EP1483431B1 - Minimising carbon transfer in an electrolytic cell - Google Patents
Minimising carbon transfer in an electrolytic cell Download PDFInfo
- Publication number
- EP1483431B1 EP1483431B1 EP03743766A EP03743766A EP1483431B1 EP 1483431 B1 EP1483431 B1 EP 1483431B1 EP 03743766 A EP03743766 A EP 03743766A EP 03743766 A EP03743766 A EP 03743766A EP 1483431 B1 EP1483431 B1 EP 1483431B1
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- European Patent Office
- Prior art keywords
- cell
- cathode
- potential
- carbon
- anode
- Prior art date
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- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 35
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 29
- 238000012546 transfer Methods 0.000 title description 9
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 40
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 15
- 150000004706 metal oxides Chemical class 0.000 claims abstract description 15
- 239000012528 membrane Substances 0.000 claims abstract description 12
- 239000007787 solid Substances 0.000 claims abstract description 11
- -1 titania Chemical class 0.000 claims abstract description 10
- 238000013508 migration Methods 0.000 claims abstract description 8
- 230000005012 migration Effects 0.000 claims abstract description 8
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 7
- 239000001301 oxygen Substances 0.000 claims abstract description 7
- 239000003792 electrolyte Substances 0.000 claims description 28
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims description 18
- 229910001628 calcium chloride Inorganic materials 0.000 claims description 18
- 239000001110 calcium chloride Substances 0.000 claims description 18
- 238000000354 decomposition reaction Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 12
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 10
- 229910002804 graphite Inorganic materials 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 6
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 claims description 5
- 239000000470 constituent Substances 0.000 claims description 4
- 239000007784 solid electrolyte Substances 0.000 claims description 4
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 3
- 150000001768 cations Chemical class 0.000 claims description 2
- 239000004020 conductor Substances 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 9
- 238000006722 reduction reaction Methods 0.000 description 9
- 239000010936 titanium Substances 0.000 description 9
- 229910052719 titanium Inorganic materials 0.000 description 9
- 239000011575 calcium Substances 0.000 description 8
- 230000009467 reduction Effects 0.000 description 7
- 238000002474 experimental method Methods 0.000 description 5
- 230000004888 barrier function Effects 0.000 description 3
- 230000007248 cellular mechanism Effects 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- LLSDKQJKOVVTOJ-UHFFFAOYSA-L calcium chloride dihydrate Chemical compound O.O.[Cl-].[Cl-].[Ca+2] LLSDKQJKOVVTOJ-UHFFFAOYSA-L 0.000 description 2
- 229940052299 calcium chloride dihydrate Drugs 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 230000000007 visual effect Effects 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000004411 aluminium Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910001626 barium chloride Inorganic materials 0.000 description 1
- WDIHJSXYQDMJHN-UHFFFAOYSA-L barium chloride Chemical group [Cl-].[Cl-].[Ba+2] WDIHJSXYQDMJHN-UHFFFAOYSA-L 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 238000004070 electrodeposition Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 229910052735 hafnium Inorganic materials 0.000 description 1
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 description 1
- 229910000953 kanthal Inorganic materials 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 235000012054 meals Nutrition 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
- C25C7/005—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells of cells for the electrolysis of melts
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B34/00—Obtaining refractory metals
- C22B34/10—Obtaining titanium, zirconium or hafnium
- C22B34/12—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08
- C22B34/129—Obtaining titanium or titanium compounds from ores or scrap by metallurgical processing; preparation of titanium compounds from other titanium compounds see C01G23/00 - C01G23/08 obtaining metallic titanium from titanium compounds by dissociation, e.g. thermic dissociation of titanium tetraiodide, or by electrolysis or with the use of an electric arc
Definitions
- the present invention relates to reduction of metal oxides in a solid state in an electrolytic cell.
- the present invention was made during the course of an on-going research project on solid state reduction of titania (TiO 2 ) carried out by the applicant.
- the CaCl 2 -based electrolyte was a commercially available source of CaCl 2 , namely calcium chloride dihydrate, that partially decomposed on heating and produced CaO.
- the applicant operated the electrolytic cell at a potential above the decomposition potential of CaO and below the decomposition potential of CaCl 2 .
- the experimental work was carried out using a CaCl 2 -based electrolyte at a cell potential below the decomposition potential of CaCl 2 .
