JP2003057390A - Method for controlling dissolved oxygen concentration in liquid metal - Google Patents
Method for controlling dissolved oxygen concentration in liquid metalInfo
- Publication number
- JP2003057390A JP2003057390A JP2001245394A JP2001245394A JP2003057390A JP 2003057390 A JP2003057390 A JP 2003057390A JP 2001245394 A JP2001245394 A JP 2001245394A JP 2001245394 A JP2001245394 A JP 2001245394A JP 2003057390 A JP2003057390 A JP 2003057390A
- Authority
- JP
- Japan
- Prior art keywords
- liquid metal
- oxygen
- concentration
- dissolved oxygen
- oxygen concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Abstract
(57)【要約】
【課題】液体金属中の溶解酸素濃度を、酸素透過能を有
する混合導電体を用いて制御し、構造材に対して高い腐
食性を示す液体金属による腐食を抑制する。
【解決手段】酸素イオン導電性と電子導電性とを有する
混合導電体１を隔壁とし、その一方を液体金属３に浸漬
させ、他の一方を制御すべき酸素濃度に相当する平衡酸
素分圧を有する金属とその酸化物からなる酸素濃度制御
用標準物質４に接触させる。前記液体金属３中の溶解酸
素濃度を、前記液体金属３と前記酸素濃度制御用標準物
質４の酸素濃度差を駆動力とする酸素透過により制御す
る。
[PROBLEMS] To control the concentration of dissolved oxygen in a liquid metal by using a mixed conductor having oxygen permeability, thereby suppressing corrosion by a liquid metal having high corrosiveness to a structural material. A mixed conductor having oxygen ion conductivity and electron conductivity is used as a partition, one of which is immersed in a liquid metal, and the other is provided with an equilibrium oxygen partial pressure corresponding to an oxygen concentration to be controlled. It is brought into contact with a standard substance 4 for controlling oxygen concentration, which comprises a metal and an oxide thereof. The dissolved oxygen concentration in the liquid metal 3 is controlled by oxygen permeation using a difference in oxygen concentration between the liquid metal 3 and the oxygen concentration control standard substance 4 as a driving force.
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、液体金属中の溶解
酸素濃度制御方法に関し、更に詳しくは、原子炉冷却材
や廃熱回収冷却材などの液体金属中の溶解酸素濃度制御
方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling dissolved oxygen concentration in liquid metal, and more particularly to a method for controlling dissolved oxygen concentration in liquid metal such as reactor coolant and waste heat recovery coolant. is there.
【０００２】[0002]
【従来の技術】液体金属は、熱や放射線に対して安定で
ある。また、熱伝導性が優れていることから冷却材とし
て使用されている。その代表的な例が高速増殖炉の液体
ナトリウム金属である。このような目的に用いられる金
属は、主として、Ｎａ、Ｎａ−Ｋ、Ｌｉ、Ｂｉ、Ｐｂな
どの低融点金属である。しかし、こうした液体金属を冷
却材として使用する場合には、液体金属による機器や配
管などの構造材の腐食が問題となる。Liquid metal is stable to heat and radiation. Further, it is used as a coolant because of its excellent thermal conductivity. A typical example thereof is liquid sodium metal for fast breeder reactors. The metals used for such purpose are mainly low melting point metals such as Na, Na—K, Li, Bi and Pb. However, when such liquid metal is used as a coolant, corrosion of structural materials such as equipment and piping due to the liquid metal poses a problem.
【０００３】液体金属による腐食は、水溶液などの腐食
に見られる電気化学過程ではなく、金属元素の液体金属
中への溶解が主原因である。したがって、冷却材として
使われる液体金属が、その熱回収のために、高温部と低
温部とを循環する場合、高温部で構造材から溶解した元
素が低温部で過飽和となって析出する、いわゆる、質量
移動現象が生じる。Corrosion by a liquid metal is mainly caused by dissolution of a metal element in a liquid metal, not an electrochemical process found in corrosion of an aqueous solution or the like. Therefore, when the liquid metal used as the coolant circulates between the high temperature portion and the low temperature portion for recovering the heat, the element dissolved from the structural material in the high temperature portion is supersaturated and precipitates in the low temperature portion, so-called. , Mass transfer phenomenon occurs.
【０００４】この質量移動は、繰り返され、機器や配管
などの構造材が腐食され続け、低温部では不純物が析出
し、小口径の配管などの液体金属流路を閉鎖させる恐れ
もある。溶解速度を支配するのは、高温部での不飽和度
によるが、ループの構成、形状などの装置の状況、流
量、温度、温度差、表面粗度、不純物濃度など多種多様
な条件により左右される。中でも、液体金属中の不純
物、特に、溶解酸素濃度は、腐食現象および速度に大き
く影響を及ぼすことが知られている。This mass transfer is repeated, and structural materials such as equipment and pipes continue to be corroded, impurities are precipitated in a low temperature portion, and liquid metal flow paths such as pipes having a small diameter may be closed. The dissolution rate is governed by the degree of unsaturation at high temperature, but it depends on a variety of conditions such as the loop configuration and device conditions such as shape, flow rate, temperature, temperature difference, surface roughness, and impurity concentration. It Among them, it is known that impurities in liquid metal, particularly dissolved oxygen concentration, have a great influence on the corrosion phenomenon and rate.
