JPS6140343B2 - - Google Patents
Info
- Publication number
- JPS6140343B2 JPS6140343B2 JP55174249A JP17424980A JPS6140343B2 JP S6140343 B2 JPS6140343 B2 JP S6140343B2 JP 55174249 A JP55174249 A JP 55174249A JP 17424980 A JP17424980 A JP 17424980A JP S6140343 B2 JPS6140343 B2 JP S6140343B2
- Authority
- JP
- Japan
- Prior art keywords
- sulfur
- metal
- sulfide
- standard electrode
- amount
- 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.)
- Expired
Links
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims description 57
- 229910052717 sulfur Inorganic materials 0.000 claims description 57
- 239000011593 sulfur Substances 0.000 claims description 57
- 239000002184 metal Substances 0.000 claims description 38
- 229910052751 metal Inorganic materials 0.000 claims description 37
- 238000000034 method Methods 0.000 claims description 26
- 229910052976 metal sulfide Inorganic materials 0.000 claims description 19
- 239000000126 substance Substances 0.000 claims description 15
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims description 13
- 239000002203 sulfidic glass Substances 0.000 claims description 11
- 239000000203 mixture Substances 0.000 claims description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 18
- 229910052760 oxygen Inorganic materials 0.000 description 18
- 239000001301 oxygen Substances 0.000 description 18
- 230000003647 oxidation Effects 0.000 description 11
- 238000007254 oxidation reaction Methods 0.000 description 11
- 239000007789 gas Substances 0.000 description 9
- 238000005259 measurement Methods 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 6
- -1 alkaline earth metal sulfides Chemical class 0.000 description 6
- 238000004458 analytical method Methods 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 239000003779 heat-resistant material Substances 0.000 description 5
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 229910000805 Pig iron Inorganic materials 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 238000006477 desulfuration reaction Methods 0.000 description 3
- 230000023556 desulfurization Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 150000003568 thioethers Chemical class 0.000 description 3
- PAYRUJLWNCNPSJ-UHFFFAOYSA-N Aniline Chemical compound NC1=CC=CC=C1 PAYRUJLWNCNPSJ-UHFFFAOYSA-N 0.000 description 2
- 238000009529 body temperature measurement Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000012733 comparative method Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000010079 rubber tapping Methods 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000004448 titration Methods 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- 229910000915 Free machining steel Inorganic materials 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000012958 reprocessing Methods 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007784 solid electrolyte Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000000870 ultraviolet spectroscopy Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/403—Cells and electrode assemblies
- G01N27/406—Cells and probes with solid electrolytes
- G01N27/411—Cells and probes with solid electrolytes for investigating or analysing of liquid metals
- G01N27/4112—Composition or fabrication of the solid electrolyte
- G01N27/4114—Composition or fabrication of the solid electrolyte for detection of gases other than oxygen
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Description
本発明は物質、例えば溶融金属、ガス中の硫黄
量の迅速測定法に関する。
溶銑、溶鋼等の溶融鉄（合金を含む）中に硫黄
が含有されていると、含硫黄快削鋼等の特別な場
合は別として、一般にその鉄鋼材料の性質、例え
ば、機械的強度を劣化させる等の問題を生じるた
め、鉄鋼の製造時に常時硫黄含有量を監視し、所
望の材料に適した範囲に維持する必要がある。そ
こで、このような鉄鋼材料の硫黄量の管理を適格
に行なうためには、その測定、分析が極めて重要
なウエイトを占めることになる。
従来の硫黄の分析は、重量法、中和滴定法、沃
素滴定法およびパラゾールアニリン吸光光度法等
が行なわれていたが（これらはJISG1215で規定
されている。）、分析時間10分〜数10分と長く、ま
た、他に赤外線吸収法により金属中の硫黄を測定
する方法もあり（これはJIS規格に規定されてい
