Abstract: A method of reducing the overvoltages for hydrogen and oxygen evolution in alkaline water electrolyzers while preventing displacement of the potential of electrically-floating cell components to a region where they are susceptible to corrosion is disclosed. The method comprises adding to the electrolyte between 0.01 and 10 gpl of vanadium ions and controlling the potential of the electrically-floating cell components so as to maintain such potential out of the region where corrosion cracking may occur by simultaneously adding between 0.1 and 20 gpl chromium ions to the electrolyte, or by using an electrical circuitry requiring no external source of power.

Abstract: A continuous polyelectrolyte feed system is disclosed. The system comprises means for providing a metered stream of dilution water, means for adding metered quantity of polyelectrolyte to the dilution water stream, means for flash mixing the polyelectrolyte in the dilution water stream, a plug flow reactor for aging the polyelectrolyte solution so as to allow the polyelectrolyte sufficient time to become active, and means for flash diluting the polyelectrolyte before injection into the waste water.

Abstract: A transferred-arc plasma reactor is disclosed. The reactor comprises a bottom portion defining a crucible for collecting molten material, an anode adapted to contact the molten material in the crucible, a sleeve mounted on top of the crucible and electrically insulated therefrom, a cathode assembly including a cathode mounted on top of the sleeve and electrically insulated therefrom, means for introducing feed material conveyed by a carrier gas near the top of the sleeve so that the material is fed against the inner wall of the sleeve, melted under the heating energy radiated by a plasma arc formed between the cathode and the molten material to form a falling film of molten material which flows down along the inner wall of the sleeve and drops into the crucible underneath, and outlet ports in the bottom portion of the reactor for exiting the carrier gas and the non-reacted plasma forming gas.

Abstract: A hood assembly for use with a metallurgical converter is disclosed. The hood assembly comprises a hood resting on a supporting structure and having sidewalls the lower ends of which extend downwardly to a short distance from the apron plate of the converter and around a portion of the periphery of the converter corresponding to the angular movement of the mouth of the converter from the blowing to the charging position, and the upper ends of which follow a curve-linear or straight path extending from the upper back end of the hood until it meets with the lower ends of the sidewalls at the front of the hood, and a roof bridging the sidewalls except for an opening at the front of the hood extending over the mouth of the converter in the charging position.

Abstract: A hydrometallurgical process for the recovery of cobalt from cobaltite-pyrite concentrates containing substantial amounts of cobalt, arsenic, iron and sulphur is disclosed. The hydrometallurgical process comprises pressure leaching of the cobaltite-pyrite concentrates with a sodium chloride or sodium sulphate solution at a temperature in the range of 130.degree.-160.degree. C. and under oxygen partial pressures in the range of 75-200 psi to solubilize at least 90% of the cobalt content, while simultaneously precipitating most of the iron and arsenic as jarosite and ferric arsenate.

Abstract: A method is disclosed for treating dore slag resulting from smelting of a dore furnace charge, by grinding such slag and then subjecting the obtained pulp to froth flotation in the presence of a suitable frother and collector to produce a precious metals concentrate which is then filtered and returned to the dore furnace with the next charge. The tails from the froth flotation may then be finely ground and subjected to several additional flotation stages to improve recovery of the precious metals, and the entire operation is preferably carried out as a closed loop process so that only the tailings from the rougher flotation are removed and shipped to the smelter.

Abstract: A heat transfer device having an augmented surface is disclosed. The device comprises a base wall of heat conductive material having a plurality of pyramid-fins formed integrally with the surface of the base wall. The pyramid-fins are regularly spaced apart in the range of about 80-500 pyramid-fins per square inch and have a height in the range of 0.015 to 0.040 inch. The base wall is preferably a cylindrical tube and the pyramid-fins are formed as a knurled diamond pattern around the outside periphery of the tube.

Abstract: A method for reducing excessive air inleakage and fuel consumption in open ring-type carbon baking furnaces is disclosed. This method consists in covering the preheat sections of the fire with covers. Each cover is preferably mounted on legs and a flexible sealing skirt is located all around to accommodate the height variations across each furnace section. There are usually more than one preheat section and the covers are identical in construction and dimension to minimize movement of the covers when the fire progresses. To further reduce fuel consumption, covers can also be placed on some of the cooling sections behind the fuel-fired sections and air can be blown or sucked into these sections to force cool these sections and to provide preheated air for combustion in the fuel-fired sections.

Abstract: A process and a system for drying a solution, a slurry or a solid suspension of a material non-sensitive to heat is disclosed. A spray of finely divided particles is formed in a chamber and a plasma of superheated steam is used as the heat source for drying the particles as they pass through the chamber. The resulting product is removed from the chamber in the form of a suspension of dry particles in superheated steam.

Abstract: A method is provided for recovering copper values from a copper-bearing hematite residue in a single stage. It comprises leaching the residue in an aqueous sulphuric acid solution in the presence of ammonium, sodium or potassium ions, at a temperature between about 80.degree. C. and the boiling point of the solution so that copper values are dissolved while iron is precipitated as jarosite. The method is particularly suitable for the treatment of residues resulting from an oxidizing pressure leach of copper concentrates.

