Abstract: A method for manufacturing a bent substrate, which forms a bent part in at least a part of a substrate, in which the substrate includes a second region and a first region, the method for manufacturing including: supporting the first region of the substrate on a substrate support surface of a support member including a mold surface having a same curved surface shape as that of the bent part and the substrate support surface that supports the first region, in a state of facing the second region of the substrate to the mold surface; heating the second region of the substrate to soften the second region of the substrate by the heating; placing the second region along the mold surface of the support member by an own weight of the second region; and transferring the curved surface shape of the mold surface to the second region by an external force.

Abstract: The present invention relates to a method of fabricating an improved lithium silicate glass ceramic and to that material for the manufacture of blocks for dental appliances using a CAD/CAM process and hot pressing system. The lithium silicate material has a chemical composition that is different from those reported in the prior art with 1 to 10% of germanium dioxide in final composition. The softening points are close to the crystallization final temperature of 800° C. indicating that the samples will support the temperature process without shape deformation.

Abstract: There are provided a one-press manufacturing method for a glass container that can form uneven shapes on an inner peripheral surface of a glass container and a glass container that is obtained by the one-press manufacturing method.

Abstract: A glass lens blank for polishing in which a thickness of a defect-containing layer is suppressed to a minimum and thus it is possible to shorten the processing time required for grinding and polishing the glass lens blank for polishing after press-molding, a method of manufacturing the same, and a method of manufacturing an optical lens. A glass lens blank for polishing of which at least a main surface is a press-molding surface, wherein a defect-containing layer formed on the main surface has a thickness of 50 ?m or less.

Abstract: A compositional range of high strain point and/or intermediate expansion coefficient alkali metal free aluminosilicate and boroaluminosilicate glasses are described herein. The glasses can be used as substrates or superstrates for photovoltaic devices, for example, thin film photovoltaic devices such as CdTe or CIGS photovoltaic devices or crystalline silicon wafer devices. These glasses can be characterized as having strain points ?600° C., thermal expansion coefficient of from 35 to 50×10?7/° C.

Abstract: The present invention relates to a float glass plate that is formed by continuously supplying a molten glass onto a molten metal in a bath and allowing the molten glass to flow on the molten metal, wherein the float glass plate satisfies the following expression (1) when, on a coordinate axis that is parallel to a through-thickness direction and has, as an origin, an arbitrary point on a principal surface which is positioned on the molten metal side in the bath among both principal surfaces of the float glass plate, a water concentration in glass at a coordinate x (?m) indicating a distance from the origin is represented by C(x) (mass ppm), the thickness of the float glass plate is represented by D (?m), a maximum value of the C(x) is represented by Ca (mass ppm), and a coordinate at which the C(x) is maximum is represented by Da (?m). [ Math . ? 1 ] 0.5 < ? 0 Da ? ( Ca - C ? ( x ) ) ? ? x Ca × D × 100 ? 2.

Abstract: A method for manufacturing an optical element includes floating an optical element material in gas to heat the optical element material, and thereafter making first and second shaping molds contact the floating optical element material at the same time, and pressurizing the optical element material by using the first and second shaping molds.

Abstract: The invention relates to a method for producing an optical lens element, more particularly for illumination purposes, more particularly for producing a headlamp lens for a vehicle headlamp, more particularly for a motor vehicle headlamp, according to which method liquid, transparent, more particularly amorphous, synthetic material is placed into a lower mold. The synthetic material is then pressed between the lower mold and an upper mold by putting the lower mold and the upper mold together. The lower mold and the upper mold are then separated. Further liquid, transparent, more particularly amorphous, synthetic material is then added to the pressed synthetic material and the synthetic material is then pressed, more particularly precision pressed, to form the lens element.

Abstract: A picking system enables a user to easily know when an article that has been placed is different from an article originally scheduled to be placed in a particular position. The picking system includes a picking robot, an ID reader, an encoder, a comparing unit, and a terminal screen. The picking robot picks a workpiece from a first predetermined position and places the article in a second predetermined position. The ID reader acquires identification information of the workpiece picked by the picking robot. The comparing unit compares the identification information acquired by the ID reader with identification information of a workpiece scheduled to be picked. The terminal screen indicates, based on a result of the comparison executed by the comparing unit, a placement position of a workpiece whose identification information does not match the identification information of the workpiece scheduled to be picked.

