second vessels, and a flexible member comprising a gas-tight seal separates an atmosphere enclosed by the sealing apparatus and an ambient atmosphere. The sealing apparatus is useful for flexibly sealing a non-contact joint between conduits for supplying molten glass to a forming body.

Abstract: New and improved compositions of doped fluorophosphate glasses for lasers have a high refractive index (nD) of approximately 1.6 to 1.7, high transmission in the near infrared part of the spectrum and a wide glass forming domain. These glass systems, Ba(PO3)2—Al(PO3)3—BaF2-Dopants, utilize dopants from the group of oxides or fluorides of the rare earth elements Sm, Eu, Nd, Er, Yb, Tm, Tb, Ho and Pr as well as MnO; and mixtures thereof. The composition of glass includes chemical durability, efficiency of laser use in the infrared spectrum and improved duration of luminescence.

Abstract: Provided are a process for the production of a precision press-molded article having a high transmittance a method of treating a glass to color or decolor the glass, the process comprising heat-treating a press-molded article containing at least one selected from WO3, Nb2O5 or TiO2 in an oxidizing atmosphere to produce a glass molded article, and the method comprising heat-treating a colored glass containing at least one oxide of WO3 and Nb2O5 in an oxidizing atmosphere to decolor the glass, or heat-treating a glass containing at least one oxide selected from WO3, Nb2O5 or TiO2 in a non-oxidizing atmosphere to color the glass.

Abstract: New and improved compositions of doped fluorophosphate glasses for lasers have a high refractive index (nD) of approximately 1.6 to 1.7, high transmission in the near infrared part of the spectrum and a wide glass forming domain. These glass systems, Ba(PO3)2—Al(PO3)3—BaF2-Dopants, utilize dopants from the group of oxides or fluorides of the rare earth elements Sm, Eu, Nd, Er, Yb, Tm, Tb, Ho and Pr as well as MnO; and mixtures thereof. The composition of glass includes chemical durability, efficiency of laser use in the infrared spectrum and improved duration of luminescence.

Abstract: A process for producing a glass substrate, which includes forming molten glass obtained by melting raw materials into a glass ribbon in a float bath, annealing the glass ribbon by a cooling apparatus, and cutting the glass ribbon to form the glass substrate, where the hydrogen concentration in the atmosphere of a float bath exceeds 3%, and the glass retention time in the float bath is from 4 to 15 minutes.

Abstract: Discloses are processes for preparing conductive glass-ceramics employ segregation or ion exchange.

Abstract: A green light-emitting glass and the method of preparing the same are provided. The components with parts by mole of the green light-emitting glass are alkali oxide 25-40, Y2O3 0.01-15, SiO2 40-70, Tb2O3 0.01-15. The method of preparing the glass includes mixing alkali salt with Y2O3, SiO2 and Tb4O7, firing the mixture at 1200° C-1500° C. for 1-5 hours, cooling the precursor to the room temperature and annealing the precursor in a reducing atmosphere at 600° C-1200° C. for 1-20 hours. A green light-emitting glass with good transparence, high uniformity, easily being made into big bulk and high stability is provided. The process of capsulation of parts by using the glass is simple. And a method of preparing the glass with simple process and low cost is provided.

Abstract: A method for processing a coated glass substrate may include a high-temperature activation process.

Abstract: The present disclosure provides a method and apparatus for manufacturing a silicon substrate using inert gas blowing during continuous casting to provide excellent productivity and surface quality. The apparatus includes a raw silicon feeder through which raw silicon is fed, a silicon melting unit disposed under the raw silicon feeder and melting the raw silicon to form molten silicon, a molten silicon storage unit storing the molten silicon supplied from the silicon melting unit and tapping the molten silicon to provide a silicon melt having a constant thickness, a transfer unit transferring the silicon melt tapped from the molten silicon storage unit, and a cooling unit cooling the silicon melt transferred by the transfer unit. Here, the cooling unit cools the silicon melt by blowing inert gas at a rate of 0.1˜2.5 Nm3/h.

