Abstract: Fire-refined blister copper is produced from copper concentrate by a process comprising:A. melting and oxidizing the copper concentrate in a smelting furnace to produce molten matte and slag, and to separate one from the other;B. removing the molten matte from the smelting furnace;C. solidifying the molten matte;D. injecting the solidified matte into a converting furnace in which the matte is converted to blister copper and slag; andE. transferring the blister copper from the converting furnace to an anode furnace to produce fire-refined blister copper.After the fire-refined blister copper is produced in the anode furnace, it is typically transferred to an anode casting wheel on which it is converted to copper anodes suitable for subsequent electrolytic refining to cathode copper.

Abstract: Impurity streams generated during the pyrometallurgy of copper are hydrometallurgically processed at ambient pressure for recovery of primary values in an energy-efficient manner and with the capture and conversion of metallic impurities to states that are acceptable for disposal into the environment. Hallmark features of the various embodiments of this invention include the water leach of flue dust, the extraction of water-soluble copper as a separate product, a controlled acid leach stage in which bismuth is solubilized, the return of copper to the smelting process as a sulfide, the ability to operate the various process stages at essentially ambient pressure, and the gradual reduction in temperature over the course of the process without the use of indirect heating or cooling operations.

Abstract: The present invention relates to a method and apparatus for sharing a load between individual sections of a vertical column. Although particularly useful in conjunction with glass lined steel columns, the present load distribution means is also useful in other vertical columns which are assembled in sections and have gasketed joints. The load sharing, or distribution, means comprises a radially extending annular member, rigidly secured along the outer periphery of each column section to be joined. The annular member is positioned adjacent to the section end. The annular members are aligned as the column sections are assembled and are spacedly secured one from another. Thus, the annular member on one section is secured, but at a distance, from the annular member on an adjacent section.

Abstract: An oscillating cooled mold assembly for the continuous, high-speed casting of metallic strands, especially upcasting strands of copper alloys such as brass, has a hollow die in fluid communication with a melt typically held in a casting furnace. A coolerbody surrounds the die in a tight-fitting relationship to form a solidification front in the melt as it advances through the casting zone of the die. During assembly, the die is preferably slip fit in the coolerbody. A shoulder on the die engages a lower face of the coolerbody and, together with a small irregularity on the upper coolerbody wall, prevents any axial movement of the die before it thermally expands against the coolerbody. An insulating member located between the die and the coolerbody and below the solidification front fixes the location of the front within a dimensionally uniform area of the die.

Abstract: The present invention minimizes the problem of thermal stresses in a glass lined vessel by providing a heat transfer sump in the bottom portion of the vessel. A heat transfer compartment is formed by enclosing the annular space between the exterior portion of the skirt and the bottom portion of the vessel by means of an annular ring. The heat transfer compartment is enclosed by the annular ring, the interior portion of the skirt, and the bottom portion of the vessel. The heat transfer compartment is adapted to receive and hold a heat transfer medium and in this manner form a heat transfer sump.

Abstract: A furnace for the sintering of refractory or ceramic materials using plasma heated gases. The furnace comprises a sintering chamber with strategic positioning of the plasma torch inlets and exhaust outlet, a furnace temperature controlling device during sintering so that the article being sintered does not decompose. The devices which can be used for controlling the temperature of the furnace during sintering include: (1) Tangential injection of a secondary colder gas stream into the hot primary plasma gas stream; (2) Utilization of a plasma torch or torches which can be temperature controlled to achieve stable and lower plasma gas temperatures; and (3) Introduction of a secondary cooler gas directly into the furnace sintering chamber.

Abstract: A system to prevent, retard or reverse the decomposition of silicon carbide articles during high temperature plasma sintering. Preferably, the system comprises sintering a silicon carbide refractory or ceramic green body in a closed sintering environment, such as a closed tube, with strategic placement of the plasma torch or torches, exhaust outlet and tube. As sintering proceeds, a silicon vapor pressure builds up within the tube, retarding the decomposition of the silicon carbide body. The plasma torch, exhaust outlet, and tubes are positioned so that buoyant convective flow is maximized to increase the heat transfer and energy efficiency. In another embodiment, a "sacrificial" source of silicon carbide is placed into the sintering furnace. The silicon carbide in the sacrificial source starts to decompose before the silicon carbide refractory or ceramic article, creating a supersaturated atmosphere of silicon vapor species in the furnace.

