Patents by Inventor Bohdan Gnyra

Bohdan Gnyra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5167787
    Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions from the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. In another embodiment joints between the conductive and non-conductive regions are positioned such that they are covered by cell freeze (solid electrolyte) during operation of the cell. This prevents liquid cell contents penetrating the joint and adversely affecting the cell lining, thus shortening the life of the cell. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids.
    Type: Grant
    Filed: May 6, 1991
    Date of Patent: December 1, 1992
    Assignee: Alcan International Limited
    Inventors: Tom J. Hudson, John McIntyre, Pierre Tremblay, Claude Allaire, Bohdan Gnyra
  • Patent number: 5062929
    Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions from the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids. Optionally, the mixture may be bonded together with amorphous alumina, in which case the mixture can also be used for cell wall linings. The linings can be used in reduction cells of conventional design and reduces undesirable magnetohydrodynamic effects as well as pollution hazards caused by conventional carbonaceous cell linings.
    Type: Grant
    Filed: August 11, 1989
    Date of Patent: November 5, 1991
    Assignee: Alcan International Limited
    Inventors: Tom J. Hudson, John McIntyre, Pierre Tremblay, Claude Allaire, Bohdan Gnyra
  • Patent number: 5033721
    Abstract: Insulating lightweight refractory materials which are resistant to attack by molten metals, particularly molten aluminum and its alloys and compositions used to form such materials. The materials are settable compositions which comprise a mixture of ceramic fibres, wollastonite powder, milled and/or screened vermiculite (optional), aqueous colloidal silica having a solids content of about 5-25% and preferably 12-15% by weight, and unmilled vermiculite. The weight ratio of the ceramic fibers to the wollastonite powder to the milled and/or screened vermiculite (when present) is 0.8-1.2:1.5-2.5:0.25-0.75, respectively. The amount of the unmilled vermiculite is up to 50% by weight of the total weight of the other solid ingredients. The composition optionally contains carbon fibres, metal fibres or inorganic fibres as reinforcements. The composition can be cast to form shaped products or used as a joining material or as a "face-off" material to protect an underlying article.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: July 23, 1991
    Assignee: Alcan International Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4877507
    Abstract: The amount of electrically conductive material in the bottom floor lining of a conventional aluminum reduction cell is reduced by using a non-conductive lining material in its place. The non-conductive material separates the remaining electrically conductive regions form the sidewall linings of the cell and preferably confines the electrically conductive material to the "anode shadow" region of the cell floor. The non-conductive material preferably comprises a particulate alumina mixture made up of large shapes which firmly compact together and smaller particles which fill the remaining voids. Optionally, the mixture may be bonded together with amorphous alumina, in which case the mixture can also be used for cell wall linings. The linings can be used in reduction cells of conventional design and reduces undesirable magnetohydrodynamic effects as well as pollution hazards caused by conventional carbonaceous cell linings.
    Type: Grant
    Filed: July 13, 1988
    Date of Patent: October 31, 1989
    Assignee: Alcan International Limited
    Inventors: Tom J. Hudson, John McIntyre, Pierre Tremblay, Claude Allaire, Bohdan Gnyra
  • Patent number: 4873209
    Abstract: Insulating lightweight refractory materials which are resistant to attack by molten metals, particularly molten aluminum and its alloys and compositions used to form such materials. The materials are settable compositions which comprise a mixture of ceramic fibers, wollastonite powder and aqueous colloidal silica having a solids content of about 5-25% and preferably 12-15% by weight. The weight ratio of the ceramic fibers to the wollastonite powder is 0.8-1.2:1.5-2.5, respectively. The composition optionally contains carbon fibers or metal fibers as reinforcements. The composition can be cast to form shaped products or used as a joining material or as a "face-off" material to protect an underlying article. When dried, the composition forms a material which is insulating, light-weight and resistant to high temperature and chemical attack by metals. The material can be made even more resistant to attack by a silicate and/or fluoride surface treatment.
    Type: Grant
    Filed: June 17, 1988
    Date of Patent: October 10, 1989
    Assignee: Alcan International Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4681819
    Abstract: A method of treating formed refractory articles for protection against attack by molten aluminum metal, including the steps of impregnating surface portions of the formed articles with an aqueous solution of magnesium fluosilicate and heating to decompose the magnesium fluosilicate for producing, in situ, fluoride values that inhibit wetting of the treated surfaces by the molten metal. Colliodal alumina may be incorporated in the impregnating solution. A silicate coating may be applied over the impregnated surface portions; in such case, the coating when dried is itself impregnated with a further application of magnesium fluosilicate solution. The treated articles have anti-wetting fluoride values on or in their surface portions and exhibit enhanced resistance to attack by molten aluminum.
    Type: Grant
    Filed: June 11, 1984
    Date of Patent: July 21, 1987
    Assignee: Alcan International Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4632292
    Abstract: A method is described for joining an inner metal pipe with an outer surrounding metal tubular portion by means of explosive welding in which a contact anvil is placed inside the inner pipe to support it during welding. With the anvil in place, the pipes are subjected to explosive welding such that the outer surface of the inner pipe is joined metallurgically to the inner surface of the outer tubular portion. According to the novel feature, the anvil is made from hydrated aluminum sulphate, preferably a water soluble commercial alum, which not only disintegrates during welding but is also water soluble.
    Type: Grant
    Filed: June 20, 1984
    Date of Patent: December 30, 1986
    Assignee: Alcan International Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4394365
    Abstract: In the generation of hydrogen fluoride gas for the production of AlF.sub.3 by the reaction of fluorspar with concentrated sulphuric acid a small amount of aluminium sulphate is introduced into the reactive mix to assist in the retention of phosphorous compounds in the solid residues of the reaction and thus reduce the phosphorous content of the gaseous HF. Aluminium sulphate may be added as alum or may be generated in situ in the sulphuric acid by addition of an alumina hydrate, preferably before the acid is brought into contact with fluorspar. The addition of a small amount of calcium carbonate to the fluorspar also improves retention of phosphorous compounds in the solid residues in some instances.
    Type: Grant
    Filed: December 17, 1981
    Date of Patent: July 19, 1983
    Assignee: Alcan International Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4275043
    Abstract: Sodium oxalate is supersaturated solution in Bayer spent liquor stabilized by the presence of humic material is precipitated by the treatment with an adsorbent which adsorbs the humic material to give an insoluble product, thus removing it from solution and destabilizing the solution with respect to precipitation of sodium oxalate. The preferred adsorbent is activated carbon. The activated carbon can be dispersed in the spent liquor as a fine powder or the spent liquor can be passed through a column of particulate carbon. Precipitation of sodium oxalate can be expidited by addition to seed crystals and/or addition of sodium oxalate solution which is supersaturated at a temperature higher than that of the spent liquor.
    Type: Grant
    Filed: January 22, 1980
    Date of Patent: June 23, 1981
    Assignee: Alcan Research and Development Limited
    Inventor: Bohdan Gnyra
  • Patent number: 4051222
    Abstract: Alumina dust, particularly partially calcined alumina dust, is coarsened by forming an aqueous admixture or slurry comprising the alumina dust and finely divided calcium carbonate and introducing the resulting aqueous admixture or slurry into Bayer pregnant liquor and precipitating alumina trihydrate from the resulting Bayer pregnant liquor.
    Type: Grant
    Filed: June 26, 1975
    Date of Patent: September 27, 1977
    Assignee: Alcan Research and Development Limited
    Inventor: Bohdan Gnyra