Abstract: A method of recovering AlF3 from spent potliner using an acid digest to form gaseous HF which is converted to hydrofluoric acid and reacted with alumina trihydrate to form AlF3.

Abstract: A shaft for use in a method for treating molten aluminum using an impeller mounted on the shaft comprising a protective refractory sleeve resistant to attack by molten aluminum, the protective sleeve mounted on the shaft by casting to extend above and below the molten aluminum surface when the shaft is in use.

Abstract: An improved shaft suitable for use in the treatment of molten aluminum including pumping or fluxing employing an impeller, comprised of a shaft material comprised of a carbon or graphite surface treated to provide a reacted surface and a refractory layer provided to cover the reacted surface of the shaft. The refractory layer is resistant to attack by the molten metal. The refractory layer and the carbon or graphite material have a coefficient of thermal expansion less than 5.times.10.sup.-6 in/in/.degree. F., the refractory layer has a ratio of coefficient of thermal expansion in the range of 5:1 to 1:5.

Abstract: A method of removing a solidified body of polyethylene from a Unipol reactor using a robotic apparatus extended through a porthole on top of the reactor.

Abstract: An improved shaft suitable for use in the treatment of molten aluminum including pumping or fluxing employing an impeller, comprised of a shaft material comprised of a carbon or graphite having an exterior surface and a refractory layer provided to cover the exterior surface of the shaft. The refractory layer is resistant to attack by the molten metal. The refractory layer and the carbon or graphite material have a coefficient of thermal expansion less than 5.times.10.sup.-6 in/in/.degree. F., the refractory layer has a ratio of coefficient of thermal expansion in the range of 5:1 to 1:5.

Abstract: An adaptive control method for producing high purity water, the method having the ability to produce high purity water on a continuous basis having a resistivity in the range of 0.8 to 4 megohm-cm. The method comprises the steps of providing a feedwater to be purified and providing a first reverse osmosis unit having a first high pressure side and a first low pressure side and having a first permeate produced at the first low pressure side. The pH of the feedwater to be introduced to the high pressure of the first reverse osmosis unit is monitored before introducing the feedwater to the high pressure side of the first reverse osmosis unit. Also, the feedwater is maintained in a temperature range of 45.degree. to 80.degree. F. A second reverse osmosis unit is provided having a second high pressure side and a second low pressure side for producing high purity product water.

Abstract: A process of treating spent potliner material from aluminum reduction cells and recovering useful products. In the process of the present invention, spent potliner material is introduced into an acid digester containing, for example, sulfuric acid. As a result of this step, a gas component is produced which includes hydrogen fluoride, silicon tetrafluoride and hydrogen cyanide. Also, a slurry component is produced which includes carbon, a refractory material including silica, alumina, sodium compounds such as sodium sulfate, aluminum compounds such as aluminum sulfate, iron compounds such as iron sulfate, magnesium and calcium compounds such as magnesium and calcium sulfate. The slurry component remains in the digester after the gas component is removed. The gas component is recovered and heated an effective amount to convert or decompose the silicon tetrafluoride to fumed silica, hydrogen cyanide to a remaining gas component including CO.sub.2, H.sub.2 O, and nitrogen oxides, as well as HF gas.

Abstract: A method of purifying impure water to provide drinking water using an apparatus, the method comprising the steps of providing a microfiltration unit, a reverse osmosis unit and a CIP (clean-in-place) tank containing retentate interconnected to permit backflushing the microfiltration filter with retentate and continued or uninterrupted operation of the reverse osmosis unit by directing retentate thereto.

Abstract: A method for producing high purity product water using a three pass reverse osmosis system.

Abstract: A method suitable for treating used oil to remove ash and metal contaminants therefrom with minimum oxidation of the oil, the metal including at least one of the components of iron, lead, copper, zinc, sodium, magnesium, and calcium, to provide a highly purified oil product having less than 10 ppm of at least one of the contaminants and less than 0.15 wt. % of ash content. The method comprises providing a body of oil to be purified and chemically treating the oil to condition ash and metals contained therein to facilitate removal of ash and metal during membrane purification of the oil.

Abstract: A method for forming a grating suitable for bridge decks using a punch and die, the die having a die opening having a generally cross shaped configuration having a generally vertical or first extent having a top and bottom and a generally horizontal or second extent having a first side and a second side, the distance between the top and bottom of the vertical extent being shorter than the distance between the first side and the second side of the horizontal extent, the opening having a first land and a second land substantially opposite to each other, the first land extending from the top of the vertical extent to the second side, the second land extending from the first side to the bottom, the punch having a cross-section configuration to mate with the die opening to punch the web openings in the web.