ない。）この方法は分析時間が１〜２分と短かい
が、サンプリングに熟練を要し、かつ、このサン
プリングを含めると５〜10分程度かかり全体とし
ての時間が長くなる。
そして、例えば、鉄鋼製錬において高炉出銑
時、溶銑鍋、混銑車、混銑炉などにおける溶銑の
脱硫処理、転炉吹錬、および、出鋼脱硫、取鍋精
錬のような溶鋼の各種の炉外脱硫処理等におい
て、上記した硫黄分析法のように硫黄分析に長時
間を要すると目標成分への対処がおくれ規格から
はずれたり、また、再吹錬や再処理までの待ち時
間が長くなり、この結果生産性が非常に低下する
という問題が生じる。
しかして、このような問題点に対処するために
本発明者等は硫黄量の迅速測定法を研究開発し、
（特願昭54―31748号特開昭55―124061号公報）お
よび、特願昭55―41090号（特開昭56―137148号
公報）として出願を完了している。この２つの方
法により溶融金属、例えば、溶銑中の硫黄量を測
定する場合、Ar雰囲気中においては硫黄量に応
じた起電力を発生するが（第１図Γ印参照）、大
気中或いは酸化性雰囲気における溶銑中の硫黄量
の測定においては起電力が高目になることがあつ
て、硫黄量に対応せず硫黄の定量が不可能になる
場合がある。これは種々検討した結果によれば主
に雰囲気中の酸素による標準極の酸化い起因する
ものであることがわかつたのである。
この標準極の酸化による起電力におよぼす影響
について説明すると、先ず、この硫黄量の測定法
の原理である濃淡電池は次に示すものである。
The present invention relates to a rapid method for determining the amount of sulfur in a substance, such as a molten metal or gas. When sulfur is contained in molten iron (including alloys) such as hot pig iron and molten steel, it generally deteriorates the properties of the steel material, such as mechanical strength, apart from special cases such as sulfur-containing free-cutting steel. Therefore, during the production of steel, it is necessary to constantly monitor the sulfur content and maintain it within a range suitable for the desired material. Therefore, in order to appropriately manage the sulfur content of such steel materials, its measurement and analysis are extremely important. Conventional sulfur analysis has been carried out by gravimetric method, neutralization titration method, iodine titration method, and parazole aniline absorption spectrophotometry method (these are specified in JISG1215), but the analysis time ranges from 10 minutes to several tens of minutes. There is also another method of measuring sulfur in metals using infrared absorption method (this is not stipulated by JIS standards).This method requires a short analysis time of 1 to 2 minutes, but This requires skill, and if this sampling is included, it takes about 5 to 10 minutes, which increases the overall time. For example, in iron and steel smelting, various furnaces for molten steel such as blast furnace tapping, desulfurization treatment of hot metal in hot metal ladle, pig iron mixer car, pig iron mixing furnace, converter blowing, tapping desulfurization, ladle refining, etc. In external desulfurization treatment, etc., if sulfur analysis takes a long time as in the sulfur analysis method described above, the target components may not be addressed and the product may deviate from the specifications, and the waiting time for reblowing or reprocessing may become longer. As a result, a problem arises in that productivity is greatly reduced. Therefore, in order to deal with such problems, the present inventors researched and developed a method for rapidly measuring the amount of sulfur.
Applications have been completed as Japanese Patent Application No. 54-31748 (Japanese Unexamined Patent Publication No. 55-124061) and Japanese Patent Application No. 55-41090 (Japanese Unexamined Patent Publication No. 56-137148). When measuring the amount of sulfur in molten metal, such as hot metal, using these two methods, an electromotive force corresponding to the amount of sulfur is generated in an Ar atmosphere (see the Γ mark in Figure 1), but in the atmosphere or in oxidizing When measuring the amount of sulfur in hot metal in an atmosphere, the electromotive force may be high and may not correspond to the amount of sulfur, making it impossible to quantify sulfur. According to the results of various studies, it was found that this was mainly due to oxidation of the standard electrode due to oxygen in the atmosphere. To explain the influence of the oxidation of the standard electrode on the electromotive force, first, the concentration cell which is the principle of this method for measuring the amount of sulfur is as follows.