Abstract: The present invention provides a glass substrate for flat panel display in which yellowing occurring in a case of forming silver electrodes on glass substrate surface is inhibited. A glass substrate for flat panel display, which is formed by a float method, which has a composition consisting essentially of, in terms of oxide amount in mass %: SiO2 50 to 72%, Al2O3 0.15 to 15%, MgO + CaO + SrO + BaO 4 to 30%, Na2O more than 0% and at most 10%, K2O 1 to 21%, Li2O 0 to 1%, Na2O + K2O + Li2O 6 to 25%, ZrO2 0 to 10%, and Fe2O3 0.0725 to 0.15%; and wherein the average Fe2+ content in a surface layer of the glass substrate within a depth of 10 ?m from the a top surface is at most 0.0725% in terms of Fe2O3 amount.

Abstract: A fused silica glass and a fused silica article having a combined concentration of at least one of OH and OD of up to about 50 ppm. The fused silica glass is formed by drying a fused silica soot blank or preform in an inert atmosphere containing a drying agent, followed by removal of residual drying agent from the dried soot blank by heating the dried soot blank in an atmosphere comprising an inert gas and of oxygen.

Abstract: A polarizing element includes fine metal particles formed in numerous regions that were occupied by respective substantially needle-like metal halide fine particles before reduction that are oriented and dispersed in a glass substrate such that the lengthwise directions thereof are almost the same, the fine metal particles being produced by heat-treating the glass substrate in a reducing atmosphere to reduce the substantially needle-like metal halide fine particles. The number of fine metal particles present in at least some of the numerous regions is two or more in each region, 90% or more of the regions each have a volume of 2,500 to 2,500,000 nm3, and the individual volumes of the fine metal particles present in each region are 4 to 40% of the volume of the region in 90% or more of the total number of the regions.

Abstract: First of all, there is provided a production process of a synthetic quartz glass which has less impurity, has a high-temperature viscosity characteristic equal to or more than that of a natural quartz glass, and hardly deforms even in a high-temperature environment, and especially a production process of a highly heat resistant synthetic quartz glass which is free from the generation of bubbles and is dense. Secondly, there is provided a highly heat resistant synthetic quartz glass body which is easily obtained by the production process of the present invention, and especially a transparent or black quartz glass body which is free from the generation of bubbles, is dense, has high infrared absorption rate and emission rate, and has an extremely high effect for preventing diffusion of alkali metal. The process is a process of producing a highly heat resistant quartz glass body having an absorption coefficient at 245 nm of 0.

Abstract: The present invention is directed to a device and method for shaping optical components with improved uniformity and higher throughput. A curved oven provides a plurality of sequential chambers arranged in a curved path, with walls separating the chambers. The walls of the chambers may have openings shaped to match the profile of shaping molds and pedestals which are transported through the oven. An optional dual temperature control system may provide for the separate temperature regulation of upper and lower regions of the chambers. Optical components, such as for solar energy sytems, are manufactured by conveying material and molds on a transport system through the curved oven and shaping them by controlled heat and vacuum assisted slumping. The chambers may be grouped into regions, with the materials undergoing different processes as they traverse each region.

Abstract: The present invention is to provide a molten glass producing apparatus realizing simultaneously the production of a glass article of high quality and save-energy in producing molten glass, a molten glass producing method employing the molten glass producing apparatus and a method for producing a glass article. In the molten glass producing apparatus having a vacuum degassing apparatus, the melting tank is provided with a separating means for separating the area for circulating the molten glass in the melting tank into an upstream circulation flow and a downstream circulation flow, the distance from the separating means to the downstream end of the molten glass flow path in the melting tank is from 0.1 LE to 0.

Abstract: A process for producing a transparent or opaque silica glass product including mixing a silica fine powder and a cellulose derivative and injection molding the mixture, followed by degreasing treatment and baking treatment, which is characterized in that the cellulose derivative is a cellulose derivative which causes reversible thermal gelation in an aqueous solution of at least one member selected from methyl cellulose, hydroxypropylmethyl cellulose and hydroxyethylmethyl cellulose; in producing a transparent silica glass product, the cellulose derivative is added in water heated at a gelation temperature thereof or higher, and after cooling, the formed aqueous solution is kneaded with the silica fine powder; and in producing an opaque silica glass product, the cellulose derivative is added in a silica slurry containing a silica powder and heated at a gelation temperature of the cellulose derivative or higher.

