JP2007247002A - Method for electrochemical reduction of titanium oxide - Google Patents
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- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 90
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000010936 titanium Substances 0.000 claims abstract description 84
- 150000003839 salts Chemical class 0.000 claims abstract description 71
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 69
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 48
- 229910052751 metal Inorganic materials 0.000 claims abstract description 30
- 239000002184 metal Substances 0.000 claims abstract description 30
- 239000004408 titanium dioxide Substances 0.000 claims abstract description 29
- 238000004070 electrodeposition Methods 0.000 claims abstract description 25
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 claims abstract description 15
- 229910001628 calcium chloride Inorganic materials 0.000 claims abstract description 15
- 239000001110 calcium chloride Substances 0.000 claims abstract description 15
- 229910001514 alkali metal chloride Inorganic materials 0.000 claims abstract description 10
- 238000000151 deposition Methods 0.000 claims abstract description 10
- 230000008021 deposition Effects 0.000 claims abstract description 10
- 239000002994 raw material Substances 0.000 claims abstract description 8
- 238000006722 reduction reaction Methods 0.000 claims description 50
- 238000006243 chemical reaction Methods 0.000 claims description 24
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- 239000003638 chemical reducing agent Substances 0.000 claims description 7
- 239000000460 chlorine Substances 0.000 claims description 7
- 229910052801 chlorine Inorganic materials 0.000 claims description 7
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 6
- 150000002500 ions Chemical class 0.000 claims description 6
- AHKZTVQIVOEVFO-UHFFFAOYSA-N oxide(2-) Chemical compound [O-2] AHKZTVQIVOEVFO-UHFFFAOYSA-N 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 4
- 238000004090 dissolution Methods 0.000 claims description 3
- 239000010416 ion conductor Substances 0.000 claims description 3
- 239000010409 thin film Substances 0.000 claims description 3
- RPFLLVICGMTMIE-UHFFFAOYSA-L calcium;sodium;dichloride Chemical compound [Na+].[Cl-].[Cl-].[Ca+2] RPFLLVICGMTMIE-UHFFFAOYSA-L 0.000 claims 1
- 230000005611 electricity Effects 0.000 claims 1
- -1 titanium ions Chemical class 0.000 abstract description 21
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 16
- 239000011575 calcium Substances 0.000 description 14
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 13
- 229910052791 calcium Inorganic materials 0.000 description 13
- 239000011780 sodium chloride Substances 0.000 description 12
- 239000000047 product Substances 0.000 description 8
- LCKIEQZJEYYRIY-UHFFFAOYSA-N Titanium ion Chemical compound [Ti+4] LCKIEQZJEYYRIY-UHFFFAOYSA-N 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 238000005868 electrolysis reaction Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910052783 alkali metal Inorganic materials 0.000 description 3
- 150000001340 alkali metals Chemical class 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000005192 partition Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 2
- 238000010923 batch production Methods 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005265 energy consumption Methods 0.000 description 2
- 230000005496 eutectics Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- KWGKDLIKAYFUFQ-UHFFFAOYSA-M lithium chloride Chemical compound [Li+].[Cl-] KWGKDLIKAYFUFQ-UHFFFAOYSA-M 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 229910052750 molybdenum Inorganic materials 0.000 description 2
- 239000011733 molybdenum Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000002244 precipitate Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910001773 titanium mineral Inorganic materials 0.000 description 2
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 2
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- 229910001069 Ti alloy Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 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
- 230000033228 biological regulation Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 239000013626 chemical specie Substances 0.000 description 1
- 238000004737 colorimetric analysis Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000001493 electron microscopy Methods 0.000 description 1
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- YDZQQRWRVYGNER-UHFFFAOYSA-N iron;titanium;trihydrate Chemical compound O.O.O.[Ti].[Fe] YDZQQRWRVYGNER-UHFFFAOYSA-N 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical group [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 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
- 238000010587 phase diagram Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 229910001233 yttria-stabilized zirconia Inorganic materials 0.000 description 1
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- Electrolytic Production Of Metals (AREA)
Abstract
Description
本発明は、混合溶融塩浴中でチタン酸化物を電気化学的に還元して金属チタンを製造する方法に関する。 The present invention relates to a method for producing titanium metal by electrochemically reducing titanium oxide in a mixed molten salt bath.
チタンは、ルチル(ＴｉＯ2含有量：９５〜１００質量％の天然ルチル)，イルメナイト(ＴｉＯ2含有量：５２.７質量％のＦｅＴｉＯ3)等として自然界に豊富に存在する金属資源であり、一般的にはクロール法で製錬されている。
クロール法では、チタン鉱物を炭素及び塩素と反応させ、不純物を取り除いて四塩化チタン(ＴｉＣｌ4)を生成する。次いで、四塩化チタンを金属マグネシウムで金属チタンに還元する。副生成物：ＭｇＣｌ2は、真空蒸留等で反応系から分離した後、電解法で金属マグネシウムとして再利用される。
Titanium is a metal resource that is abundant in nature as rutile (TiO 2 content: natural rutile of 95-100% by mass), ilmenite (TiO 2 content: 52.7% by mass of FeTiO 3 ), etc. It is smelted by the crawl method.
In the crawl method, titanium minerals are reacted with carbon and chlorine to remove impurities and produce titanium tetrachloride (TiCl 4 ). Next, titanium tetrachloride is reduced to metallic titanium with metallic magnesium. By-product: MgCl 2 is separated from the reaction system by vacuum distillation or the like and then reused as magnesium metal in the electrolytic method.
