Patents by Inventor Ramamritham Sridhar

Ramamritham Sridhar 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: 20180347007
    Abstract: A process for leaching a value metal from a titaniferous ore material comprising the step of leaching the ore material at atmospheric pressure with a lixiviant comprising magnesium chloride and hydrochloric acid is disclosed. Iron and titanium are leached into solution. Iron in the ferric state may be separated from titanium in solution using extraction with alkyl ketone. More effective separation of titanium with lower contamination with iron is obtained.
    Type: Application
    Filed: August 7, 2018
    Publication date: December 6, 2018
    Inventors: Vaikuntam I. LAKSHMANAN, Ramamritham SRIDHAR, Dipak PATEL
  • Patent number: 10053750
    Abstract: The invention provides a process for the leaching of a laterite ore or concentrate for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step with a lixiviant comprising hydrochloric acid to leach nickel from the laterite ore. Nickel is extracted with an oxime at a lower pH than other processes for extraction of nickel from solution, especially after separation of iron and cobalt values.
    Type: Grant
    Filed: March 26, 2014
    Date of Patent: August 21, 2018
    Assignee: PROCESS RESEARCH ORTECH INC.
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Md. Abdul Halim, Jonathan Chen, Robert J. DeLaat
  • Patent number: 10041141
    Abstract: A process for leaching a value metal from a titaniferous ore material comprising the step of leaching the ore material at atmospheric pressure with a lixiviant comprising magnesium chloride and hydrochloric acid is disclosed. Iron and titanium are leached into solution. Iron in the ferric state may be separated from titanium in solution using extraction with alkyl ketone. More effective separation of titanium with lower contamination with iron is obtained.
    Type: Grant
    Filed: November 29, 2013
    Date of Patent: August 7, 2018
    Assignee: Process Research Ortech Inc.
    Inventors: Vaikuntam I Lakshmanan, Ramamritham Sridhar, Dipak Patel
  • Patent number: 9732398
    Abstract: A process for the extraction of gold from a gold-bearing ore or concentrate, comprising the steps of leaching the gold-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of at least 90° C. and an Eh of at least 900 mV. After a liquid/solids separation step, the solution obtained is subjected to an organic solvent extraction step using an oxime to obtain a solution of organic solvent containing gold, which is stripped with sodium thiosulphate to recover gold. The extraction may be operated to extract gold with or without iron. Materials used in the process may be recycled. The process avoids environmental and other hazards associated with the use of cyanide to extract gold.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: August 15, 2017
    Assignee: Process Research Ortech Inc.
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, M. A. Halim
  • Publication number: 20160301108
    Abstract: The present invention relates to storage batteries, also known as rechargeable batteries, using a chloride electrolyte, especially in which the electrolyte is a ternary chloroaluminate. In particular embodiments, the electrolyte is molten chloroaluminate and especially molten at a temperature of about 140° C. In another embodiment, the electrolyte is in a liquid state, especially at a temperature in the range of ?27° C. to 110° C. The preferred electrodes are aluminum and graphite. The batteries have a variety of uses, particularly including storage of electricity for future use.
    Type: Application
    Filed: April 7, 2016
    Publication date: October 13, 2016
    Applicant: PROCESS RESEARCH ORTECH INC.
    Inventors: Ashok Bhowmick, Ramamritham Sridhar, Vaikuntam I. Lakshmanan
  • Publication number: 20150315677
    Abstract: A process for leaching a value metal from a titaniferous ore material comprising the step of leaching the ore material at atmospheric pressure with a lixiviant comprising magnesium chloride and hydrochloric acid is disclosed. Iron and titanium are leached into solution. Iron in the ferric state may be separated from titanium in solution using extraction with alkyl ketone. More effective separation of titanium with lower contamination with iron is obtained.
    Type: Application
    Filed: November 29, 2013
    Publication date: November 5, 2015
    Inventors: Vaikuntam I LAKSHMANAN, Ramamritham SRIDHAR, Dipak PATEL
  • Patent number: 9115419
    Abstract: A process for the extraction of rare earth elements, including yttrium, from a rare earth element-bearing ore or concentrate, comprising the steps of leaching the rare earth element-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90° C. to the boiling point of the solution and at an Eh of at least 200 mV. After a liquid/solids separation step, the solution obtained is subjected to steps for removal of iron and for recovery of rare earth elements. Alternatively, rare earth element-bearing ore or concentrate may be leached with sulphuric acid and liquid obtained subjected to extraction of iron and other impurities. Raffinate obtained may be treated with oxalic acid, the precipitate dissolved in hydrochloric acid and subjected to solvent extraction for rare earth elements or the raffinate may be subjected to solvent extraction for removal of rare earth elements and then stripped with hydrochloric acid.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: August 25, 2015
    Assignee: PROCESS RESEARCH ORTECH INC.
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, M. A. Halim
  • Patent number: 8916116
    Abstract: The invention provides a process for the leaching of a laterite ore, concentrate, tailings or waste rock for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step with a lixiviant comprising hydrochloric acid to leach nickel from the laterite ore, followed by a liquid/solids separation step. The liquid obtained is subject to solvent extraction with a dialkyl ketone, to obtain a solution rich in iron and a raffinate. Separation of iron from cobalt and nickel is obtained.