- the applicant believes that the initial deposition of Ca metal on the cathode was due to the presence of Ca ++ cations and O -- anions derived from CaO in the electrolyte.
- the decomposition potential of CaO is less than the decomposition potential of CaCl 2 .
- the-cell operation is dependent, at least during the early stages of cell operation, on decomposition of CaO, with Ca ++ cations migrating to the cathode and depositing as Ca metal and O -- anions migrating to the anode and forming CO and/or CO 2 (in a situation in which the anode is a graphite anode).
- the applicant also believes that at later stages of the cell operation part of the Ca metal that deposited on the cathode was deposited directly on partially deoxidised titanium and thereafter participated in chemical reduction of titanium.
- Carbon in the titanium is an undesirable contaminant.
- carbon transfer was partially responsible for low energy efficiency of the cell. Both problems are significant barriers to commercialisation of electrolytic reduction technology.
- the applicant carried out experimental work to identify the mechanism for carbon transfer and to determine how to minimise carbon transfer and/or to minimise the adverse effects of carbon transfer.
- the present invention provides an electrolytic cell for reducing a metal oxide in a solid state, which electrolytic cell includes an anode formed from carbon, a cathode formed at least in part from the metal oxide, and a membrane that is permeable to oxygen anions and is impermeable to carbon in ionic and non-ionic forms positioned between the cathode and the anode to thereby prevent migration of carbon to the cathode.
- the anode is formed from graphite.
- the membrane may be formed from any suitable material.
- the membrane is formed from a solid electrolyte.
- One suitable solid electrolyte tested by the applicant is yttria stabilised zirconia.
- the cathode also includes an electrical conductor.
- the present invention also provides a method of reducing a metal oxide in a solid state using the above-described electrolytic cell.
- the method includes a step of operating the cell at a potential that is above a decomposition potential of at least one of the constituents of the electrolyte so that there are cations of a metal other than that of the metal oxide in the electrolyte.
- the metal oxide is a titanium oxide, such as titania
- the electrolyte be a CaCl 2 -based electrolyte that includes CaO as one of constituents.
- the cell potential be above the decomposition potential for CaO.
- the cell potential be below the decomposition potential for CaCl 2 .
- the cell potential be less than or equal to 3.0 V.
- the cell potential be below 2.5 V.
- the cell potential be below 2.0 V.
- the cell potential be above 1.5 V.
- the CaCl 2 -based electrolyte may be a commercially available source of CaCl 2 , such as calcium chloride dihydrate, that partially decomposes on heating and produces CaO or otherwise includes CaO.
- the CaCl 2 -based electrolyte may include CaCl 2 and CaO that are added separately or pre-mixed to form the electrolyte.
- the cell included a high density graphite crucible that formed the anode of the cell, a pool of molten CaCl 2 electrolyte in the crucible, and a cathode that included solid titania.
- the solid titania was in the form of titania pellets connected to a lower end of a Kanthal or stainless steel electrically conductive wire.
- the ionic barrier was in the form of a yttria stabilised zirconia membrane positioned between the anode and the cathode, thereby dividing the cell into an outer anode chamber and an inner cathode chamber.
- Figure 1 is a schematic of the cell set-up for the experiment.
- the cell included a graphite crucible 3 that formed the anode, a pool 19 of molten CaCl 2 electrolyte in the crucible, titania pellets 5 and an electrically conductive wire 7 that formed the cathode immersed in the electrolyte, and a yttria stabilised zirconia membrane 9 immersed in the electrolyte between the anode and the cathode.
- the cell was located in a resistance furnace 11 heated to a temperature to maintain the electrolyte in a molten state.
- the experimental set-up also included gas monitoring, cleaning, and analysis equipment.
- the cell was operated at an applied potential of 3V for a period of 35 hours, during which time there was continuous monitoring of the off-gas from the furnace. At the conclusion of the experiment, the cell was cooled and the solidified electrolyte, the membrane, the anode and the cathode were analysed.
- FIG. 2 is a summary of the results of the experiment.
- Figure 2 shows measured voltage, current, CO and CO 2 composition of the off-gas for the experiment.
- the invention is not so limited and extends to electrolytic reduction of other titanium oxides and to oxides of other metals and alloys.