【０００５】高速増殖炉の液体ナトリウム金属冷却材の
場合、ナトリウムの酸化物標準生成自由エネルギー（酸
素ポテンシャル）の絶対値は、鋼材の主要元素（Ｆｅ、
Ｎｉ、Ｃｒ）や、一般的な合金元素の酸化物標準生成自
由エネルギーの絶対値より大きい。すなわち、液体ナト
リウム金属と接触している構造材表面は、還元され、液
体ナトリウム金属は、酸化される傾向にある。In the case of a liquid sodium metal coolant for a fast breeder reactor, the absolute value of the standard free energy of formation of sodium oxide (oxygen potential) is the main element (Fe,
Ni, Cr) or the standard free energy of formation of oxides of general alloying elements is larger than the absolute value. That is, the surface of the structural material that is in contact with the liquid sodium metal tends to be reduced, and the liquid sodium metal tends to be oxidized.
【０００６】従って、構造材の腐食条件は、本質的にそ
れら主要元素の液体ナトリウム金属中への溶解度によっ
て決定される。構造材主要元素の液体ナトリウム金属中
への溶解度の増加とともに腐食速度が増大することが分
かっている。構造材がステンレス鋼の場合、成分元素の
Ｃｒ、Ｎｉが高温部で溶出し、低温部で析出する。そし
て、液体ナトリウム金属中の酸素濃度が高いと、Ｃｒの
溶出が促進されると言われている。Therefore, the corrosion conditions of structural materials are essentially determined by the solubilities of these major elements in liquid sodium metal. It has been found that the corrosion rate increases with increasing solubility of the main structural element in liquid sodium metal. When the structural material is stainless steel, the constituent elements Cr and Ni elute in the high temperature portion and precipitate in the low temperature portion. And, it is said that the elution of Cr is promoted when the oxygen concentration in the liquid sodium metal is high.
【０００７】従って、構造材の腐食防止、質量移行現象
の抑止などの観点から液体金属中の溶解酸素濃度を管理
制御することは非常に重要となる。Therefore, it is very important to manage and control the concentration of dissolved oxygen in the liquid metal from the viewpoints of preventing corrosion of structural materials and suppressing the mass transfer phenomenon.
【０００８】従来の液体金属中の溶解酸素濃度の制御方
法については、その方法の１つにコールドトラップ法が
ある。この方法は、金属液体中の不純物を除去する精製
法の一種であり、不純物の溶解度が低温で小さくなる性
質を利用して金属液体中の酸素、炭素などの不純物を低
温下でいろいろな化合物の形（反応生成物）で析出除去
し、分離回収する方法である。ナトリウムの場合、コー
ルドトラップ法で液体ナトリウム金属中の溶解酸素濃度
を１０ｐｐｍ以下程度まで低減でき、ステンレス鋼およ
びＦｅ、Ｃｒ、Ｎｉ、Ｃｏ、Ｍｏなどとの両立性を計っ
ている。As a conventional method for controlling the concentration of dissolved oxygen in a liquid metal, there is a cold trap method. This method is one of the purification methods for removing impurities in a metal liquid, and utilizes the property that the solubility of impurities decreases at low temperatures to remove impurities such as oxygen and carbon in metal liquids at low temperatures from various compounds. It is a method of separating and collecting by precipitating and removing in the form (reaction product). In the case of sodium, the concentration of dissolved oxygen in liquid sodium metal can be reduced to about 10 ppm or less by the cold trap method, and compatibility with stainless steel and Fe, Cr, Ni, Co, Mo, etc. is measured.
【０００９】また、別の方法として、ホットトラップ方
法がある。この方法は、コールドトラップ法で得られる
純度よりも更に高い純度を得たい時に用いられ、高温で
酸素などの不純物とよく結合する金属ゲッターに液体金
属を通して、液体金属中の不純物を金属ゲッターと反応
させてゲッター中に固定除去する方法である。例えば、
液体ナトリウム金属中の酸素に対して酸化ナトリウムよ
りも安定な酸化物を生成する金属として、Ｔｉ、Ｚｒ及
びＴｉ−Ｚｒ合金などが用いられ、約６００℃の液体ナ
トリウム金属中の溶解酸素濃度を数ｐｐｍ以下に管理で
きている。更に、水素ガスによる還元処理、酸素ガス、
水蒸気などによる酸化処理により溶解酸素濃度を制御し
ている。Another method is a hot trap method. This method is used when it is desired to obtain a higher purity than that obtained by the cold trap method, and the liquid metal is passed through a metal getter that binds well to impurities such as oxygen at high temperature, and the impurities in the liquid metal react with the metal getter. This is a method of fixing and removing in the getter. For example,
Ti, Zr, and Ti-Zr alloys are used as metals that generate oxides that are more stable than oxygen in liquid sodium metal, and the dissolved oxygen concentration in liquid sodium metal at about 600 ° C It can be controlled below ppm. Furthermore, reduction treatment with hydrogen gas, oxygen gas,
The concentration of dissolved oxygen is controlled by the oxidation treatment with water vapor.
