Process for the preparation of mother alloys of iron and neodymium by electrolysis of oxygen-bearing salts in a medium of molten fluorides
US4828658A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 4, 1988 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Apr 4, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25C3/34
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention concerns a process for the electrolytic preparation of a mother alloy of iron and neodymium by the reduction of a mixture comprising at least one reactive oxygen-bearing compound of neodymium in a bath of molten halides with at least one metallic cathode, preferably of iron, and a carbon anode. In accordance with the invention, the bath is primarily formed by a mixture of molten fluorides whose decomposition potential is close to that of NdF.sub.3 or more negative, such as for example NdF.sub.3, MgF.sub.2, ScF.sub.3, CeF.sub.3, LaF.sub.3, BaF.sub.2, CaF.sub.2 and SrF.sub.2, and permitting solubilization of the oxides by a complexing effect, the solute to be reduced is formed by a mixture of salts primarily containing a reactive oxygen-bearing compound of neodymium which is very rapidly soluble in the molten electrolyte. The working temperature is in a range of from 640.degree. to 1030.degree. C., the anodic current density is from 0.1 to 1.5 A/cm.sup.2, and the cathodic current density is between 2 and 30 A/cm.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.