Abstract: The present invention provides a method for efficiently manufacturing a glass substrate for magnetic disk having good accuracy of a surface irregularity and an impact resistance. The method includes the steps of: performing press forming to molten glass to prepare a sheet glass material, the sheet glass material having a roughness of the principal surface of 0.01 ?m or less and target flatness of a glass substrate for magnetic disk; chemically strengthening the sheet glass material by dipping the sheet glass material in a chemically strengthening salt, thereby preparing a disk substrate; polishing the principal surfaces of the disk substrate. A thickness of the sheet glass material prepared in the press forming step is larger than a target thickness of the glass substrate for magnetic disk by a polishing quantity of the principal surface polishing step.

Abstract: A neuro-probe device is provided. The neuro-probe device includes a carrier including bio-resorbable glass, and a neuro-probe mounted on the carrier.

Abstract: An apparatus and method for manufacturing glass objects comprising a blowing glass blowing pipe and a metal mounting insert configured to melt with glass to form a glass piece that is easily removed from the glass blowing pipe without the need to break the glass from the headstock of the glass blowing pipe. A method for manufacturing a glass object utilizing a metal mounting insert is described. A glass object having a metal mounting insert for installation and use in other applications is also described.

Abstract: The present invention provides a glass substrate for magnetic disk in which surface irregularity of a principal surface is suppressed and a method for efficiently manufacturing a glass substrate for magnetic disk. The method includes the steps of: forming a sheet glass material by performing press forming to molten glass, a principal surface of the sheet glass material having target flatness for the glass substrate for magnetic disk, the sheet glass material having a surface shape to be ground using a grinding abrasive grain; grinding the sheet glass material using a fixed abrasive grain; and polishing the sheet glass material using a loose abrasive grain, the sheet glass material having surface irregularity of the principal surface ground using the fixed abrasive grain.

Abstract: In a method of manufacturing a glass molding, a lower mold includes a recess having a bottom portion and a side portion surrounding the bottom portion, and an outer peripheral planar portion surrounding an upper end of the side portion. A crossing angle between the side portion and the outer peripheral planar portion is set at more than or equal to 45 degrees. A dropping volume of the molten glass drop is such that, when dropped onto the lower mold, a volume of the molten glass drop located above the outer peripheral planar portion is 1.5 times to 6.0 times the volume of the molten glass drop filling the recess.

Abstract: Methods and apparatus for manufacturing high purity polysilicon. The apparatus includes a vacuum chamber; first and second electron guns disposed at an upper side of the vacuum chamber to irradiate electron beams into the vacuum chamber; a silicon melting unit which is placed on a first electron beam-irradiating region corresponding to the first electron gun and to which powdery raw silicon is fed and melted by the first electron beam; and a unidirectional solidification unit placed on a second electron beam-irradiating region corresponding to the second electron gun. The unidirectional solidification unit is provided therein with a start block driven in a downward direction to transfer molten silicon in the downward direction and is formed at a lower side thereof with a cooling channel. The start block includes a dummy bar having a silicon button joined to an upper portion of the dummy bar.

Abstract: Arnold (13) includes a recessed portion (21) for receiving a melt (2). The recessed portion (21) is constituted by an inner wall surface (29) for converting the melt (2) into a solidified portion when the inner wall surface (29) contacts the melt (2), and opens in a withdrawal direction (D1) of the solidified portion. A curved line formed by a first contour (23p) and a second contour (25p) has a cusp at a position of start points (43 and 45). The distance between the first contour (23p) and the second contour (25p) in a width direction (D2) increases continuously from an upstream side to a downstream side of the withdrawal direction (D1). The shape of the inner wall surface (29) of the recessed portion (21) is determined so that a cast rod (3) can be rotationally displaced clockwise or counterclockwise about an axis passing through a first end point (33) or a second end point (35) and perpendicular to a section of the mold 13.

Abstract: There are provided, a method for efficiently manufacturing a glass substrate for magnetic disk in which the degree of surface irregularity of the principal surface is suppressed, and the glass substrate for magnetic disk. When manufacturing a glass substrate for magnetic disk including a pair of principal surfaces, a glass blank is formed by pressing molten glass or softened glass with planar press forming surfaces of dies in such a way that the molten glass or the softened glass is sandwiched from the both sides. Temperature condition is equalized around the pair of principal surfaces of the glass blank during the pressing.