【００１０】[0010]
【発明が解決しようとする課題】しかしながら、従来の
コールドトラップ法やホットトラップ法による液体金属
中の溶解酸素濃度の制御方法は、液体金属中の溶解酸素
濃度の上限を制御するものである。しかし、このような
制御方法は、液体金属の種類によって以下のような不都
合を生じる。However, the conventional method of controlling the concentration of dissolved oxygen in liquid metal by the cold trap method or the hot trap method is to control the upper limit of the concentration of dissolved oxygen in liquid metal. However, such a control method causes the following inconveniences depending on the type of liquid metal.
【００１１】例えば、液体金属にＰｂ−Ｂｉを使用した
場合、液体Ｐｂ−Ｂｉ合金に対する鋼材主要元素の溶解
度が大きく、液体Ｐｂ−Ｂｉ合金中の溶解酸素濃度を上
限以下に制御するだけでは構造材の腐食の進展を抑制す
ることが困難である。すなわち、溶解酸素濃度が小さ過
ぎてもかえって構造材の腐食を加速させる、という問題
がある。For example, when Pb-Bi is used as the liquid metal, the solubility of the main elements of the steel material in the liquid Pb-Bi alloy is large, and it is necessary to control the dissolved oxygen concentration in the liquid Pb-Bi alloy below the upper limit. It is difficult to suppress the progress of corrosion. That is, there is a problem that the corrosion of the structural material is accelerated even if the dissolved oxygen concentration is too low.
【００１２】上記の問題を回避するため、構造材の溶解
速度を減少させる方法として、インヒピターの添加によ
り構造材表面に保護皮膜を形成させる方法があるが、こ
の場合、保護皮膜が厚く成長し過ぎると、膜剥がれや熱
衝撃によるクラックが発生し、こうした部分を起点に局
部的に腐食が進行するといった問題があった。In order to avoid the above problems, there is a method of forming a protective film on the surface of the structural material by adding inhibitor as a method of decreasing the dissolution rate of the structural material. In this case, the protective film grows too thick. Then, there is a problem that film peeling or cracks due to thermal shock occur, and corrosion locally progresses from such a portion as a starting point.
【００１３】従って、ＰｂやＢｉのような構造材主要元
素の溶解度が大きい液体金属や液体合金の冷却材への適
用は、従来技術では十分な腐食抑制ができていなかっ
た。また、ガスによる酸化還元処理法は、ガス供給設備
が必要な上、水素還元では水蒸気が生成され、水蒸気の
系内からの排出が必要となってくる。Therefore, the application of a liquid metal or liquid alloy having a large solubility of the main structural element such as Pb and Bi to a coolant has not been able to sufficiently suppress corrosion in the prior art. In addition, the oxidation-reduction treatment method using a gas requires a gas supply facility, and steam is generated in the hydrogen reduction, and the steam needs to be discharged from the system.
【００１４】本発明は、このような問題点を解決するも
のであり、その目的とするところは、液体金属中の溶解
酸素濃度を、酸素透過能を有する混合導電体を用いて制
御することにより、構造材に対して高い腐食性を示す液
体金属においても腐食を抑制することが可能な液体金属
中の溶解酸素濃度制御方法を提供することにある。ま
た、他の目的は、上記の問題解決ばかりでなく、新たな
デバイスの創造に寄与するところにある。The present invention solves such a problem, and its purpose is to control the concentration of dissolved oxygen in a liquid metal by using a mixed conductor having oxygen permeability. Another object of the present invention is to provide a method for controlling the concentration of dissolved oxygen in a liquid metal, which is capable of suppressing the corrosion even in the liquid metal showing a high corrosiveness to a structural material. Another purpose is not only to solve the above problems but also to contribute to the creation of new devices.
【００１５】[0015]
【課題を解決するための手段】このような目的は、下記
（１）〜（５）の本発明により達成される。These objects are achieved by the present invention described in (1) to (5) below.
【００１６】（１） 酸素イオン導電性と電子又はホー
ル導電性とを有する混合導電体を隔壁とし、その一方を
液体金属に浸漬させ、他の一方を制御すべき酸素濃度に
相当する平衡酸素分圧を有する金属とその酸化物とから
なる酸素濃度制御用標準物質に接触させ、液体金属中の
溶解酸素濃度を、前記液体金属と前記酸素濃度制御用標
準物質との酸素濃度差を駆動力とする酸素透過により制
御することを特徴とする液体金属中の溶解酸素濃度制御
方法。(1) A mixed conductor having oxygen ion conductivity and electron or hole conductivity is used as a partition wall, one of which is immersed in a liquid metal, and the other one of which has an equilibrium oxygen content corresponding to an oxygen concentration to be controlled. It is brought into contact with an oxygen concentration control standard substance consisting of a metal having a pressure and its oxide, the dissolved oxygen concentration in the liquid metal, the difference in oxygen concentration between the liquid metal and the oxygen concentration control standard substance is the driving force. The method for controlling the concentration of dissolved oxygen in a liquid metal is characterized by controlling the oxygen permeation.
