JPH0649894B2 - Method for dephosphorizing molten iron containing chromium - Google Patents
Method for dephosphorizing molten iron containing chromiumInfo
- Publication number
- JPH0649894B2 JPH0649894B2 JP63046940A JP4694088A JPH0649894B2 JP H0649894 B2 JPH0649894 B2 JP H0649894B2 JP 63046940 A JP63046940 A JP 63046940A JP 4694088 A JP4694088 A JP 4694088A JP H0649894 B2 JPH0649894 B2 JP H0649894B2
- Authority
- JP
- Japan
- Prior art keywords
- molten iron
- dephosphorization
- flux
- cao
- bao
- 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 - Lifetime
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims description 116
- 229910052742 iron Inorganic materials 0.000 title claims description 57
- 239000011651 chromium Substances 0.000 title claims description 41
- 238000000034 method Methods 0.000 title claims description 18
- 229910052804 chromium Inorganic materials 0.000 title claims description 14
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims description 13
- 230000004907 flux Effects 0.000 claims description 30
- 239000000203 mixture Substances 0.000 claims description 19
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 15
- 229910052799 carbon Inorganic materials 0.000 claims description 15
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims description 3
- 239000011574 phosphorus Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 description 8
- 238000013329 compounding Methods 0.000 description 7
- 229910004261 CaF 2 Inorganic materials 0.000 description 6
- 229910000831 Steel Inorganic materials 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000006477 desulfuration reaction Methods 0.000 description 6
- 230000023556 desulfurization Effects 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 5
- 229910000423 chromium oxide Inorganic materials 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- 229910001220 stainless steel Inorganic materials 0.000 description 4
- 238000002156 mixing Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 description 1
- 229910004283 SiO 4 Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000002301 combined effect Effects 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- QDOXWKRWXJOMAK-UHFFFAOYSA-N dichromium trioxide Chemical compound O=[Cr]O[Cr]=O QDOXWKRWXJOMAK-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
【発明の詳細な説明】 ［産業上の利用分野］ この発明はステンレス鋼又は高クロム（Ｃｒ）鋼等のク
ロム含有溶鉄の脱燐方法に関する。The present invention relates to a method for dephosphorizing molten iron containing chromium such as stainless steel or high chromium (Cr) steel.
［従来の技術］ ステンレス鋼、又は高クロム（Ｃｒ）鋼等の燐（Ｐ）
は、鋼の機械的性質を劣化させ、耐応力割れ性を低下さ
せる。また、Ｐはオーステナイト系ステンレス鋼の高温
割れ特性並びにフェライト系ステンレス鋼の張り出し成
形性を低下させる。このため、これらの鋼の精錬の際
に、溶鉄を脱燐する必要がある。普通炭素鋼の脱燐方法
としては、溶解酸素が高い溶融炭素鋼に、ＣａＯ−Ｆｅ
Ｏ系、ＣａＯ−ＣａＦ２−ＳｉＯ２−ＦｅＯ系、ＣａＯ
−Ｎａ２Ｏ−ＳｉＯ２−ＦｅＯ系、又はＮａ２ＣＯ３系
等のフラックスを添加する方法が公知である。しかし、
これらのフラックスをＣｒを含有する溶鉄に添加する
と、Ｃｒの酸化反応が優先的に進行し、脱燐反応はほと
んど進行しない。一方、Ｃｒを含有する溶鉄を脱燐する
ことができる方法として、ＣａＯ−ＣａＦ２系、ＣａＣ
２−ＣａＦ２系又はＣａＣ２単独フラックスを使用する
還元脱燐方法が公知である。この方法において溶鉄中の
Ｐを下記（１）式にて示す反応により、Ｐ３−としてス
ラグ中に移行させることによって溶鉄を脱燐する。[Prior Art] Phosphorus (P) such as stainless steel or high chromium (Cr) steel
Reduces the mechanical properties of the steel and reduces the stress crack resistance. Further, P deteriorates the hot cracking property of austenitic stainless steel and the stretch formability of ferritic stainless steel. Therefore, when refining these steels, it is necessary to dephosphorize the molten iron. As a dephosphorization method for ordinary carbon steel, CaO-Fe is added to molten carbon steel with high dissolved oxygen.