Abstract: The present invention provides a method of pressureless sintering silicon carbide in which the silicon carbide starting material is in the form of a multimodal composition, or mixture, of coarse and submicron particles. The present sinterable silicon carbide mixtures consist of separate fractions of sized particles. Each fraction is present in amounts of from about 5 to about 75% by weight of the mixture, and more preferably from about 10 to about 65% by weight of the mixture. One fraction has a particle size ranging between about 0.21 mm (210 microns) to about 3.4 mm (3400 microns) and preferably the larger particles have a size less than about 2.4 mm. A second fraction has a particle size ranging between about 0.003 mm (3 microns) up to about 0.21 mm. A third fraction has a size less than 0.003 mm, but has an average size less than 1 micron. The present products are produced by sintering particulate silicon carbide in the presence of a sintering aid and a slight excess carbon.

Abstract: Disclosed is an apparatus and method for the integrated, continuous, high speed manufacture of metallic strip, especially brass, from a melt. The apparatus comprises a chilled casting mold in liquid communication with a melt, means for drawing a rod through the mold at a constant rate and means for oscillating the mold in a pattern of forward and reverse strokes with respect to the direction of travel of the rod. Conversion of the rod to strip comprises flattening in a hot rolling mill, and quenching. In accordance with known procedures, the produced strip can be further reduced in cross section in one or more cold rolling mill or other hot rolling mills if desired.

Abstract: An extended life capacitor is disclosed in which an enclosing body is made from a tantalum can and tantalum cap and enclosing a plurality of double layer capacitor cells. Each of the capacitor cells includes a conductive material, such as activated carbon, with an aqueous electrolyte therein such as dilute sulfuric acid. In the preferred embodiment, this is about 38% by weight of sulfuric acid, and the remainder water. Lead-ins are provided to make electronic connection to the two ends of the capacitor cell stack as anode and cathode electrodes. The entire unit is hermetically sealed to inhibit the loss of electrolyte from the capacitor body to less than 2% per year, and the electrodes are at least partly coated with a noble metal such as gold to limit the establishment of a spurious capacitor which would be in series with the stack of plurality cells, which would otherwise greatly decrease the capacity of the entire unit.

Abstract: A cylindrical pressure vessel housing a filter media wherein the vessel is formed from a tubular thermoplastic pipe portion having opposite conical shaped end portions integrally formed with molded internal base portions with one base portion having integrally molded thereto the filter media in sealed position within the vessel housing.

Abstract: A process for the sintering of silicon carbide refractory or ceramic articles using plasma arc gases. In the process of the invention, a formed silicon carbide article is heated in a plasma fired furnace to a sintering temperature of between 2000.degree. C.-2500.degree. C. at a heating rate of 300.degree. C./hr-2000.degree. C./hr, and held at the sintering temperature for 0.1-2 hours. The enthalpy of the plasma gas is 2000 BTU/lb-4000 BTU/lb, when nitrogen is used as the plasma gas. The total cycle time for the process of the invention, including cooling and loading, is 1.5-20 hours. Silicon carbide articles, produced in accordance with the invention, have high strength, high density, high corrosion resistance and high dimensional stability.

Abstract: An improved process for sintering extruded powder shapes comprising drying or calcining an extruded shape in a microwave furnace and rapid sintering the shape in a plasma fired furnace. Alternatively, calcining or drying may take place within a furnace heated by the plasma furnace's exhaust. The process of the invention is especially useful for silicon carbide extruded materials and for tubular shapes. This process significantly reduces sintering times and costs. Use of the process yields a high strength sintered product.

Abstract: Method of producing silicon carbide and of automatically separating a high grade fraction thereof using magnetic separation techniques. In the method of the invention, a silicon source, a carbon source and a ferromagnetic element source are admixed and the admixture is heated from the center outward to form a cylinder containing silicon carbide with a center to exterior temperature gradient. The ferromagnetic element migrates from the hotter center to the cooler exterior portions of the cylinder. The cylinder is cooled and crushed. The lower grade silicon carbide particles are then separated from the high grade silicon carbide crystals using magnetic separation means.