【００１７】（２） 前記混合導電体が、欠陥ペロプス
カイト型酸化物からなることを特徴とする（１）記載の
液体金属中の溶解酸素濃度制御方法。(2) The method for controlling the concentration of dissolved oxygen in liquid metal according to (1), wherein the mixed conductor is made of a defective perovskite type oxide.
【００１８】（３） 前記液体金属が、本質的に鉛、ビ
スマス、鉛ビスマス合金のいずれかであることを特徴と
する（１）又は（２）記載の液体金属中の溶解酸素濃度
制御方法。(3) The method for controlling the concentration of dissolved oxygen in a liquid metal according to (1) or (2), wherein the liquid metal is essentially lead, bismuth, or a lead-bismuth alloy.
【００１９】（４） 前記液体金属を、少なくとも低合
金鋼、特殊鋼、炭素鋼の中から選ばれた１種からなる容
器に収容することを特徴とする（１）乃至（３）のいず
れか１項記載の液体金属中の溶解酸素濃度制御方法。(4) The liquid metal is contained in a container made of at least one selected from low alloy steel, special steel, and carbon steel, (1) to (3) Item 1. A method for controlling the concentration of dissolved oxygen in liquid metal according to item 1.
【００２０】（５） 前記液体金属の温度範囲が、前ー
ー体金属の融点〜６５０℃であることを特徴とする
（１）乃至（４）のいずれか１項記載の液体金属中の溶
解酸素濃度制御方法。(5) Dissolved oxygen in the liquid metal according to any one of (1) to (4), wherein the temperature range of the liquid metal is from the melting point of the precursor metal to 650 ° C. Concentration control method.
【００２１】[0021]
【発明の実施の形態】以下、本発明の実施の形態につい
て説明する。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
【００２２】液体金属としては、Ｐｂ系、Ｂｉ系、Ｐｂ
−Ｂｉ系が挙げられる。Liquid metals include Pb-based, Bi-based, and Pb
-Bi system is mentioned.
【００２３】液体金属を収容する容器としては、低合金
鋼、特殊鋼、炭素鋼が挙げられる。特殊鋼の代表的なも
のとしては、Ｃｒ−Ｍｏ系鋼、フェライトあるいはマル
テンサイト系Ｃｒ含有鋼、オーステナイト鋼が好まし
い。Ｐｂ、Ｂｉに対するＮｉの溶解度が高いため、Ｎｉ
を多く含んだ鋼材は好ましくない。Examples of the container for containing the liquid metal include low alloy steel, special steel, and carbon steel. As typical examples of the special steel, Cr-Mo steel, ferrite or martensite Cr-containing steel, and austenitic steel are preferable. Since the solubility of Ni in Pb and Bi is high, Ni
Steel containing a large amount of is not preferable.
【００２４】次に、液体金属中の溶解酸素濃度と容器構
造材の酸化皮膜との関係に関して説明する。熱力学的観
点、すなわち、酸化物の標準生成自由エネルギーの比較
から、本発明に係る主な液体金属成分及び容器主要成分
の酸化物の安定性の序列は、酸化ケイ素＞酸化クロム＞
酸化モリブデン＞酸化鉄＞酸化鉛＞酸化ビスマスの順で
ある。Next, the relationship between the concentration of dissolved oxygen in the liquid metal and the oxide film of the container structural material will be described. From the thermodynamic point of view, that is, from the comparison of the standard free energy of formation of oxides, the order of stability of the oxides of the main liquid metal component and the main component of the container according to the present invention is silicon oxide> chromium oxide>
The order is molybdenum oxide> iron oxide> lead oxide> bismuth oxide.
【００２５】これを基に液体金属及び容器主要成分と酸
素との相互作用による腐食性については、液体金属中の
溶解酸素濃度レベルにより、下記の３つの場合に大きく
分類される。Based on this, the corrosiveness due to the interaction between the liquid metal and the main components of the container and oxygen is roughly classified into the following three cases depending on the concentration level of dissolved oxygen in the liquid metal.
【００２６】すなわち、
（１） 液体金属の溶解酸素濃度レベルが十分に低く、
鉄が酸化されないような条件では、液体金属中に鉄が溶
解し、容器の腐食が進行する。That is, (1) the dissolved oxygen concentration level of the liquid metal is sufficiently low,
Under the condition that the iron is not oxidized, the iron dissolves in the liquid metal and the corrosion of the container progresses.
【００２７】（２） 液体金属の溶解酸素濃度レベルが
十分に高くなり、鉄が酸化されるような条件では、容器
表面に酸化鉄、酸化クロム、鉄クロム複合酸化物などの
酸化皮膜が生成され、これらの酸化皮膜は、液体金属中
で安定な保護皮膜となり、腐食が防止される。(2) Under conditions where the dissolved oxygen concentration level of the liquid metal is sufficiently high and iron is oxidized, an oxide film of iron oxide, chromium oxide, iron-chromium composite oxide, etc. is formed on the surface of the container. These oxide films serve as a stable protective film in liquid metal and prevent corrosion.