Abstract: An aspect of the present invention relates to optical glass, which is oxide glass, having a refractive index nd ranging from 1.95 to 2.50 and an Abbé number ?d ranging from 18 to 40, including essential components in the form of Si4+, B3+, La3+, Ti4+, Nb5+, and at least one from among Gd3+, Y3+, and Yb3+, including, denoted as cation %, 1 to 30% of Si4+, 1 to 50% of B3+, wherein a total of Si4+ and B3+ ranges from 5 to 55%, a total of 11 to 70% of La3+, Gd3+, Y3+, and Yb3+, with 10 to 50% of La3+, a total of 23 to 70% of Ti4+, Nb5+, Ta5+, and W6+, with equal to or greater than 1% of Nb5+ and greater than 22% of Ti4+.

Abstract: A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free and antimony-free with the exception of any unavoidable raw material impurities and a sulfate compound and SnO2 as refining agents are used. The glass mixture is melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1560° C. and an average melt residence time (t1) is set at t1>2 hours. The proportion of SO3 resulting from the decomposition of the sulfate compound is reduced to less than 0.002 wt. % as the primary refinement is carried out. A secondary refinement is carried out in a second region of the melting tank, an average melting temperature (T2) is set at T2>1640° C. and an average melt residence time (t2) is set at t2>1 hour.

Abstract: Methods for producing crucibles for holding molten material that contain a reduced amount of gas pockets are disclosed. The methods may involve use of molten silica that may be outgassed prior to or during formation of the crucible. Crucibles produced from such methods and ingots and wafers that are produced from crucibles with a reduced amount of gas pockets are also disclosed.

Abstract: A method for manufacturing an optical glass element, comprising: annealing a press-molded product obtained by press molding into a lens shape a glass material comprised of a core portion comprised of an optical glass (first glass) with a transition temperature of 550° C. or higher and a covering portion comprised of a second glass covering the surface of said core portion; and then removing the covering layer from the surface of the press-molded product to obtain an optical glass element. To provide a method for manufacturing high-optical-performance mold-pressed lenses in which the defective external appearance of optical elements comprised of high-temperature glass materials with a Tg of 550° C. or higher is prevented.

Abstract: A manufacturing method of a glass blank for magnetic disk including a pair of principal surfaces, the method including: dropping process for dropping a lump of molten glass; pressing process for forming a sheet glass material by sandwiching simultaneously the lump from both sides of the dropping path of the lump with surfaces of the pair of dies facing together, and performing press forming to the lump; and temperature adjusting process for adjusting temperature of the lump before the pressing process such that viscosity variation of the lump is reduced with respect to positions over the entirety of the lump in the pressing process.

Abstract: Apparatus and method for manufacturing high purity polysilicon. The apparatus includes a vacuum chamber maintaining a vacuum atmosphere; first and second electron guns disposed at an upper side of the vacuum chamber to irradiate electron beams into the vacuum chamber; a silicon melting unit placed on a first electron beam-irradiating region corresponding to the first electron gun and in which powdery raw silicon is placed and melted by the first electron beam; and a unidirectional solidification unit placed on a second electron beam-irradiating region corresponding to the second electron gun and connected to the silicon melting unit via a runner. The unidirectional solidification unit is formed at a lower part thereof with a cooling channel and is provided therein with a start block driven in a downward direction.

Abstract: A method for manufacturing a diffractive optical element by pressing a glass material with a molding die in which an inverted shape relative to a shape of a diffractive surface of the diffractive optical element is formed. The method includes: preparing the molding die, a molding surface of the molding die being formed with a plurality of raised portions chamfered at tip ends thereof; and pressing, with the molding die, the glass material into the diffractive optical element in which raised portions and recessed portions are alternately arranged on the diffractive surface and valley bottoms of the recessed portions are formed to have a chamfered shape.

Abstract: The subject invention is directed to a method for producing a pre-reacted clinker used in the manufacture of E glass. The clinker is fed into an E glass furnace, and melts down into a finished E glass product at high efficiencies and short production times. The clinker allows glass to be produced at a lower cost as compared with known methods.

Abstract: A glass container and related methods of manufacturing. The glass container has a glass composition including soda-lime base glass materials, and an oxide of vanadium for good ultraviolet light blocking properties and an oxide of selenium to decolor the glass for good clarity and decolorization. The glass composition of the glass container also may include an oxide of sulfur.