O system, CaO-CaF 2 -SiO 2 -FeO system, CaO
A method of adding a flux of —Na 2 O—SiO 2 —FeO system or Na 2 CO 3 system is known. But,
When these fluxes are added to molten iron containing Cr, the oxidation reaction of Cr preferentially proceeds and the dephosphorization reaction hardly proceeds. On the other hand, as a method capable of dephosphorizing molten iron containing Cr, CaO-CaF 2 system, CaC
2 -CaF 2 system or CaC 2 alone flux reduction dephosphorization method of using are known. In this method, the molten iron is dephosphorized by transferring P in the molten iron into the slag as P 3− by the reaction represented by the following formula (1).
３Ｃａ＋２Ｐ→（Ｃａ３Ｐ２） …（１） しかし、この還元脱燐方法においては、非酸化性雰囲気
で脱燐する必要があり、又、脱燐処理後のスラグを高温
で酸化処理する必要がある。これは脱燐処理後のスラグ
を放置すると、下記（２）式にて示す反応により大気中
のＨ２Ｏと反応して有毒なフォスフィン（ＰＨ３）ガス
が発生するからである。3Ca + 2P → (Ca 3 P 2 ) (1) However, in this reductive dephosphorization method, it is necessary to dephosphorize in a non-oxidizing atmosphere, and it is necessary to oxidize the slag after the dephosphorizing treatment at a high temperature. is there. This is because if the slag after the dephosphorization treatment is left as it is, the toxic phosphine (PH 3 ) gas is generated by reacting with H 2 O in the atmosphere by the reaction represented by the following formula (2).
（Ｃａ３Ｐ２）＋３Ｈ２Ｏ →３（ＣａＯ）＋２ＰＨ３ …（２） このような事情から、還元脱燐法においては、大量の溶
鉄を迅速に脱燐処理することは困難であり、実用性が低
い。一方、酸化脱燐方法においては、大気圧下で脱燐処
理することができ、又、脱燐により生成したスラグの酸
化処理が不要である。この酸化脱燐方法において、Ｃｒ
含有溶鉄を脱燐することができる脱燐スラグとしては、
ＣａＯ−ＦｅＣｌ２系、ＣａＯ−ＣａＣｌ２系、Ｌｉ２
ＣＯ３系、ももしくはＬｉ２ＣＯ３を含有するＣａＯ−
ＣａＦ２−ＦｅＯ系フラックス、又はＢａＯ−ＢａＣｌ
２−Ｃｒ２Ｏ３系もしくはＮａ４ＳｉＯ４−ＮａＦ系フ
ラックスがある。(Ca 3 P 2 ) + 3H 2 O → 3 (CaO) + 2PH 3 (2) Under such circumstances, it is difficult to rapidly dephosphorize a large amount of molten iron in the reductive dephosphorization method, and it is practical. It is not very popular. On the other hand, in the oxidative dephosphorization method, the dephosphorization treatment can be performed under atmospheric pressure, and the slag produced by the dephosphorization need not be oxidized. In this oxidative dephosphorization method, Cr
As the dephosphorization slag capable of dephosphorizing the contained molten iron,
CaO-FeCl 2 system, CaO-CaCl 2 system, Li 2
CO 3 system, or CaO − containing Li 2 CO 3
CaF 2 -FeO based flux or BaO-BaCl
There are 2 -Cr 2 O 3 system or Na 4 SiO 4 -NaF type flux.
