Patent · US Expired

Processes for the preparation of alkali metal dichromates and chromic acid

US5094729A · kind A · utility

1Cited by

3References

5Claims

0Family size

Assignee

BAYER HEALTHCARE LLC · DE

Inventors

Helmut Klotz · Friedrichshafen, DE
Hans-Dieter Pinter · Wermelskirchen, DE
Rainer Weber · Leverkusen, DE
Hans-Dieter Block · Cologne, DE
Norbert Lonhoff · Leverkusen, DE

Key dates

Filing date	Feb 22, 1991
Grant date	Mar 10, 1992
Priority date	—
Expiry date	Feb 22, 2011

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC25B1/22
WIPO fieldSurface technology, coating
WIPO sectorChemistry

Abstract

A process for the preparation of alkali metal dichromates and chromic acid by the electrolysis of monochromate and/or dichromate solutions in an electrolytic cell in which the anode and cathode chamber are separated by a cation exchanger membrane anolyte fluid containing dichromate and/or chromic acid being formed in the anode chamber and alkaline catholyte fluid containing alkali metal ions being formed in the cathode chamber, the improvement wherein the catholyte fluids are periodically replaced by a solution which is at a pH below 6.

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