Abstract: A method and system for converting copper cyanide to copper oxide is provided. The method includes contacting a copper cyanide solution with an acidic solution in a precipitation tank under reaction conditions sufficient to produce a copper cyanide slurry, removing the copper cyanide slurry from the precipitation tank, separating solid copper cyanide from the copper cyanide slurry in a first separation device, removing the solid copper cyanide from the first separation device, contacting the solid copper cyanide with a sodium hydroxide solution in a production tank under reaction conditions sufficient to produce a copper oxide slurry, removing the copper oxide slurry from the production tank, separating solid copper oxide from the copper oxide slurry in a second separation device, and removing from the second separation device any residual sodium hydroxide not reacted during the process of contacting the solid copper cyanide with the sodium hydroxide solution in the production tank.

Abstract: A method and system for converting copper cyanide to copper oxide is provided. The method includes contacting a copper cyanide solution with an acidic solution in a precipitation tank under reaction conditions sufficient to produce a copper cyanide slurry, removing the copper cyanide slurry from the precipitation tank, separating solid copper cyanide from the copper cyanide slurry in a first separation device, removing the solid copper cyanide from the first separation device, contacting the solid copper cyanide with a sodium hydroxide solution in a production tank under reaction conditions sufficient to produce a copper oxide slurry, removing the copper oxide slurry from the production tank, separating solid copper oxide from the copper oxide slurry in a second separation device, and removing from the second separation device any residual sodium hydroxide not reacted during the process of contacting the solid copper cyanide with the sodium hydroxide solution in the production tank.

Abstract: This invention relates to a method for reducing decomposition of an aqueous sodium cyanide solution by passing an inert gas through the aqueous sodium cyanide solution to remove carbon dioxide from the solution, and/or storing the aqueous sodium cyanide solution under an inert gas or under a vacuum. This invention also relates to a method for reducing decomposition of a sodium cyanide slurry, a sodium cyanide paste, or a solid sodium cyanide composition by storing the sodium cyanide paste, the sodium cyanide slurry, or the solid sodium cyanide under an inert gas or under a vacuum.

Abstract: A method and system for converting copper cyanide to copper oxide is provided. The method includes contacting a copper cyanide solution with an acidic solution in a precipitation tank under reaction conditions sufficient to produce a copper cyanide slurry, removing the copper cyanide slurry from the precipitation tank, separating solid copper cyanide from the copper cyanide slurry in a first separation device, removing the solid copper cyanide from the first separation device, contacting the solid copper cyanide with a sodium hydroxide solution in a production tank under reaction conditions sufficient to produce a copper oxide slurry, removing the copper oxide slurry from the production tank, separating solid copper oxide from the copper oxide slurry in a second separation device, and removing from the second separation device any residual sodium hydroxide not reacted during the process of contacting the solid copper cyanide with the sodium hydroxide solution in the production tank.

Abstract: This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.

Abstract: This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.

Abstract: A process for treating effluent containing cyanide by contacting the effluent with a mixture formed from a source of hydrogen peroxide and a source of magnesium ion to oxidize the cyanide. The ratio of hydrogen peroxide to cyanide is up to 10:1 and the amount of magnesium ion is present in the concentration of 0.1 to 1000 ppm per liter of aqueous waste effluent.

Abstract: This invention pertains to a method of treating cyanide contained in wastewater with particularly high levels of solids in the stream. The process involves either simultaneous or step-wise dosage of hydrogen peroxide in the form of an aqueous solution of a concentration between 35% to 90% by weight, preferably at least 50% by weight, and SO.sub.2 either in the form of gaseous SO.sub.2 or solution of sodium and/or potassium sulfite or metabisulfite resulting in the conversion of cyanide ions to non-toxic cyanate ions.

Abstract: A process is disclosed for the detoxification of effluents containing cyanide by treating with a mixture of hydrogen peroxide and phosphoric acid.

Abstract: Treatment of effluent containing cayanide is disclosed wherein a mixture of H.sub.2 SO.sub.4 and H.sub.2 O.sub.2 with between 0.01 and 0.5 moles of H.sub.2 SO.sub.4 per mole of H.sub.2 O.sub.2 is used.

Abstract: A process for treating effluents contaiing cyanide from mining operations wherein magnetic separation is used prior to treatment with hydrogen peroxide.

Abstract: A process for the treatment of aqueous effluent containing cyanide and toxic or heavy metals, wherein the effluent is contacted with a sufficient amount of hydrogen peroxide to oxidize at least a substantial portion of the cyanide in the effluent in the presence of sufficient trimercaptotriazine to react with a substantial portion of the metal present in said effluent, and precipitating said metal component.