Abstract: The present invention relates to a silicon part and a method of producing the silicon part. The silicon part is not worn quickly and particle formation is suppressed even if it is positioned in the reaction chamber of a plasma etching apparatus. The silicon part for the plasma etching apparatus is made of any one selected from a group consisting of poly-crystalline silicon, mono-like silicon, and single-crystalline silicon. Also, the silicon part includes boron as a dopant in a range from 1×1018 atoms/cc or higher to 1×1020 atoms/cc or lower.

Abstract: A device for taking up a silicon melt comprises at least one block of a refractory with a capillary structure.

Abstract: A method for manufacturing a glass molding by using a molding device (100), the method including the steps of: supplying molten glass (82) from an outflow nozzle (12) onto an upper surface of a holding member (20), with an opening/closing portion (25) closed, and thereby forming a glass gob on an inner side of a drip pan ring (30); opening the opening/closing portion (25) after the glass gob reaches a prescribed amount, and thereby allowing the glass gob to fall; and press molding the glass gob by using a lower die (60) and an upper die (70), wherein in the step of supplying the molten glass (82) from the outflow nozzle (12) onto the upper surface of the holding member (20), a vibration generating device (40) vibrates the drip pan ring (30) at a prescribed frequency. A high-quality glass gob is formed and a high-precision glass molding is obtained.

Abstract: A system and method for providing component based glass casting are disclosed. One embodiment comprises arranging at least one metal shape to define boundaries of a casting dam, lining the boundaries with ceramic fiber paper to create a containment including the at least one metal shape and the ceramic fiber paper, inserting glass in the containment, and firing the glass and the containment in a kiln to cast a glass shape corresponding to a portion of the containment.

Abstract: Method of manufacturing an optical element capable of providing a satisfactory shape accuracy even where a plurality of optical elements are molded. By providing a protruding portion 12d to change the flow of molten glass drop GD for an optical element with a forming mold 10, it is possible to make the glass drop GD for an optical element flow along an optical surface transferring surface 12a in the vicinity of edge side close to the drop point of the glass drop GD for an optical element, among the optical surface transferring surfaces 12a. According to this, even where a plurality of glass lenses 100 are collectively molded, it is possible to transfer an optical function surface 101a of the glass lens 100 to each optical surface transferring surface 12a with a high accuracy and to collectively manufacture the glass lenses 100 with a satisfactory shape accuracy.

Abstract: The present invention provides a method for efficiently manufacturing a glass substrate for magnetic disk having good accuracy of a surface irregularity and an impact resistance. The method includes the steps of: performing press forming to molten glass to prepare a sheet glass material, the sheet glass material having a roughness of the principal surface of 0.01 ?m or less and target flatness of a glass substrate for magnetic disk; chemically strengthening the sheet glass material by dipping the sheet glass material in a chemically strengthening salt, thereby preparing a disk substrate; polishing the principal surfaces of the disk substrate. A thickness of the sheet glass material prepared in the press forming step is larger than a target thickness of the glass substrate for magnetic disk by a polishing quantity of the principal surface polishing step.

Abstract: An optical glass in the form of an oxide glass, characterized by comprising, denoted as cation percentages: P5+ 14 to 36%; Bi3+ 12 to 34%; Nb5+ 12 to 34%; Ti4+ 5 to 20%; and W6+ 0 to 22%; wherein the total content of Bi3+, Nb5+, Ti4+, and W6+ is equal to or greater than 50%; and in that the Knoop hardness is equal to or higher than 370, the refractive index nd is equal to or higher than 2.02, and the Abbé number vd is equal to or lower than 19.0. A glass material for press molding and an optical element comprised of this optical glass. A method for manufacturing a glass material for press molding comprising the step of mechanically processing this optical glass.

Abstract: To provide a process for producing granules, wherein a component in an exhaust gas discharged from a glass melting furnace can be reused as a raw material for alkali-free glass, and a heating and drying step is not required for the reuse. Exhaust gas G1 formed in a process for melting a raw material of glass containing a boron component is brought in contact with contacting liquids L1 and L2 to obtain treated liquids S1, S2 and S3 having the boron component in the exhaust gas G1 dissolved therein; magnesium hydroxide is added to the mixture of the treated liquids in a treated liquid tank 14 to obtain a liquid containing a boron component and a magnesium component; by using the liquid, a granulation liquid is prepared; and in the presence of the granulation liquid, a raw material mixture for producing alkali-free borosilicate glass is granulated to produce granules.