クロール法ではエネルギー効率が低く、原料から製品を得るまでに複雑なプロセスを経ることが、製造された金属チタンのコストを上げる原因になっている。バッチプロセスで反応から冷却までの一サイクルに十日程度かかり生産性が悪く、バッチ内での品質にバラツキがあることも欠点である。そのため、クロール法に代わる新たなチタン製造法の開発が望まれている。
クロール法に代わる製造法として、溶融塩中で二酸化チタンを還元する方法が盛んに研究されている。溶融塩を用いた製造法は、主に金属カルシウム等の還元剤を用いた化学還元法(非特許文献１)，金属酸化物を電極として用い金属まで直接還元する電気化学的還元法(非特許文献２)に大別される。
As a production method replacing the crawl method, a method of reducing titanium dioxide in molten salt has been actively studied. The manufacturing method using molten salt is mainly a chemical reduction method using a reducing agent such as metallic calcium (Non-patent Document 1), or an electrochemical reduction method in which a metal oxide is used as an electrode to directly reduce the metal (non-patent). It is roughly divided into the literature 2).
化学還元法では、ＣａＣｌ2の電気分解で生成した金属カルシウムをＣａＣｌ2浴中でＴｉＯ2粉末に反応させ、陰極近傍の熱還元反応(ＴｉＯ2＋２Ｃａ→Ｔｉ＋２ＣａＯ)でチタンを製造している。副生成物ＣａＯはＣａＣｌ2に溶解し、酸素は陽極近傍の反応(２ＣａＯ＋Ｃ→２Ｃａ＋ＣＯ2)に従ってＣＯ，ＣＯ2等として系外に排出される。ＣＯ，ＣＯ2等の排出が遅延すると、陰極近傍のＣａと反応して溶融塩中に炭素が遊離し、遊離炭素がＴｉと反応して製品チタンに悪影響を及ぼす。 The chemical reduction method, the calcium metal generated by electrolysis of CaCl 2 is reacted to TiO 2 powder with CaCl 2 bath, manufactures titanium thermal reduction reaction near the cathode (TiO 2 + 2Ca → Ti + 2CaO). By-product CaO is dissolved in CaCl 2 , and oxygen is discharged out of the system as CO, CO 2, etc. according to the reaction near the anode (2CaO + C → 2Ca + CO 2 ). When the discharge of CO, CO 2, etc. is delayed, it reacts with Ca in the vicinity of the cathode and carbon is liberated in the molten salt, and the free carbon reacts with Ti and adversely affects the product titanium.
溶融塩に対する金属カルシウムの溶解度が低く、ＴｉＯ2の還元反応の速度に限界があること、溶融塩に金属カルシウムが溶解すると溶融塩自体に電子伝導性が付与され、陰極と陽極間に短絡電流が流れエネルギー効率を低下させること等も問題である。因みに、還元剤に使用する金属マグネシウムや金属カルシウムを製造するためには、二酸化チタンを金属チタンに還元するよりも多量の化学エネルギーを必要とする。 The solubility of metallic calcium in the molten salt is low, the rate of reduction of TiO 2 is limited, and when metallic calcium dissolves in the molten salt, the molten salt itself is given electronic conductivity, and a short-circuit current is generated between the cathode and the anode. Decreasing flow energy efficiency is also a problem. Incidentally, in order to produce metallic magnesium and metallic calcium used as a reducing agent, a larger amount of chemical energy is required than when titanium dioxide is reduced to metallic titanium.
他方、電気化学的還元法(FFC法)は、溶融塩浴中で酸化チタンを金属チタンに直接還元しているので高効率を期待できる。FFC法は、ＴｉＯ2粉末の焼結成形体を陰極としてＣａＣｌ2浴に浸漬し、黒鉛陽極との間の電解反応で金属チタンまで直接還元している。
しかし、これまで提案されているFFC法では、低酸素濃度の金属チタンを得る上で金属カルシウムの共析を必要とする。金属カルシウムの共析は、化学還元法と同様にエネルギー効率を低下させる原因となる。また、金属チタンへの炭素混入を防止する有効な対策もたっていない。
On the other hand, the electrochemical reduction method (FFC method) can be expected to be highly efficient because titanium oxide is directly reduced to titanium metal in a molten salt bath. In the FFC method, a sintered compact of TiO 2 powder is immersed in a CaCl 2 bath as a cathode and directly reduced to metal titanium by an electrolytic reaction with a graphite anode.
However, the FFC methods that have been proposed so far require eutectoidation of metallic calcium in order to obtain metallic titanium having a low oxygen concentration. The eutectoid of metallic calcium causes a decrease in energy efficiency as in the chemical reduction method. In addition, there is no effective measure for preventing carbon contamination of titanium metal.
そこで、金属カルシウムの共析を必要とすることなく、ルチル等のチタン鉱物を金属チタンまで還元できるFFC法を種々調査・検討した。調査・検討の過程で、ＣａＣｌ2とＮａＣｌの混合溶融塩を反応場とすると、チタン酸化物は低次の酸化物になるほど、具体的にはＴｉＯ2よりもＴｉＯが高い溶解度を示し、しかも溶融塩にイオン状態で溶融しているチタンは金属チタンとして電解析出することを見出した。 Therefore, we investigated and studied various FFC methods that can reduce titanium minerals such as rutile to metallic titanium without requiring eutectoidation of metallic calcium. If a mixed molten salt of CaCl 2 and NaCl is used as the reaction field during the investigation and examination process, the lower the oxide of titanium oxide, the higher the solubility of TiO than TiO 2, and more It has been found that titanium melted in an ionic state in the salt is electrolytically deposited as metallic titanium.