- Examples of other potentially important meals are aluminium, silicon, germanium, hafnium, magnesium, and molybdenum.
- suitable electrolytes will be salts and oxides that are soluble in salts.
- a potentially suitable electrolyte is BaCl 2 .
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Electrochemistry (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Manufacturing & Machinery (AREA)
- Electrolytic Production Of Metals (AREA)
- Electrodes For Compound Or Non-Metal Manufacture (AREA)
- Inert Electrodes (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Abstract
Description
- The present invention relates to reduction of metal oxides in a solid state in an electrolytic cell.
- The present invention was made during the course of an on-going research project on solid state reduction of titania (TiO2) carried out by the applicant.
- During the course of the research project the applicant carried out experimental work on the reduction of titania using an electrolytic cell that included a graphite crucible that formed an anode of the cell, a pool of molten CaCl2-based electrolyte in the crucible, and a range of cathodes that included solid titania.
- The CaCl2-based electrolyte was a commercially available source of CaCl2, namely calcium chloride dihydrate, that partially decomposed on heating and produced CaO.
- The applicant operated the electrolytic cell at a potential above the decomposition potential of CaO and below the decomposition potential of CaCl2.
- The applicant found that the cell could electrochemically reduce titania to titanium with very low concentrations of oxygen.
- The applicant does not have a clear understanding of the electrolytic cell mechanism at this stage. Nevertheless, whilst not wishing to be bound by the comments in this and the following paragraphs, the applicant offers the following comments by way of an outline of a possible cell mechanism.
- The experimental work carried out by the applicant produced evidence of Ca metal dissolved in the electrolyte. The applicant believes that, at least during the early stages of operation of the cell, the Ca metal was the result of electrodeposition of Ca++ cations as Ca metal on electrically conductive sections of the cathode.
- The experimental work was carried out using a CaCl2-based electrolyte at a cell potential below the decomposition potential of CaCl2. The applicant believes that the initial deposition of Ca metal on the cathode was due to the presence of Ca++ cations and O-- anions derived from CaO in the electrolyte. The decomposition potential of CaO is less than the decomposition potential of CaCl2. In this cell mechanism the-cell operation is dependent, at least during the early stages of cell operation, on decomposition of CaO, with Ca++ cations migrating to the cathode and depositing as Ca metal and O-- anions migrating to the anode and forming CO and/or CO2 (in a situation in which the anode is a graphite anode).
- The applicant believes that the Ca metal that deposited on electrically conductive sections of the cathode was deposited predominantly as a separate phase in the early stages of cell operation and thereafter dissolved in the electrolyte and migrated to the vicinity of the titania in the cathode and participated in chemical reduction of titania.
- The applicant also believes that at later stages of the cell operation part of the Ca metal that deposited on the cathode was deposited directly on partially deoxidised titanium and thereafter participated in chemical reduction of titanium.
- The applicant also believes that the O-- anions, once extracted from the titania, migrated to the anode and reacted with anode carbon and produced CO and/or CO2 (and in some instances CaO) and released electrons that facilitated electrolytic deposition of Ca metal on the cathode.
- However, notwithstanding that the cell could electrochemically reduce titania to titanium with very low concentrations of oxygen, the applicant also found that there were relatively significant amounts of carbon transferred from the anode to the electrolyte and to the titanium produced at the cathode under a wide range of cell operating conditions.
- Carbon in the titanium is an undesirable contaminant. In addition, carbon transfer was partially responsible for low energy efficiency of the cell. Both problems are significant barriers to commercialisation of electrolytic reduction technology.
- The applicant carried out experimental work to identify the mechanism for carbon transfer and to determine how to minimise carbon transfer and/or to minimise the adverse effects of carbon transfer.
- The experimental work indicated that the mechanism of carbon transfer is electrochemical rather than erosion and that one way of minimising carbon transfer and therefore contamination of titanium produced at the cathode by electrochemical reduction of titania at the cathode is to position a membrane that is permeable to oxygen anions and is impermeable to carbon in ionic and non-ionic forms between the cathode and the anode and thereby prevent migration of carbon to the cathode.
- Accordingly, the present invention provides an electrolytic cell for reducing a metal oxide in a solid state, which electrolytic cell includes an anode formed from carbon, a cathode formed at least in part from the metal oxide, and a membrane that is permeable to oxygen anions and is impermeable to carbon in ionic and non-ionic forms positioned between the cathode and the anode to thereby prevent migration of carbon to the cathode.