Abstract: This invention pertains to a process of bonding a magnesium aluminate spinel article or articles and a germanate glass article or articles including the step of heating them together above the softening temperature of the glass.

Abstract: A mold-press forming apparatus for applying a molding pressure to a mold containing a forming material to perform press forming includes a loading chamber (that is, an airtight chamber) P1 kept airtight. The loading chamber P1 is connected to a pressure reducing member which includes evacuating members 14 and 13 arranged in an evacuating path 7 connected to the loading chamber P1 for evacuating a gas in the loading chamber P1, and a plurality of valves 11 and 12 arranged in the evacuating path 7 in parallel to each other. When the loading chamber P1 is evacuated, the pressure reducing member changes a pressure reducing rate in the course of pressure reduction.

Abstract: Starting from an optical component of quartz glass for transmitting ultraviolet radiation of a wavelength between 190 nm and 250 nm, with a glass structure essentially without oxygen defects, a hydrogen content ranging from 0.1×1016 molecules/cm3 to 5.0×1016 molecules/cm3, and with a content of SiH groups of less than 5×1016 molecules/cm3, to provide such a component which is particularly well suited for use with linearly polarized UV laser radiation, the present invention suggests that the component should have a content of hydroxyl groups ranging from 10 to 250 wt ppm and a fictive temperature above 1000° C.

Abstract: A process for the manufacture of a substantially bubble-free article of synthetic vitreous silica free from localised variations in refractive index (striae) and suitable for optical applications, wherein an ingot of synthetic vitreous silica containing unacceptable bubbles is submitted to a first heat treatment process consisting of hot isostatic pressing at a temperature in the range 1,250° C. to 1,500° C. at a pressure in the range 10 MPa to 250 MPa, followed by a second heat treatment process at a pressure in the range 0.01 to 1 MPa and at a temperature in the range 1,550° C. to 1,850° C.

Abstract: Disclosed are high purity synthetic silica glass material having a high OH concentration homogeneity in a plane perpendicular to the optical axis, and process of making the same. The glass has high refractive index homogeneity. The glass can have high internal transmission of at least 99.65%/cm at 193 nm. The process does not require a post-sintering homogenization step. The controlling factors for high compositional homogeneity, thus high refractive index homogeneity, include high initial local soot density uniformity in the soot preform and slow sintering, notably isothermal treatment during consolidation.

Abstract: Disclosed are high purity synthetic silica material having an internal transmission at 193 nm of at least 99.65%/cm and method of preparing such material. The material is also featured by a high compositional homogeneity in a plane transverse to the intended optical axis. The soot-to-glass process for making the material includes a step of consolidating the soot preform in the presence of H2O and/or O2.

Abstract: The present invention provides a manufacturing method of a glass substrate for an image display device having high picture quality. The reducing force in a float furnace is controlled to be decreased so that Sn++ content on a surface of the glass substrate forming an Ag electrode is a predetermined value or less. When the resultant Sn++ content on the surface of the glass substrate forming the Ag electrode exceeds the predetermined value, the surface is partially removed to decrease the Sn++ content to the predetermined value or less to suppress the occurrence of yellowing of the glass substrate.

Abstract: To provide titania-silica glass which is transparent glass of low thermal expansion, in particular, is of a low thermal expansion coefficient over a wide range of temperatures of 0 to 100° C. (an operating temperature range) when it is used as a photomask or a mirror material in extreme ultraviolet ray lithography, and which is excellent in homogeneity within the field and stability. Titania-silica glass is used which has 8 to 10% by weight of titania and 90 to 92% by weight of silica, where a Ti3+ concentration is 10 to 60 ppm by weight.

Abstract: The invention relates to a method and apparatus for the production of high-melting glass materials or high-melting glass ceramic materials by a process during which a temperature of a molten mass exceeds 1,760° C., wherein a shard material or raw material is molten to a molten mass, the molten mass is fined, and the molten mass emerges via a tubular outlet made of iridium or an iridium alloy having an iridium content of at least 50 wt.-%. According to the invention the temperature of a section of said tubular outlet, which is in contact with the ambient atmosphere having a natural gas composition, is controlled or regulated such that said temperature is held below 1,000° C. except during pouring out the molten mass out of said tubular outlet. Thus, an oxidative decomposition of the apparatus can be prevented.