Forming Insoluble Substance In Liquid Patents (Class 423/101)
  • Patent number: 3985858
    Abstract: A dilute aqueous slurry of hydrated zinc oxide is subjected to heat and pressure to obtain solids having improved filtering characteristics. The process is especially useful in the treatment of neutralized waste liquor from the viscose rayon system to provide a more economical method for the recovery of zinc sulfate.
    Type: Grant
    Filed: April 8, 1975
    Date of Patent: October 12, 1976
    Assignee: FMC Corporation
    Inventor: John H. Cosgrove
  • Patent number: 3976743
    Abstract: A process for the treatment of zinc plant residue formed on leaching zinc calcine with sulphuric acid in which the residue is leached in a first leaching step with a sulphuric acid solution at atmospheric pressure, and a temperature above about 60.degree.C, in the presence of excess zinc sulphide reductant whereby ferric iron in the residue is reduced to the ferrous state, thereby forming a zinc sulphate solution containing excess acid, ferrous iron and other dissolved impurities such as germanium, indium, gallium, antimony and arsenic nd a mixture of solids containing undigested zinc residue, lead residue, and unreacted zinc sulphide. Clarified solution is separated, preferably by thickening, from the mixture of solids. The mixture of solids is leached in a second residue leaching step at atmospheric pressure and at a temperature above about 60.degree.
    Type: Grant
    Filed: August 5, 1975
    Date of Patent: August 24, 1976
    Assignee: Cominco Ltd.
    Inventors: Louis Landucci, Donald Roderick McKay, Ernest George Parker
  • Patent number: 3974254
    Abstract: The present invention relates to a process for purifying metallurgical gases containing sulphuric anhydride by extracting mercury, using the sulphurous anhydride which accompanies the metallurgical gases as an oxidizing agent for the mercury, an additional contribution of sulphurous anhydride being made when the latter is deficient, and employing in addition an acid to facilitate the oxidization of the mercury and a soluble thiocyanate in order to complete the oxidation of the mercury.
    Type: Grant
    Filed: December 10, 1973
    Date of Patent: August 10, 1976
    Assignee: Patronato de Investigacion Cientifica y Tecnica "Juan de la Cierva" del Consejo Superior de Investigaciones Cientificas
    Inventors: Antonio de la Cuadra Herrera, Miguel Fernandez Tallante, Armando Rodriguez Sanchez
  • Patent number: 3969182
    Abstract: Dimethylsulfoxide is used as a solvent for the growth of red mercuric iodide (HgI.sub.2) crystals for use in radiation detectors. The hygroscopic property of the solvent allows controlled amounts of water to enter into the solvent phase and diminish the large solubility of HgI.sub.2 so that the precipitating solid collects as well-defined euhedral crystals which grow into a volume of several cc.
    Type: Grant
    Filed: July 16, 1975
    Date of Patent: July 13, 1976
    Assignee: The United States of America as represented by the United States Energy Research and Development Administration
    Inventor: Richard C. Carlston
  • Patent number: 3965239
    Abstract: The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149.degree.C (300.degree.F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.
    Type: Grant
    Filed: April 18, 1975
    Date of Patent: June 22, 1976
    Assignee: International Ore Technology, Inc.
    Inventor: John G. Posel
  • Patent number: 3964901
    Abstract: A hydrometallurgical process for treating iron containing metal sulfides for rendering iron and non-ferrous metal values active and amenable for selective extraction and separate recovery. Sulfur values can be controllably produced as elemental sulfur or as sulfuric acid to supply acid requirements of the process, while substantially obviating the discharge of sulfur-containing gases to the atmosphere. Ores and concentrates of the sulfides are thermally activated by sequentially heating and reducing said sulfides in a countercurrent flow of heating and reducing gases respectively in a reactor whereby the reaction products of the reducing gas and sulfides, together with liberated labile sulfur, are controllably combusted with oxygen to satisfy heat requirements of the thermal activation process and to convert sulfur values to SO.sub.2 gas. The activated sulfides are subjected to an acid leach in aqueous sulfuric acid for production of ferrous sulfate and evolution of H.sub.
    Type: Grant
    Filed: October 19, 1973
    Date of Patent: June 22, 1976
    Assignees: Sherritt Gordon Mines Limited, Cominco Ltd.
    Inventors: Godefridus Maria Swinkels, Robert Arthur Furber, Edward Francis Godfrey Milner, Roman Michael Genik-Sas-Berezowsky, Charles Ray Kirby
  • Patent number: 3954937
    Abstract: In a process for the treatment of a material containing zinc and soluble silica by dilute aqueous solutions of sulphuric acid at a temperature below its boiling point under atmospheric pressure, the acid is progressively added to the zinc containing material over a period of at least 3 hours, in such a quantity that the final acidity of the solution will be 1.5 to 15 g/l, while carefully maintaining the temperature at 70.degree. to 90.degree.C, thereby inducing the lixiviation of the material and simultaneously the reprecipitation of silica in a crystalline form which can readily be eliminated by filtration.
    Type: Grant
    Filed: August 2, 1974
    Date of Patent: May 4, 1976
    Inventor: Fernand Jacques Joseph Bodson
  • Patent number: 3948656
    Abstract: Disclosed is an improved method for the preparation of CdSSe by the reaction in an aqueous medium of CdCO.sub.3 with a soluble metal sulfide and selenium to form a raw cake which is subsequently calcined to form the desired product. During calcination, an inert gas is allowed to flow over the raw cake thereby forming a CdSSe pigment with improved electrical properties for use in electrostatographic copying.
    Type: Grant
    Filed: May 16, 1974
    Date of Patent: April 6, 1976
    Assignee: Xerox Corporation
    Inventor: Kenneth H. Maxwell