# US 4,399,008 A · Composition for inert electrodes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,008 A - Document ID: US4399008A - Status: Granted - Kind: A - Application number: 06/205,652 - Filed: 1980-11-10 - Granted: 1983-08-16 - Earliest claimed: 1980-11-10 - Assignees: Aluminum Company of America - Inventors: Siba P. Ray - Web page: https://patentgrep.com/patent/US4399008A ## CPC - C25C 7/02: Electrodes (consumable anodes for the refining the metals C25C1/00 - C25C5/00); Connections thereof - C25C 3/12: Anodes - C25C: PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR ## Abstract Disclosed is a composition suitable for fabricating into an inert electrode for use in the electrolytic production of metal from a metal compound dissolved in a molten salt. The electrode comprises at least two metal oxides combined to provide a combination metal oxide consisting essentially of a composition defined by the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K where y is a number less than one and greater than 0 and M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5 and M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, z is a number selected from the group consisting of 2, 3 and 4 and K is a number in the range of 2 to 4.4, the electrode being highly conductive and being substantially inert with respect to the molten salt. ## Claims ### Claim 1 A composition for fabricating into an inert electrode for use in the electrolytic production of metal from a metal compound dissolved in a molten salt, the electrode comprising: two metal compounds combined to provide a combination metal compound having a first phase and a second phase, the first phase consisting essentially of a composition defined by the formula M(M'.sub.y M.sub.1-y).sub.z X.sub.K, and the second phase containing one of said metal compounds, in the formula, y is a number in the range of 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9 and M is a metal having a valence selected from the group consisting of 1, 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, z is a number selected from the group consisting of 2, 3 and 4, X is at least one material selected from the group consisting of O, F, N, S, C and B, and K is a number in the range of 2 to 4.4, the electrode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 2 (depends on 1) The composition in accordance with claim 1 wherein K is in the range of 3.9 to 4.4. ### Claim 3 (depends on 1) The composition in accordance with claim 1 wherein X is oxygen. ### Claim 4 (depends on 1) The composition in accordance with claim 1 wherein the metal compounds aremetal oxides. ### Claim 5 (depends on 1) The composition in accordance with claim 1 wherein M is a metal selected from the group consisting of Ni, Sn, Zr, Zn, Co, Mn, Ti, Nb, Ta, Fe, Hf and Li. ### Claim 6 (depends on 1) The composition in accordance with claim 1 wherein M' is a metal selected from the group consisting of Fe, V, Cr, Mn, Al, Nb, Ta, Sn, Zn, Co, Ni, Hf and Y. ### Claim 7 (depends on 1) The composition in accordance with claim 1 wherein M is a metal selected from the group consisting of Ni, Sn, Mn, Ti, Zr and Zn. ### Claim 8 (depends on 1) The composition in accordance with claim 1 wherein M' is a metal selected from the group consisting of Fe, Cr and V. ### Claim 9 (depends on 1) The composition in accordance with claim 1 wherein M is formulated from NiO. ### Claim 10 (depends on 1) The composition in accordance with claim 1 wherein M' is formulated from Fe.sub.2 O.sub.3. ### Claim 11 (depends on 1) The composition in accordance with claim 1 wherein the metal compounds are NiO and Fe.sub.2 O.sub.3. ### Claim 12 (depends on 1) The composition in accordance with claim 1 wherein the metal compounds are SnO.sub.2 and Cr.sub.2 O.sub.3. ### Claim 13 (depends on 1) The composition in accordance with claim 1 wherein the metal compounds are Fe.sub.2 O.sub.3 and Co.sub.3 O.sub.4. ### Claim 14 (depends on 1) The composition in accordance with claim 1 wherein the electrode is an anode. ### Claim 15 A metal oxide composition for use as an inert electrode in the electrolytic production of metal from a metal compound in a molten salt, the electrode comprising: two metal oxides combined to provide a metal oxide composition having a first and second phase, the first phase having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K, the second phase having one of said metal oxides, in the formula y is a number from 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, O is oxygen, M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 3.9 to 4.4, an electrode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 16 A metal oxide composition for use as an inert electrode in the electrolytic production of metal from at least one of the metal oxide and metal salt dissolved in a molten salt, the electrode having a composition comprising: two metal oxides which are combined to provide an electrode metal oxide composition having a first phase and a second phase, the first phase consisting essentially of a material having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K and the second phase containing one of said metal oxides in the formula, y is a number in the range of 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, O is oxygen, M is a metal selected from the group consisting of Ni, Sn, Zr, Zn, Co, Mn, Ti, Nb and Ta, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4, an electrode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 17 In an improved process for the electrolytic production of metal from a metal compound dissolved in a molten salt using an inert electrode, the improvement comprising: electrolyzing the metal compound using an inert electrode fabricated from two metal compounds combined to provide a combination metal compound consisting essentially of a composition defined by the formula M(M'.sub.y M.sub.1-y).sub.z X.sub.K where y is a number in the range of 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 1, 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, z is a number selected from the group consisting of 2, 3 and 4, X is at least one material selected from the group consisting of O, F, N, S, C and B, and K is a number in the range of 2 to 4.4, an electrode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 18 (depends on 17) The composition in accordance with claim 17 wherein K is in the range of 3.9 to 4.4. ### Claim 19 (depends on 17) The composition in accordance with claim 17 wherein the composition is comprised of a first phase and a second phase, the first phase having the formula of claim 17. ### Claim 20 (depends on 19) The composition in accordance with claim 19 wherein the second phase has the formula MO. ### Claim 21 (depends on 19) The composition in accordance with claim 19 wherein the second hase is comprised of at least one of the metal oxides used to