- Preferably, the anode is formed from graphite.
- The membrane may be formed from any suitable material.
- Preferably, the membrane is formed from a solid electrolyte.
- One suitable solid electrolyte tested by the applicant is yttria stabilised zirconia.
- Preferably, the cathode also includes an electrical conductor.
- The present invention also provides a method of reducing a metal oxide in a solid state using the above-described electrolytic cell.
- Preferably, the method includes a step of operating the cell at a potential that is above a decomposition potential of at least one of the constituents of the electrolyte so that there are cations of a metal other than that of the metal oxide in the electrolyte.
- In a situation in which the metal oxide is a titanium oxide, such as titania, it is preferred that the electrolyte be a CaCl2-based electrolyte that includes CaO as one of constituents.
- In such a situation it is preferred that the cell potential be above the decomposition potential for CaO.
- It is also preferred that the cell potential be below the decomposition potential for CaCl2.
- It is preferred that the cell potential be less than or equal to 3.0 V.
- It is preferred particularly that the cell potential be below 2.5 V.
- It is preferred more particularly that the cell potential be below 2.0 V.
- It is preferred that the cell potential be above 1.5 V.
- The CaCl2-based electrolyte may be a commercially available source of CaCl2, such as calcium chloride dihydrate, that partially decomposes on heating and produces CaO or otherwise includes CaO.
- Alternatively, or in addition, the CaCl2-based electrolyte may include CaCl2 and CaO that are added separately or pre-mixed to form the electrolyte.
- The present invention is described further with reference to the following Example that relates to experimental work on the above-described electrolytic cell.
- As indicated above, the cell included a high density graphite crucible that formed the anode of the cell, a pool of molten CaCl2 electrolyte in the crucible, and a cathode that included solid titania. In the initial experimental set-up the solid titania was in the form of titania pellets connected to a lower end of a Kanthal or stainless steel electrically conductive wire.
- As indicated above, experimental work on the cell identified carbon transfer as a significant issue in terms of contamination of cathode titanium and causing low energy efficiency of the cell. In addition, as indicated above, the experimental work established that carbon transfer was caused by an electrochemical reaction at the anode.
- Thereafter the applicant carried out experimental work to investigate whether it was possible to prevent migration of carbon from the anode to the cathode.
- One experiment investigated the impact of a solid ionic barrier on carbon migration.
- The ionic barrier was in the form of a yttria stabilised zirconia membrane positioned between the anode and the cathode, thereby dividing the cell into an outer anode chamber and an inner cathode chamber.
- Figure 1 is a schematic of the cell set-up for the experiment. With reference to the Figure, the cell included a
graphite crucible 3 that formed the anode, apool 19 of molten CaCl2 electrolyte in the crucible,titania pellets 5 and an electrically conductive wire 7 that formed the cathode immersed in the electrolyte, and a yttria stabilisedzirconia membrane 9 immersed in the electrolyte between the anode and the cathode. The cell was located in aresistance furnace 11 heated to a temperature to maintain the electrolyte in a molten state. The experimental set-up also included gas monitoring, cleaning, and analysis equipment. The cell was operated at an applied potential of 3V for a period of 35 hours, during which time there was continuous monitoring of the off-gas from the furnace. At the conclusion of the experiment, the cell was cooled and the solidified electrolyte, the membrane, the anode and the cathode were analysed. - Figure 2 is a summary of the results of the experiment.
- Figure 2 shows measured voltage, current, CO and CO2 composition of the off-gas for the experiment.
- Visual and analytical examination of the cathode and the cathode chamber indicated that there was no carbon on the cathode and in the cathode chamber.
- In addition, the visual and analytical examination of the cathode indicated that titania was reduced to titanium. It follows from this finding that the yttria stabilised zirconia membrane did not restrict migration of O-- anions from the cathode to the anode.
- Many modifications may be made to the present invention as described above without departing from the spirit and scope of the invention.
- By way of example, whilst the above description of the invention focuses on reduction of titania, the invention is not so limited and extends to electrolytic reduction of other titanium oxides and to oxides of other metals and alloys.
- Examples of other potentially important meals are aluminium, silicon, germanium, hafnium, magnesium, and molybdenum.
