Chromic acid production process using a three-compartment cell
US4290864A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1980 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | May 6, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25B1/22
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Chromic acid production is now simplified in a process using the concentrated dichromate typically available at an intermediate stage when chromic acid is produced from chrome ore. In the process, the dichromate is treated in a three-compartment cell as, for example, after removal of the sulfate or carbonate salt evolved in the overall production process. The dichromate feed enters the center compartment of the three-compartment cell and then flows through a porous diaphragm to the anode compartment of the cell and is electrolyzed at elevated current density. Depleted feed solution may be withdrawn from the center compartment and recirculated for reuse. Concentrated, water-white alkali product is produced in the cathode compartment. The anolyte from the cell, rich in chromic acid, can be concentrated, cooled, and the chromic acid recovered. Liquid removed from chromic acid recovery can be recirculated for subsequent electrolysis, as by combination with the feed. Both alkali product and anolyte chromic acid can be produced at enhanced current efficiency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.