本発明は、かかる溶融塩中におけるチタン酸化物，チタンイオンの挙動に関する知見をベースとし、チタン酸化物がイオンとなって溶け込みやすく且つチタンイオンが金属チタンとして電解析出しやすい混合溶融塩を反応場に使用し、二酸化チタンの低次酸化物への電気化学的還元及びチタンイオンを金属チタンとして析出させる電解還元とを組み合わせることにより、連続運転の可能性も見込め、エネルギー消費効率よく金属チタンを製造することを目的とする。 The present invention is based on the knowledge about the behavior of titanium oxide and titanium ions in the molten salt, and the mixed molten salt is easily dissolved as titanium oxide as ions and the titanium ions are easily electrolytically deposited as metallic titanium in the reaction field. In combination with electrochemical reduction of titanium dioxide to lower oxides and electrolytic reduction of titanium ions as metal titanium, the possibility of continuous operation is expected, and metal titanium is produced with high energy consumption efficiency. The purpose is to do.
本発明の電気化学的還元方法では、塩化カルシウム，アルカリ金属塩化物の混合溶融塩浴を使用し、原料の二酸化チタン粉末から作製された還元用陰極を混合溶融塩浴に浸漬する。混合溶融塩浴には、還元用陰極の他に電析用陰極，陽極が浸漬される。また、陰極を必要電位に維持するため、混合溶融塩浴に浸漬した参照電極で陰極の電位を測定し、測定値に基づいて陰極電位を制御することが好ましい。 In the electrochemical reduction method of the present invention, a mixed molten salt bath of calcium chloride and alkali metal chloride is used, and a reducing cathode made from a raw material titanium dioxide powder is immersed in the mixed molten salt bath. In the mixed molten salt bath, the cathode and anode for electrodeposition are immersed in addition to the cathode for reduction. In order to maintain the cathode at a required potential, it is preferable to measure the cathode potential with a reference electrode immersed in a mixed molten salt bath and control the cathode potential based on the measured value.
還元用陰極は、二酸化チタンを低次のチタン酸化物に還元するため、式(１)の還元反応に必要な電位に維持される。還元反応で生成した低次チタン酸化物は式(２)の溶解反応に従ってイオンとして混合溶融塩に溶け込み、混合溶融塩浴に拡散する。式(３)の電解析出反応に必要な電位に維持されている電析用陰極にチタンイオンが達すると、チタンイオンが金属チタンとして電析用陰極上に析出する。
ＴｉＯ2＋2xｅ-→ＴｉＯ2-x＋xＯ2- ・・・・(１)
ＴｉＯ＝Ｔｉ2+＋Ｏ2- ・・・・(２)
Ｔｉ2+＋2ｅ-＝Ｔｉ ・・・・(３)
The reduction cathode is maintained at the potential required for the reduction reaction of formula (1) in order to reduce titanium dioxide to lower-order titanium oxide. The low-order titanium oxide produced by the reduction reaction dissolves in the mixed molten salt as ions according to the dissolution reaction of formula (2) and diffuses into the mixed molten salt bath. When titanium ions reach the electrodeposition electrode maintained at the potential required for the electrolytic deposition reaction of formula (3), the titanium ions are deposited on the electrodeposition electrode as titanium metal.
TiO 2 + 2xe − → TiO 2−x + xO 2− (1)
TiO = Ti2 + 2 + O2 -... (2)
Ti 2+ + 2e - = Ti ···· (3)
混合溶融塩は、塩化カルシウムとアルカリ金属塩化物との混合物であり、代表的にはＣａＣｌ2-ＮａＣｌの等モル混合塩が使用される。ＣａＣｌ2-ＮａＣｌ等モルの混合溶融塩を使用する場合、浴温を５５０〜６００℃の範囲に維持することが好ましい。浴温：５５０℃のＣａＣｌ2-ＮａＣｌ等モル混合溶融塩浴中では、式(１)の還元反応に必要な電位は塩素電極基準で-２.３〜-１.５Ｖの範囲に、式(３)の電解析出反応に必要な電位は同じく-３.５〜-２.３Ｖの範囲にある。
溶融塩に溶解するチタンイオンが陽極上で酸化することを防止するため、酸化物イオン伝導体薄膜等の隔膜で陽極を隔離することもできる。
The mixed molten salt is a mixture of calcium chloride and alkali metal chloride, and typically an equimolar mixed salt of CaCl 2 -NaCl is used. When using an equimolar mixed molten salt of CaCl 2 -NaCl, the bath temperature is preferably maintained in the range of 550 to 600 ° C. Bath temperature: In a CaCl 2 -NaCl equimolar mixed molten salt bath at 550 ° C., the potential required for the reduction reaction of the formula (1) falls within the range of −2.3 to −1.5 V on the basis of the chlorine electrode. The potential required for the electrolytic deposition reaction of 3) is also in the range of -3.5 to -2.3V.
In order to prevent titanium ions dissolved in the molten salt from being oxidized on the anode, the anode can be isolated by a diaphragm such as an oxide ion conductor thin film.
チタン酸化物には常温で安定な相が多数あり、ＴｉnＯ2n-1(ｎ=４〜９)で表されるマグネリ相，Ｔｉ2Ｏ3，ＴｉＯ，Ｔｉ3Ｏ2，α-Ｔｉ(酸素が固溶した金属チタン)等が挙げられる。溶融塩浴中での電解により何れの相が生成するかは電極電位によって決まり、一般的に電位の低下に応じより低次酸化状態の相が生成する。
本発明者等は、塩化カルシウムとアルカリ金属塩化物との混合溶融塩を用い、さまざまな電位で二酸化チタン(陰極)を電気化学的に還元することによって種々のチタン酸化物を得ることができることを実験的に確認した。しかし、単に電気化学的に還元したのでは、従来から報告されているように、化学的還元剤として作用し得る金属カルシウムの共析を伴わずに純度の高い金属チタンを得ることができない。
Titanium oxide has many stable phases at room temperature, and is represented by a magnetic phase represented by Ti n O 2n-1 (n = 4 to 9), Ti 2 O 3 , TiO, Ti 3 O 2 , α-Ti ( Metal titanium in which oxygen is dissolved, and the like. Which phase is generated by electrolysis in the molten salt bath is determined by the electrode potential, and generally a lower oxidation state phase is generated as the potential decreases.