【００２８】（３） 液体金属の溶解酸素濃度レベルが
更に高くなり、鉛が酸化されるような条件では、酸化鉛
のスラグが液体金属中に発生し、冷却機能の悪化、配管
のプラグなどを生じる。更に、酸化皮膜が厚く成長し過
ぎて膜剥がれや、熱衝撃に寄るクラックが発生し易くな
り、こうした部分を起点に局部腐食が進行する。(3) Under the condition that the dissolved oxygen concentration level of the liquid metal is further increased and lead is oxidized, slag of lead oxide is generated in the liquid metal, the cooling function is deteriorated, the plug of the pipe, etc. Occurs. Furthermore, the oxide film grows too thick and film peeling and cracks due to thermal shock are likely to occur, and local corrosion proceeds from such a portion as a starting point.
【００２９】従って、本発明は、基本的に、上記第
（２）項の条件、すなわち、鉄は酸化され、鉛は酸化さ
れないような溶解酸素濃度に制御すれば良いことにな
る。Therefore, in the present invention, basically, the condition of the above (2), that is, the dissolved oxygen concentration is controlled so that iron is oxidized and lead is not oxidized.
【００３０】混合導電体としては、酸化イオン導電体と
電子或いはホール導電性とを有する欠陥ペロプスカイト
型酸化物が挙げられる。Examples of the mixed conductor include a defective perovskite type oxide having an oxide ion conductor and electron or hole conductivity.
【００３１】欠陥ペロプスカイト型酸化物は、一般式
（Ａ1-X Ａ′X ）（Ｂ1-Y Ｂ′Y ）Ｏ a-δ で表され
る。Defective perovskite oxides have the general formula
(A1-XA 'X) (B1-YB 'Y) O a-represented by δ
It
【００３２】ここで、Ａは希土類元素、Ａ′はアルカリ
金属、アルカリ土類金属、Ｂ，Ｂ′はチタン、バナジウ
ム、クロム、マンガン、鉄、コバルト、ニッケル、銅、
亜鉛などが用いられ、Ｘの値は、大きいほど酸素欠陥量
δが多くなる傾向がある。Here, A is a rare earth element, A'is an alkali metal, an alkaline earth metal, B and B'are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper,
Zinc or the like is used, and the larger the value of X, the larger the oxygen defect amount δ tends to be.
【００３３】具体的には、（Ｌａ0.2 Ｓｒ0.8 ）（Ｃｏ
0.8 Ｆｅ0.2 ）Ｏa-δ、（Ｇｄ0.6Ｓｒ0.4 ）（Ｃｏ）
Ｏ3-δ、（Ｌａ0.6 Ｂａ0.4 ）（Ｃｏ0.9 Ｃｕ0.1 ）Ｏ
3-δなどが挙げられる。Specifically, (La 0.2 Sr 0.8 ) (Co
0.8 Fe 0.2 ) O a- δ, (Gd 0.6 Sr 0.4 ) (Co)
O 3- δ, (La 0.6 Ba 0.4 ) (Co 0.9 Cu 0.1 ) O
3- δ and the like.
【００３４】このような欠陥ペロプスカイト型酸化物
は、酸素濃度の異なる２室の隔壁として用いると、高酸
素濃度側から低酸素濃度側へ外部回路や電極を必要とし
ないで酸素の選択透過が可能となる。そして、酸素濃度
の異なる２室の酸素濃度差が無くなるように酸素透過が
起こる。When such a defective perovskite oxide is used as a partition wall of two chambers having different oxygen concentrations, selective permeation of oxygen can be achieved from the high oxygen concentration side to the low oxygen concentration side without the need for an external circuit or electrodes. It will be possible. Oxygen permeation occurs so that there is no difference in oxygen concentration between the two chambers having different oxygen concentrations.
【００３５】従って、一方の酸素濃度を一定にしておく
と、酸素透過を通じて最終的には、もう一方の酸素濃度
も同じ酸素濃度になるように酸素の透過が起こる。Therefore, if one of the oxygen concentrations is kept constant, the oxygen permeation finally occurs through the oxygen permeation so that the other oxygen concentration also becomes the same oxygen concentration.
【００３６】本発明においては、上記のように、鉄は酸
化され、鉛は酸化されないような溶解酸素濃度に制御す
る必要があり、酸素濃度制御用標準物質としては、酸化
物の安定性の序列から考慮して、Ｆｅ−Ｆｅ3 Ｏ4 系と
Ｐｂ−ＰｂＯ系の間に位置する平衡酸素分圧を有する金
属とその酸化物にする必要がある。具体的には、Ｓｎ−
ＳｎＯ2 系、Ｎｉ−ＮｉＯ系、Ｃｏ−ＣｏＯ系などが挙
げられるが、使用する温度で金属が溶融状態にあるＳｎ
−ＳｎＯ2 系が特に好ましい。In the present invention, as described above, it is necessary to control the dissolved oxygen concentration such that iron is oxidized and lead is not oxidized. As a standard substance for controlling oxygen concentration, the order of stability of oxides is used. In consideration of the above, it is necessary to use a metal having an equilibrium oxygen partial pressure located between the Fe—Fe 3 O 4 system and the Pb—PbO system and its oxide. Specifically, Sn-
Examples include SnO 2 series, Ni—NiO series, Co—CoO series, and the like, where the metal is in a molten state at the temperature used.
