Abstract: The present invention describes a roll for use in glass manufacture, especially non-dusting TFT glass. The roll may include a hollow fused silica cylinder. End caps are mechanically fixed to the roll. Pulling flats are fixed in place by inner and outer end plates. A compression fitting secures at least the outer end plate to the roll. The roll may be reinforced with an internal metal rod that is secured to the shaft by a plurality of supports. The supports accommodate differences in thermal expansion.

Abstract: A low-water-content castable composition produces cast products with an increased modulus of rupture, an increased cold crushing strength, and decreased porosity. The composition employs closed fractions of constituent particles with specified populations and specified gaps in the particle size distribution to produce these properties. The composition is suitable for refractory applications.

Abstract: The present invention relates to a ladle block for use in a bottom of a molten metal ladle. The ladle block reduces the amount of contaminants, particularly slag, exiting the ladle during casting operations. The ladle block includes a floor defining an outlet and sidewalls substantially orthogonal to the floor. The floor and sidewalls define a channel having dimensions of length, width and height. Channel dimensions are determined from the Froude number, which is based at least partially on the casting flow rate.

Abstract: The present invention concerns stopper rod system for use in a metallurgical vessel, comprising a stopper rod and a nozzle. At least one of the stopper rod nose and the internal surface of the nozzle bore comprise a plurality of ripples that are arranged such that the size of a flow channel between the stopper rod nose and the internal stopper rod when the stopper rod system is in an open position discontinuously increases in size as a function of the distance downstream from the point of contact between the stopper rod and the nozzle.

Abstract: The present invention concerns a submerged entry nozzle for use in the continuous casting of liquid metal. The nozzle comprises a central bore and a plurality of pairs of discharge outlets. The cross-sectional area of the central bore decreases between pairs of discharge outlets, such that ratio of height to width of any outlet is one or less.

Abstract: An electric arc roof furnace top contains a central portion and a peripheral portion surrounding the central portion. Each of these portions has an inner surface suitable for facing the furnace inner space. The inner surfaces of the peripheral and central portions form together a step so as to raise the inner surface of the central portion in relation to the inner surface of the peripheral portion with respect to the furnace inner space.

Abstract: The present invention relates to refractory articles in general having improved surface properties. The objective of the invention is to propose an improvement of the refractory articles comprised of a fused silica matrix which will overcome the some of the defects while keeping the excellent known properties of the fused silica matrix. This objective is reached when a sintered ceramic phase is present in the porosity of at least a portion of at least a surface of the matrix. The present invention also relates to a process for producing such an article.

Abstract: A method for deciding objectively whether a refractory plate of a slide gate valve used to control the flow of a molten metal during the pouring of the metal from an upper vessel to a lower vessel can be reused or should be discarded. Values of parameters measured during pouring or proper to the plate are determined during successive uses of the plate. The values are compared to threshold values to reach a decision. Also, a device for making decisions according to this method.

Abstract: A crucible for the treatment of molten silicon includes a basic body with a bottom surface and lateral walls defining an inner volume. The basic body comprises at least 65% by weight of silicon carbide, and from 12 to 30% by weight of a constituent selected from silicon oxide or nitride. Moreover, the basic body comprises at least one silicon oxide and/or nitride coating, at least on the surfaces defining the inner volume of the crucible.

Abstract: The invention provides an apparatus for measuring the temperature of a molten bath comprising a) a refractory mounting sleeve (1,1?) having an outer surface (2) for contacting the molten bath and an inner cavity (3), said inner cavity having an inner surface (4), an outer opening (6) and an inner closed end (5); and b) an optical pyrometer (7) attached to the mounting sleeve and adapted to measure the thermal radiation emitted by a measurement zone (10) located inside the inner cavity of the mounting sleeve and under the molten bath level. The inner cavity outer opening (6) is adapted to receive fixedly the optical pyrometer (7). The apparatus is characterized in that the mounting plate (8) is adapted to engage in a complementary recess located at the inner cavity outer opening (6) of the mounting sleeve (1,1?). Thereby, the accuracy and reproducibility of the measure is greatly increased.

Abstract: A protective coating is prepared for, and applied to, crucibles used in the handling of molten materials that are solidified in the crucible and then removed as ingots. Crucibles containing this protective coating may be used for the solidification of silicon. The coating has a specified oxygen content and contains a mineral binder and silicon nitride or silicon oxynitride.

Abstract: A crucible and method for the crystallization of silicon utilize release coatings. The crucible is used in the handling of molten materials that are solidified in the crucible and then removed as ingots. The crucible does not require the preparation of a very thick coating at the end user facilities, is faster and cheaper to produce, presents an improved release effect and allows the production of silicon ingot without cracks. The crucible includes a base body, a substrate layer containing silicon nitride, an intermediate layer containing silica, and a surface layer containing silicon nitride, silicon dioxide and silicon.