The present inventors have found that various titanium oxides can be obtained by electrochemically reducing titanium dioxide (cathode) at various potentials using a mixed molten salt of calcium chloride and alkali metal chloride. Confirmed experimentally. However, simply reducing electrochemically cannot provide high-purity metallic titanium without the eutectoid of metallic calcium that can act as a chemical reducing agent, as previously reported.
ところで、塩化カルシウムとアルカリ金属塩化物との混合溶融塩は、塩化カルシウム単独の溶融塩に比べて低次のチタン酸化物に高い溶解能を示すことが報告されている(非特許文献３)。この混合溶融塩の特性を利用して、二酸化チタン(陰極)を溶解度の高い低次のチタン酸化物まで電気化学的に還元し、混合溶融塩に溶け込んだチタンイオンを別途配置した陰極上に還元析出させることに想到した。低次酸化物への電気化学的還元，チタンイオンから金属チタンの電解析出と二段階の電解反応を同時に行わせると、後述の実施例から明らかなように、金属カルシウムの共析を必要とせず純度の高い金属チタン又は低次チタン酸化物が得られる。
塩化カルシウムとアルカリ金属塩化物との混合溶融塩は、操作性の面でも有利である。塩化カルシウム単独の溶融塩では、塩化カルシウムの融点が７７０℃と高いため、十分な電気伝導率を得るために操作温度を９００℃程度に保持する必要がある。これに対し、塩化カルシウムとアルカリ金属塩化物との混合溶融塩では、操作温度の大幅な低下が可能になる。たとえば、ＣａＣｌ2-ＮａＣｌ等モル混合溶融塩は、共晶点が５００℃であり、５５０〜６００℃程度の操作温度を採用できる。共晶点から外れると若干高い操作温度が必要になるが、ＣａＣｌ2含有量を４０〜６０モル％の範囲に調整する限り６００℃を超えない操作温度を確保できる。 A mixed molten salt of calcium chloride and alkali metal chloride is also advantageous in terms of operability. In the molten salt of calcium chloride alone, since the melting point of calcium chloride is as high as 770 ° C., it is necessary to maintain the operation temperature at about 900 ° C. in order to obtain sufficient electric conductivity. On the other hand, the mixed molten salt of calcium chloride and alkali metal chloride can greatly reduce the operating temperature. For example, an equimolar mixed molten salt of CaCl 2 -NaCl has a eutectic point of 500 ° C., and an operating temperature of about 550 to 600 ° C. can be adopted. A slightly higher operating temperature is required when the eutectic point is deviated, but an operating temperature not exceeding 600 ° C. can be secured as long as the CaCl 2 content is adjusted to a range of 40 to 60 mol%.
混合溶融塩は、チタン酸化物の溶解度を上げる上でも有効である。金属酸化物の溶解度は溶融塩の組成に依存し、塩化カルシウム単独の溶融塩においては低次チタン酸化物，二酸化チタン共に同様な溶解度を示すが、塩化カルシウムにアルカリ金属塩化物のような他の成分を加えることによって低次チタン酸化物の溶解度が変化する。たとえば、ＣａＣｌ2-ＮａＣｌ等モル混合溶融塩では、二酸化チタンの溶解度積：１０-20に対しＴｉＯの溶解度積は１０-9と大きな値を示す。
低次チタン酸化物の溶解度はアルカリ金属の種類にも依存することが予想される。実際、ＮａＣｌに代えてＬｉＣｌやＫＣｌをＣａＣｌ2と混合した二元系又は三元系以上の混合溶融塩においても、ＮａＣｌ配合の場合と同様な融点降下，ひいては操作温度の低下及び低次チタン酸化物の溶解度上昇がみられる。
The mixed molten salt is also effective in increasing the solubility of titanium oxide. The solubility of the metal oxide depends on the composition of the molten salt. In the molten salt of calcium chloride alone, both low-order titanium oxide and titanium dioxide show similar solubility, but calcium chloride has other properties such as alkali metal chloride. The solubility of the low-order titanium oxide is changed by adding components. For example, in a CaCl 2 -NaCl equimolar mixed molten salt, the solubility product of TiO is as large as 10 −9 as compared with the solubility product of titanium dioxide: 10 −20 .
It is expected that the solubility of the low-order titanium oxide also depends on the type of alkali metal. In fact, even in the case of binary or ternary mixed molten salts in which LiCl or KCl is mixed with CaCl 2 instead of NaCl, the melting point drop is the same as in the case of NaCl blending, resulting in a lower operating temperature and lower titanium oxidation. There is an increase in the solubility of the product.
本発明では、二酸化チタンの還元用陰極及びチタンイオンの電析用陰極を備えた電解装置が使用される。この電解装置は、たとえば電解浴槽10に収容している混合溶融塩11に還元用陰極12，電析用陰極13及び対極としての陽極14を浸漬し、更に電位制御のための参照電極15を浸漬している(図１)。 In the present invention, an electrolytic device including a titanium dioxide reduction cathode and a titanium ion electrodeposition cathode is used. In this electrolysis apparatus, for example, a reducing cathode 12, an electrodeposition cathode 13 and an anode 14 as a counter electrode are immersed in a mixed molten salt 11 accommodated in an electrolytic bath 10, and a reference electrode 15 for potential control is further immersed. (Fig. 1).