- Furthermore, whilst the above description focuses on CaCl2-based electrolyte, the invention is not so limited and extends to any other suitable electrolytes.
- Generally, suitable electrolytes will be salts and oxides that are soluble in salts. One example of a potentially suitable electrolyte is BaCl2.
Claims (14)
- An electrolytic cell for reducing a metal oxide in a solid state, which electrolytic cell includes an anode formed from carbon, a cathode formed at least in part from the metal oxide, and a membrane that is permeable to oxygen anions and is impermeable to carbon in ionic and non-ionic forms positioned between the cathode and the anode to thereby prevent migration of carbon to the cathode.
- The cell defined in claim 1 wherein the anode is formed from graphite.
- The cell defined in claim 1 or claim 2 wherein the membrane is formed from a solid electrolyte.
- The cell defined in claim 3 wherein the solid electrolyte is yttria stabilised zirconia.
- The cell defined in any one of the preceding claims wherein the cathode also includes an electrical conductor.
- A method of reducing a metal oxide in a solid state using an electrolytic cell that includes an anode formed from carbon, a cathode formed at least in part from the metal oxide, and a membrane that is permeable to oxygen anions and is impermeable to carbon in ionic and non-ionic forms positioned between the cathode and the anode to thereby prevent migration of carbon to the cathode, which method includes operating the cell at a potential that electrolytically reduces the metal oxide.
- The method defined in claim 6 includes operating the cell at a potential that is above a decomposition potential of at least one of the constituents of the electrolyte so that there are cations of a metal other than that of the metal oxide in the electrolyte.
- The method defined in claim 6 or claim 7 wherein the metal oxide is a titanium oxide, such as titania and the electrolyte is a CaCl2-based electrolyte that includes CaO as one of constituents.
- The method defined in claim 8 includes operating the cell at a potential that is above the decomposition potential for CaO.
- The method defined in claim 8 or claim 9 includes operating the cell at a potential that is below the decomposition potential for CaCl2.
- The method defined in any one of claims 6 to 10 wherein the cell potential is less than or equal to 3.0 V.
- The method defined in claim 11 wherein the cell potential is below 2.5 V.
- The method defined in claim 12 wherein the cell potential is below 2.0 V.
- The method defined in any one of claims 6 to 13 wherein the cell potential is above 1.5 V.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPS1170A AUPS117002A0 (en) | 2002-03-13 | 2002-03-13 | Minimising carbon transfer in an electrolytic cell |
AUPS117002 | 2002-03-13 | ||
PCT/AU2003/000305 WO2003076692A1 (en) | 2002-03-13 | 2003-03-13 | Minimising carbon transfer in an electrolytic cell |
Publications (3)
Publication Number | Publication Date |
---|---|
EP1483431A1 EP1483431A1 (en) | 2004-12-08 |
EP1483431A4 EP1483431A4 (en) | 2006-06-28 |
EP1483431B1 true EP1483431B1 (en) | 2007-07-18 |
Family
ID=3834768
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP03743766A Expired - Lifetime EP1483431B1 (en) | 2002-03-13 | 2003-03-13 | Minimising carbon transfer in an electrolytic cell |
Country Status (12)
Country | Link |
---|---|
US (1) | US20050092129A1 (en) |
EP (1) | EP1483431B1 (en) |
JP (1) | JP2005520046A (en) |
CN (1) | CN1650052A (en) |
AT (1) | ATE367461T1 (en) |
AU (1) | AUPS117002A0 (en) |
CA (1) | CA2479050A1 (en) |
DE (1) | DE60314999D1 (en) |
MX (1) | MXPA04008886A (en) |
RU (1) | RU2302482C2 (en) |
WO (1) | WO2003076692A1 (en) |