Abstract: Apparatus for converting relatively high, variable frequency, variable amplitude electrical power into substantially constant amplitude and substantially constant, relatively lower frequency power of a preselected waveform. The power source signal is divided into a number of varying amplitude, same frequency segments. The segment having the amplitude nearest that of the preselected waveform is transmitted by a switching network during each of many time periods. The switching network is preferably controlled by a microprocessor that senses the amplitudes of the segments and compares them to the desired waveform amplitude as a function of time. The microprocessor provides control signals to the switching network in response to the comparison. Because the low frequency output signal is constructed with reference to a memorized signal, the output signal is particularly stable in spite of variations in the power source signal.

Abstract: A jacket for an enameled vessel with a lower outlet nozzle is described comprising an upper weld ring welded along the outer circumference of the vessel, and comprising a lower weld ring surrounding the lower outlet nozzle, and also the jacket as such. The upper weld ring is conically tapering to its lower end, and the lower end of the lower weld ring is shaped cylindrically. Therefore, the upper end of the jacket can be easily welded with the outer side of the lower end of the upper weld ring, since the lower end of the jacket can be moved into a proper position along the cylindrical end of the lower weld ring.

Abstract: A system to prevent, retard or reverse the decomposition of silicon carbide articles during high temperature plasma sintering. Preferably, the system comprises sintering a silicon carbide refractory or ceramic green body in a closed sintering environment, such as a covered crucible, with strategic placement of the plasma torch or torches, exhaust outlet and crucibles. As sintering proceeds, a silicon vapor pressure builds up within the crucible, retarding the decomposition of the silicon carbide body. The plasma torch, exhaust outlet, and crucibles are positioned so that buoyant convective flow is maximized to increase the heat transfer and energy efficiency. In another embodiment, a "sacrificial" source of silicon carbide is placed into the sintering furnace. The silicon carbide in the sacrificial source starts to decompose before the silicon carbide refractory or ceramic article, creating a supersaturated atmosphere of silicon vapor species in the furnace.

Abstract: A work conveyor sprocket and link assembly includes a sprocket having a body member. The body member includes a plurality of radially extending teeth connected by arcuate root portions. The body member further includes shoulder portions which extend outwardly from the sides of the body member. The link assembly includes a plurality of individual links connected to each other by link pins. Conveyor slats are secured to one side of the links; small flanges project from the other side of the links. Fasteners are connected to the flanges in order to retain the link pins in place. When assembled, the links engage both the teeth and the shoulder portions so as to distribute applied forces over a large area.

Abstract: A thermal insulation is formed by simultaneously spraying ceramic fibers and a binder at a surface to be covered. An aqueous binder is prepared prior to application to the fiber during the spraying operation. The binder includes an organic component which provides necessary wet and green adhesion to the substrate surface and wet and green cohesion to the newly formed lining prior to firing of the sprayed-on layer. The binder also includes an inorganic component which functions at and after exposure to a high temperature to secure the ceramic fibers to the substrate and to one another. Drying and firing of the layer develops strength in the inorganic binder. Known ceramic fibers such as alumina-silica amorphous fibers, alumina-silica-zirconia fibers, polycrystalline mullite fibers, alumina fibers, mineral fibers, or combinations thereof, and the like may be employed. The fiber may be precoated with the organic binder.

Abstract: This relates to a device for crushing sand lumps. The device includes a tub which is resiliently mounted and is provided with means for vibrating the same in a generally vertical direction parallel to a rear wall of the tub. The tub rear wall is hollow and is provided on the inner face with perforated crusher plates. Sand flow through the crusher plates is down through the hollow rear wall and there is an upwardly directed airwash for the falling sand. The lower portion of the rear wall is in the form of a door mounted for swinging movement about a horizontal axis. The door is operated by a cylinder having an axis parallel to the direction of vibration and the door is opened during the vibration of the tub so as to direct scrap and uncrushed lumps out through the lower portion of the rear wall in the same direction of salvaged sand flow.