還元用陰極12には原料の二酸化チタンMが使用され、原料供給口16から適宜送り込まれる。電析用陰極13には、後述の実施例ではチタンの生成量を調査するためチタンと合金化しない材料が使用されているが、工業生産レベルではチタン又はチタン合金も陰極13に使用できる。陰極12では残渣の発生，陰極13では析出した金属チタンの脱落が予想されるため、残渣や脱落チタンの回収を考慮したコンベア状の電極にすることも可能である。 Raw material titanium dioxide M is used for the reduction cathode 12 and is appropriately fed from the raw material supply port 16. In the examples described later, a material that is not alloyed with titanium is used for the electrodeposition cathode 13 in order to investigate the amount of titanium produced, but titanium or a titanium alloy can also be used for the cathode 13 at the industrial production level. Since the generation of residue is expected at the cathode 12 and the deposited titanium metal is expected to fall off at the cathode 13, it is possible to form a conveyor-like electrode in consideration of the recovery of the residue and the dropped titanium.
陽極14の材料は炭素又は耐塩素腐食性の金属が代表的であるが、不溶性陽極14として酸化物電極の使用も可能である。炭素電極を陽極14に使用する場合、ＣＯ，ＣＯ2が優先的に発生する。ＣＯ，ＣＯ2の優先的な発生は、Ｏ2が発生する場合に比較して陰極12，13／陽極14間の電位差を小さくでき、エネルギー消費量の節約をもたらす。しかし、炭素質の陽極14は、電解反応の進行に従って消耗するので連続運転には適さない。 The material of the anode 14 is typically carbon or a chlorine-resistant metal, but an oxide electrode can be used as the insoluble anode 14. When a carbon electrode is used for the anode 14, CO and CO 2 are preferentially generated. The preferential generation of CO and CO 2 can reduce the potential difference between the cathodes 12 and 13 / anode 14 as compared with the case where O 2 is generated, thereby saving energy consumption. However, since the carbonaceous anode 14 is consumed as the electrolytic reaction proceeds, it is not suitable for continuous operation.
陰極12，13と陽極14との間には、必要に応じて隔壁17が設けられる。また、電解浴槽10の内部を不活性雰囲気にするため、Ａｒガス導入口10a，10bが陰極側，陽極側それぞれの槽壁に設けられ、陰極側の槽壁にはＡｒガス排出口10c，陽極側の槽壁にはＣＯ2，ＣＯ，Ｃｌ2，Ａｒ等の排気口10dが設けられる。 A partition wall 17 is provided between the cathodes 12 and 13 and the anode 14 as necessary. Further, in order to make the inside of the electrolytic bath 10 an inert atmosphere, Ar gas inlets 10a and 10b are provided in the tank walls on the cathode side and the anode side, respectively, and the Ar gas discharge port 10c and anode are provided on the tank wall on the cathode side. An exhaust port 10d for CO 2 , CO, Cl 2 , Ar, etc. is provided on the side tank wall.
参照電極15の電位を基準として二酸化チタンMが還元される電位に還元用陰極12を維持すると、陰極12上で式(１)の還元反応が進行し、二酸化チタンが低次のチタン酸化物に還元される。
ＴｉＯ2＋2xｅ-→ＴｉＯ2-x＋xＯ2- ・・・・(１)
If the reduction cathode 12 is maintained at a potential at which the titanium dioxide M is reduced with reference to the potential of the reference electrode 15, the reduction reaction of the formula (1) proceeds on the cathode 12, and the titanium dioxide becomes a lower-order titanium oxide. Reduced.
TiO 2 + 2xe − → TiO 2−x + xO 2− (1)
低次のチタン酸化物は二酸化チタンに比較して溶融塩に対する溶解度が高く、しかも塩化カルシウム，アルカリ金属塩化物の混合溶融塩を反応場に使用しているので、式(１)の反応で生成した低次チタン酸化物は混合溶融塩11にチタンイオンとして溶解する。低次チタン酸化物は、式(２)の溶解反応に従ってチタンイオンとなって混合溶融塩11中を拡散して陰極12から離間するため、式(１)の還元反応が促進される。
ＴｉＯ＝Ｔｉ2+＋Ｏ2- ・・・・(２)
Low-order titanium oxide has higher solubility in molten salt than titanium dioxide, and uses a mixed molten salt of calcium chloride and alkali metal chloride in the reaction field. The low order titanium oxide is dissolved in the mixed molten salt 11 as titanium ions. Since the low-order titanium oxide becomes titanium ions according to the dissolution reaction of the formula (2) and diffuses in the mixed molten salt 11 and is separated from the cathode 12, the reduction reaction of the formula (1) is promoted.
TiO = Ti2 + 2 + O2 -... (2)
混合溶融塩11を拡散して電析用陰極13に至ったチタンイオンは、式(３)の電解析出反応に従って陰極13上で電解還元され、金属チタンとなって陰極13に析出する。
Ｔｉ2+＋2ｅ-＝Ｔｉ ・・・・(３)
陰極13に析出した金属チタンは原理的には酸素を含まない析出物であるので、従来のFFC法に比較して純度の高い金属チタンが得られる。また、還元用陰極12で二酸化チタンを低次チタン酸化物に還元し、電析用陰極13でチタンイオンから金属チタンを析出させる方式であるため半連続運転も可能であり、バッチプロセスであるクロール法に比較して生産性が格段に向上する。
Titanium ions diffusing the mixed molten salt 11 and reaching the electrodeposition cathode 13 are electrolytically reduced on the cathode 13 according to the electrolytic deposition reaction of the formula (3), and are deposited on the cathode 13 as metallic titanium.