Abstract: A method for manufacturing a disklike glass material comprising the successive molding of multiple pieces of disklike glass material from glass melt. Being suppressed variation over time in the concentration of infrared radiation-absorbing ions contained in the glass melt being molded into the pieces of disklike glass material so that the variation in the sheet thickness of the multiple pieces of disklike glass material falls within a range of ±15 percent of a reference value. The reference value being the median between the maximum value and the minimum value of the sheet thickness of 1,000 pieces of the glass material. In the course of molding multiple pieces of disklike glass material comprised of glass containing 0.1 to 100 ppm of infrared radiation-absorbing ions, vaiiation over time in the concentration of the infrared radiation-absorbing contained in the glass melt is suppressed to suppress variation in the sheet thickness of the multiple pieces of sheet like glass material.

Abstract: Solid or semi-solid feedstock is melted in an open bottom electric induction cold crucible furnace. Directionally solidified multi-crystalline solid purified material continuously exits the bottom of the furnace and may optionally pass through a thermal conditioning chamber before being gravity fed into a transport mold where an ingot of the purified multi-crystalline solid material is transported to a remote holding area after the transport mold is filled with the multi-crystalline material and cut from the continuous supply of material. Cool down of the ingot is accomplished remote from the open bottom of the electric induction cold crucible furnace.

Abstract: A manufacturing apparatus of the present invention has a pair of dies that form each cylindrical surface, and a plane member that forms side surfaces of an element. The upper die and the lower die has a cylindrical surface which is worked so as to have generatrix which connects intersection points between a non-arc axis and a cylindrical section and between an arc center axis and the cylindrical section. The plane member is pressed against reference surfaces of the upper die and the lower die. In this state, a glass material is put between the upper die and the lower die, and a distance between the upper die and the lower die is decreased. As a result, the cylindrical surfaces of the upper die and the lower die and the plane of the plane member are transferred onto the glass material.

Abstract: A method for producing a solar concentrator, the method comprising providing an upper mold, adapted for molding a light exit face, providing a bottom mold, adapted for molding a light entry face, and blank molding the transparent material between the upper mold and the bottom mold to form a solar concentrator comprising a light entry face and a light exit face.

Abstract: To provide a vacuum-degassing method and a vacuum degassing apparatus excellent in the effect of vacuum-degassing molten glass, more specifically, a method for vacuum-degassing molten glass and a vacuum degassing apparatus, capable of effectively suppressing formation of reboil bubbles. A method for vacuum-degassing molten glass, which comprises melting glass materials to be silicate glass and passing the resulting molten glass in a flow passage in a vacuum degassing vessel, the interior of which is maintained in a reduced pressure state, to vacuum-degas the molten glass, wherein vacuum-degassing is carried out under conditions satisfying the following formula (1) at a bottom portion of the vacuum degassing vessel: SS=pSO2/Pabs<2.0??(1) wherein SS is the supersaturation degree of SO2 in the molten glass, pSO2 is the partial pressure (Pa) of SO2, and Pabs is the pressure (Pa) at the bottom portion of the glass flow passage of the vacuum degassing vessel.

Abstract: A method of replicating at least one optical element is provided, the method including the steps of: providing a substrate with two large sides and at least one pre-defined replication site defined by a through hole or blind holes at corresponding locations on both large sides of the substrate; and adding, by replication, a replicated structure to the substrate, the replicated structure adhering to the substrate and having, at the replication site, replication material in the through hole or in the two blind holes, respectively and a first replicated surface and a second replicated surface, the first and second replication surfaces facing towards opposite sides.

Abstract: An apparatus and method for manufacturing glass objects comprising a blowing glass blowing pipe and a metal mounting insert configured to melt with glass to form a glass piece that is easily removed from the glass blowing pipe without the need to break the glass from the headstock of the glass blowing pipe. A method for manufacturing a glass object utilizing a metal mounting insert is described. A glass object having a metal mounting insert for installation and use in other applications is also described.

Abstract: The present invention provide a fluorophosphate glass comprising 3 to 25 cation % of P5+, more than 30 cation % and 40 cation % or less of Al3+, 0.5 to 20 cation % of Li+ and 65 anion % or more of F? as glass ingredients, and having a liquid phase temperature of 700° C. or less. The fluorophosphate glass of the present invention has ultra low dispersibility and stability, and is preferably used for glass materials for press molding, optical element blanks and optical elements.

