Patent · US Expired

Process for the separation of heavy metal compounds from phosphoric acid

US4479924A · kind A · utility

7Cited by

4References

5Claims

0Family size

Assignee

Hoechst GmbH · DE

Inventors

Helmold von Plessen · Kelkheim, DE
Reinhard Gradl · Hürth, DE
G/u/ nther Schimmel · Lechenich, DE

Key dates

Filing date	Apr 1, 1983
Grant date	Oct 30, 1984
Priority date	—
Expiry date	Apr 1, 2003

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY02P10/20
WIPO fieldMaterials, metallurgy
WIPO sectorChemistry

Abstract

A process for the separation of heavy metal components, especially of compounds of cadmium, mercury and lead, from crude phosphoric acid obtained according to the Odda process, which comprises adjusting this crude phosphoric acid with ammonia to a pH of from 0.5 to 1.5, contacting it subsequently with a diorganyl-dithiophosphorus compound and an adsorbent, and then separating the acid from the absorbent containing the heavy metal impurities.

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