Patent · US Expired

Purification of phosphoric acid

US3996336A · kind A · utility

2Cited by

4References

6Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Bernhard Wojtech · Bad Soden am Taunus, DE
Klaus-Peter Ehlers
Wolfgang Scheibitz · Frankfurt am Main, DE

Key dates

Filing date	Jul 1, 1975
Grant date	Dec 7, 1976
Priority date	—
Expiry date	Jul 1, 1995

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01B25/464
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

Phosphoric acid is purified. To this end, it is dissolved in an organic solvent completely miscible with water. More particularly, the phosphoric acid is mixed with a solvent having a boiling point higher than that of water or higher than that of the resulting azeotrope; the resulting solution is heated to temperatures between the boiling point of water or the azeotrope and that of the solvent for as long a period as necessary to distillatively free the solution from the bulk of uncombined water therein; and the phosphoric acid solution is separated from residue.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.