【表】
ここでＰs2（），Ｐs2（）はそれぞれ標準
極、および、被測定物質である溶融金属極、また
は、ガス極の硫黄分圧である。この場合、イオン
伝導性を有する硫化物固体電解質のイオン輸率が
１の時、この濃淡電池の起電力Ｅは次式
（Nernstの式）で与えられ、式中Ｒはガス定数、
Ｆはフアラテ一定数である。
Ｅ＝ＲＴ／４ＦlnｐＳ２（）／ＰＳ２（）
なお、実際にはイオン伝導性を有する硫化物固
体電解質の輸率が１より小さく部分電子伝導の影
響を受ける場合がありその際には補正する必要が
ある。
一般に、溶融金属中の硫黄量を測定する際の標
準極は、一定の温度で一定の硫黄分圧が得られる
ように金属と金属硫化物の二相平衡混合物を使用
するのであるが、たとえ僅かのこの標準極、即
ち、金属＋金属硫化物が酸化することによつたて
生成する酸化物や硫化物が硫胃黄分圧に影響を与
え超電力は大きく変化する。さらに、酸素によつ
て標準極が酸化されると、標準極の平衡硫黄分圧
Ｐs2（）が変化するとともに標準極と溶融金属
との間に酸素分圧が発生し、酸素分圧と硫黄分圧
とが混在した形で起電力が生じるため、起電力は
溶融金属中の硫黄量に対応した値を示さなくな
る。
このような標準極の酸化は極力防止することが
必要であり、その防止策としては次に示す方法が
ある。
(1) 標準極を密閉して大気から遮断する。
(2) 標準極の雰囲気を制御する。
(3) 標準極の近傍に酸素ゲツターを配置する。
しかしながら、(1)の場合は標準極を完全に密閉
することは困難であり、密閉することによつて昇
温時の圧力で電解質を破損することもあり、ま
た、完全に密閉しても標準極を構成する金属と金
属硫化物の粉末の隙間に元々混入している酸素は
除くことはできない等の問題があり、さらに、(2)
の場合は標準極にArなどの不活性ガスを送給す
るか、または、封入することが考えられるが、送
給のためのポンプ、配管が必要となり、不便であ
り、かつ、煩雑となり、封入は溶融金属の温度に
おいて完全に封することは困難であり、たとえ封
入されたとしても昇温時の圧力の影響については
考慮しなければならず実用上難点がある。
さらに、(3)の場合は酸素ゲツターとして金属粉
を用いると金属は酸化して金属酸化物となり、溶
融金属中の酸素測定の標準極においては有効であ
るが、硫黄の測定に際しては全く効果がないばか
りか、逆に有害である。
さらに、上記(1)(2)の方法が具備する問題を解消
する簡便な方法として(3)の方法があるが、例え
ば、代表的な酸素ゲツターとして知られる易酸化
性金属（Na，ｋ，Ca，Mg等）を用いた場合は酸
素は除去されるもののこれに伴なつて生成する金
属酸化物がなお硫黄の分圧に悪影響を与え正確な
起電力が得られないという不利が生じる。そこ
で、本発明者等はこの(3)の方法に着目し、かつ、
酸素ゲツターとして最適な物質を選定すべく種々
の実験検討を積み重ねた結果本発明を完成するに
至つた。
本発明は上述してきたように溶融金属、ガスな
どに含まれている硫黄を高い精度で迅速に測定す
るに際しての種々の欠点や問題に鑑みなされたも
のでであつて、特に、溶融金属やガス中に含まれ
ている硫黄量を通常の大気圧下或いは酸化性雰囲
気下においても正確に測定することのできる硫黄
量の迅速測定法を提供するものである。
本発明に係る硫黄量の迅速測定法の特徴とする
ところは、一定の硫黄ポテンシヤルを有する金属
および金属硫化物混合体に、該金属および該金属
硫化物より酸化されやすい別の硫化物を共存させ
たものを標準極とし、硫黄を含有している被測定
物質を他方の電極とし、これらの両電極をイオン
伝導性を有する硫化物固体電解質で接続すること
により電池を形成して両電極間に生じる起電力を
測定し、同時に該物質の温度を測定し、この両測
定値より該物質中の硫黄量を求めることにある。
以下、本発明に係る硫黄量の迅速測定法につい
て詳細に説明する。
先づ、本発明に係る硫黄量の迅速測定法におい
て、基本的には、一定の硫黄ポテンシヤルを有す
る物質一方の電極（標準極）測定対象となる溶融
金属（または、ガス）を他方の電極となし、両電
極間をイオン伝導性を有する硫化物固体電解質に
より接続して電池を形成し、この電池の起電力並
びに溶融金属（または、ガス）の温度とから硫黄
量を求めるのである。
そして、この一定の硫黄ポテンシヤルを有する
物質の一方の電極、即ち、標準極として構成する
金属Ｍ、金属硫化物MSxの両物質の酸化を防止
するために、この金属Ｍ、金属硫化物MSxより
も酸化されやすい別の硫化物M′Syを混入したも
のを使用する。この場合、この標準極の起電力が
硫化物M′Sy、或いは、この硫化物M′Syが酸化し
てできたM′Oyの影響を受けないことが重要なこ
とである。
しかして、別の硫化物M′Syが金属硫化物MSx
により酸化されやすいということは、
M′Sy＋Ｙ／２O2＝M′Oy＋Ｙ／２S2の反応の自由エネル
ギ
ー変化△Ｇの絶対値が、
MSx＋Ｘ／２O2＝MOx＋Ｘ／２S2の反応の自由ェネルギー
変化△Ｇの絶対値より大きくなければならず、ま
た、別の硫化物M′Sy、或いは、生成酸化物M′Oy
が標準極の硫黄分圧Ｐs2（）に影響を与えない
ためにはM′とM′Syの平衡硫黄分圧がＰs2（）
よりも低くなければならず。M′とM′Oyの平衡酸
素分圧も極端に低くなければならないのである。
さらに、金属硫化物MSxと酸化されやすい別
の硫化物M′Syとは相互に溶け合つて融体とはな
らず、また、固体状態においても中間化合物
MM′wSzを生成せず、また、相互溶解度は極力小
さいものでなければならない。
この標準極を構成する金属と金属硫化物は、Ｗ
とWS2，M0とM0BS3，CrとCrS，またMnとMnS
などが用いられ、酸化されやすい別の硫化物とし
ては、MgS，CaSなどのアルカリ土類金属硫化
物、Y2S3，Ｌa2SC，Ｃe2S3などの希土類硫化物、
また、Tis2，ZrS2，HfS2などのチタン族硫化物
が適している。この酸化しやすい別の硫化物は標
準極を構成する物質の約20％末満とするのが好ま
しい範囲である。
同硫化物の共存のさせ方としては標準極を構成
する前記金属と金属硫化物と直接混合させても、
又酸素が侵入するこれらの金属および金属硫化物
の上部に充てんさせて良く、更なに両方法を併用
しても差支えない。
次に本発明の優れた効果を明らかにするため実
