Patents by Inventor Inderjit Nirdosh

Inderjit Nirdosh 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: 10005088
    Abstract: The main objective of the invention was to develop a new flotation collector that could eliminate or reduce the amount of copper sulfate used in the flotation of sphalerite. Different series of collectors such as cupferrons, arylhydroxamic acids and amino mercaptans or amino thiols were synthesized and tested. Amino mercaptans/aminothiols were found to be very effective in floating sphalerite from a lead-zinc ore using only 10-15% of copper sulfate used with conventional xanthate collector. The present invention does not require any alteration in the current mill practices. This warrants only changing the flotation collector in zinc flotation stage from, for example, potassium amyl xanthate (PAX) to the new collector.
    Type: Grant
    Filed: December 23, 2016
    Date of Patent: June 26, 2018
    Assignee: LAKEHEAD UNIVERSITY
    Inventors: Inderjit Nirdosh, Natarajan Ramanathan
  • Publication number: 20170209873
    Abstract: The main objective of the invention was to develop a new flotation collector that could eliminate or reduce the amount of copper sulfate used in the flotation of sphalerite. Different series of collectors such as cupferrons, arylhydroxamic acids and amino mercaptans or amino thiols were synthesized and tested. Amino mercaptans/aminothiols were found to be very effective in floating sphalerite from a lead-zinc ore using only 10-15% of copper sulfate used with conventional xanthate collector. The present invention does not require any alteration in the current mill practices. This warrants only changing the flotation collector in zinc flotation stage from, for example, potassium amyl xanthate (PAX) to the new collector.
    Type: Application
    Filed: December 23, 2016
    Publication date: July 27, 2017
    Inventors: Inderjit Nirdosh, Natarajan Ramanathan
  • Patent number: 4654200
    Abstract: The removal of radium from acid-leached uranium mill tailings has been difficult due to its strong retention as mixed sulfates and in adsorbed forms. With this invention the leaching action of a complexing agent (reducing the free radium cation concentration in solution) is combined with that of a reducing agent. Thus, high valency metal hydroxides and basic salts (notably Fe.sup.3+) which tend to retain radium are converted to the lower valency form which is much more soluble in the complexing agent. The reducing agent employed is sodium hydrosulfite, in combination with various organic complexing agents; the preferred complexing agent is EDTA. Over 90% of the radium in uranium leach tailings from Elliot Lake can be removed in 1 hour contact at room temperature with a solution comprising 0.04M of both sodium hydrosulfite and EDTA, with 1.0M potassium chloride added as a surface charge depressant. The gradual addition of the solids to liquid permits the use of low liquid/solid ratios.
    Type: Grant
    Filed: June 1, 1984
    Date of Patent: March 31, 1987
    Inventors: Inderjit Nirdosh, Malcolm H. Baird, Sirugamani V. Muthuswami
  • Patent number: 4649029
    Abstract: Ferric nitrate leaching at 75.degree. C. is found to remove up to 97% of the uranium and 93% of the radium from ores occurring in the Elliot Lake area of Canada, after an initial flotation-separation of the sulfide minerals from the ore. In processes of the invention an aqueous acidic ferric nitrate solution of relatively low concentration, e.g. 0.01M to 0.1M is used, giving tailings which are effectively sulfide-free (less than 0.45 wt %) and with radium levels approaching a desired maximum value of 24 pCi/g. Radium may be removed from the leachate by adsorption and uranium by solvent extraction. 80-87% of the ferric nitrate may be recirculated for further leaching. Because of the low reagent concentrations and the recycle of the ferric nitrate, it is possible to keep nitrate ion levels in the effluent below the prescribed level of 10 ppm.
    Type: Grant
    Filed: April 13, 1984
    Date of Patent: March 10, 1987
    Inventor: Inderjit Nirdosh
  • Patent number: 4523456
    Abstract: The determination of the surface tension of a liquid or of the interfacial tension between two immiscible liquids is effected by drainage methods in which the movement of an air bubble or a droplet of the lighter liquid is observed, certain measurements made and the surface tension or interfacial tension determined from such measurments. The apparatus used, comprising a tapered tube, a rotating uniform diameter tube or a tilted uniform diameter tube, is simple and inexpensive and accurate measurements are obtained.
    Type: Grant
    Filed: May 28, 1982
    Date of Patent: June 18, 1985
    Assignee: University of Waterloo
    Inventors: Malcolm H. I. Baird, Inderjit Nirdosh
  • Patent number: 4454097
    Abstract: Ferric chloride leaching at temperatures in the range 47.degree.-74.degree. C. is found to remove up to 97% of the uranium from ores occurring in the Elliot Lake area of Canada, but radium removal was found to be poor due to the formation of sulphates from the sulphides present in the ore. In processes of the invention the sulphides are initially removed by flotation, when aqueous acidic ferric chloride of relatively low concentration, e.g. 0.1 M can extract as much as 92% of the radium, giving tailings which are effectively sulphide-free and with radium levels approaching a desired maximum of 24 pCi/g. Radium may be removed by adsorption on manganese dioxide and uranium may be removed by liquid extraction with D2EHPA (DAPEX process). The ferric chloride may be recirculated for further leaching, with reduction before the uranium extraction and reoxidation afterwards. Because of the recycle, it is possible to keep chloride ion levels in the effluent below the prescribed level in Ontario, Canada of 750 ppm.
    Type: Grant
    Filed: October 21, 1982
    Date of Patent: June 12, 1984
    Inventors: Inderjit Nirdosh, Malcolm H. Baird, Sanjoy Banerjee, Sirugamani V. Muthuswami