ZA (1) | ZA200407433B (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU2002951962A0 (en) * | 2002-10-09 | 2002-10-24 | Bhp Billiton Innovation Pty Ltd | Electrolytic reduction of metal oxides |
AU2002952083A0 (en) * | 2002-10-16 | 2002-10-31 | Bhp Billiton Innovation Pty Ltd | Minimising carbon transfer in an electrolytic cell |
EP1776491A4 (en) * | 2004-06-28 | 2007-10-10 | Bhp Billiton Innovation Pty | Production of titanium |
EA014138B1 (en) * | 2005-08-01 | 2010-10-29 | БиЭйчПи БИЛЛИТОН ИННОВЕЙШН ПТИ ЛТД. | Electrochemical reduction of metal oxides |
AU2007212481A1 (en) * | 2006-02-06 | 2007-08-16 | E. I. Du Pont De Nemours And Company | Method for electrolytic production of titanium and other metal powders |
Family Cites Families (11)
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JPH07113158B2 (en) * | 1984-04-14 | 1995-12-06 | 新日本製鐵株式会社 | Method of cleaning molten steel |
JPH03115592A (en) * | 1989-09-28 | 1991-05-16 | Osaka Titanium Co Ltd | Molten salt electrolytic cell |
US5670270A (en) * | 1995-11-16 | 1997-09-23 | The Dow Chemical Company | Electrode structure for solid state electrochemical devices |
GB9812169D0 (en) * | 1998-06-05 | 1998-08-05 | Univ Cambridge Tech | Purification method |
US6187168B1 (en) * | 1998-10-06 | 2001-02-13 | Aluminum Company Of America | Electrolysis in a cell having a solid oxide ion conductor |
DE60130322T2 (en) * | 2000-02-22 | 2008-06-12 | Metalysis Ltd., Wath-Upon-Dearne | METHOD OF PREPARING METAL FOAM BY ELECTROLYTIC REDUCTION OF POROUS OXIDIC PREPARATIONS |
GB2359564B (en) * | 2000-02-22 | 2004-09-29 | Secr Defence | Improvements in the electrolytic reduction of metal oxides |
US6540902B1 (en) * | 2001-09-05 | 2003-04-01 | The United States Of America As Represented By The United States Department Of Energy | Direct electrochemical reduction of metal-oxides |
JP4089944B2 (en) * | 2001-11-30 | 2008-05-28 | 財団法人電力中央研究所 | Electrolytic reduction apparatus and method |
CN1650051B (en) * | 2002-03-13 | 2011-02-23 | Bhp比利顿创新公司 | Reduction of metal oxides in an electrolytic cell |
JP4252531B2 (en) * | 2004-12-15 | 2009-04-08 | 株式会社大阪チタニウムテクノロジーズ | Metal manufacturing method |
-
2002
- 2002-03-13 AU AUPS1170A patent/AUPS117002A0/en not_active Abandoned
-
2003
- 2003-03-13 MX MXPA04008886A patent/MXPA04008886A/en not_active Application Discontinuation
- 2003-03-13 CN CNA038092743A patent/CN1650052A/en active Pending
- 2003-03-13 WO PCT/AU2003/000305 patent/WO2003076692A1/en active IP Right Grant
- 2003-03-13 JP JP2003574884A patent/JP2005520046A/en active Pending
- 2003-03-13 CA CA002479050A patent/CA2479050A1/en not_active Abandoned
- 2003-03-13 DE DE60314999T patent/DE60314999D1/en not_active Expired - Lifetime
- 2003-03-13 EP EP03743766A patent/EP1483431B1/en not_active Expired - Lifetime
- 2003-03-13 AT AT03743766T patent/ATE367461T1/en not_active IP Right Cessation
- 2003-03-13 RU RU2004130453/02A patent/RU2302482C2/en not_active IP Right Cessation
-
2004
- 2004-09-10 US US10/939,001 patent/US20050092129A1/en not_active Abandoned
- 2004-09-16 ZA ZA200407433A patent/ZA200407433B/en unknown
Also Published As
Publication number | Publication date |
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RU2302482C2 (en) | 2007-07-10 |
AUPS117002A0 (en) | 2002-04-18 |
CA2479050A1 (en) | 2003-09-18 |
EP1483431A1 (en) | 2004-12-08 |
US20050092129A1 (en) | 2005-05-05 |
ATE367461T1 (en) | 2007-08-15 |
DE60314999D1 (en) | 2007-08-30 |
RU2004130453A (en) | 2005-06-10 |
MXPA04008886A (en) | 2004-11-26 |
CN1650052A (en) | 2005-08-03 |
JP2005520046A (en) | 2005-07-07 |
EP1483431A4 (en) | 2006-06-28 |
ZA200407433B (en) | 2005-10-10 |
WO2003076692A1 (en) | 2003-09-18 |
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