The --SnO 2 system is particularly preferred.
【００３７】混合導電体の形状、寸法などは、特に限定
されるものではなく、酸素濃度の異なる２室を隔離でき
ればよい。例えば、一端封管型、ペレット型などの形状
のものが可能であり、その大きさもあらゆる大きさのも
のが可能である。また、多孔質支持体上にペースト塗布
法、溶射法、スパッタ法等を用いて混合導電膜を形成す
ることも可能である。ただし、厚みは、厚すぎると、酸
素の透過速度が小さくなるため、２ｍｍ以下が好まし
く、１〜０．３ｍｍがより好ましい。The shape and size of the mixed conductor are not particularly limited as long as two chambers having different oxygen concentrations can be isolated. For example, one-sided tube type, pellet type and the like are possible, and the size can be any size. It is also possible to form a mixed conductive film on the porous support by using a paste coating method, a thermal spraying method, a sputtering method or the like. However, the thickness is preferably 2 mm or less, and more preferably 1 to 0.3 mm, because if the thickness is too large, the oxygen permeation rate decreases.
【００３８】また、混合導電体の数は、特に限定される
ものではなく、酸素の透過面積を増加させるために、複
数使用しても良い。更に、モジュール化して使用しても
よい。The number of mixed conductors is not particularly limited, and a plurality of mixed conductors may be used to increase the oxygen permeation area. Furthermore, it may be modularized and used.
【００３９】本発明において、液体金属の温度範囲は、
使用する液体金属の融点〜６５０℃であることが好まし
く、Ｐｂ系では、３３０℃〜６００℃、Ｂｉ系及びＰｂ
−Ｂｉ系は、３００℃〜６００℃がより好ましい。温度
が低すぎると、混合導電体による酸素の透過が困難とな
る。また、温度が高すぎると、容器鋼材の腐食が激しく
なる。In the present invention, the temperature range of the liquid metal is
The melting point of the liquid metal used is preferably 650 ° C., and in the Pb system, 330 ° C. to 600 ° C., the Bi system and the Pb system.
The temperature of the -Bi system is more preferably 300 ° C to 600 ° C. If the temperature is too low, it becomes difficult for oxygen to permeate through the mixed conductor. Further, if the temperature is too high, the corrosion of the steel material of the container becomes severe.
【００４０】[0040]
【実施例】以下、本発明について具体的に説明する。図
１は、本発明の液体金属中の溶解酸素濃度制御方法の一
実施例を示す模式図である。The present invention will be described in detail below. FIG. 1 is a schematic view showing an embodiment of the method for controlling the concentration of dissolved oxygen in liquid metal according to the present invention.
【００４１】液体金属３を収容した容器２内に一端封管
型（例えば、試験管型）の混合導電体１を挿入配置す
る。一端封管型の混合導電体１内には、制御すべき酸素
濃度に相当する平衡酸素分圧を有する金属とその酸化物
からなる酸素濃度制御用標準物質４を充填させている。
混合導電体１の上部開口部は、シール部５でシールさ
れ、混合導電体破損時等に液体金属３の逆流（流出）を
防止している。A one-end sealed tube type (for example, a test tube type) mixed conductor 1 is inserted and arranged in a container 2 containing a liquid metal 3. The one-end sealed tube type mixed conductor 1 is filled with an oxygen concentration control standard substance 4 composed of a metal having an equilibrium oxygen partial pressure corresponding to the oxygen concentration to be controlled and its oxide.
The upper opening of the mixed conductor 1 is sealed by the seal portion 5 to prevent backflow (outflow) of the liquid metal 3 when the mixed conductor is damaged.
【００４２】混合導電体１による酸素の選択透過は、液
体金属３側と酸素濃度制御用標準物質４側との酸素ポテ
ンシャルの差を駆動力として生ずる。この時、電極や外
部回路の必要はなく、極めて簡単な構成により酸素の透
過を可能とする。そして、混合導電体１を液体金属３中
に浸漬しておくだけで、液体金属３側と酸素濃度制御用
標準物質４側との酸素ポテンシャルが同じになるよう
に、高酸素側から低酸素側への酸素透過を通じて自発的
に液体金属３中の溶解酸素濃度が制御される。The selective permeation of oxygen by the mixed conductor 1 is caused by a difference in oxygen potential between the liquid metal 3 side and the oxygen concentration control standard substance 4 side as a driving force. At this time, there is no need for electrodes or external circuits, and oxygen can be permeated with an extremely simple structure. Then, just by immersing the mixed conductor 1 in the liquid metal 3, the oxygen concentration is controlled from the high oxygen side to the low oxygen side so that the oxygen potentials of the liquid metal 3 side and the oxygen concentration control standard substance 4 side become the same. The concentration of dissolved oxygen in the liquid metal 3 is spontaneously controlled through the permeation of oxygen into the liquid metal 3.