Ti 2+ + 2e - = Ti ···· (3)
Since the titanium metal deposited on the cathode 13 is in principle a precipitate containing no oxygen, a titanium metal having a higher purity than that of the conventional FFC method can be obtained. In addition, because it is a system in which titanium dioxide is reduced to low-order titanium oxide at the reducing cathode 12 and metal titanium is deposited from titanium ions at the cathode 13 for electrodeposition, semi-continuous operation is possible and crawl is a batch process. Productivity is greatly improved compared to the law.
ＮａＣｌ-ＣａＣｌ2等モル，浴温：５５０℃の混合溶融塩11を反応場とするとき、酸化物イオン濃度pＯ2-が８付近で図２に斜線で示す領域(１)，(２)それぞれに還元用陰極12，電析用陰極13の電位を維持する必要がある。混合溶融塩浴11の組成，温度，二酸化チタン投入量，チタンイオン濃度等にもよるが、ＣａＣｌ2-ＮａＣｌ等モル混合溶融塩では領域(１)が塩素電極基準で-２.３〜-１.５Ｖ，領域(２)が同じく-３.５〜-２.３Ｖの範囲にある。 NaCl-CaCl 2 equimolar, bath temperature: When the mixed molten salt 11 in 550 ° C. for a reaction field, the area shown in FIG. 2 by oblique lines in oxide ion concentration pO 2-is around 8 (1), (2), respectively In addition, the potentials of the reduction cathode 12 and electrodeposition cathode 13 must be maintained. Depending on the composition, temperature, amount of titanium dioxide input, titanium ion concentration, etc. of the mixed molten salt bath 11, the region (1) is -2.3 to -1 based on the chlorine electrode in the case of CaCl 2 -NaCl equimolar mixed molten salt. 0.5V, region (2) is also in the range of -3.5 to -2.3V.
還元用陰極12が領域(1)より高い電位にあると式(１)の還元反応が進行せず、領域(１)より低い電位では還元用陰極12上に酸素濃度の高いα-Ｔｉが生成し、混合溶融塩に溶解しているチタンイオンの還元反応がα-Ｔｉ又は還元用陰極12に接続したリード線上で起こるため純度の高い金属チタンが得られない。
電析用陰極13が領域(２)より高い電位にあると式(３)の電解析出反応が進行せず、領域(２)より低い電位では混合溶融塩からアルカリ金属，金属カルシウムが生じる還元反応が起こり、生成したアルカリ金属，金属カルシウムが混合溶融塩に溶解して溶融塩自体に電子伝導性を付与する。その結果、陰極と陽極間に短絡電流が流れやすくなり、エネルギー効率が低下する。
When the reducing cathode 12 is at a higher potential than the region (1), the reduction reaction of the formula (1) does not proceed, and at a potential lower than the region (1), α-Ti having a high oxygen concentration is generated on the reducing cathode 12. In addition, since the reduction reaction of the titanium ions dissolved in the mixed molten salt occurs on the lead wire connected to α-Ti or the reduction cathode 12, high-purity titanium metal cannot be obtained.
When the electrodeposition cathode 13 is at a higher potential than the region (2), the electrolytic deposition reaction of the formula (3) does not proceed, and at a potential lower than the region (2), reduction occurs where alkali metal and metallic calcium are generated from the mixed molten salt. The reaction occurs, and the generated alkali metal and calcium metal are dissolved in the mixed molten salt to give electronic conductivity to the molten salt itself. As a result, a short-circuit current easily flows between the cathode and the anode, and energy efficiency is reduced.
式(１)の還元反応で生成したチタンイオンは、還元用陰極12から混合溶融塩を拡散して陽極14に達することもある。チタンイオンは、陽極14上で四価まで酸化され、混合溶融塩11中の塩化物イオンと反応して蒸気圧の高いＴｉＣｌ4となって系外に散逸する虞がある。散逸による収率低下は、陰極12，13と陽極14との間をイットリア安定化ジルコニア等の酸化物イオン伝導体薄膜等からなる隔壁17で仕切ることにより防止でき、陽極14では主として酸化物イオンが消費される。 The titanium ions generated by the reduction reaction of the formula (1) may reach the anode 14 by diffusing the mixed molten salt from the reduction cathode 12. Titanium ions are oxidized to tetravalent on the anode 14 and react with chloride ions in the mixed molten salt 11 to become TiCl 4 having a high vapor pressure and may be dissipated out of the system. Yield reduction due to dissipation can be prevented by partitioning the cathodes 12 and 13 and the anode 14 with a partition wall 17 made of an oxide ion conductor thin film such as yttria-stabilized zirconia. The anode 14 mainly contains oxide ions. Is consumed.
十分な加熱真空乾燥で水分を除去した高純度の薬品からＣａＣｌ2-ＮａＣｌ混合溶融塩を調合すると、電気化学的に還元し得る化学種はナトリウムイオンとカルシウムイオンのみである。したがって、陰極12，13の電位をナトリウムの析出電位(-３.５８５Ｖ)よりも低く設定しない限り、他の還元反応は一切起こらない。不純物を含まない二酸化チタンをＣａＣｌ2-ＮａＣｌ系に添加しても、二酸化チタンの溶解度積が極めて小さく、四価のチタンイオン種の生成を無視できる上、仮にＴｉ(IV)が生成した場合でも直ちに塩化物イオンと化合して揮発性のＴｉＣｌ4となって系外に散逸する。 When a CaCl 2 -NaCl mixed molten salt is prepared from a high-purity chemical from which moisture has been removed by sufficient heating and vacuum drying, the only chemical species that can be electrochemically reduced are sodium ions and calcium ions. Therefore, unless the potentials of the cathodes 12 and 13 are set lower than the deposition potential of sodium (−3.585 V), no other reduction reaction occurs. Even if titanium dioxide that does not contain impurities is added to the CaCl 2 -NaCl system, the solubility product of titanium dioxide is extremely small, generation of tetravalent titanium ion species can be ignored, and even if Ti (IV) is generated. Immediately combined with chloride ions, it becomes volatile TiCl 4 and dissipates out of the system.
