Process for preparing alkali metal and alkaline-earth metal cyanates
AssigneeStamicarbon B.V.
InventorJohannes D. M. Verstegen
Life of this patent
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Abstract
Cyanates of alkali and alkaline-earth metals are prepared by reacting a salt such as the hydroxide, carbamate or carbonate of the metal in aqueous solution or slurry with cracked urea gas which is a gaseous mixture of ammonia and (iso)cyanic acid.
Claims6
A process for the preparation of alkali metal cyanate or alkaline-earth metal cyanates in relatively high yield comprising first cracking urea forming a gaseous mixture of (iso)cyanic acid and ammonia, then supplying the freshly prepared urea cracking gas to an absorption zone and contacting it at a temperature of about 20.degree. to about 90.degree. C with a hydroxide, carbamate or carbonate of a metal of Group IA or Group IIA of the periodic system in an aqueous solution or suspension thereof and maintaining the reaction within the stated temperature range and separating the resulting cyanate product from the reaction mixture.
A process for preparing an alkali metal cyanate or an alkaline earth metal cyanate in relatively high yield comprising supplying an aqueous solution or suspension of a hydroxide, carbamate or carbonate of one of said metals to an absorption zone, reacting together in said absorption zone the alkali metal or alkaline earth metal hydroxide, carbamate or carbonate with a gaseous mixture of ammonia and (iso)cyanic acid which has been previously prepared by cracking urea, separating the thus produced cyanate from the reaction medium and recycling at least a portion of the reaction medium to said absorption zone.
Dependencies are inferred from the claim text.