Pechiney Ugine Kuhlmann

Pechiney

Pechine Ugine Kuhlmann

Marcel Armand

Jean-Pierre Garnier

Philippe Moinard

Process for producing transition metal powders by electrolysis in melted

The present invention relates to a process for improving the purity of transition metals produced by electrolysis of halides thereof in a bath of molten salts in a tank having a metal internal wall. The process is characterised in that a cathodic potential with respect to the anode of the cell is permanently imposed on the tank. It finds application in the production of metals such as in particular titanium, zirconium, hafnium, vanadium, niobium and tantalum, with a low proportion of oxygen and foreign metal elements.

Process for improving the purity of transition metals produced by

A process for measuring the potential of an indicator electrode of a transition metal, which dips into a bath of molten chlorides disposed in an electrolytic cell relative to a reference electrode. It is characterized by introducing into the bath an amount of alkali metal and/or alkaline earth fluorides such that the molar ratio of the fluorine contained in the bath to the amount of dissolved transitions metal is between 4 and 8.

Process for continuously controlling the proportion of metal dissolved

The electrolysis cell according to the invention is concerned with the preparation of Zr or Hf by electrolysis, from a molten mixture of alkali metal or alkaline earth chlorides and fluorides. It comprises a graphite collector which defines the anodic space and which is extended at the lower end below the level of the electrolyte by a metal wall made of metal to be deposited or coated with said metal. The wall may advantageously be made in the form of a porous diaphragm.

Process and cell for the preparation of polyvalent metals such as Zr or

The apparatus and the process according to the invention concern the preparation of titanium by electrolysis in a bath of molten halides. The apparatus comprises a porous diaphragm which is disposed around a feed cathode permitting partial reduction of the TiCl.sub.4 introduced into the electrolyte. The intensity of the current which passes through the feed cathode is so regulated as to maintain a low but non-zero voltage drop, across the diaphragm which is insulated with respect to the feed cathode.

Novel apparatus and process for the TiCl.sub.4 feed to electrolysis

The process according to the invention concerns the production of polyvalent metals such as titanium by electrolysis of molten halides. It comprises controlling the permeability of the diaphragm which separates the anolyte from the catholyte, by causing growth or re-dissolution of a deposit of the metal to be produced. The process is applied in particular to the production of titanium by electrolysis from TiCl.sub.4.

Process for controlling the permeability of diaphragms in the

The process which is the subject of this invention concerns the preparation of titanium by electrolysis from a bath of molten halides. It comprises effecting partial reduction of the TiCl.sub.4 which is used as the starting material in a separate reaction vessel, and then directly feeding the electrolyzing apparatus by means of titanium halides with a valency of less than 3. The partial reduction of the TiCl.sub.4 is effected by means of divided titanium or another metal such as Na.

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Meylan, France

Marcel Armand