US3930967A — Process for the electrolysis of a molten charge u…

Claim 1

Independent Claim 162 words

In a process for the production of metals in a multicell type furnace, by the electrolysis of metal compounds dissolved in a molten electrolyte, comprising the steps of: disposing a first anode and a first cathode spaced apart therefrom in the furnace, dividing said furnace into cells by disposing at least one inconsumable bipolar electrode between said first anode and said first cathode, said bipolar electrode including a second anode the surface of which is composed of electron conductive ceramic oxide and a second cathode the surface of which is composed of another electron conductive material, joined together in such a way that, under conditions found in the operating cell, they form a mechanical and an electrical unit, maintaining a predetermined electrical potential across the first anode and the first cathode whereby a current flows through the cell and the anions have their charges removed at the anodes, and the metal ions have their charges removed at the surface of the cathodes.

Claim 2

Dependent Claim 162 words

In a process for the production of metals in a multicell type furnace, by the electrolysis of metal compounds dissolved in a molten electrolyte, comprising the steps of: disposing a first anode and a first cathode spaced apart therefrom in the furnace, dividing said furnace into cells by disposing at least one inconsumable bipolar electrode between said first anode and said first cathode, said bipolar electrode including a second anode the surface of which is composed of electron conductive ceramic oxide and a second cathode the surface of which is composed of another electron conductive material, joined together in such a way that, under conditions found in the operating cell, they form a mechanical and an electrical unit, maintaining a predetermined electrical potential across the first anode and the first cathode whereby a current flows through the cell and the anions have their charges removed at the anodes, and the metal ions have their charges removed at the surface of the cathodes.

Claim 3

Dependent Claim 22 words

In a process as claimed in claim 1, wherein said metal compound is a metal oxide, and said anions are oxygen ions.

Claim 4

Dependent Claim 20 words

In a process as claimed in claim 1, wherein said metal is aluminum and said metal oxide is aluminum oxide.

Claim 5

Dependent Claim 28 words

In a process as claimed in claim 1, wherein said second cathode is composed of materials compatible with the second anode materials under operating conditions of the cell.

Claim 6

Dependent Claim 21 words

Process in accordance with claim 1, whereby the current density at the anode surfaces is at least 0.001 A/cm 2 .

Claim 7

Dependent Claim 17 words

Process in accordance with claim 5, whereby the current density is at least 0.01 A/cm 2 .

Claim 8

Dependent Claim 17 words

Process in accordance with claim 6, whereby the current density is at least 0.025 A/cm 2 .

Claim 9

Dependent Claim 34 words

Process in accordance with claim 1, characterized in that, the surface level of the molten electrolyte is so maintained, that at least the free surface of the anode is completely immersed in the melt.

Claim 10

Dependent Claim 28 words

Method in accordance with claim 8, wherein the top surface of the electrolyte melt lies in the region of the upper edge of the frame of the electrode.

Claim 11

Dependent Claim 13 words

Method in accordance with claim 1, wherein the electrolyte has a cryolite basis.

Claim 12

Dependent Claim 13 words

Method in accordance with claim 1, wherein the electrolyte has an oxide basis.

Claim 13

Dependent Claim 131 words

In a multicell furnace for production of metals by electrolysis of metal compounds dissolved in a molten electrolyte, a first anode and a first cathode disposed spaced apart in said furnace; and at least one inconsumable bipolar electrode disposed substantially parallel to and between said first anode and first cathode dividing said furnace into separate cells, including a second anode the surface of which is composed of electron conductive ceramic oxide and a second cathode the surface of which is composed of another electron conductive material, joined together in such a way that, under conditions found in the operating cell, they form a mechanical and an electrical unit; said first and second anode being composed of the same material and said first and second cathode being composed of the same material.

Claim 14

Dependent Claim 131 words

In a multicell furnace for production of metals by electrolysis of metal compounds dissolved in a molten electrolyte, a first anode and a first cathode disposed spaced apart in said furnace; and at least one inconsumable bipolar electrode disposed substantially parallel to and between said first anode and first cathode dividing said furnace into separate cells, including a second anode the surface of which is composed of electron conductive ceramic oxide and a second cathode the surface of which is composed of another electron conductive material, joined together in such a way that, under conditions found in the operating cell, they form a mechanical and an electrical unit; said first and second anode being composed of the same material and said first and second cathode being composed of the same material.

