Reacting A Sulfide Patents (Class 423/571)
  • Patent number: 3972989
    Abstract: The consumption of anthraquinone disulfonate by oxidation, employed in the Stretford process which treats hydrogen sulfide-containing gases to yield a sulfur-free effluent gas and elemental sulfur, is reduced by the addition of a chemical precursor to the solution which increases the thiosulfate ion concentration of the solution.
    Type: Grant
    Filed: August 14, 1974
    Date of Patent: August 3, 1976
    Assignee: Union Oil Company of California
    Inventors: Donald M. Fenton, Raoul P. Vaell
  • Patent number: 3966876
    Abstract: Gas purification processes for removing hydrogen sulphide (H.sub.2 S) from a foul gas stream, such as coal carbonization gases, involving a circulating liquid reagent in which the H.sub.2 S is absorbed and converted to sulphur which is recovered and the reagent regenerated and recycled exhibit progressive deterioration of the circulating reagent due to contamination by process by-products. The invention provides a method of decontaminating such a circulating reagent by subjecting a bled-off sidestream to high temperature hydrolysis, so producing gaseous products recyclable to the foul gas stream. Solid products may also be produced which may be recycled to the reagent, perhaps after high-temperature reduction.
    Type: Grant
    Filed: December 18, 1973
    Date of Patent: June 29, 1976
    Assignee: Woodall-Duckham, Limited
    Inventors: Frank Henry Singleton, Derek Vernon Gosden, Graham Woodhouse
  • 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: 3962409
    Abstract: Sulfur and hydrogen are produced from hydrogen sulfide according to the present invention by bringing hydrogen sulfide into contact, at a temperature exceeding the boiling point of sulfur, with at least one member selected from the group consisting of the sulfides of molybdenum, tungsten and ruthenium to give rise to a gaseous mixture consisting of hydrogen sulfide, hydrogen and sulfur, cooling the produced mixture to separate therefrom the sulfur component in the condensed form and leave behind a gaseous mixture wherein the hydrogen component makes up the majority of the total weight thereof and subsequently removing hydrogen sulfide from this mixture by means of condensation or absorption.
    Type: Grant
    Filed: October 24, 1974
    Date of Patent: June 8, 1976
    Assignee: Agency of Industrial Science & Technology
    Inventors: Yoshihide Kotera, Naoyuki Todo, Kenzo Fukuda
  • Patent number: 3959068
    Abstract: A new chemical recovery process and apparatus for a polysulfide pulping system is described wherein sulfur is recovered from the weak black liquor and is returned to the process, along with makeup sulfur, to reconstitute the polysulfide solution.After the polysulfide digestion, the spent liquor is contacted with ferric oxide Fe.sub.2 O.sub.3 whereby ferrous sulfide, FeS, is formed. After separation of the ferrous sulfide from the remaining liquid, the ferrous sulfide is oxidized to form elemental sulfur, and ferric oxide. After the melting of the sulfur and the separating of the products, the sulfur can be returned to the Sulfur Dissolving Tank wherein, along with makeup sulfur as required, the white liquor from the causticizing plant can be treated to form the polysulfide liquor for digestion. The ferric oxide can be reused for contacting the black liquor to form ferrous sulfide. The resulting smelt of reduced sulfidity from the recovery furnace can be reprocessed to form the white liquor.
    Type: Grant
    Filed: October 24, 1974
    Date of Patent: May 25, 1976
    Assignee: The Babcock & Wilcox Company
    Inventors: Robert A. McIlroy, Robert E. Matty, Walter C. Lapple
  • Patent number: 3948639
    Abstract: A process and device to be used in the flash smelting of sulphide ores or concentrates is disclosed, wherein the gases emerging from the rising zone of the flash smelting furnace are fed together with the sulphide ore or concentrate into a pretreatment zone, from where the cooled gases are removed for the recovery of sulphur and the pre-treated sulphide ore or concentrate is fed into the upper end of the reaction zone of the flash smelting furnace.
    Type: Grant
    Filed: October 24, 1973
    Date of Patent: April 6, 1976
    Assignee: Outokumpu Oy
    Inventors: Esko Olavi Nermes, Timo Tapani Talonen
  • Patent number: 3941875
    Abstract: A process for treating a hydrogen sulfide-containing gas in a closed loop system wherein said gas is passed through and absorbed by an alkaline aqueous absorbent containing an alkali carbonate and an oxidation catalyst. The solution containing the dissolved hydrogen sulfide is oxidized with an oxygen-containing gas to convert the absorbed hydrogen sulfide into elementary sulfur and sulfur salt compounds. After separation of the elementary sulfur from the solution, the solution is re-circulated for use as alkaline absorbent. A part of the re-circulated solution is diverted and subjected to mixed-combustion with an auxiliary fuel in a combustion furnace at an air ratio lower than 0.9 and at a temperature of 700.degree.C to 1100.degree.C to thermally decompose the sulfur compounds into hydrogen sulfide and an alkali carbonate.
    Type: Grant
    Filed: April 26, 1973
    Date of Patent: March 2, 1976
    Assignee: Nittetu Chemical Engineering Ltd.
    Inventors: Hidemasa Tsuruta, Yukinori Hiwatashi, Teruhiko Hirabayashi, Seiji Kumata
  • Patent number: 3933973
    Abstract: A method is disclosed for leaching finely divided lead sulphide bearing material to convert contained lead values to soluble lead acetate with concurrent conversion of sulphur values associated with the lead sulphide to an elemental state. The method involves forming a slurry consisting of the material dispersed in an aqueous medium containing free acetate ions and having a pH below 5.1. The slurry is reacted at a temperature of 60.degree. to 120.degree.C. with a free oxygen-bearing gas under a partial pressure of oxygen of 20 to 60 p.s.i. in order to convert lead sulphide to soluble lead acetate with concurrent production of insoluble elemental sulphur.
    Type: Grant
    Filed: October 16, 1973
    Date of Patent: January 20, 1976
    Assignee: Sherritt Gordon Mines Limited
    Inventors: David John Ivor Evans, Ian M. Masters
  • Patent number: 3932584
    Abstract: Hydrogen sulfide-containing waste gases whose complete treatment is indispensable from the viewpoint of environmental pollution problem, are purified in two steps consisting of a first step in which the gases are absorbed in an aqueous solution of sodium hydroxide or/and sodium sulfide, and a second step in which sulfuric acid and sulfur dioxide gas are simultaneously introduced into the resulting solution after absorption to deposit sulfur. Further, for recovery of the resulting sulfur, a particular apparatus is provided.
    Type: Grant
    Filed: January 25, 1974
    Date of Patent: January 13, 1976
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Tokuzo Asakusa, Taketoshi Honma, Isao Hirashita, Koichi Yasui, Yoshio Nishi, Koichi Murayama