際の硫黄測定結果につき従来あるいは前述の他の
酸化対策として説明する。すなわち、第１図は大
気下において溶銑を対象とし後述の第２図ａに示
す硫黄測定装置を用いて起電力を実測し、この起
電力とこれから求められる硫黄量との関係を図示
したグラフで、図中、●印は標準極としてＷ＋
WS2にMgSを５重量％混合したものを用いた場合
（本発明法）、△印は標準極としてＷ＋WS2のみを
用い何ら酸化対策を施こさなかつた場合（従来
法）、又×印は標準極としてＷ＋WS2を用い酸化
対策として同極側にArガスを300c.c.／分の割合で
送給した場合（比較法）を示している。なお、こ
れらの測定結果の精度を確めるため同様にＷ＋
WS2を標準極としてAr雰囲気中で測定した結果
をΓ印として併せて図中に示した。
この第２図からわかるように、比較法（×印）
の場合は、標準極の酸化防止にはある程度の効果
が認められるもののArの供給に伴なう標準極の
温度低下に起因してAr雰囲気中での測定結果と
比べて起電力が低く、又従来法（△印）は雰囲気
の酸素の影響を受けて起電力が異常に高く測定精
度の上で全く問題とならず、しかして、本発明の
方法（●印）は第１図におけるAr雰囲気中の測
定結果とよく一致しており、極めて高い精度で測
定しうることが明らかである。
また、第２図ａは溶融金属を対象として本発明
に係る硫黄量の迅速測定法を実施するための装置
の１例を示す概略断面図であり（硫黄をを含有し
ている被測定物質については図示してない。）、即
ち、耐熱性管４内に一定の硫黄ポテンシヤルを有
する金属および金属硫化物混合体に、酸素ゲツタ
ーとして該金属および該金属硫化物よりも酸化さ
れやすい別の硫化物を混合させた標準極３と、こ
れに密接し、かつ、硫黄を含有している被測定物
質と接するイオン伝導性を有する硫化物固体電解
質（例えば、CaS―TcS2糸固体電解質）２とが
密着挿入されており、そして、これらの標準極３
とイオン伝導性を有する硫化物固体電解質２とに
接するリード線５と被測定物質と接するリード線
６とより構成されている起電力測定用電池が耐熱
性物質、例えば、アルミナセメント１１に保持さ
れており、また、被測定物質の温度を測定するシ
リカチユーブ８内にＰ系熱電対７よりなる温度測
定用熱電対が耐熱材１４に保持されており、起電
力測定用電池と温度測定用熱電対とを保持する耐
熱性物質１１および耐熱材１４は本体１に、それ
ぞれ下端が被測定物質に接するように固定されて
いるものである。なお、ガスを測定対象とする場
合は、耐熱性管４とリード線６を短絡させた装置
構成を採用する必要があることはいうまでもな
い。
第２図ｂは、一定の硫黄ポテンシヤルを有する
金属および金属硫化物混合体に、酸素ゲツターと
して該金属および該金属硫化物より酸化されやす
い別の硫化物を混合し、かつ、この混合層１３′
の上部にさらに同硫化物の単独層１３″を充填構
成した標準極１３を、イオン伝導性を有する硫化
物固体電解質（例えば、CaS―TcS2糸固体電解
質）で成形した坩堝状容器１２内に密着固定し、
この両者に接するようにリード線１５を設けた第
３図ａで示した耐熱性管４の代りにイオン伝導性
を有する硫化物固体電解質で成形した坩堝状容器
１２とした変形例である。このような構造にする
ことによつて、第３図ａの場合において何らかの
原因で、イオン伝導性を有する硫化物固体電解質
２と耐熱性管４との密着が破損すると、被測定物
質が破損部分から侵入して直接標準極３に接する
という不測の事態を防止することができると共に
標準極への酸素の侵入をより確実に排気すること
ができる。
以上説明したように、本発明に係る硫黄量の迅
速測定法は、上記の構成を有しているものである
から、大気下或いは酸化性雰囲気下においても雰
囲気中の酸素等に影響されることなく、比較的容
易に、かつ、使用される装置も簡単なもので、被
測定物中の硫黄量を極めて短時間に正確に測定す
ることができるものである。[Table] Here, P s2 () and P s2 () are the sulfur partial pressures of the standard electrode and the molten metal electrode or gas electrode, respectively, which are the substances to be measured. In this case, when the ionic transport number of the sulfide solid electrolyte with ionic conductivity is 1, the electromotive force E of this concentration cell is given by the following formula (Nernst's formula), where R is the gas constant,
F is a Huarate constant. E=RT/4Flnp S2 ()/P S2 () In reality, the transfer number of a sulfide solid electrolyte with ionic conductivity is smaller than 1 and may be affected by partial electron conduction, so in that case, it should be corrected. There is a need. Generally, the standard electrode used to measure the amount of sulfur in molten metal uses a two-phase equilibrium mixture of metal and metal sulfide to obtain a constant sulfur partial pressure at a constant temperature. The oxides and sulfides produced by the oxidation of this standard electrode, that is, metal + metal sulfide, affect the partial pressure