Abstract: A process for recovering one of alumina hydrate, magnesium hydroxide and magnesium aluminate spinel (MgAl.sub.2 O.sub.4) from aluminum dross wherein the dross is processed to a non-metallic product (NMP). The dross may contain fluxing salts which are removed in providing the NMP. The NMP may be derived from aluminum dross which does not contain fluxing salts sometimes referred to as white dross. The process comprises digesting the non-metallic product with an acid selected from the group consisting of sulfuric, hydrochloric, hydrofluoric and phosphoric acid or mixtures thereof to provide a slurry containing dissolved alumina, magnesia and a solid component, for example, containing magnesium aluminate spinel. Instead of an acid, a base such as sodium hydroxide may be used. The slurry is filtered to separate the solid component from the liquid containing dissolved constituents such as alumina and magnesia to recover the solid component.

Abstract: An adaptive control method for producing high purity water, the method having the ability to produce high purity water on a continuous basis having a resistivity in the range of 0.8 to 4 megohm-cm. The method comprises the steps of providing a feedwater to be purified and providing a first reverse osmosis unit having a first high pressure side and a first low pressure side and having a first permeate produced at the first low pressure side. The pH of the feedwater to be introduced to the high pressure of the first reverse osmosis unit is monitored before introducing the feedwater to the high pressure side of the first reverse osmosis unit. A second reverse osmosis unit is provided having a second high pressure side and a second low pressure side for producing high purity product water.

Abstract: A method of melting metal scrap in a molten melting media, the method comprising (a) providing a source of molten melting media in a furnace, the melting media in the furnace having a first surface level; (b) providing a first melting bay in fluid communication with the furnace to receive molten melting media from the furnace to provide a body of molten melting media in the first melting bay for purposes of melting floatable metal scrap, the first melting bay having: (i) a bottom; and (ii) an outer wall connected to the bottom defining the first melting bay, the outer wall having a generally spiral shaped cross section terminating in a mouth of a channel for removing melting media and molten scrap to an adjacent bay, the spiral shaped cross section receding away from a generally central axis of the first melting bay.

Abstract: A method and system of heating a body of molten aluminum, for example, contained in a heating bay, the method comprising providing a body of molten aluminum; projecting an electric powered heater into the body of molten aluminum; passing electric current through the element and adding heat to the body of molten aluminum. The heater is comprised of a sleeve suitable for immersing in the molten aluminum. The sleeve may have a closed end and is comprised of a composite material comprised of an inner layer of titanium or titanium alloy having an outside surface having a refractory coating thereon exposed to the molten aluminum, the refractory coating resistant to attack by the molten aluminum. An electric heating element is located in the sleeve in heat transfer relationship therewith for adding heat to the molten aluminum.

Abstract: A method of heating a body of molten metal passing through a treatment bay. The method comprises providing a body of molten metal in a treatment bay and providing a baffle heater in the treatment bay to contact the molten metal. The baffle heater is comprised of a member fabricated from a material substantially inert to the molten metal, the member containing at least one heating element receptacle. An electric heating element is positioned in the receptacle for heating the member, the element protected from the molten metal by the material constituting the member.

Abstract: A weldless grating comprising a plurality of longitudinally extending primary load-bearing members having an upper portion, a lower portion and a web located between the upper portion and the lower portion, the primary load-bearing member having a plurality of spaced-apart, generally rectangular-shaped openings in the web, the openings in each of the primary load-bearing members being aligned with the openings in adjacent primary load-bearing members. A plurality of secondary and tertiary load bearing members are provided.

Abstract: A method of conditioning a process stream of air in an air conditioning system wherein a process stream of air is dehumidified and cooled to provide a conditioned stream of air for introducing to a conditioned space. The method comprises the steps of providing an adsorption wheel having a multiplicity of passages through which process air can flow for adsorbing moisture therefrom, the wheel capable of adsorption of moisture from the process air and of regeneration on a continuous basis as the wheel rotates. An indirect evaporative cooler is provided having a dry side and a wet side separated by a moisture-inpervious wall wherein heat is extracted from said dry side through the wall to the wet side. Cooling in the dry side is achieved by evaporation of water into air passing through the wet side. The process air is passed through the adsorption wheel to remove moisture therefrom to provide a moisture-depleted stream of process air exiting the adsorption wheel.

Abstract: An improved crucible for containing a body of molten aluminum and maintaining the molten aluminum at a predetermined temperature for transportation, the crucible comprised of a bottom and sides joined together to contain the molten aluminum and a liner comprised of a refractory substantially inert to the molten aluminum. A series of heating element receptacles are provided in the liner, the receptacles are lined with a ceramic tube fabricated from a material selected from the group consisting of mullite, boron nitride, silicon nitride, silicon carbide, and silicon aluminum oxynitride, zirconia, stabilized zirconia and mixtures thereof. An electric heating element is provided in the ceramic tube for transferring heat to the body of aluminum.

Abstract: A method of electrolytically separating a paint coating from a metal surface comprising the steps of providing a metal member having a surface having a paint coating thereon and contacting the member with an essentially neutral electrolytic solution. The metal member is made cathodic in an electrolytic cell and current is passed from an anode electrode pad through the electrolytic solution to the metal member for a time sufficient to cause the paint coating to separate from the metal member. The pad is comprised of a first blanket for contacting the paint coating, a second blanket to cover the first blanket and an electrode mesh positioned between the first and second blankets.