Method for separating metals such as zirconium and hafnium
AssigneeCompagnie Europeenne du Zirconium Cezus
InventorsNoël Ozanne, Marc Lionel Lemaire, Alain Jean-Louis Guy, Jacques Henri Foos, Stéphane Pellet-Rostaing, Frédéric Chitry
Life of this patent
Estimating the term…
Abstract
A method for separating a metal (a) from a metal (2), preferably zirconium from hafnium, which consists in dissolving said metals in an aqueous solution wherein said metals are in a state preventing them from passing through a nanofiltration membrane; treating the aqueous medium with a ligand, for example EDTA, which is complexed with metal (1) and/or metal (2), then in passing the resulting treated medium on a filtering membrane allowing through the ligand-metal complexes, but retaining the metals not complexed with the ligand.
Claims26
A process for separating a metal 1 from a metal 2 starting from a solution of the metals in an aqueous medium in which the metals form at least one of polymers and copolymers that do not pass through a nanofiltration membrane, the process comprising the steps of:
- treating the aqueous medium with a ligand which complexes with one of the metal 1 and the metal 2;
- and
- passing the aqueous medium over a filtration membrane, after the treating, which allows ligand-metal complexes to pass but which retains the metals not complexed with the ligand.
A process for separating a metal 1 from a metal 2 starting from a solution of the metals in an aqueous medium in which the metals are in a state which does not allow the metals to pass through a nanofiltration membrane, the process comprising the steps of:
- treating the aqueous medium with a ligand which complexes with at least one of the metal 1 and with the metal 2;
- and
- passing the aqueous medium over a filtration membrane, after the treating which allows ligand-metal complexes to pass but retains the metals not complexed with the ligand wherein the metals are zirconium and hafnium in solution in an acidic aqueous medium.
A process for separating a metal 1 from a metal 2 starting from a solution of the metals in an aqueous medium in which the metals are in a state which does not allow the metals to pass through a nanofiltration membrane, the process comprising the steps of:
- treating the aqueous medium with a ligand which complexes with at least one of the metal 1 and with the metal 2;
- and
- passing the aqueous medium over a filtration membrane, after the treating, which allows ligand-metal complexes to pass but retains the metals not complexed with the ligand wherein the process is applied to a ZrCl4+HfCl4 mixture.
A process for separating a metal 1 from a metal 2 starting from a solution of the metals in an aqueous medium in which the metals are in a state which does not allow the metals to pass through a nanofiltration membrane, the process comprising the steps of:
- treating the aqueous medium with a ligand which complexes with at least one of the metal 1 and with the metal 2;
- and
- passing the aqueous medium over a filtration membrane, after the treating, which allows ligand-metal complexes to pass but and retains the metals not complexed with the ligand wherein the process is applied to one of a ZrO2+HfO2 and ZrCl4+HfCl4 mixture which has been subjected to treatment with nitric acid.
Dependencies are inferred from the claim text.