【００４３】（実施例１）液体金属３としてＰｂ−Ｂｉ
共晶合金を、容器鋼材として１８Ｃｒ−１Ｍｏ鋼の密閉
タンク２を用い、５５０℃に設定した液体金属３中に、
酸素濃度制御用標準物質４であるＳｎ−ＳｎＯ2 を充填
させた（Ｇｄ0.6 Ｓｒ0.4 ）（Ｃｏ）Ｏ3-δよりなる一
端封管型混合導電体１を浸漬させ、液体金属３中の溶解
酸素濃度を酸素センサー（図示せず）を用いて評価し
た。(Example 1) Pb-Bi as the liquid metal 3
The eutectic alloy is used as a container steel in a closed tank 2 of 18Cr-1Mo steel in a liquid metal 3 set at 550 ° C.
The one-end sealed tube-type mixed conductor 1 made of (Gd 0.6 Sr 0.4 ) (Co) O 3 − δ filled with Sn—SnO 2 which is the oxygen concentration control standard substance 4 is immersed and dissolved in the liquid metal 3. The oxygen concentration was evaluated using an oxygen sensor (not shown).
【００４４】液体金属３中の溶解酸素濃度を１０-5ｍａ
ｓｓ％まで減少させた後、上記混合導電体１を挿入し
た。すると、徐々に液体金属３中の酸素濃度が増加し、
約２４時間で１０-7ｍａｓｓ％に達し、その後、この酸
素濃度は、長期に渡って維持された。The dissolved oxygen concentration in the liquid metal 3 is set to 10 −5 ma
After reducing to ss%, the mixed conductor 1 was inserted. Then, the oxygen concentration in the liquid metal 3 gradually increases,
It reached 10 −7 mass% in about 24 hours, after which this oxygen concentration was maintained for a long time.
【００４５】次に、液体金属３中の溶解酸素濃度を１０
-3ｍａｓｓ％まで増加させた後、上記混合導電体１を挿
入した。すると、徐々に液体金属３中の酸素濃度が減少
し、約４０時間で１０-7ｍａｓｓ％に達し、その後、こ
の酸素濃度は、長期に渡って維持された。Next, the concentration of dissolved oxygen in the liquid metal 3 is set to 10
After increasing to -3 mass%, the mixed conductor 1 was inserted. Then, the oxygen concentration in the liquid metal 3 gradually decreased, reaching 10 −7 mass% in about 40 hours, and thereafter, this oxygen concentration was maintained for a long time.
【００４６】（比較例１）これに対し、Ａサイトを置換
していない酸素欠陥が導入されていないペロブスカイト
型酸化物ＬａＣｏ0.6 Ｆｅ0.4 Ｏ3 を用いた場合、酸素
の透過が認められなく、溶解酸素濃度を制御することが
できなかった。(Comparative Example 1) On the other hand, when the perovskite type oxide LaCo 0.6 Fe 0.4 O 3 in which the A site was not substituted and oxygen defects were not introduced was used, no permeation of oxygen was observed and dissolution was observed. The oxygen concentration could not be controlled.
【００４７】[0047]
【発明の効果】上記のように、本発明によれば、酸素透
過能を有する混合導電体を用いることにより、極めて簡
単に液体金属中の溶解酸素濃度を制御することが可能と
なる。その結果、これまで使用することが困難であった
腐食性の高いＰｂ，Ｂｉ系の液体金属を冷却材に使用す
ることができるようになった。As described above, according to the present invention, it is possible to control the dissolved oxygen concentration in the liquid metal very easily by using the mixed conductor having oxygen permeability. As a result, it has become possible to use a highly corrosive Pb, Bi-based liquid metal that has been difficult to use until now as a coolant.
【００４８】更に、従来、Ｎａ冷却材で問題とされた反
応性（特に、水との反応性）の高さに関して、より化学
的に不活性なＰｂ，Ｂｉ系が使用できるようになるな
ど、その適用範囲は極めて広い。Further, with respect to the high reactivity (particularly, the reactivity with water) which has hitherto been a problem with the Na coolant, a more chemically inactive Pb, Bi system can be used. Its application range is extremely wide.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明に係る液体金属中の酸素濃度制御装置の
概略図である。FIG. 1 is a schematic view of an apparatus for controlling oxygen concentration in liquid metal according to the present invention.
１ 混合導電体 ２ 容器 ３ 液体金属 ４ 酸素濃度制御用標準物質 ５ シール部 1 mixed conductor 2 containers 3 liquid metal 4 Standard substances for oxygen concentration control 5 Seal part
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｇ２１Ｄ 3/08 Ｇ２１Ｆ 9/06 Ｚ Ｇ２１Ｆ 9/06 Ｇ２１Ｃ 19/30 Ｂ ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) G21D 3/08 G21F 9/06 Z G21F 9/06 G21C 19/30 B
Claims (5)
性とを有する混合導電体を隔壁とし、その一方を液体金
属に浸漬させ、他の一方を制御すべき酸素濃度に相当す
る平衡酸素分圧を有する金属とその酸化物とからなる酸
素濃度制御用標準物質に接触させ、液体金属中の溶解酸
素濃度を、前記液体金属と前記酸素濃度制御用標準物質
との酸素濃度差を駆動力とする酸素透過により制御する
ことを特徴とする液体金属中の溶解酸素濃度制御方法。1. An equilibrium oxygen partial pressure corresponding to the oxygen concentration to be controlled, with one partition being a mixed conductor having oxygen ion conductivity and electron or hole conductivity, one being immersed in a liquid metal. A dissolved oxygen concentration in the liquid metal, and a difference in oxygen concentration between the liquid metal and the oxygen concentration control standard substance as a driving force. A method for controlling the concentration of dissolved oxygen in a liquid metal, characterized by controlling by oxygen permeation.
