Abstract: A method of recovering palladium from a palladium-containing aqueous solution by electrolysis is provided. The method comprises the steps of dc-electrolyzing the palladium-containing aqueous solution acidified with nitric acid by using an electrolytic cell equipped with a platinum electrode as a cathode to thereby deposit and collect palladium on the cathode, taking the cathode on which palladium has been deposited and collected out of the electrolytic cell, transferring the palladium-deposited cathode to a recovery vessel containing dilute nitric acid therein, and mechanically shaking the cathode in the recovery vessel to remove and recover palladium from the cathode. An apparatus for carrying out the above-described method is also provided.
Type:
Grant
Filed:
April 22, 1992
Date of Patent:
October 5, 1993
Assignees:
Doryokuro Kakunenryo Kaihatsu Jigyodan, Johoku Chemical Co., Ltd.
Abstract: In a process for reducing dyes in aqueous solution, a pair of electrodes is immersed in the solution. The cathode potential is maintained below the value at which hydrogen is evolved. A reducing agent is used, the redox potential of which, increased by the charge transfer overvoltage required for the reduction of the oxidized form of the reducing agent to the reduced form at the cathode, is less than the cathode potential.
Type:
Grant
Filed:
January 29, 1991
Date of Patent:
September 14, 1993
Assignee:
Verein Zur Forderung der Forschung und Entwicklung in der Textilwirtschaft
Abstract: A method for manufacturing an electrogalvanized steel sheet excellent in spot weldability, which comprises the steps of: adding, into an acidic electrogalvanizing solution containing an oxidizer, a complexing agent, which is capable of forming a stable complex with zinc, in an amount within a range of from 0.001 to 10 moles per liter of the electrogalvanizing solution, or a pH buffer, which has a pH buffering effect in a solution having a pH value within a range of from 5 to 12, in an amount within a range of from 1 to 50 g per liter of the electrogalvanizing solution; and electrogalvanizing a steel sheet in the resultant acidic electrogalvanizing solution containing the complexing agent or the pH buffer in addition to the oxidizer, to form a galvanizing layer comprising zinc oxide or zinc hydroxide on the surface of the steel sheet.
Abstract: The invention relates to a method for producing metal powders from reactive metals, when the employed raw materials are metal ions in a liquid phase. According to the invention, the metal ions are first reduced into metal in a molten salt electrolysis. The obtained reduction products are further subjected to a high-temperature treatment, for example by means of plasma, in order to improve the powder qualities of the metal. The metal to be treated is for instance titanium or zirconium.
Type:
Grant
Filed:
June 4, 1991
Date of Patent:
January 5, 1993
Assignee:
Outokumpu Oy
Inventors:
Heikki J. Volotinen, Jyri J. Talja, Pekka A. Taskinen
Abstract: Disclosed is a method of reducing the sodium chloride content of potassium chloride by forming an aqueous slurry of potassium chloride feed crystals having a wide particle size distribution with an average diameter of about 0.1 to about 50 microns in a liquor saturated with potassium chloride and undersaturated with sodium chloride, which is at least 50% saturated with sodium chloride, whereby the smaller of the feed crystals dissolve and potassium chloride grows on the larger of the feed crystals to form product crystals removing the product crystals from the slurry. Also disclosed is an apparatus for carrying out this process.
Abstract: A process for the removal of mercury from natural gas condensate wherein the natural gas condensate is passed over a catalyst, while also passing a stream of methane containing hydrogen sulfide over the catalyst.
Abstract: Process for selective removal and destruction of hydrogen cyanide contained in nitrous gases, in which the nitrous-containing gases are washed with nitric acid in counter-current in an absorption column and the nitric acid charged with hydrogen cyanide is regenerated at elevated temperature, with simultaneous hydrolysis and oxidation of the hydrogen cyanide.