provide the electrode composition. ### Claim 22 (depends on 17) The composition in accordance with claim 17 wherein X is oxygen. ### Claim 23 (depends on 17) The composition in accordance with claim 17 wherein the metal compounds are metal oxides. ### Claim 24 (depends on 17) The composition in accordance with claim 17 wherein the metal compounds are metal oxides and the oxides are combined to provide a combination metal oxide having a first phase and a second phase, the first phase consisting essentially of a composition defined by the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K and the second phase containing at least one of said metal oxides, in the formula, y is a number in the range of 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 1, 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4.4. ### Claim 25 (depends on 17) The composition in accordance with claim 17 wherein M is a metal selected from the group consisting of Ni, Sn, Zr, Zn, Co, Mn, Ti, Nb, Ta, Fe, Hf and Li. ### Claim 26 (depends on 17) The composition in accordance with claim 17 wherein M' is a metal selected from the group consisting of Fe, V, Cr, Mn, Al, Nb, Ta, Sn, Zn, Co, Ni, Hf and Y. ### Claim 27 (depends on 17) The composition in accordance with claim 17 wherein M is a metal selected from the group consisting of Ni, Sn, Mn, Ti, Zr and Zn. ### Claim 28 (depends on 17) The composition in accordance with claim 17 wherein M' is a metal selected from the group consisting of Fe, Cr and V. ### Claim 29 (depends on 17) The composition in accordance with claim 17 wherein M is formulated from NiO. ### Claim 30 (depends on 17) The composition in accordance with claim 17 wherein M' is formulated from Fe.sub.2 O.sub.3. ### Claim 31 (depends on 17) The composition in accordance with claim 17 wherein the metal compounds are NiO and Fe.sub.2 O.sub.3. ### Claim 32 (depends on 17) The composition in accordance with claim 17 wherein the metal compounds are SnO.sub.2 and Cr.sub.2 O.sub.3. ### Claim 33 (depends on 17) The composition in accordance with claim 17 wherein the metal compounds are Fe.sub.2 O.sub.3 and Co.sub.3 O.sub.4. ### Claim 34 (depends on 17) The composition in accordance with claim 17 wherein the metal produced from the metal compound electrolysis is aluminum. ### Claim 35 (depends on 17) The composition in accordance with claim 17 wherein the metal compound dissolved in the molten salt is alumina. ### Claim 36 (depends on 17) The composition in accordance with claim 17 wherein the electrode is an anode. ### Claim 37 In an improved process for the electrolytic production of metal from a metal compound dissolved in a molten salt using an inert electrode, the improvement comprising: electrolyzing the metal compound using an inert electrode fabricated from two metal oxides combined to provide an anode metal oxide composition wherein one of the two metal oxides is selected from the group consisting of NiO, SnO.sub.2, ZrO.sub.2, ZnO, CoO, MnO, TiO.sub.2 and Ta.sub.2 O.sub.5, the composition containing a material having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K where y is a number in the range of about 0.1.ltoreq.y.ltoreq.0.4 and 0.6.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4.4, an anode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 38 In an improved process for the electrolytic production of metal from a metal compound dissolved in a molten salt using an inert electrode, the improvement comprising: electrolyzing the metal compound using an inert electrode fabricated from two metal oxides combined to provide an anode metal oxide composition wherein one of the two metal oxides is selected from the group consisting of Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, Mn.sub.2 O.sub.3, and Y.sub.2 O.sub.3, the composition containing a material having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K where y is number in the range of 0.1.ltoreq.y.ltoreq.0.4 and 0.6.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being two different metals, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4.4, an anode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 39 In an improved process for the electrolytic production of metal from a metal compound dissolved in a molten salt using an inert electrode, the improvement comprising: electrolyzing the metal compound using an inert electrode fabricated from two metal oxides combined to provide a metal oxide composition wherein one of the two metal oxides is selected from the group consisting of NiO, SnO.sub.2, ZrO.sub.2, ZnO, CoO, MnO and TiO.sub.2, the other metal oxide is selected from the group consisting of Fe.sub.2 O.sub.3, Cr.sub.2 O.sub.3, Mn.sub.2 O.sub.3, and Y.sub.2 O.sub.3, the composition containing a material having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K where y is a number in the range of 0.1.ltoreq.y.ltoreq.0.4 and 0.6.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being two different metals, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4.4, an anode formulated from the composition being highly conductive and being inert with respect to said molten salt. ### Claim 40 In an improved process for the electrolytic production of metal from a metal compound dissolved in a motion salt using an inert electrode, the improvement comprising: electrolyzing the metal compound using an inert electrode fabricated from two metal oxides combined to provide a metal oxide composition having a first and second phase, the first phase having the formula M(M'hd yM.sub.1-y).sub.z O.sub.K, the second phase containing one of said metal oxides, in the formula, y is a number from 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, M is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 3.9 to 4.4, an electrode formulated from said composition being highly conductive and being inert with respect to said molten salt. ### Claim 41 In an improved process for the electrolytic production of metal from a metal compound dissolved in a molten salt using an inert electrode, the improvement comprising: two metal oxides which are combined to provide an electrode metal oxide composition having a first phase and a second phase, the first phase consisting essentially of a material having the formula M(M'.sub.y M.sub.1-y).sub.z O.sub.K, the second phase containing one of said metal oxides, in the formula, y is a number in the range of 0.1.ltoreq.y.ltoreq.0.45 and 0.55.ltoreq.y.ltoreq.0.9, M is a metal selected from the group consisting of Ni, Sn, Zr, Zn, Co, Mn, Ti, Nb and Ta, M' is a metal having a valence selected from the group consisting of 2, 3, 4 and 5, M and M' being different metals, O is oxygen, z is a number selected from the group consisting of 2, 3 and 4, and K is a number in the range of 2 to 4, an electrode formulated from said composition being highly conductive and being inert with respect to said molten salt.