Claim 15

Dependent Claim 23 words

Multi-cell furnace, in accordance claim 12, wherein an electrically conductive intermediate layer is arranged between anode and cathode material of the bi-polar electrode.

Claim 16

Dependent Claim 26 words

Multi-cell furnace, in accordance with claim 13, wherein the intermediate layer consists of a metal or a carbide, nitride, boride, silicide or a mixture of these.

Claim 17

Dependent Claim 17 words

Multi-cell furnace, in accordance with claim 14, wherein the metal is silver, nickel, copper, cobalt or molybdenum.

Claim 18

Dependent Claim 26 words

Multi-cell furnace, in accordance with claim 12, wherein said ceramic oxide material is tin oxide, iron oxide, chromium oxide, cobalt oxide, nickel oxide or zinc oxide.

Claim 19

Dependent Claim 20 words

Multi-cell furnace in accordance with claim 16, wherein said ceramic oxide is doped with at least one other metal oxide.

Claim 20

Dependent Claim 30 words

Multi-cell furnace in accordance with claim 17, wherein said ceramic oxide consists of SnO 2 and at least one other metal oxide in a concentration of 0.01 - 20 %.

Claim 21

Dependent Claim 22 words

Multi-cell furnace in accordance with claim 18, wherein the other metal oxide is present in a concentration of 0.05 - 2 %.

Claim 22

Dependent Claim 40 words

Multi-cell furnace in accordance with claim 17, wherein the metallic components of the additional oxide are selected from the group consisting of Fe, Sb, Cu, Mn, Nb, Zn, Cr, Co, W, Cd, Zr, Ta, In, Ni, Ca, Ba and Bi.

Claim 23

Dependent Claim 29 words

Multi-cell furnace, in accordance with claim 20, wherein said ceramic oxide is doped with 0.5 - 2 % CuO and 0.5 - 2 % Sb 2 O 3 .

Claim 24

Dependent Claim 29 words

Multi-cell furnace in accordance with claim 12, wherein the cathode of the bipolar electrode is made of carbon or borides, carbides, nitrides or silicides which are good electrical conductors.

Claim 25

Dependent Claim 16 words

Multi-cell furnace in accordance with claim 22, wherein the cathode is made of carbon as graphite.

Claim 26

Dependent Claim 55 words

Multi-cell furnace in accordance with claim 22, wherein the cathode is made of a material selected from the group consisting of borides, carbides, nitrides or silicides of the elements C and Si of the IV main group, the metals of the IV - VI subgroups of the periodic system of elements or mixtures of these.

Claim 27

Dependent Claim 22 words

Multi-cell furnace in accordance with claim 24, wherein the cathode is made of titanium carbide, titanium boride, zirconium boride or silicon carbide.

Claim 28

Dependent Claim 27 words

Multi-cell furnace in accordance with claim 16, wherein the anode or cathode or both are made as an adherent coating on a substrate using a known method.

Claim 29

Dependent Claim 15 words

Multi-cell furnace in accordance with claim 26, wherein the substrate serves as an intermediate layer.

Claim 30

Dependent Claim 37 words

Multi-cell furnace in accordance with claim 12, wherein the individual parts of the bi-polar electrode are held together by a holding means which is a poor electrical conductor and which is stable at the temperature of operation.

Claim 31

Dependent Claim 22 words

Multi-cell furnace in accordance with claim 28, wherein said holding means consists of boron nitride, silicon nitride, aluminum oxide or magnesium oxide.

Claim 32

Dependent Claim 14 words

Multi-cell furnace in accordance with claim 28, wherein said holding means is a frame.

Claim 33

Dependent Claim 33 words

Multi-cell furnace in accordance with claim 12, wherein the individual parts of the electrode are operable to be held in place by solidified electrolytic material and insulated in recesses in the furnace lining.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1979-01-05	1979-07-07	1980-01-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1983-01-05	1983-07-07	1984-01-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1987-01-05	1987-07-07	1988-01-06	$7700.00	Window Closed / Lapsed

Process for the electrolysis of a molten charge using inconsumable bi-polar electrodes

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