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.

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.

The present invention is to provide a novel adsorbent which is low in cost, has versatility and high adsorption ability. Specifically, the present invention is to provide an adsorbent of a specific metal element containing a metal salt of a cyanometallic acid, a method for producing the same, and a method for removing the ion of the element that is the target of adsorption using such an adsorbent.

The present invention is to provide a novel adsorbent which is low in cost, has versatility and has high adsorption ability. Specifically, the present invention is to provide an adsorbent containing a metal salt of a cyanometallic acid obtained by a reaction of a salt of a cyanometallic acid and a compound containing a metal element, wherein the reaction is carried out using the compound containing a metal element in an amount of less than 100 mol % of the theoretical amount relative to 1 mol of the salt of a cyanometallic acid, a method of producing the same, and a method for removing harmful ions from water using such an adsorbent.

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.

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.

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.

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.

The invention relates to a process for the preparation of alkali metal cyanides as a solid substance, comprising the steps of: i) an absorption step in the form of an absorption of hydrogen cyanide from a hydrogen cyanide-containing synthesis gas in an aqueous alkali metal hydroxide solution; ii) a crystallization step in the form of introducing said alkali metal cyanide solution into an evaporative crystallizer; iii) a separation step; iv) a recycle step; v) a drying step.

The invention relates to a process for the preparation of alkali metal cyanides as a solid substance, comprising the steps of: i) an absorption step in the form of an absorption of hydrogen cyanide from a hydrogen cyanide-containing synthesis gas in an aqueous alkali metal hydroxide solution; ii) a crystallization step in the form of introducing said alkali metal cyanide solution into an evaporative crystallizer; iii) a separation step; iv) a recycle step; v) a drying step.