Method for electrolytic production and refining of metals
AssigneeElkem AS
InventorsKai Johansen, Donald R. Sadoway, Bjorn Myhre, Marianne Engvoll, Krister Engvoll
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AssigneeElkem AS
InventorsKai Johansen, Donald R. Sadoway, Bjorn Myhre, Marianne Engvoll, Krister Engvoll
Estimating the term…
The present invention relates to a method for electrolytic production and refining of metals having a melting point above about 1000° C., particularly silicon, where there is provided a first electrolytic cell having an upper molten electrolyte layer of a first electrolyte, a lower molten alloy layer of an alloy of the metal to be refined and at least one metal more noble than the metal to be refined. The lower alloy layer is the cathode in the first cell and an anode is positioned in the upper molten electrolyte layer. A second electrolytic cell is also provided with an upper molten metal layer of the same metal as the metal to be refined, said layer constituting a cathode, a lower molten alloy layer, said lower layer constituting an anode, said alloy having a higher density than the metal to be refined, and an intermediate molten electrolyte layer having a density between the density of the upper and lower molten layers. Both electrolytes are oxide based electrolytes containing oxide of the metal to be refined, and the electrolyte is in molten state and has a melting point below the operating temperature of the process. Raw material comprising an oxide of the metal to be refined is added to the first cell and direct electric current is passed through the anode to the cathode such that the metal to be refined is moved from the anode and deposited in molten state at the cathode. The two cells can be operated in two separate steps. One to produce an alloy and the other to refine metal from the alloy.
A method for producing and refining a metal in an electrolytic method characterized in that:
A method for electrolytic refining of metals having a melting point above about 1000° C., particularly silicon, characterized in that providing an upper molten metal layer comprising a metal of the same metal as the metal to be refined, said upper molten metal layer constituting a cathode, a lower molten alloy layer comprising an alloy of the metal to be refined and at least one metal more noble than the metal to be refined, said lower molten alloy layer constituting an anode, said alloy having a higher density than the metal to be refined, and an intermediate molten electrolyte layer comprising an oxide-based electrolyte containing an oxide of the metal to be refined and calcium oxide, where the electrolyte is in molten state and has a melting point below the operating temperature of the process, said electrolyte having a density between the density of the upper molten metal layer and lower molten alloy layer;
A method to electrolytically produce an alloy comprising a first and second metal characterized in that:
Dependencies are inferred from the claim text.