of sulfur gas, and the superpower changes greatly. Furthermore, when the standard electrode is oxidized by oxygen, the equilibrium sulfur partial pressure P s2 () of the standard electrode changes and oxygen partial pressure is generated between the standard electrode and the molten metal, and the oxygen partial pressure and sulfur Since the electromotive force is generated in a mixed manner with the partial pressure, the electromotive force no longer shows a value corresponding to the amount of sulfur in the molten metal. It is necessary to prevent such oxidation of the standard electrode as much as possible, and the following methods can be used to prevent it. (1) Seal the standard electrode and isolate it from the atmosphere. (2) Control the atmosphere of the standard electrode. (3) Place an oxygen getter near the standard electrode. However, in the case of (1), it is difficult to completely seal the standard electrode. There are problems such as the fact that oxygen that is originally mixed in the gap between the metal and metal sulfide powder that makes up the electrode cannot be removed, and (2)
In this case, it is possible to supply or enclose an inert gas such as Ar to the standard electrode, but this requires a pump and piping for supply, which is inconvenient and complicated, so enclosing it is not recommended. It is difficult to completely seal the metal at the temperature of the molten metal, and even if the metal is sealed, the influence of pressure during temperature rise must be considered, which is a practical problem. Furthermore, in case (3), if metal powder is used as an oxygen getter, the metal will oxidize and become a metal oxide, which is effective as a standard electrode for measuring oxygen in molten metal, but is completely ineffective when measuring sulfur. Not only is it not possible, but it is actually harmful. Furthermore, method (3) is a simple method to solve the problems of methods (1) and (2) above. When oxygen is removed (Ca, Mg, etc.), the metal oxide produced along with this still adversely affects the partial pressure of sulfur, resulting in the disadvantage that accurate electromotive force cannot be obtained. Therefore, the present inventors focused on method (3), and
The present invention has been completed as a result of various experimental studies in order to select the most suitable substance as an oxygen getter. As mentioned above, the present invention was made in view of the various drawbacks and problems in rapidly and highly accurate measurement of sulfur contained in molten metals, gases, etc. The object of the present invention is to provide a rapid method for measuring the amount of sulfur contained in the sulfur content, which can accurately measure the amount of sulfur