型酸化物からなることを特徴とする請求項１記載の液体
金属中の溶解酸素濃度制御方法。2. The method for controlling the concentration of dissolved oxygen in liquid metal according to claim 1, wherein the mixed conductor is made of a defective perovskite oxide.
ス、鉛ビスマス合金のいずれかであることを特徴とする
請求項１又は２記載の液体金属中の溶解酸素濃度制御方
法。3. The method for controlling the concentration of dissolved oxygen in a liquid metal according to claim 1 or 2, wherein the liquid metal is essentially one of lead, bismuth and a lead-bismuth alloy.
特殊鋼、炭素鋼の中から選ばれた１種からなる容器に収
容することを特徴とする請求項１乃至３のいずれか１項
記載の液体金属中の溶解酸素濃度制御方法。4. The liquid metal is at least a low alloy steel,
The method for controlling the concentration of dissolved oxygen in liquid metal according to any one of claims 1 to 3, wherein the method is stored in a container made of one selected from special steel and carbon steel.
属の融点〜６５０℃であることを特徴とする請求項１乃
至４のいずれか１項記載の液体金属中の溶解酸素濃度制
御方法。5. The method for controlling the concentration of dissolved oxygen in liquid metal according to claim 1, wherein the temperature range of the liquid metal is a melting point of the liquid metal to 650 ° C.
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|---|---|---|---|
| JP2001245394A JP4488658B2 (en) | 2001-08-13 | 2001-08-13 | Method for controlling dissolved oxygen concentration in liquid metal |
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ID=19075152
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3056266A4 (en) * | 2013-08-26 | 2017-07-19 | Joint Stock Company "Akme-Engineering" | Mass transfer apparatus |
| KR101797093B1 (en) | 2013-11-12 | 2017-11-13 | 조인트 스탁 컴퍼니 ″아크메-엔지니어링″ | Liquid metal cooled nuclear reactor, system for monitoring oxygen thermodynamic activity in such reactors and method for monitoring oxygen thermodynamic activity |
| CN115354271A (en) * | 2022-08-22 | 2022-11-18 | 中国科学技术大学 | Systems and methods for mitigating corrosion of lead-cooled fast reactor fuel assembly rod bundle cladding |
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|---|---|---|---|---|
| JPH01291151A (en) * | 1988-05-18 | 1989-11-22 | Chichibu Cement Co Ltd | Oxygen sensor |
| JPH04177200A (en) * | 1990-11-13 | 1992-06-24 | Mitsubishi Heavy Ind Ltd | Operation of liquid metal purification system |
| JPH11269684A (en) * | 1998-03-20 | 1999-10-05 | Japan Atom Energy Res Inst | Electrochemical reactor |
| JP2001108793A (en) * | 1999-10-13 | 2001-04-20 | Mitsubishi Heavy Ind Ltd | Method and apparatus for purifying lead-bismuth eutectic alloy |
| JP2001272493A (en) * | 2000-03-28 | 2001-10-05 | Tokyo Inst Of Technol | Lead-based metal circulation device |
-
2001
- 2001-08-13 JP JP2001245394A patent/JP4488658B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01291151A (en) * | 1988-05-18 | 1989-11-22 | Chichibu Cement Co Ltd | Oxygen sensor |
| JPH04177200A (en) * | 1990-11-13 | 1992-06-24 | Mitsubishi Heavy Ind Ltd | Operation of liquid metal purification system |
| JPH11269684A (en) * | 1998-03-20 | 1999-10-05 | Japan Atom Energy Res Inst | Electrochemical reactor |
| JP2001108793A (en) * | 1999-10-13 | 2001-04-20 | Mitsubishi Heavy Ind Ltd | Method and apparatus for purifying lead-bismuth eutectic alloy |
| JP2001272493A (en) * | 2000-03-28 | 2001-10-05 | Tokyo Inst Of Technol | Lead-based metal circulation device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3056266A4 (en) * | 2013-08-26 | 2017-07-19 | Joint Stock Company "Akme-Engineering" | Mass transfer apparatus |
| KR101797093B1 (en) | 2013-11-12 | 2017-11-13 | 조인트 스탁 컴퍼니 ″아크메-엔지니어링″ | Liquid metal cooled nuclear reactor, system for monitoring oxygen thermodynamic activity in such reactors and method for monitoring oxygen thermodynamic activity |
| CN115354271A (en) * | 2022-08-22 | 2022-11-18 | 中国科学技术大学 | Systems and methods for mitigating corrosion of lead-cooled fast reactor fuel assembly rod bundle cladding |
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|---|---|
| JP4488658B2 (en) | 2010-06-23 |
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