Abstract: A memorial product is presently disclosed that includes a glass structure having a first helix of cremation remains and a second helix of a second material, wherein the helix of the cremation remains and the helix of the second material are intertwined to form a double helix in the glass structure. In some embodiments, the second material is additional cremation remains or a colored material selected to correspond to the deceased represented by the cremation remains. Also disclosed is a method of manufacturing a memorial product including forming a first portion of molten glass into a substantially cylindrical shape having an exterior surface, applying cremation remains on a first portion of the exterior surface, applying a second material on a second portion of the exterior surface, and gathering a second portion of molten glass over the first portion of molten glass to encase the cremation remains and the second material.

Abstract: An oxygen-fuel burner for a glass-melting furnace generally includes a first (or inner) conduit for fuel, a second (or middle) conduit for waste glass cullet, and a third (or outer) conduit for combustion oxygen. The first, second, and third conduits are nested and define respective paths for fuel, cullet, and oxygen flows. A cullet supply funnel is coupled to the second conduit such that cullet can be introduced into the second conduit through the funnel. Organic contaminants in the waste glass cullet are incinerated in an almost pure oxygen environment proximate where cullet particles exit from the burner and prior to reaching the glass surface below.

Abstract: It is an object of the present invention to provide a vacuum degassing apparatus configured so as to be capable of carrying out more simply exchange operation for an extension pipe made of heat-resisting metal and immersed in molten glass. The present invention includes a vacuum housing, a vacuum vessel, an introduction pipe and a discharge pipe which are assembled by a plurality of bricks, and an extension pipe connected to at least one of the introduction pipe and the discharge pipe and made of heat-resisting metal. The extension pipe is constituted by a base end portion, a body portion formed so as to be continuous to the base end portion, and a sealing flange extending from an outer peripheral side of the body portion.

Abstract: A method for manufacturing an optical element includes pressing a phosphate-based glass containing Bi2O3 in a proportion of 10 mass % or higher and 30 mass % or lower with a hot mold; and then cooling the same, in which pressure equal to or higher than the critical pressure of oxygen and equal to or lower than a strength of glass is continuously applied to the glass from the time of bringing the glass into contact with the pressing surface of the mold at a glass viscosity of log ?=9 [dPa·sec] or higher and 10 [dPa·sec] or lower until the glass viscosity log ? increases to 12 [dPa·sec] by cooling.

Abstract: The method for making a lens with a first convex lens surface (32) and a second lens surface (33) includes feeding a glass melt drop into a concave mold (2, 10), precise pressing both sides of the glass melt drop in the concave mold (2, 10) together with a press die (20) and immersing the press die (20) in the glass melt drop so that a supporting rim (34) with predetermined dimensions, which protrudes beyond a highest point of the second lens surface (33), is formed on the lens by glass material displaced by the precise pressing. The apparatus for precise pressing includes an upper mold part (10) a lower mold part (2) and the press die (20).

Abstract: The present invention provides a process for producing a molten glass which can produce a molten glass having a good quality, a glass-melting furnace, a process for producing glass products and an apparatus for producing glass products. While an oxygen combustion burner 20 is rotated by a motor 38, glass raw material particles (not shown) are dropped into a high-temperature gas phase atmosphere produced by a flame F of the oxygen combustion burner 20, to be changed into liquid glass particles. By rotation of an outlet (nozzle) of the oxygen combustion burner 20, the falling position of the liquid glass particles 26, changes with time. Accordingly, generation of bubbles caused by continuous fall of the liquid glass particles in a particular position on a molten glass liquid surface is prevented. Accordingly, it is possible to produce a molten glass having a good quality with few bubbles.

Abstract: A method for manufacturing a crucible for the crystallization of silicium comprising the steps of •preparing a slurry of solids and liquids, said solids consisting of •silicon metal powder •up to 25% (w/w) SiC powder •up to 10% (w/w) SiN •up to 0.5% (w/w) of a catalyst •up to 1% (w/w) of a binder •forming the slurry into a green body of a crucible •heating the green body in a nitrogen atmosphere, optionally comprising inert gas, to react the silicon at least partially to silicon nitride.

Abstract: A high-refractivity low-dispersion optical glass that can be stably supplied and has excellent glass stability and that has coloring reduced, composed of in mass %, 5 to 32% of total of SiO2 and B2O2, 45 to 65% of total of La2O2, Gd2O2 and Y2O2, 0.5 to 10% of ZnO, 1 to 20% of total of TiO2 and Nb2O5, and optionally other components. The optical glass has a refractive index nd of 1.89 to 2.0, an Abbe's number ?d of 32 to 38 and a coloring degree ?70 of 430 nm or less.