Abstract: A method and apparatus for automatically controlling a carbon bake furnace to thereby reduce uniformly baked anodes is disclosed. In its method aspects, the invention contemplates the use of flue and pit temperatures to produce a control signal to operate a valve for varying the air fuel mixture of a burner associated with said valve. In its apparatus aspects, the invention utilizes a plurality of infrared detectors to measure the pit and flue temperatures. The signals produced by these sensors are fed to a computer which produces a control signal for operating a valve associated with at least one of a plurality of burners which is to have its air/fuel ratio adjusted to thus adjust the temperature in the pit heated by the selected burner to a desired target temperature.

Abstract: Disclosed is an improved high velocity dual fuel burner and a method for firing a vertical shaft metal melting furnace with gaseous or liquid fuel in which the burner nozzle is adapted to mix and ignite both types of fuels alternately or in combination by means of three concentric nozzles including a central oil spraying nozzle, an intermediate nozzle to supply natural gas and an outermost nozzle to supply combustion air.

Abstract: A process is provided for purification of nickel sulfate via ammoniacal leaching and pH regulated solvent-extraction, while providing for regeneration of the extractant and the leach solution. The process is especially suited for hydrometallurgical extraction of high purity nickel sulfate from residue resulting in the regeneration of spent electrolyte in the electrorefining of secondary copper. According to the process, the starting material is leached in an ammonia solution of selected pH to solubilize the nickel as polyammine sulfate, followed by extracting the solubilized nickel by pH regulated solvent-extraction. The extractant is then stripped and regenerated with sulfuric acid by first scrubbing in a first pH range to remove ions that are more electropositive than nickel, then stripping with sulfuric acid in a second pH range to remove nickel ions, and then regenerating the extractant by stripping in a third pH range to remove ions that are less electropositive than nickel.

Abstract: Disclosed is a multiple chamber vertical shaft furnace for melting granulated metal. Granulated scrap metal, high-grade crystalline ore or a combination thereof is preheated and sintered into a coherent columnar mass by the present invention. It is then melted in an enlarged melting chamber by multiple burners located in the walls of the furnace which direct heat tangent to the coherent columnar mass in a tubular heating space between the outer surface of the coherent columnar mass and the inner surface of the furnace walls, and flows out of the present invention through a tapping outlet for further processing.

Abstract: A vertical shaft furnace for continuously melting metal materials, such as scrap, copper cathode pieces and the like is disclosed. The furnace comprises an elongated cylindrical melting chamber having an opening in the upper portion thereof for intermittently gravity-charging the furnace with metal pieces, which form a descending metal column in the melting chamber. A plurality of plasma arc generators is mounted in the sidewalls of the melting chamber extending inwardly thereof in a downwardly inclined attitude. The plasma arc torches are arranged in upper and lower vertically spaced planes for respectively preheating and melting the metal charged to the furnace. Protective refractory shrouds are provided which extend inwardly from the inside wall of the melting chamber and at least partly surround the plasma arc torches to substantially prevent damage to the torches by the descending or dropped metal charge.

Abstract: Disclosed is an apparatus and method for extruding primary insulation and insulation shielding onto an advancing shielded conductor strand in one operation without causing inward protrusions of insulation shielding compound particles into the primary insulation comprising an extruder head with a starter tip, an antiprotrusion tip and a die.

Abstract: An improved vertical furnace for melting metal pieces, such as pieces of copper cathode. The furnace has a generally round interior wall of refractory brick material which encloses a vertical melting chamber having a plurality of burner openings through the refractory wall. Heat, being injected through these openings by means of a novel burner design, melts the metal pieces under metallurgically controlled conditions. The burners are arranged near the bottom floor of the melting chamber which is sloped toward a single outlet thus allowing the molten metal to continuously drain from the melting chamber. The burners are fed a mixture of fuel and air from a plurality of remote mixing stations so as to reduce turbulence at the burners thereby significantly reducing the operating noise level and refractory wear compared to prior art furnaces.

Abstract: A lightning protection circuit involves the grounding of the neutral center point of a direct current circuit carrying current to electrolytic reduction cells in a pot room of an aluminum reduction plant. The grounding is accomplished to earth ground via buried grounding rods which are connected to the center point via an interruptible grounding circuit. A safety circuit arrangement is provided which is responsive to direct current and effects the opening of the grounding circuit whenever the current in the grounding circuit exceeds a predetermined value. The safety circuit arrangement also involves a voltage sensing path responsive to the magnitude of the voltage between plant ground and the center point of the direct current circuit which effects an interruption of the grounding circuit whenever this voltage exceeds a predetermined value in either the positive or negative direction.