Abstract: A method of bleaching a pulp at low consistency employs chlorine dioxide and/or chlorine, to partially bleach the pulp. The aqueous partially bleached pulp flows along a sinuous flow path providing a high ratio of flow path of aqueous pulp to length of effective travel of the aqueous pulp. Ozone is introduced to the aqueous pulp at spaced apart locations in the flow path so that a low partial pressure of ozone is established in the flow path which favors chemical oxidation of the lignin and low chemical attack on cellulose. In this way effective bleaching is achieved with reduced use of chlorine or chlorine dioxide and reduced production of chlorinated compounds.

Abstract: In an electrolysis cell wherein powdered material are added to a bath of molten electrolyte, the anode is provided with a duct through which the powdered material may be fed to the electrolyte. Simultaneously, a gas which is preferably inert, is also fed together with the powdered material through the duct, and both are injected beneath the surface of the electrolyte.

Abstract: A multi-part oxy-fuel cutting tip has mixture outlet passages formed in the tip skirt to form grooves. The grooves then cooperate with the tip core to form the outlet passages when the skirt is placed over the tip core. Oppositely directed circumferential inlet passages for the preheat oxygen and fuel promote rapid mixing while producing a non-rotating mixture flow. In addition, the sectional areas of the outlet passages decrease in the flow direction. The tip core has an annular chamfer at its outlet end. These features promote the rapid creation of a laminar mixture flow.

Abstract: Provided is a method for regenerating cyanide from thiocyanate. The method comprises contacting the thiocyanate with an oxidizing gas containing ozone, generally a mixture of oxygen and ozone. The pH of the contacting medium is generally less than 7.0 to assure that HCN is the predominant species relative to CN.sup.-. The method has important applications to processes involving cyanidation procedures, such as gold leaching, plating and coal conversion.

Abstract: A multi-part oxy-fuel cutting tip has mixture outlet passages formed in the tip skirt to form grooves. The grooves then cooperate with the tip core to form the outlet passages when the skirt is placed over the tip core. Oppositely directed circumferential inlet passages for the preheat oxygen and fuel promote rapid mixing while producing a non-rotating mixture flow. In addition, the sectional areas of the outlet passages decrease in the flow direction. The tip core has an annular chamfer at its outlet end. These features promote the rapid creation of a laminar mixture flow.

Abstract: A shielding gas for flux cored arc welding. The specific gas combination is intended to promote significantly lower fume emission levels while providing equivalent or better welding performance.

Abstract: A fluffy pulp previously dried, having a consistency by 90%, is introduced in a baler where it is subjected to a carbon dioxide comprising atmosphere in order to both reduce or eliminate the fire risk in the baler and to decrease the pH of the pulp by chemically reacting with it. Both gaseous and liquid (snow) carbon dioxide can be used. Preferably, carbon dioxide snow is injected at the bottom of the baler to accelerate the pH control of the pulp, just before compressing the pulp in bales, which compression enhances the pH control reaction between the pulp and the carbon dioxide.

Abstract: A multi-part oxy-fuel cutting tip has mixture outlet passages formed by swaging the tip skirt to form grooves. The grooves then cooperate with the tip core to form the outlet passages when the skirt is placed over the tip core. Oppositely directed circumferential inlet passages for the preheat oxygen and fuel promote rapid mixing while producing a non-rotating mixture flow. In addition, the sectional areas of the outlet passages decrease in the flow direction. These features promote the rapid creation of a laminar mixture flow.

Abstract: A process and apparatus for leaching metal values from a particulate mineral ore containing metal values employs a fluidized bed of the particles; a leaching agent solution containing dissolved oxygen flows upwardly of the bed in a lower leaching zone, to an upper clarification zone; a velocity profile is maintained to promote settling of particles so that the particulate solids remain in the leaching zone and a clarified leachant-containing liquid low in suspended solids rises and collects in the clarification zone; the process is carried out with a minimum of undissolved gas and avoids the need for mechanical agitation, but the kinetics of the chemical leaching reaction is improved and heat loss via escaping gases is avoided.

Abstract: A process is provided for supplying nitrogen from an on-site air separation plant providing at least oxygen as a product, which entails feeding an air feed stream to an instrument-air compressor which is oversized relative to compressed air needed to feed an instrument controlling the plant, feeding at least a portion of the compressed air stream from the instrument-air compressor to a nitrogen membrane separator, thereby providing a stream of nitrogen product, and venting an oxygen-enriched air stream from the membrane.

Abstract: A gas, for example, oxygen which has low solubility in water is efficiently dissolved and reacted with a substance in a flowing liquid medium by injecting the gas into the flowing liquid at spaced apart points such that a bubble flow condition is maintained and the injected gas is dissolved and substantially consumed by reaction with the substance in the interval between adjacent injection points; in this way the gas is injected at a point at which the aqueous liquid has maximum dissolving capacity and the number of injection points can be minimized; in another embodiment oxygen injection is controlled to maintain a desired oxygen:liquid ratio effective for efficient dissolving of the oxygen while maintaining the bubble flow condition, however, this requires more injection points.