［発明が解決しようとする課題］ しかしながら、この酸化脱燐方法においては、前記した
ＣａＯ−ＦｅＣｌ２系、ＣａＯ−ＣａＣｌ２系等の脱燐
フラックスを用いて脱燐処理を行うと、酸化脱燐反応は
溶鉄中の炭素濃度〔Ｃ％〕が５％以上の場合には進行す
るが、炭素濃度〔Ｃ％〕が５％以下の場合には進行せ
ず、Ｃｒの酸化反応が起こると言う問題があった。又、
Ｌｉ２ＣＯ３系等のフラックスを使用したときには、こ
れらのフラックスが極めて高価であるため、脱燐処理コ
ストが上昇するという問題があった。[Problems to be Solved by the Invention] However, in the oxidative dephosphorization method, when the dephosphorization treatment is performed using the dephosphorization flux of the above-mentioned CaO-FeCl 2 system, CaO-CaCl 2 system, etc. The reaction proceeds when the carbon concentration [C%] in the molten iron is 5% or more, but does not proceed when the carbon concentration [C%] is 5% or less, and an oxidation reaction of Cr occurs. was there. or,
When Li 2 CO 3 based flux is used, there is a problem that the dephosphorization treatment cost increases because these fluxes are extremely expensive.
この発明は、溶鉄中の炭素濃度が低い場合には脱燐反応
が進行しないと言う従来技術の問題点を解決したもので
あって、ステンレス鋼又は高クロム（Ｃｒ）鋼等のクロ
ムを含有する溶鉄をその炭素濃度に拘らず、Ｃｒを酸化
損失させることなく、高効率かつ低コストな含有溶鉄の
脱燐方法を提供することを目的とする。This invention solves the problem of the prior art that the dephosphorization reaction does not proceed when the carbon concentration in molten iron is low, and it contains chromium such as stainless steel or high chromium (Cr) steel. It is an object of the present invention to provide a highly efficient and low-cost dephosphorization method of molten iron contained in molten iron regardless of its carbon concentration without causing oxidation loss of Cr.
［課題を解決するための手段］ この発明に係わるクロム含有溶鉄の脱燐方法は、ＣａＯ
−ＢａＯ−ＮａＦ系フラックスをクロムを含有する溶鉄
に添加して溶鉄中の燐を除去するクロム含有溶鉄の脱燐
方法において、ＢａＯを１０〜９０重量％、ＮａＦを最
大40重量％、ＣａＯとＢａＯの総量を60〜100重量％に
した組成のフラックスを、クロムを含有し且つ炭素濃度
が５％以下の溶鉄に添加する。[Means for Solving the Problems] The method for dephosphorizing molten iron containing chromium according to the present invention is based on CaO.
In a dephosphorization method of molten iron containing chromium, wherein BaO-NaF flux is added to molten iron containing chromium to remove phosphorus in the molten iron, 10 to 90% by weight of BaO, 40% by weight of NaF at the maximum, CaO and BaO are added. A flux having a composition of 60 to 100% by weight is added to molten iron containing chromium and having a carbon concentration of 5% or less.
［作用］ 本願発明者等は酸化脱燐の利点を生かしつつ、炭素濃度
が低い溶鉄に対してもＣｒを酸化させることなく高効率
で脱燐することができるフラックスを開発すべく種々実
験研究を重ねた結果、ＣａＯとＢａＯとＣａＦ２とを混
合させたフラックスが高脱燐効果を有していることを見
出した。しかしながらこのフラックスは特に溶鉄中低炭
素濃度域では脱燐能が充分高いとは言えず、更に高い脱
燐能を持つフラックスを開発する必要があった。本願発
明者等はフラックス中のカチオンが２種になったことに
よって脱燐能に対して複合効果を生ずることに着目し、
ＣａＦ２の代替としてＮａＦを使用することによって高
い脱燐能を得ることを見出した。しかも、このＣａＯ−
ＢａＯ−ＮａＦ系フラックスは低コストであり実用性が
高い。この発明は、このような知見に基づいてなされた
ものである。なお、このフラックスの添加により脱硫反
応も生じ、溶鉄中の硫黄濃度［Ｓ％］も低下する。[Operation] The inventors of the present application have conducted various experimental studies in order to develop a flux capable of efficiently dephosphorizing molten iron having a low carbon concentration without oxidizing Cr, while taking advantage of the advantages of oxidative dephosphorization. As a result of stacking, it was found that the flux obtained by mixing CaO, BaO and CaF 2 has a high dephosphorization effect. However, this flux cannot be said to have a sufficiently high dephosphorization ability especially in the low carbon concentration region in molten iron, and it was necessary to develop a flux having a higher dephosphorization ability. The inventors of the present application have noticed that the combination of two kinds of cations in the flux produces a combined effect on the dephosphorization ability,
It has been found that a high dephosphorization capacity is obtained by using NaF as an alternative to CaF 2 . Moreover, this CaO-
BaO-NaF based flux is low in cost and highly practical. The present invention was made based on such knowledge. The addition of this flux also causes a desulfurization reaction, and the sulfur concentration [S%] in the molten iron also decreases.