二酸化チタンを電気化学的に還元すると、より低次のチタン酸化物が生成し、低次チタン酸化物が溶融塩に溶解することによってチタンイオンと酸化物イオンが生じる。酸化物イオンはそれ以上還元されないため、陰極での反応には関与しない。二酸化チタンの還元反応は、電位を適切に維持する限り他の副反応を伴わない。電析用電極でも、チタンイオンの還元反応が生じるだけである。 When titanium dioxide is electrochemically reduced, lower order titanium oxide is generated, and the lower order titanium oxide is dissolved in the molten salt to generate titanium ions and oxide ions. Since the oxide ions are not reduced any more, they are not involved in the reaction at the cathode. The reduction reaction of titanium dioxide is not accompanied by other side reactions as long as the potential is properly maintained. Even the electrode for electrodeposition only causes a reduction reaction of titanium ions.
電位規制に基づく本発明法では、原理的には電流効率がほぼ１００％となり、従来法のように金属カルシウムや金属マグネシウムの製造に要するエネルギーの多量消費がない。すなわち、二酸化チタン→金属チタンの還元に必要なエネルギー以外、混合溶融塩浴11，隔壁17の抵抗，陰極12，13及び陽極14における反応過電圧によって失われるエネルギーだけであり、従来法に比較して格段に効率のよい方法といえる。 In the method of the present invention based on potential regulation, in principle, the current efficiency is almost 100%, and there is no large consumption of energy required for the production of metallic calcium or metallic magnesium as in the conventional method. That is, in addition to the energy required for the reduction of titanium dioxide → titanium, it is only the energy lost by the reaction overvoltage in the mixed molten salt bath 11, the partition wall 17, the cathode 12, 13 and the anode 14, compared to the conventional method. It can be said to be a much more efficient method.
等モルでＮａＣｌ，ＣａＣｌ2を配合した混合塩を電解浴槽10に収容し、５５０℃に加熱保持することにより混合溶融塩浴11を用意した。混合溶融塩浴11に還元用陰極12(二酸化チタン：原料)，モリブデン製の電析用陰極13を浸漬し、式(１)の還元反応に必要な電位(-２.１Ｖ)に還元用陰極12を、式(３)の電解析出反応に必要な電位(-３.１Ｖ)に電析用陰極13を保持した。陰極12，13何れの電位も、塩素電極基準で示す。電解操作中、参照電極15の電位から陰極12，13の電位を判定し、それぞれを必要電位に制御した。 A mixed molten salt bath 11 was prepared by storing a mixed salt containing NaCl and CaCl 2 in equimolar amounts in an electrolytic bath 10 and heating and holding at 550 ° C. A cathode 12 for reduction (titanium dioxide: raw material) and a cathode 13 for electrodeposition made of molybdenum are immersed in a mixed molten salt bath 11, and the cathode for reduction is brought to the potential (-2.1 V) required for the reduction reaction of formula (1). The electrodeposition cathode 13 was held at a potential (-3.1 V) required for the electrolytic deposition reaction of Formula (3). The potentials of the cathodes 12 and 13 are shown with reference to the chlorine electrode. During the electrolysis operation, the potentials of the cathodes 12 and 13 were determined from the potential of the reference electrode 15, and each was controlled to the required potential.
反応を３時間継続させた後で混合溶融塩浴11から陰極13を引き上げ、陰極13上に析出している生成物を剥離し、蒸留水で洗浄した。洗浄後の生成物をアルミニウム製の試験皿に載せ、電子顕微鏡法及びエネルギー分散型Ｘ線分析法で分析した結果、金属チタンの生成が確認された。電子顕微鏡を用いた観察結果は、図３のSEM像にみられるように、モリブデン製の電極基板(黒色)の上に金属チタン(白色)が析出したことを示している。 After the reaction was continued for 3 hours, the cathode 13 was pulled up from the mixed molten salt bath 11, the product deposited on the cathode 13 was peeled off, and washed with distilled water. The washed product was placed on an aluminum test dish and analyzed by electron microscopy and energy dispersive X-ray analysis. As a result, formation of titanium metal was confirmed. The observation result using the electron microscope shows that metal titanium (white) is deposited on the molybdenum electrode substrate (black) as seen in the SEM image of FIG.
電解操作中に混合溶融塩浴11を比色分析してチタンイオン濃度を演算したところ、１〜１０-5質量モル濃度の範囲でチタンイオン濃度が推移した。チタンイオン濃度は、還元用陰極12への通電を停止したところ電気化学的測定法による検出限界以下まで低下した。通電停止に伴うチタンイオンの濃度低下は、混合溶融塩浴11に溶け込んでいたチタンイオンが効率よく金属チタンとなって電析用陰極13に析出したことを示している。 When the mixed molten salt bath 11 was subjected to colorimetric analysis during the electrolysis operation and the titanium ion concentration was calculated, the titanium ion concentration changed in the range of 1 to 10 -5 mass mol. The titanium ion concentration dropped below the detection limit by the electrochemical measurement method when the energization of the reduction cathode 12 was stopped. The decrease in the concentration of titanium ions due to the stoppage of current indicates that the titanium ions dissolved in the mixed molten salt bath 11 were efficiently converted into metallic titanium and deposited on the electrodeposition electrode 13.
