Patents by Inventor Vaikuntam I. Lakshmanan

Vaikuntam I. Lakshmanan 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).

  • Publication number: 20110052475
    Abstract: A process to the production of silicon from amorphous silica is disclosed. The amorphous silica is formed from a material rich in silica, especially rice husk ash or silica fume. The process comprises subjecting the amorphous silica to leaching with a lixiviant of aqueous mineral acid, especially hydrochloric acid. Preferably, material rich in silica is roasted at a temperature of not more than 850° C., subjected to leaching and then subjected to a second roasting at a temperature of less than 750° C. The process provides for the production of high purity silicon, especially to the production of solar grade silicon (SoG-Si).
    Type: Application
    Filed: August 25, 2010
    Publication date: March 3, 2011
    Inventors: Mansoor Barati, Kingsley Kweku Larbi, Raja Roy, Vaikuntam I. Lakshmanan, Ramamritham Sridhar
  • Patent number: 7736606
    Abstract: A process for leaching a value metal from a base metal sulfide ore, comprising the step of leaching the ore with a lixiviant comprising a chloride, an oxidant and hydrochloric acid is disclosed. The leaching is controlled, by use of low concentrations of hydrochloric acid and a redox potential, to effect formation of hydrogen sulfide from the base metal sulfide ore. The hydrogen sulfide is stripped from the leach solution, thereby reducing the amount of sulfate generated in the leach to very low levels. The leaching may also be conducted to limit the co-dissolution of platinum group metals and gold with the base value metals. The leach forms a value metal-rich leachate and a solids residue. The solids residue may be subsequently leached to recover the platinum group metals and gold. The value metal-rich leachate can be is oxidized and neutralized to recover the value base metals. In an embodiment, the chloride is magnesium chloride and lixiviant solution is regenerated.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: June 15, 2010
    Assignee: Jaguar Nickel Inc.
    Inventors: G. Bryn Harris, Vaikuntam I. Lakshmanan, Ramamritham Sridhar, George Puvvada
  • Publication number: 20090013829
    Abstract: A process for leaching a value metal from a base metal sulfide ore, comprising the step of leaching the ore with a lixiviant comprising a chloride, an oxidant and hydrochloric acid is disclosed. The leaching is controlled, by use of low concentrations of hydrochloric acid and a redox potential, to effect formation of hydrogen sulfide from the base metal sulfide ore. The hydrogen sulfide is stripped from the leach solution, thereby reducing the amount of sulfate generated in the leach to very low levels. The leaching may also be conducted to limit the co-dissolution of platinum group metals and gold with the base value metals. The leach forms a value metal-rich leachate and a solids residue. The solids residue may be subsequently leached to recover the platinum group metals and gold. The value metal-rich leachate can be oxidized and neutralized to recover the value base metals.
    Type: Application
    Filed: September 29, 2008
    Publication date: January 15, 2009
    Inventors: G. Bryn Harris, Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Geroge Puvvada
  • Patent number: 7329396
    Abstract: A process for leaching a value metal from oxidic materials, such as a lateritic nickel ore, comprising the step of leaching the ore with a lixiviant comprising a cationic salt (e.g., magnesium chloride) and hydrochloric acid is disclosed. An oxidant or additional metal chloride (such as that which results from the leaching operation) may be added. In one embodiment, the process comprises recovery of a value metal from ore comprising the steps of: leaching the ore with a lixiviant; separating a value metal-rich leachate from the ore in a first solid-liquid separation; oxidizing and neutralizing the value metal-rich leachate so obtained; and separating a solution of magnesium chloride from the leachate so obtained in a second solid-liquid separation. In another embodiment, the lixiviant solution is regenerated from the solution of magnesium chloride. In a further embodiment, regeneration of the lixiviant solution includes a step of producing magnesium oxide from the solution of magnesium chloride.
    Type: Grant
    Filed: May 13, 2004
    Date of Patent: February 12, 2008
    Assignee: Jaguar Nickel Inc.