［実施例］ 以下、この発明について詳細に説明する。この発明にお
いては、ＢａＯが１０〜９０重量％、ＮａＦが最大４０
重量％、ＣａＯとＢａＯの総量が６０〜１００重量％で
あるＣａＯ−ＢａＯ−ＮａＦ系フラックスを使用する。
第１図は、横軸にＮａＦの配合比（重量％）をとり、縦
軸に脱燐率をとって、種々のＢａＯ及びＮａＦ配合比
（重量％）について、ＣａＯ−ＢａＯ−ＮａＦ系フラッ
クスの脱燐率を示すグラフである。なお、グラフ中の数
値ＢａＯの配合比が１０％未満及び９０％超の場合に
は、このフラックスによる溶鉄の脱燐率が著しく低下す
る。このためＢａＯの配合率を１０〜９０％とした。[Examples] Hereinafter, the present invention will be described in detail. In this invention, BaO is 10 to 90% by weight, and NaF is 40 at the maximum.
A CaO-BaO-NaF-based flux having a weight percentage of CaO and BaO of 60 to 100 wt% is used.
In FIG. 1, the abscissa represents the NaF compounding ratio (% by weight) and the ordinate represents the dephosphorization rate. For various BaO and NaF compounding ratios (% by weight), the CaO-BaO-NaF system flux It is a graph which shows a dephosphorization rate. When the compounding ratio of the numerical value BaO in the graph is less than 10% or more than 90%, the dephosphorization rate of molten iron due to this flux is significantly reduced. Therefore, the blending ratio of BaO is set to 10 to 90%.
グラフ中の数値はＢａＯの配合値を示す。脱燐処理前の
溶鉄組成は下記の第１表に示す通りである。Numerical values in the graph indicate the blending value of BaO. The molten iron composition before the dephosphorization treatment is as shown in Table 1 below.
この第１表において、単位は重量％であり、残部は鉄
（Ｆｅ）及び不可避不純物である。脱燐率は、この１６
％Ｃｒ鋼を高周波溶解炉で５Ｋｇ溶解し、この溶鉄にフ
ラックスを溶鉄１Ｋｇ当たり１００ｇ投入することによ
り求めた。第１図から明らかなようにＮａＦの配合比が
４０％以下の場合は脱燐率が７０％以上と高いがこのＮ
ａＦ配合比が４０％を超えると、脱燐率が低下する。こ
のため、ＮａＦの配合比は最大４０％であり、ＣａＯと
ＢａＯの総量（ＣａＯ＋ＢａＯ）は、６０〜１００重量
％である。 In Table 1, the unit is% by weight, and the balance is iron (Fe) and inevitable impurities. The dephosphorization rate is 16
% Cr steel was melted in a high frequency melting furnace for 5 kg, and 100 g of flux was added to this molten iron per 1 kg of molten iron. As is clear from FIG. 1, when the NaF compounding ratio is 40% or less, the dephosphorization rate is as high as 70% or more.