contained in the sulfur content even under normal atmospheric pressure or an oxidizing atmosphere. The rapid measurement method for sulfur content according to the present invention is characterized in that a metal and metal sulfide mixture having a certain sulfur potential coexists with another sulfide that is more easily oxidized than the metal and the metal sulfide. A battery is formed by connecting the two electrodes with a sulfide solid electrolyte with ionic conductivity, using the sulfur-containing sulfide solid electrolyte as the standard electrode and the sulfur-containing substance to be measured as the other electrode. The purpose is to measure the electromotive force generated and at the same time measure the temperature of the substance, and determine the amount of sulfur in the substance from these two measured values. Hereinafter, the method for rapidly measuring the amount of sulfur according to the present invention will be explained in detail. First, in the rapid method for measuring the amount of sulfur according to the present invention, basically, a substance having a certain sulfur potential is connected to one electrode (standard electrode), and the molten metal (or gas) to be measured is connected to the other electrode. A battery is formed by connecting both electrodes with a sulfide solid electrolyte having ionic conductivity, and the amount of sulfur is determined from the electromotive force of this battery and the temperature of the molten metal (or gas). In order to prevent the oxidation of one electrode of this material having a certain sulfur potential, that is, the metal M and the metal sulfide MSx, which constitute the standard electrode, the metal M and the metal sulfide MSx are A mixture containing M′Sy, another sulfide that is easily oxidized, is used. In this case, it is important that the electromotive force of this standard electrode is not affected by sulfide M'Sy or M'Oy produced by oxidation of this sulfide M'Sy. Therefore, another sulfide M′Sy is a metal sulfide MSx
The fact that it is easily oxidized by M′Sy+Y/2O 2 = M′Oy+Y/2S 2 reaction free energy change △ is the absolute value of MSx+X/2O 2 = MOx+X/2S 2 reaction free energy change △ must be larger than the absolute value of G, and another sulfide M′Sy or the produced oxide M′Oy
In order for M′ and M′Sy to have no effect on the sulfur partial pressure P s2 () at the standard electrode, the equilibrium sulfur partial pressure of M′ and M′Sy must be P s2 ()
Must be lower than . The equilibrium oxygen partial pressures of M' and M'Oy must also be extremely low. Furthermore, the metal sulfide MSx and another easily oxidized sulfide M′Sy do not melt together to form a melt, and even in the solid state they form intermediate compounds.
