Method of producing aluminum using graphite cathode coated with refractory hard metal
US4308115A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 15, 1980 |
| Grant date | Dec 29, 1981 |
| Priority date | — |
| Expiry date | Aug 15, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C3/08
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A metal such as aluminum is produced by electrolysis of a compound of the metal in a solvent such as a molten salt. Electrolysis is carried out by passing a current from an anode to a cathode between which the solvent bath is situated. The cathode or cathode member is composed of a graphite substrate coated with a refractory hard metal such as titanium diboride. The coating adhesion of the TiB.sub.2 is improved through control of the manufacture and structure of the graphite substrate to favor a higher coefficient of thermal expansion and to have the density of the graphite fall within a range of 1.6 to 1.85 grams per cubic centimeter. The steps in producing the graphite may include working it so as to provide a grain direction. One embodiment includes aligning the refractory hard metal coated graphite in the electrolytic cell with the graphite grain direction parallel to the direction of current flow from anode to cathode. The refractory hard metal coating can be imparted by chemical vapor deposition and should exhibit a dense columnar structure which reduces penetration of the coating by molten aluminum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.