    Type: Grant
    Filed: December 12, 2012
    Date of Patent: December 23, 2014
    Assignee: Process Research Ortech inc.
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Jonathan Chen, M. A. Halim, Robert DeLaat
  • Publication number: 20140301919
    Abstract: A process for the extraction of alumina from an aluminum-bearing ore or concentrate, comprising the steps of leaching the aluminum-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90° C. to the boiling point of the solution and at an Eh of at least 200 mV. After a liquid/solids separation step, the solution obtained is subjected to steps for removal of iron and for recovery of alumina.
    Type: Application
    Filed: March 13, 2014
    Publication date: October 9, 2014
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Md. Abdul Halim, Dipak Patel, Paul Doherty
  • Publication number: 20140294702
    Abstract: The invention provides a process for the leaching of a laterite ore or concentrate for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step with a lixiviant comprising hydrochloric acid to leach nickel from the laterite ore. Nickel is extracted with an oxime at a lower pH than other processes for extraction of nickel from solution, especially after separation of iron and cobalt values.
    Type: Application
    Filed: March 26, 2014
    Publication date: October 2, 2014
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Md. Abdul Halim, Jonathan Chen, Robert J. DeLaat
  • Publication number: 20130283977
    Abstract: A process for the extraction of rare earth elements, including yttrium, from a rare earth element-bearing ore or concentrate, comprising the steps of leaching the rare earth element-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of from 90° C. to the boiling point of the solution and at an Eh of at least 200 mV. After a liquid/solids separation step, the solution obtained is subjected to steps for removal of iron and for recovery of rare earth elements. Alternatively, rare earth element-bearing ore or concentrate may be leached with sulphuric acid and liquid obtained subjected to extraction of iron and other impurities. Raffinate obtained may be treated with oxalic acid, the precipitate dissolved in hydrochloric acid and subjected to solvent extraction for rare earth elements or the raffinate may be subjected to solvent extraction for removal of rare earth elements and then stripped with hydrochloric acid.
    Type: Application
    Filed: April 8, 2013
    Publication date: October 31, 2013
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, M. A. Halim
  • Publication number: 20130283976
    Abstract: A process for the extraction of gold from a gold-bearing ore or concentrate, comprising the steps of leaching the gold-bearing ore or concentrate with a lixiviant of hydrochloric acid and magnesium chloride at atmospheric pressure at a temperature of at least 90° C. and an Eh of at least 900 mV. After a liquid/solids separation step, the solution obtained is subjected to an organic solvent extraction step using an oxime to obtain a solution of organic solvent containing gold, which is stripped with sodium thiosulphate to recover gold. The extraction may be operated to extract gold with or without iron. Materials used in the process may be recycled. The process avoids environmental and other hazards associated with the use of cyanide to extract gold.
    Type: Application
    Filed: April 8, 2013
    Publication date: October 31, 2013
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, M. A. Halim
  • Publication number: 20130149219
    Abstract: The invention provides a process for the leaching of a laterite ore, concentrate, tailings or waste rock for the recovery of value metals, at least one value metal being nickel. The laterite ore or concentrate is subjected to a leaching step with a lixiviant comprising hydrochloric acid to leach nickel from the laterite ore, followed by a liquid/solids separation step. The liquid obtained is subject to solvent extraction with a dialkyl ketone, to obtain a solution rich in iron and a raffinate. Separation of iron from cobalt and nickel is obtained.
    Type: Application
    Filed: December 12, 2012
    Publication date: June 13, 2013
    Inventors: Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Jonathan Chen, M. A. Halim, Robert DeLaat
  • Patent number: 8337795
    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: Grant
    Filed: August 25, 2010
    Date of Patent: December 25, 2012
    Assignee: Process Research Ortech Inc.
    Inventors: Mansoor Barati, Kingsley Kweku Larbi, Raja Roy, Vaikuntam I. Lakshmanan, Ramamritham Sridhar
  • Publication number: 20120230904
    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: September 13, 2012
    Inventors: Mansoor Barati, Kingsley Kweku Larbi, Raja Roy, Vaikuntam I. Lakshmanan, Ramamritham Sridhar
  • Patent number: 7968065
    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. In an embodiment, the chloride is magnesium chloride and lixiviant solution is regenerated.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: June 28, 2011
    Assignee: Jaguar Nickel Inc.
    Inventors: G. Bryn Harris, Vaikuntam I. Lakshmanan, Ramamritham Sridhar, Geroge Puvvada
  • 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: 7803336
    Abstract: A process for leaching a value metal from a titanium-bearing ore material comprising the step of leaching the ore material at atmospheric pressure with a lixiviant comprising a chloride and hydrochloric acid is disclosed. The leaching conditions are such that titanium is leached and remains in solution. The temperature is maintained at less that 85° C., and the concentration of hydrochloric acid is preferably less than 20% (mass ratio). The preferred chloride is magnesium chloride. The lixiviant may contain oxidant e.g. sodium chlorate or chlorine.
    Type: Grant
    Filed: November 4, 2004
    Date of Patent: September 28, 2010
    Assignee: Process Research Ortech, Inc.
    Inventors: Vaikuntum I. Lakshmanan, Ramamritham Sridhar, G. Bryn Harris, George Puvvada
  • 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