Production of chromic acid using two-compartment and three-compartment cells
US4273628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1979 |
| Grant date | Jun 16, 1981 |
| Priority date | — |
| Expiry date | May 29, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25B1/22
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Chromic acid is now produced in simplified processing that also reduces acid contaminants, while using the alkali metal chromate typically available at an early stage in chromic acid production from chrome ore. In the process, chromate is converted to dichromate in the anode compartment of either a two-compartment, or three-compartment, electrolytic cell. During electrolysis, metal ion contamination is reduced. Withdrawn anolyte from this first cell may then be concentrated. The dichromate feed, possibly concentrated, is then introduced to the center compartment of a three-compartment electrolytic cell and flows through a porous diaphragm to the anode compartment of the cell. The anolyte from this later electrolytic cell, rich in chromic acid, can be concentrated, cooled, and the chromic acid recovered. Liquid removed from chromic acid recovery can be recycled. Alkali product is produced in the cathode compartment of each cell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.