Abstract: A low alloy white cast iron is disclosed. The alloy consists essentially, in weight percent, of about 2.5 to 4% carbon, 0.3 to 0.8% silicon, 0.3 to 1.0% manganese, and 1.7 to 3.5% nickel, the rest being iron except for incidental impurities commonly found in cast iron. The alloy has a microstructure consisting essentially of martensite and carbide and a minimum hardness of 600 B.H.N.

Abstract: An apparatus for measuring the density of a liquid or of a suspension of solids in a liquid is disclosed. The apparatus comprises two pressure sensors adapted to be mounted in the liquid so that the two sensors are vertically at predetermined levels apart, a differential pressure transducer, and proper tubings including a differential pressure zeroing device interconnecting the pressure sensors to the differential pressure transducer, for providing an output proportional to the density of the liquid which is compensated for the differential pressure caused by the differential neight of said pressure sensors in the liquid. In a preferred embodiment of the invention, the differential pressure zeroing device is a pair of U-tubes filled with liquid and the tubings comprise gas filled tubings interconnecting one branch of each U-tube to respective pressure sensors and the other branch of each U-tube to the differential pressure transducer.

Abstract: A method of introducing hydrogen into a gas pipeline or other pressurized gas containers is disclosed. The method comprises feeding hydrogen from a low pressure source into the gas container through a barrier which is freely permeable to hydrogen but impermeable to the gas in the container until the hydrogen partial pressure in the container becomes equal to the hydrogen pressure which is applied to the barrier.

Abstract: A voltage monitor is disclosed. The voltage monitor comprises a digital voltmeter for displaying a measured input voltage, and means for converting the varying input voltage of the monitor into a stabilized power supply voltage for the operation of the digital voltmeter. The input voltage is applied to the digital voltmeter through a response time controller providing a long time constant averaging value of input voltage to the digital voltmeter when the input voltage is within a predetermined range about a normal value, and for providing a faster response to input voltage values when the input voltage exceeds its normal value. The voltage is also applied to a stability indicator through an averaging circuit which permits the stability indicator to show short term fluctuations of input voltage about its normal value.

Abstract: A method is disclosed for heavy-water extraction from non-electrolytic hydrogen streams using a modified Combined Electrolysis and Catalytic Exchange-Heavy Water Process (CECE-HWP). The method comprises contacting feed water in a catalyst column with hydrogen gas originating partly from such non-electrolytic hydrogen stream and partly from an electrolytic hydrogen stream so as to enrich the feed water with deuterium extracted from both the non-electrolytic and electrolytic hydrogen gas, and passing the deuterium enriched water to an electrolyzer wherein the electrolytic hydrogen gas is generated and then fed through the catalyst column.

Abstract: An oxygen monitoring circuit is disclosed. The circuit comprises a high impedance follow and hold circuit adapted for connection to an oxygen probe, a readout unit connected to the high impedance follow and hold circuit, a programmer normally connecting the oxygen probe to the high impedance follow and hold circuit but momentarily disconnecting the oxygen probe from the high impedance follow and hold circuit for a relatively short time interval and loading it with a resistor having an impedance relatively higher than the normal impedance of the probe, and a probe failure indicator connected to the outputs of the oxygen probe and of the high impedance follow and hold circuit for detecting any significant change in impedance of the probe and resistor combination as a result of loading and for operating an alarm when the impedance of the probe exceeds a predetermined value.

Abstract: A method of reforming the fins of a finned tube is disclosed. The method comprises forming a tube having a plurality of internal longitudinal fins with a V-notch at the tip of the fins, and reforming the fins of the tube over a shaped plug, in long lengths, to spread the tips of the V-notch so that the tips of the fins are wider than the fin thickness.

Abstract: A process and an apparatus for electrowinning metal from metal bearing solutions is disclosed. A support solution containing a predetermined metal concentration is continuously recirculated through a cell having a porous grid supporting a bed of particulate conducting particles at a sufficiently high flow rate so as to fluidize and expand the bed by 5 to 25%. A gas is continuously fed through the bed of conducting particles so as to strongly agitate the particles at low bed expansion to maintain good mixing and uniform fluidization of the bed of particles. The cell includes an electrode arrangement suspended from the top of the cell and immersed into the bed of fluidized conducting particles.

Abstract: An electrode for the electrolytic deposition of metals is disclosed. The electrode comprises a metal plate adapted to be suspended vertically in an electrolyte solution and having round corners joining the side edges to the bottom edge thereof, and a continuous edge strip of electrically insulating material enveloping the side and bottom edges of the plate to prevent deposition of metal on the edges during electrolysis.

Abstract: A low alloy white cast iron has been developed for wear resistance applications. The alloy consists essentially of about 2 to 4% carbon, 0.3 to 1.5% silicon, 0.5 to 1.5% manganese, 0.5 to 1.5% copper and 0.25 to 1% molybdenum, the remainder being substantially iron except for incidental impurities commonly found in cast iron. The preferred alloy composition is 2.5 to 3% carbon, 0.6 to 0.9% silicon, about 1% manganese, about 1% copper and about 0.5% molybdenum, the rest being substantially iron. The process for manufacturing the above wear resistant alloy consists in melting an alloy having the composition mentioned above, casting such alloy into moulds to produce a desired product such as grinding balls or slugs, shaking the product out of the moulds at a temperature of 750.degree. C. or higher, preferably about 900.degree. C. and cooling the product at a rate of 2.degree. to 15.degree. C./sec., preferably 5.degree. to 10.degree. C./sec.