Method for the recovery of ammonia from liquor from the filters of ammonia-soda plants
AssigneeSolvay & Cie
InventorsJean Verlaeten, Paul Demilie
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Abstract
A method for the recovery of ammonia from liquor from the filters of ammonia-soda plants, which contains free ammonia and ammonium chloride. In this method the liquor is heated to release the free ammonia, and the remaining liquor is then treated successively in a prelimer with lime in an amount insufficient to decompose the whole part of the ammonium chloride and in a still with steam and an alkali metal hydroxide in an amount sufficient to decompose the remaining part of ammonium chloride.
Claims8
In a method for the recovery of ammonia from liquor from filters of ammonia-soda plants which contains free ammonia and ammonium chloride, wherein the liquor is heated and traversed by a current of steam in a heating column to release more particularly the free ammonia, then is treated in a prelimer with a basic agent in an amount sufficient to decompose the major part but not the whole of the ammonium chloride with liberation of ammonia and is finally treated with steam so as to entrain liberated gaseous products in a still where there also is introduced the balance of basic agent needed to decompose the whole of the ammonium chloride, the improvement wherein:
- prelimer is lime, the balance used in the still is an alkali metal hydroxide, and the amount of alkali metal hydroxide added is controlled in response to the presence of ammonium ions in the still outlet so as to minimize said amount of alkali metal hydroxide added.
Dependencies are inferred from the claim text.