It must not produce MM′wSz, and the mutual solubility must be as small as possible. The metal and metal sulfide that make up this standard electrode are W
and WS 2 , M 0 and M 0 BS 3 , Cr and CrS, and Mn and MnS
Other easily oxidized sulfides include alkaline earth metal sulfides such as MgS and CaS, rare earth sulfides such as Y 2 S 3 , L a2 SC and C e2 S 3 ,
Also suitable are titanium group sulfides such as Tis 2 , ZrS 2 and HfS 2 . Preferably, the content of this easily oxidized sulfide is less than about 20% of the material constituting the standard electrode. As for how to make the same sulfide coexist, even if the metal composing the standard electrode and the metal sulfide are directly mixed,
Further, the upper part of these metals and metal sulfides into which oxygen enters may be filled, and both methods may be used in combination. Next, in order to clarify the excellent effects of the present invention, actual sulfur measurement results will be explained as conventional or other oxidation countermeasures as described above. In other words, Figure 1 is a graph illustrating the relationship between the electromotive force and the amount of sulfur determined from the measured electromotive force of hot metal in the atmosphere using the sulfur measuring device shown in Figure 2a (described later). , In the figure, the ● mark is W+ as the standard pole.
When WS 2 mixed with 5% by weight of MgS is used (inventive method), △ indicates the case when only W+WS 2 is used as the standard electrode and no oxidation measures are taken (conventional method), and × indicates the case when no oxidation measures were taken (conventional method). This shows the case (comparative method) in which W+WS 2 was used as the standard electrode and Ar gas was fed to the same electrode at a rate of 300 c.c./min as a countermeasure against oxidation. In addition, to confirm the accuracy of these measurement results, W+
The results of measurements in an Ar atmosphere using WS 2 as a standard electrode are also shown in the figure as Γ symbols. As you can see from this Figure 2, the comparative method (x mark)
In this case, although some effect is observed in preventing oxidation of the standard electrode, the electromotive force is lower than that measured in an Ar atmosphere due to the temperature drop of the standard electrode caused by the supply of Ar. In the conventional method (marked with △), the electromotive force is abnormally high due to the influence of oxygen in the atmosphere, and there is no problem with measurement accuracy; however, the method of the present invention (marked with ●) It is clear that measurements can be made with extremely high precision. In addition, FIG. 2a is a schematic cross-sectional view showing an example of an apparatus for carrying out the method for rapidly measuring the amount of sulfur according to the present invention for molten metal (for substances to be measured containing sulfur). (not shown), that is, a metal and metal sulfide mixture having a certain sulfur potential in the heat-resistant tube 4 is provided with another sulfide that is more easily oxidized than the metal and the metal sulfide as an oxygen getter. A standard electrode 3 containing a mixture of These standard poles 3 are inserted closely.
A battery for measuring electromotive force, which is composed of a lead wire 5 in contact with a sulfide solid electrolyte 2 having ionic conductivity and a lead wire 6 in contact with a substance to be measured, is held in a heat-resistant material such as alumina cement 11. In addition, a thermocouple for temperature measurement consisting of a P-type thermocouple 7 is held in a heat-resistant material 14 in a silica tube 8 that measures the temperature of the substance to be measured, and a battery for measuring electromotive force and a thermocouple for temperature measurement are A heat-resistant material 11 and a heat-resistant material 14 holding the pair are fixed to the main body 1 so that their lower ends are in contact with the substance to be measured. It goes without saying that when a gas is to be measured, it is necessary to adopt an apparatus configuration in which the heat-resistant tube 4 and the lead wire 6 are short-circuited. FIG. 2b shows that a metal and metal sulfide mixture having a certain sulfur potential is mixed with another sulfide which is more easily oxidized than the metal and the metal sulfide as an oxygen getter, and this mixed layer 13'
A standard electrode 13, which is further filled with a single layer 13'' of the same sulfide on top of the sulfide, is placed in a crucible-shaped container 12 formed of a sulfide solid electrolyte having ionic conductivity (for example, CaS-TcS 2- thread solid electrolyte). Closely fixed,
In this modification, the heat-resistant tube 4 shown in FIG. 3a, in which a lead wire 15 is provided so as to be in contact with both, is replaced with a crucible-shaped container 12 formed of a sulfide solid electrolyte having ion conductivity. By adopting such a structure, if the close contact between the ion-conducting sulfide solid electrolyte 2 and the heat-resistant tube 4 is broken for some reason in the case shown in FIG. It is possible to prevent an unexpected situation in which oxygen enters the standard electrode and comes into direct contact with the standard electrode 3, and it is also possible to more reliably exhaust oxygen from entering the standard electrode. As explained above, since the method for rapidly measuring the amount of sulfur according to the present invention has the above-mentioned configuration, it is not affected by oxygen, etc. in the atmosphere even in the atmosphere or in an oxidizing atmosphere. It is relatively easy to use, the equipment used is simple, and the amount of sulfur in the object to be measured can be accurately measured in a very short time.