Abstract: A method and apparatus for sampling a cryogenic liquid for determination of its molar composition involves isolating a sample of the liquid under conditions to avoid fractionation of the sample, especially isothermal conditions, removing the conditions, allowing the liquid to vaporize intact and collecting the vaporized liquid in gas form; in particular the vaporized liquid is collected in a collection vessel which may be detached from the balance of the system and transported to a site of analysis.

Abstract: An inert gas such as helium is employed as a tracer gas in a pulp and paper mill to determine the utilization of oxygen by an aqueous cellulosic pulp particularly, as well as other parameters, in an oxygen delignification or extraction in which oxygen is dissolved in the pulp and reacted to solubilize lignins and reduce the requirement for chlorine-based bleaching chemicals.

Abstract: In a steam generating boiler having a bottom wall supporting a char bed and sidewalls with ports through which air is admitted for combustion of combustible species in the char bed and emanating therefrom, combustion is improved by introducing an oxygen-containing gas into a lower central zone of the boiler, from at least one point remote from the sidewalls to thereby cause intimate mixing of the oxygen contained in the gas with the combustible species.

Abstract: Molten steel, normally exposed to an atmosphere of air, is protected against impurities by placing a gas containing a major amount of carbon dioxide gas in such quantities and in such proximity to the surface to cause dissociation of the carbon dioxide at a rate which provides a gas barrier or shroud isolating the steel from the surrounding atmosphere. This method may be applied to protecting certain molten steels being transferred from a ladle to a mold, or from a ladle to a tundish and from the tundish to a mold in continuous casting. In a method where a number of shrouding operations are carried out in series, gas under pressure is bled, in increments, from a storage vessel containing a body of liquid carbon dioxide in an overlying ullage space containing vapor. Each increment is ultimately expanded and dispersed at ambient temperature to form the shroud.

Abstract: Enhanced recovery of oil from subterranean sedimentary formations by an in-situ combustion method employing a pattern of an injection well and several production wells, spaced-apart by a treatment zone. Combustion is controlled by placing at least one fluid conduit in a treatment zone and introducing a control fluid through it to modify the flame front. Oxygen may be introduced to take over from combustion air initially introduced through the injection well, to sustain combustion and advance the flame front. Water may be injected through the injection well, alternating with the oxygen through the control conduit to continue a wet combustion method started with air. The strategic placing of control conduits and the introduction of appropriate fluids may be employed to improve the sweep geometry by advancing the flame front or retarding it, or invading areas behind it. Safety means is provided for introducing the oxygen at a velocity greater than the maximum flame velocity encountered in the flame front.

Abstract: In the homogenization of molten metal with a gas, the gas is delivered to agitate the molten metal in a vessel, through an injector tube having a fine bore effective to prevent penetration of molten metal into and along the bore; when injection of gas is discontinued, molten metal is allowed to solidify on the tip of the tube to seal it; when gas is to be delivered to a second load of molten metal in the vessel, it is delivered, at least initially, at a pressure effective to unseal the tube at the tip to permit entry of the gas into the second load to agitate the molten metal and thereby homogenize it; the injector tube can be used for successive batches of molten metal without maintenance.

Abstract: A biological waste water treatment carried out in a single tank. The conditions in the tank are controlled to provide a biological reaction zone containing waste water and biodegrading organisms and an overlying clarification zone from which an effluent of treated waste water flows. The recycle stream is continuously withdrawn from the biological reaction zone, supplemented with influent waste water, passed through an oxygen-dissolving device, and the supplemented stream returned to the reaction zone. The oxygen is monitored and supplied to satisfy the demands of the organisms and, at the same time, to keep the oxygen in solution. The supplemented recycle stream is continuously injected along the bottom of the biological reaction zone in a horizontal shallow inflow having a width substantially greater than its depth and a flow considerably greater than that of the influent.

Abstract: A biological waste water treatment carried out in a single tank. The conditions in the tank are controlled to provide a biological reaction zone containing waste water and biodegrading organisms and an overlying clarification zone from which an effluent of treated waste water flows. The recycle stream is continuously withdrawn from the biological reaction zone, supplemented with influent waste water, passed through an oxygen-dissolving device, and the supplemented stream returned to the reaction zone. The oxygen is monitored and supplied to satisfy the demands of the organisms and, at the same time, to keep the oxygen in solution. According to the invention, the supplemented recycle stream is continuously injected along the bottom of the biological reaction zone in a horizontal shallow inflow having a width substantially greater than its depth and a flow considerably greater than that of the influent.

Abstract: An apparatus is provided for treating waste water biologically and clarifying the biologically treated water; considerable economic advantage is obtained by conducting both the biological treatment and the clarification of biologically treated water in a single vessel rather than in separate vessels; it is further found possible to treat in this system water containing much higher concentrations of waste; in the process the supply of oxygen to the biological reaction zone is carefully monitored to meet the biological oxygen demand and avoid the occurrence of undissolved oxygen in the form of gas bubbles in the biological reaction zone or the clarification zone; there is further provided improvements in oxygen dissolving devices rendering them especially suitable for the two zone treatment.