Abstract: A system and method for magnetically separating diamagnetic and paramagnetic particulate material from a dry admixture comprises a rectangular block ramp formed of multiple rectangular block magnetic elements laterally alternating with multiple rectangular soft-magnetic spacer strips. The magnetic elements are arranged in “bucking mode,” with identical poles facing each other on either side of the spacer strips. The ramp is supported at an adjustable angular inclination by a hinged mounting bracket. Two sets of product receptacles are horizontally and laterally positioned to separately collect falling bands of diamagnetic and paramagnetic material.

Abstract: The disclosed process involves the feeding of particulate SiO.sub.2 into a rotating cylindrical furnace in which a gas plasma arc has been established, for melting the feed at a temperature of at least 2400.degree. C. The feed rate is regulated so that the rate of growth of the radius of the ingot melt will not exceed the rate at which bubbles move through the melt to the inner cylindrical surface. The preferred apparatus is a rotating horizontal furnace having a pair of opposing hollow electrodes mounted in its opposing end surfaces for establishment of an arc therebetween. A feeding device introduces the SiO.sub.2 feed through the open bore of one of the electrodes for melting by the plasma arc.

Abstract: The disclosed invention provides method and apparatus for the separation of diamagnetic and paramagnetic particulate material. The invention utilizes a magnetic roll formed of either alternating permanent magnet and nonmagnetic spacer disc elements or alternating saperdisc elements and disc elements in which magnetism is induced. The dry admixture to be separated into magnetically homogeneous fractions is fed as a plurality of discrete streams onto spaced points on the upper surface of the rotating roll. The feed material undergoes lateral separation on the face of the roll and the materials of different properties part from the surface of the roll at different angular positions, thereby enabling their separate collection. For this purpose a plurality of receptacles are provided in a horizontally spaced relationship to collect the individual streams of diamagnetic material as they leave the surface of the rotating roll.

Abstract: The disclosed process separates impurities, including admixed minerals other than quartz and quartz particles having relatively high levels of lattice impurities, from a quartz containing particulate material to recover a high purity quartz product. The process involves treatment with a solvent to reduce the size of the impurities relative to the quartz product and the thus treated material is then classified by size to recover the purified product. If impurities less soluble than the quartz product are also present, a second solvent treatment is conducted to reduce the size of the quartz particles relative to the less soluble impurity and a second classification by size is conducted. In a preferred embodiment, the quartz is subjected to a heat/quench cycle to fracture quartz particles thereby exposing occluded and interstitial impurities to the solvent leach. The intermediate product exiting the final solvent treatment and classification steps is dried, blended and roasted in a vacuum to remove gases.

Abstract: A high pressure reaction vessel has a container portion and a removable head portion which houses a flow channel or channels, valve members and valve operators and which seals and covers the container portion. Each channel terminates at a tapered valve seat angled at at least 36.degree. with respect to the horizontal and each of the valve members is provided with a mating tapered surface which is wedged more tightly within the valve seat as pressure within the vessel increases. A port and a chute are provided for introducing a particulate solid feed through at least one of the channels into the interior of the vessel. In one embodiment a dip tube depends from a second valve seat (in communication with a second channel) and extends to a point adjacent the bottom of the container portion.

Abstract: The invention relates to a glass lathe for producing preforms which may be drawn into energy transmitting fibers. The apparatus includes a head stock and a tail stock for rotatably holding a starter tube and the preform as it is built from the starter tube. The tail stock is movable along the lathe bed with respect to the head stock so that a preform may be drawn down to approximately the diameter of the starter tube. A carriage is provided on the lathe bed which carries at least one burner for melting a particulate quartz feed and depositing it onto the rotating surface of the starter tube. A slide member mounted on the carriage supports a container for catching particulate quartz which does not adhere to the tube and a coolant reservoir adapted to produce a fountain for contacting and cooling the tube downstream of the burner.

Abstract: The elongated burner is described which is capable of providing a ribbon of flame through which particulate material as small as 1 micron is uniformly dispersed and transported onto a rotating forming surface for formation of an ingot. In a preferred embodiment the burner is provided with a hollow interior defined by a cylindrical surface interrupted by a longitudinal groove in communication with a longitudinal discharge slot. The sides of the groove are sloped at an angle steeper than the angle of repose of the particulate material. In the preferred embodiment the exterior surface of the burner is likewise provided with a longitudinal groove in communication with the discharge slot and providing two surfaces angled toward each other and toward the path through which the discharged material travels.

Abstract: The method of manufacturing an ingot includes the steps of rotating a housing having an inner surface which defines an opening therethrough, the housing containing a layer of insulating material between the housing outer surface and the inner surface, depositing particulate material across the inner surface, and heating the particulate material above its melting point, the rotational movement of the housing holding the molten particulate material by centrifugal force on the inner surface for forming an ingot. The particulate material is deposited on the housing inner surface by gravity from an elongated, slotted tube, by rotating the tube until the slot faces downward.

Abstract: The apparatus for manufacturing an ingot includes a rotatable housing with an inner surface defining an opening therethrough along the rotational axis of the housing. The housing is rotated about the rotational axis. The housing includes a layer of insulating material located between the inner and outer surfaces of the housing. Particulate material is deposited along the inner surface while the housing is rotating and the particulate material is heated above its melting temperature while the housing is rotating, the rotational movement holding the molten particulate material in place by centrifugal force on the inner surface for forming an ingot.

Abstract: Disclosed is a method and apparatus for forming hollow and cylindrical ingots of amorphous or fused silica and other ingot materials. The ingot is formed from a melt on a deposition surface which is lowered as the ingot is formed at a rate which maintains a constant distance between the deposition surface and a heat source vertically positioned above same. The melt is shaped into a vertical cylinder by at least one forming tool which is a roller member rotatable about a vertical axis. In a preferred embodiment the fixed distance from the heat source is maintained with the aid of the laser beam.

Abstract: Disclosed is a method and apparatus for forming hollow and cylindrical ingots of amorphous or fused silica and other ingot materials. The ingot is formed from a melt on a deposition surface which is lowered as the ingot is formed at a rate which maintains a constant distance between the deposition surface and a heat source vertically positioned above same. The melt is shaped into a vertical cylinder by at least one forming tool which is a roller member rotatable about a vertical axis. In a preferred embodiment the fixed distance from the heat source is maintained with the aid of the laser beam.

Abstract: The apparatus is a rotatable resistance heating furnace including a rotatable cylindrical body portion having an interior space in the form of a truncated cone. The base of the truncated cone forms a discharge opening for rapid discharge of the amorphous silica. The furnace is provided with a resistance heating element which extends into the furnace interior through a top opening. In one embodiment a slidable filling tube is provided for charging the furnace during rotation thereof. The process utilizes the above-described apparatus and involves heating the crystalline silica to a temperature sufficient to convert it to the amorphous state, evacuating the furnace during the conversion to draw off by-product gases, and rotating the furnace to a speed sufficient to bring about a separation between the silica charge and the resistance heating element.