第１図は本発明に係る硫黄量の迅速測定法と他
の測定法との起電力と硫黄量との関係を示すグラ
フ、第２図ａ，ｂは本発明に係る硫黄量の迅速測
定法を実施する装置の１例を示す概略断面図であ
る。
１…本体、２，１２…イオン伝導性を有する硫
化物固体電解質、３，１３…標準極、４…耐熱性
管、５，６，１５…リード線、７…熱電体、８…
シリカチユープ、１１…耐熱性物質、１４…耐熱
材。
Fig. 1 is a graph showing the relationship between electromotive force and sulfur content between the method for rapidly measuring sulfur content according to the present invention and other measuring methods, and Fig. 2 a and b are graphs showing the rapid method for measuring sulfur content according to the present invention. 1 is a schematic cross-sectional view showing an example of an apparatus for carrying out. DESCRIPTION OF SYMBOLS 1... Main body, 2, 12... Sulfide solid electrolyte with ionic conductivity, 3, 13... Standard electrode, 4... Heat resistant tube, 5, 6, 15... Lead wire, 7... Thermoelectric body, 8...
Silica tube, 11... Heat-resistant substance, 14... Heat-resistant material.
Claims (1)
金属硫化物混合体に、該金属および該金属硫化物
よりも酸化されやすい別の硫化物を共存させたも
のを標準極とし、硫黄を含有している被測定物質
を他方の電極とし、これらの両電極をイオン伝導
性を有する硫化物固体電解質で接続することによ
り電池を形成して両電極間に生じる起電力を測定
し、同時に該物質の温度を測定し、この両測定値
より該物質中の硫黄量を求めることを特徴とする
硫黄量の迅速測定法。1. The standard electrode is a mixture of metal and metal sulfide having a certain sulfur potential, and another sulfide that is more easily oxidized than the metal and metal sulfide is used as a standard electrode. A substance is used as the other electrode, and a battery is formed by connecting both electrodes with a sulfide solid electrolyte with ionic conductivity, and the electromotive force generated between the two electrodes is measured, and the temperature of the substance is measured at the same time. A rapid method for measuring the amount of sulfur, characterized in that the amount of sulfur in the substance is determined from both of these measured values.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55174249A JPS5797441A (en) | 1980-12-10 | 1980-12-10 | Rapid measuring method for quantity of sulfur |
| US06/246,944 US4406754A (en) | 1980-03-28 | 1981-03-24 | Method and probe for the rapid determination of sulfur level |
| DE3112218A DE3112218C2 (en) | 1980-03-28 | 1981-03-27 | Measuring device for the determination of sulfur in gas and metal melts |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55174249A JPS5797441A (en) | 1980-12-10 | 1980-12-10 | Rapid measuring method for quantity of sulfur |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5797441A JPS5797441A (en) | 1982-06-17 |
| JPS6140343B2 true JPS6140343B2 (en) | 1986-09-09 |
Family
ID=15975317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55174249A Granted JPS5797441A (en) | 1980-03-28 | 1980-12-10 | Rapid measuring method for quantity of sulfur |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5797441A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB9300435D0 (en) * | 1993-01-12 | 1993-03-03 | Cookson Group Plc | Sensors for the analysis of molten metals |
| AT400440B (en) * | 1993-12-06 | 1995-12-27 | Vianova Kunstharz Ag | METHOD FOR THE PRODUCTION OF WATER-THINNABLE LACQUER AND THE USE THEREOF |
| JP4620503B2 (en) * | 2005-03-08 | 2011-01-26 | 三井造船株式会社 | Oxygen concentration sensor |
-
1980
- 1980-12-10 JP JP55174249A patent/JPS5797441A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5797441A (en) | 1982-06-17 |
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