Production of hydrogen fluoride
OwnerWilliam Henry Thompson, Ralph Eric Worthington +1inventors
InventorsWilliam Henry Thompson, Ralph Eric Worthington, David John Stamper
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Abstract
Hydrogen fluoride is recovered from hydrofluosilicic acid by-product of phosphoric acid manufacture. The hydrofluosilicic acid effluent is reacted with ammonia to form ammonium fluoride which is converted to a bifluoride by reaction with an excess of soluble metal fluoride. The bifluoride is readily recoverable and decomposable to yield hydrogen fluoride.
Claims12
A process for the preparation of hydrogen fluoride, the process comprising heating ammonium fluoride in an aqueous solution, in the presence of an amount of a soluble alkali metal fluoride in excess of the stoichiometric amount for reacting to form an aqueous solution of the bifluoride of the alkali metal, such that the weight ratio of fluoride ions to ammonium ions in solution is at least 3 :
- 1, whereby the rate of reaction to form the bifluroide is increased, and recovering a solid product from the solution comprising alkali metal bifluoride, substantially free from ammonia, and decomposing the alkali metal bifluoride by heating the solid product to release hydrogen fluoride and to form metal fluoride.
A process for the prepartion of hydrogen fluoride, the process comprising heating ammonium fluoride in aqueous solution, in the presence of an amount of a soluble potassium fluoride in excess of the stoichiometric amount for reacting to form an aqueous solution of the bifluoride of the potassium, such that the weight ratio of fluoride ion to ammonium ion in solution is at least 3 :
- 1, whereby the rate of reaction to form the bifluoride is increased, and recovering a solid product comprising potassium bifluoride from the solution substantially free from ammonia, and decomposing the potassium bifluoride by heating to release hydrogen fluoride and to form metal fluoride.
Dependencies are inferred from the claim text.