Abstract: A thermocouple assembly for the continuous measurement of the temperature of a molten phase contains first and second ceramic elements contacting each other at a first junction and forming thereby a first thermocouple, a second thermocouple formed of two different conducting elements contacting each other at a second junction located on the first ceramic element and a third thermocouple formed of two different contacting elements contacting each other at a third junction located on the second ceramic element. Both positive legs or both negative legs of the second and third thermocouples are connected to a first measuring device. Both legs of the second and third thermocouple are connected respectively to a second and third measuring device as well as to a process for the measurement of the temperature of a molten phase.

Abstract: The invention relates to a crucible for the crystallization of silicon and to the preparation and application of release coatings for crucibles used in the handling of molten materials that are solidified in the crucible and then removed as ingots, and more particularly to release coatings for crucibles used in the solidification of polycrystalline silicon. The objective of the inventor was to provide a crucible which does not require the preparation of a very thick coating at the end user facilities, which is faster and cheaper to produce and which presents a stronger coating with an improved adherence to the walls. It has now been found that these problems can be solved with a crucible for the crystallization of silicon comprising a) a base body comprising a bottom surface and side walls defining an inner volume; b) an intermediate layer comprising 50 to 100 wt. % of silica at the surface of the side walls facing the inner volume; and c) a surface layer comprising 50 to 100 wt.

Abstract: The present invention relates to refractory composition consisting essentially of 40-90 dry weight % of amorphous silica aggregates, up to 40 dry weight % of alumina based compounds 10-15 dry weight % of clay, 0.2-2.0 dry weight % of a chemical binder and further containing 2 to 8% of water. These compositions are particularly useful for the repair of coke oven damaged wall in a gunning process.

Abstract: The invention relates to a crucible for the crystallization of silicon and to the preparation and application of release coatings for crucibles used in the handling of molten materials that are solidified in the crucible and then removed as ingots, and more particularly to release coatings for crucibles used in the solidification of polycrystalline silicon. The objective of the inventor was to provide a crucible which does not require the preparation of a very thick coating at the end user facilities, which is faster and cheaper to produce and which presents a stronger coating with an improved adherence to the walls. It has now been found that these problems can be solved with a crucible for the crystallization of silicon comprising a) a base body comprising a bottom surface and side walls defining an inner volume; b) an intermediate layer comprising 50 to 100 wt. % of silica at the surface of the side walls facing the inner volume; and c) a surface layer comprising 50 to 100 wt.

Abstract: The present invention relates to refractory articles for guiding or conveying a solidified material comprising a vitreous silica basis, in particular rollers or guiding elements and to a process for the manufacture of said articles which do not show the pickup problems normally observed with the articles of the art. The refractory articles of the invention comprise a vitreous basis and, homogeneously distributed therein, a carbonaceous material.

Abstract: The invention relates to an injection device for the reliable introduction of a fluid into a metallurgical vessel having a refractory lining, the device being removably insertable in the lining; comprising a refractory first body (2) and a refractory second body (3) fittingly assembled, the first body (2) being made of a refractory material less permeable to the fluid than the material of the second body (3), the first and second bodies having each a surface (4, 5) adapted to contact molten metal; and having each fluid passages (6, 7) extending from fluid feeding means (8) to a surface (4, 5) adapted to contact molten metal, the relative flow resistance of the fluid passages (7) in the second body (4) being higher than that of the fluid passages (6) in the first body (2), the fluid passages (6) in the first body (2) being constituted of slots or bores. According to the invention, the fluid passages (6) in the first body (2) are independent from the fluid passages (7) in the second body (3).

Abstract: The present invention concerns an element for the casting of a liquid metal, comprising a base body made from a refractory material, said body comprising an outer surface and an inner surface defining a pouring channel for the casting of the liquid metal. This element is characterized in that at least a part of the element inner surface is coated with an insulating coating forming, at the metal liquid contact, a gas impermeable layer. Such an element has an excellent thermal shock resistance which permits its use without preheating. Then a layer reducing advantageously the gas permeability is formed.

Abstract: The present invention concerns a mono-block stopper adapted to deliver gas during pouring of molten metal comprising a stopper body having an internal chamber (1) and a gas discharge port (2), a bore (3) connecting the internal chamber (1) to the gas discharge port (2), calibrating means (4) being provided in the bore (3) to provide a restricted path. This stopper is characterised by the fact that the calibrating means comprise a rod (4) having at least one axially-extending gas passages therealong, the gas passage(s) having a section such as to offer a predetermined resistance to flow. The stopper of the invention is far more reliable and can be easily adapted to various operational parameters.