Preparation of arsenic pentafluoride
AssigneeLithdyne International
InventorsW. Novis Smith, Joel McCloskey
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Abstract
A process for the preparation of high purity arsenic pentafluoride in high yield. The process uses sulfur trioxide or oleum and an excess of hydrogen fluoride to react arsenic acid or arsenic pentoxide in a reaction medium containing an excess of hydrogen fluoride to yield high purity arsenic pentafluoride as a gas.
Claims13
A process for preparing arsenic pentafluoride which comprises the steps of a) reacting excess anhydrous hydrogen fluoride with arsenic pentoxide or arsenic acid to form hexafluoroarsenic acid, b) reacting the resultant product with oleum or sulfur trioxide, and then c) recovering arsenic pentafluoride.
A process for preparing arsenic pentafluoride which comprises the steps of:
- a) reacting arsenic acid or arsenic pentoxide with about 7 to 100 weight percent excess of anhydrous hydrogen fluoride at a reaction temperature below 32° C. to form a solution of hexafluoroarsenic acid with excess hydrogen fluoride;
- b) adding oleum or sulfur trioxide to the solution of hexafluoroarsenic acid in a molar ratio based on water content ranging from about 0.6 to 1.0 while maintaining the temperature below 32° C.;
- c) increasing the temperature upon completion of the oleum or sulfur trioxide addition to about 150° C.;
- d) passing an evolving gaseous stream through a plurality of cooling zones to separate gaseous arsenic pentafluoride from hydrogen fluoride and other entrained compounds;
- and then
- e) recovering substantially pure arsenic pentafluoride.
A process for preparing arsenic pentafluoride comprising the steps of:
- a) reacting an excess of anhydrous hydrogen fluoride with arsenic acid to form hexafluoroarsenic acid in hydrogen fluoride;
- b) reacting oleum with the product of step a) in contact with unreacted excess of hydrogen fluoride and heating to produce a gaseous stream consisting substantially of arsenic pentafluoride and hydrogen fluoride and then
- c) recovering arsenic pentafluoride.
Dependencies are inferred from the claim text.