Patent · US Expired

Solvent extraction purification of wet-processed phosphoric acid

US4222994A · kind A · utility

2Cited by

3References

10Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Klaus-Peter Ehlers
Wolfgang Scheibitz · Frankfurt am Main, DE
Klaus Schrodter · Cologne, DE
Gero Heymer · Lechenich, DE

Key dates

Filing date	Dec 12, 1977
Grant date	Sep 16, 1980
Priority date	—
Expiry date	Dec 12, 1997

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC01B25/461
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

Wet-processed phosphoric acid is purified by counter-current extraction with the use of an organic solvent, in which water is partially soluble and which is capable of absorbing phosphoric acid, the organic phosphoric acid extract is separated from residual wet-processed phosphoric acid, unabsorbed by the solvent, and phosphoric acid is recovered from the separated organic phosphoric acid extract. More specifically, the wet-processed phosphoric acid is extracted with the use of a solvent containing more than 0 and less than 50% of water, based on the saturation concentration, and a mineral acid in a quantity corresponding to the quantity, in moles, of cation-bound phosphate in the crude acid.

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