    Inventors: G. Bryn Harris, Vaikuntam I. Lakshmanan, Ramamritham Sridhar
  • Publication number: 20040228783
    Abstract: A process for leaching a value metal from oxidic materials, such as a lateritic nickel ore, comprising the step of leaching the ore with a lixiviant comprising a cationic salt (e.g., magnesium chloride) and hydrochloric acid is disclosed. An oxidant or additional metal chloride (such as that which results from the leaching operation) may be added. In one embodiment, the process comprises recovery of a value metal from ore comprising the steps of: leaching the ore with a lixiviant; separating a value metal-rich leachate from the ore in a first solid-liquid separation; oxidizing and neutralizing the value metal-rich leachate so obtained; and separating a solution of magnesium chloride from the leachate so obtained in a second solid-liquid separation. In another embodiment, the lixiviant solution is regenerated from the solution of magnesium chloride. In a further embodiment, regeneration of the lixiviant solution includes a step of producing magnesium oxide from the solution of magnesium chloride.
    Type: Application
    Filed: May 13, 2004
    Publication date: November 18, 2004
    Applicant: Jaguar Nickel Inc.
    Inventors: G. Bryn Harris, Vaikuntam I. Lakshmanan, Ramamritham Sridhar
  • Patent number: 5290525
    Abstract: Processes are provided for substantially removing base metals and/or cyanide from gold-barren solutions resulting from gold ore processing.
    Type: Grant
    Filed: September 14, 1992
    Date of Patent: March 1, 1994
    Assignee: Ortech Corporation
    Inventor: Vaikuntam I. Lakshmanan
  • Patent number: 4966761
    Abstract: A process is described for recovering vanadium and zeolitic alumino-silicates from flyash and similar carbon-bearing heat treated materials. The process includes steps for the separation of carbon, followed by pressure leaching the carbon-depleted flyash in relatively dilute alkali metal hydroxide solutions at elevated temperatures. The leach liquor is separated from the residue and is subsequently treated in an amine containing solvent extraction process step for vanadium recovery, and optionally, for other metals present in the leach liquor. The vanadium in the strip liquor is precipitated to obtain vanadium containing compounds.The leach residue is treated separately to recover zeolitic alumino-silicates therefrom.In another variation of the process, the vanadium is recovered from the leach liquor by means of a strong base anoin exchange resin.
    Type: Grant
    Filed: July 14, 1988
    Date of Patent: October 30, 1990
    Assignee: Carbovan Inc.
    Inventors: Vaikuntam I. Lakshmanan, Dzinsars Melnbardis, Robert A. Geisler, Nairn M. McQueen
  • Patent number: 4798709
    Abstract: A process is described for recovering vanadium and zeolitic alumino-silicates from flyash and similar carbon-bearing heat treated materials. The process includes steps for the separation of carbon, followed by pressure leaching the carbon-depleted flyash in relatively dilute alkali metal hydroxide solutions at elevated temperatures. The leach liquor is separated from the residue and is subsequently treated in an amine containing solvent extraction process step for vanadium recovery, and optionally, for other metals present in the leach liquor. The vanadium in the strip liquor is precipitated to obtain vanadium containing compounds.The leach residue is treated separately to recover zeolitic alumino-silicates therefrom.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: January 17, 1989
    Assignee: Carbovan Inc.
    Inventors: Vaikuntam I. Lakshmanan, Dzinsars Melnbardis, Robert A. Geisler
  • Patent number: 4537628
    Abstract: The extent of recovery of precious metals, preferably gold and silver, from precious metal ores, concentrates, tailings and wastes which are also sulphide- and arsenic- and/or antimony-bearing, is enhanced by treatment with Caro's acid (H.sub.2 SO.sub.5).
    Type: Grant
    Filed: December 6, 1983
    Date of Patent: August 27, 1985
    Assignee: Ontario Research Foundation
    Inventors: Vaikuntam I. Lakshmanan, Jurgen K. Biskupski