比較のため、還元用陰極12の電位を図２の領域(１)より高い-１.０Ｖに保持したところ、式(１)の還元反応が進行せず電析用陰極13上に析出する金属チタンもなかった。逆に領域(１)より低い-３.１Ｖに保持したところ、還元用陰極12上に金属チタンが析出した。
また、電析用陰極13の電位を領域(２)より高い-１.５Ｖに保持したところ、式(３)の電解析出反応が進行せず電析用陰極13上に金属チタンが析出しなかった。逆に領域(２)より低い-４.０Ｖに保持したところ、ナトリウムの析出がみられ電析用陰極13／陽極14間に短絡電流が流れた。
以上の対比から、二酸化チタンを低次元チタン酸化物に還元して金属チタンとして析出させるためには、還元用陰極12，電析用陰極13をそれぞれ領域(１)，領域(２)の電位に保持する必要性を理解できる。
For comparison, when the potential of the reduction cathode 12 is maintained at −1.0 V, which is higher than the region (1) in FIG. 2, the reduction reaction of the formula (1) does not proceed and the metal deposited on the electrodeposition cathode 13 There was also no titanium. On the other hand, when the voltage was kept at −3.1 V lower than the region (1), titanium metal was deposited on the reduction cathode 12.
Further, when the potential of the electrodeposition cathode 13 was maintained at -1.5 V higher than the region (2), the electrolytic deposition reaction of the formula (3) did not proceed and metal titanium was deposited on the electrodeposition cathode 13. There wasn't. On the contrary, when the voltage was kept at −4.0 V lower than that in the region (2), precipitation of sodium was observed, and a short-circuit current flowed between the cathode 13 and the anode 14 for electrodeposition.
From the above comparison, in order to reduce titanium dioxide to low-dimensional titanium oxide and deposit it as metallic titanium, the reduction cathode 12 and the electrodeposition cathode 13 are set to the potentials of the regions (1) and (2), respectively. Understand the need to hold.
10：電解浴槽 10a，10b：Ａｒガス導入口 10c：Ａｒガス排出口 10d：排気口 11：混合溶融塩浴 12：還元用陰極 13：電析用陰極 14：陽極 15：参照電極 16：原料供給口 17：隔壁
M：二酸化チタン(原料)
10: Electrolytic bath 10a, 10b: Ar gas inlet 10c: Ar gas outlet 10d: Exhaust port 11: Mixed molten salt bath 12: Cathode for reduction 13: Cathode for electrodeposition 14: Anode 15: Reference electrode 16: Feeding material Mouth 17: Bulkhead
M: Titanium dioxide (raw material)
Claims (4)
ＴｉＯ2＋2xｅ-→ＴｉＯ2-x＋xＯ2- ・・・・(１)
ＴｉＯ＝Ｔｉ2+＋Ｏ2- ・・・・(２)
Ｔｉ2+＋2ｅ-＝Ｔｉ ・・・・(３) The reduction cathode made from the raw material titanium dioxide powder is immersed in a mixed molten salt bath of calcium chloride and alkali metal chloride together with the electrodeposition cathode and anode, and the reduction cathode is necessary for the reduction reaction of formula (1). Maintaining the potential, the low-order titanium oxide produced from titanium dioxide is dissolved in the mixed molten salt using titanium as an ion in the dissolution reaction of formula (2), and the potential required for the electrolytic deposition reaction of formula (3) is reached. A method for electrochemical reduction of titanium oxide, characterized in that titanium metal is deposited on a maintained cathode for electrodeposition.
TiO 2 + 2xe − → TiO 2−x + xO 2− ・ ・ ・ ・ (1)
TiO = Ti2 + 2 + O2 -... (2)
Ti 2+ + 2e - = Ti ···· (3)
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| CN101949038A (en) * | 2010-09-21 | 2011-01-19 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing TiCxOy composite anode with electrolysis method |
| CN102941129A (en) * | 2012-11-06 | 2013-02-27 | 中国科学院广州地球化学研究所 | Supported photocatalyst as well as preparation method and application thereof |
| CN109904439A (en) * | 2017-12-11 | 2019-06-18 | 中信国安盟固利动力科技有限公司 | A kind of low temperature preparation method of novel titanium base material |
| KR20230080059A (en) * | 2021-11-29 | 2023-06-07 | 한국생산기술연구원 | Electrolytic deoxidation method of titanium alloy and electrode cell device therefor |
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2006
- 2006-03-16 JP JP2006073274A patent/JP2007247002A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101949038A (en) * | 2010-09-21 | 2011-01-19 | 攀钢集团钢铁钒钛股份有限公司 | Method for preparing TiCxOy composite anode with electrolysis method |
| CN102941129A (en) * | 2012-11-06 | 2013-02-27 | 中国科学院广州地球化学研究所 | Supported photocatalyst as well as preparation method and application thereof |
| CN109904439A (en) * | 2017-12-11 | 2019-06-18 | 中信国安盟固利动力科技有限公司 | A kind of low temperature preparation method of novel titanium base material |
| KR20230080059A (en) * | 2021-11-29 | 2023-06-07 | 한국생산기술연구원 | Electrolytic deoxidation method of titanium alloy and electrode cell device therefor |
| KR102590654B1 (en) * | 2021-11-29 | 2023-10-19 | 한국생산기술연구원 | Electrolytic deoxidation method of titanium alloy and electrode cell device therefor |
| WO2023219397A1 (en) * | 2022-05-10 | 2023-11-16 | 한국세라믹기술원 | Hydrogen-doped reduced titania powder and preparation method therefor |
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