Abstract:
Disclosed is an apparatus and method for continuously detecting skips, protrusions, protuberances and other defects in cable conductor shield, comprising a high voltage electrode, a capacitance bridge filter circuit and a corona discharge detector. A noncontacting coaxial electrode is employed to create an electric field between the cable conductor and the electrode. In the presence of this field, defects in the shield produce corona discharges. A detection circuit employing a capacitance bridge is employed to continuously detect corona discharges and produce signals used for subsequently locating the positions of the defects on the finished cable.
Abstract:
A resulfurized ferrous alloy including lead characterized in that the lead is well dispersed in the steel matrix and the free lead globules are controlled as to size, is produced by introducing the lead into a steel melt in the form of a fine lead sulfide (PbS), or galena powder. The alloy produced exhibits improved machinability, which characteristic is further enhanced by the formation of manganese sulfide particles which are well distributed and have minimum aspect ratio (i.e., are round) when the melt has been deoxidized with manganese.
Abstract:
A hydrometallurgical process is provided for separative treatment of zinc-bearing metallurgical flue dust containing significant amounts of lead, chlorine, and iron. The process is especially suited for extraction of zinc sulfate from blast furnace white dust resulting in the smelting of secondary copper. According to the process, the flue dust is leached in sulfuric acid solution for substantially complete dissolution of soluble constituents, notably zinc, leaving insoluble residue consisting principally of lead oxide. At completion of leaching, pH is selectively adjusted corresponding to the desired extent of subsequent chloride removal. Second, the loaded leach solution is treated for chloride removal wherein chloride ion concentration is substantially and selectively reduced by precipitation of cuprous chloride, cuprous ions being provided by pH regulated reduction of cupric ions. Third, the dechlorinated leach solution is treated by pH regulated cementation with zinc to remove residual cupric copper from the previous step along with other metal impurities more noble than zinc. Fourth, iron is precipitated from the acidic leach solution by oxidation of acid-soluble ferrous ions to the relatively insoluble ferric state. Finally, the purified leach solution is subjected to evaporative crystallization to recover commercial grade zinc sulfate.
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:
A method of continuously casting a molten metal in a casting means to obtain a solidified cast bar at a hot-forming temperature, passing the cast metal at a hot-forming temperature from the casting means to a hot-forming means, and hot forming the cast bar into a wrought product by a two-stage reduction of its cross-sectional area while it is still at a hot-forming temperature, including, in the first stage, the step of forming a shell of finely distributed recrystallized grains in the surface layers of the cast bar by a selected small amount of deformation of the cast bar in its as-cast condition prior to the second stage in which substantial reduction of its cross-sectional area forms the wrought product. The shell of fine grains formed on the cast bar during the first stage of deformation permits substantial reduction of the cross-sectional area of the cast bar during the second stage of deformation without the cast bar cracking, even when the cast bar has a high impurity content.
Abstract:
A hydrometallurgical process is provided for the separative treatment of electrometallurgical anode slime containing precious metals and substantial amounts of tin dioxide and lead sulfate. The process is especially suited for treatment of anode slimes from the electrorefining of secondary copper to recover about 85% of the metal value contained therein, especially tin and precious metals. First, lead is separated by leaching the slime with diethylene triamine followed by carbonation to precipitate lead carbonate with subsequent regeneration of the leach solution. Second, tin is separated by leaching the undissolved residue from the amine leach with a solution of hydrochloric acid and chlorine to dissolve substantially all substances except tin dioxide. Third, the pregnant leach solution is contacted with an exchange resin substantially selective to adsorption of precious metals except silver followed by cementation of silver from the depleted leach solution by copper addition with subsequent regeneration of the leach solution. Fourth, the loaded resin is elutriated followed by cementation of precious metals from the loaded eluate with silver from the previous step and recycling the silver-enriched solution for cementation of silver.
Abstract:
This disclosure relates to a method and apparatus for manufacturing an aluminum alloy electrical conductor which promote the formation of a wire having a fine, stable subgrain structure of small cell size in the aluminum matrix and a fine dispersion of stable, insoluble intermetallic phase particles. The subgrain structure is improved by closely controlling the thermomechanical processing, particularly the casting rate, deformation parameters and annealing characteristics. After casting, the cast product is substantially immediately hot-formed in a rolling mill wherein the first deformation is more than 30% such that a substantially well defined subgrain structure will be formed in the aluminum matrix, thereby maximizing a refinement of the subgrain structure by permitting breaking-up thereof in each of the subsequent deformations in the rolling mill. After cold-working, without preliminary or intermediate anneals, the product is finally annealed at a temperature not exceeding approximately 700.degree. F.
Abstract:
Improved aluminum alloy electrical conductors and method for making same are disclosed. The alloy contains from about 0.55 to about 0.65 weight percent nickel, the remainder aluminum with associated trace elements including no more than 0.15 weight percent iron, no more than 0.001 weight percent magnesium and no more than 0.05 weight percent copper.
Abstract:
This disclosure relates to a method and apparatus for manufacturing zinc coated steel tubing from zinc coated steel strip. The zinc lost by volatilization during welding of the seam is replaced in a two-stage metallizing process. In the first stage an aluminum alloy is spray atomized onto the tubing. The alloy contains from 0.45 to 0.95 weight percent iron, no more than 0.10 weight percent silicon, and the remainder aluminum with associated trace elements. Thereafter, in the second stage, zinc is spray atomized over the aluminum alloy-coated substrate.