If the aF compounding ratio exceeds 40%, the dephosphorization rate decreases. Therefore, the compounding ratio of NaF is 40% at the maximum, and the total amount of CaO and BaO (CaO + BaO) is 60 to 100% by weight.
なお、酸化剤として、例えば酸化クロム（Ｃｒ２Ｏ３）
を５〜１０重量％添加することにより、脱燐速度を高め
ることができる。以下、この発明の実施例について、具
体的に説明する。The oxidizing agent may be, for example, chromium oxide (Cr 2 O 3 ).
The dephosphorization rate can be increased by adding 5 to 10% by weight. Examples of the present invention will be specifically described below.
（実施例１） この実施例においては、下記の第２表の処理前欄に記載
の組成を有するＣｒ含有溶鉄を高周波炉で５Ｋｇ溶解
し、この溶鉄を１４００℃に保持した状態で、ＣａＯが
２０重量％、ＢａＯが５５重量％、ＮａＦが２０重量％
及び酸化クロムを５重量％の組成を有する混合フラック
スを溶鉄１Ｋｇ当たり１００ｇ投入した。(Example 1) In this example, 5 kg of molten iron containing Cr having the composition described in the column before treatment in Table 2 below was melted in a high-frequency furnace and CaO was dissolved in the molten iron held at 1400 ° C. 20 wt%, BaO 55 wt%, NaF 20 wt%
Then, 100 g of a mixed flux having a composition of 5% by weight of chromium oxide was added per 1 kg of molten iron.
この結果、第２表の処理後欄に記載の組成を有する溶鉄
が得られた。この場合の脱燐率は９３％であり、脱硫率
は９７％である。又、この脱燐処理においては、Ｃｒの
損失はほとんど生じていない。 As a result, molten iron having the composition shown in the column after treatment in Table 2 was obtained. In this case, the dephosphorization rate is 93% and the desulfurization rate is 97%. Further, in this dephosphorization treatment, there is almost no loss of Cr.
（実施例２） この実施例においては、下記の第３表の処理前欄に記載
の組成を有するＣｒ含有溶鉄を高周波炉で５Ｋｇ溶解
し、この溶鉄を１４２０℃に保持した状態で、ＣａＯが
２０重量％、ＢａＯが５５重量％、ＮａＦが２０重量％
及び酸化クロムを５重量％の組成を有する混合フラック
スを溶鉄１Ｋｇ当たり１００ｇ投入した。この結果、第
３表の処理後欄に記載の組成を有する溶鉄が得られた。
この場合の脱燐率は９３％であり、脱硫率は９７％であ
る。又この脱燐処理においては、Ｃｒの損失はほとんど
生じていない。(Example 2) In this example, 5 kg of molten iron containing Cr having the composition described in the column before treatment in Table 3 below was melted in a high-frequency furnace, and CaO was dissolved in the molten iron held at 1420 ° C. 20 wt%, BaO 55 wt%, NaF 20 wt%
Then, 100 g of a mixed flux having a composition of 5% by weight of chromium oxide was added per 1 kg of molten iron. As a result, molten iron having the composition shown in the column after treatment in Table 3 was obtained.
In this case, the dephosphorization rate is 93% and the desulfurization rate is 97%. Also, in this dephosphorization treatment, almost no Cr loss occurred.
（実施例３） この実施例においては、下記の第４表の処理前欄に記載
の組成を有するＣｒ含有溶鉄を高周波炉で５Ｋｇ溶解
し、この溶鉄を１４７０℃に保持した状態で、ＣａＯが
２０重量％、ＢａＯが５５重量％、ＮａＦが２０重量％
及び酸化クロムを５重量％の組成を有する混合フラック
スを溶鉄１Ｋｇ当たり１００ｇ投入した。この結果、第
４表の処理後欄に記載の組成を有する溶鉄が得られた。
この場合の脱燐率は７４％であり、脱硫率は９７％であ
る。又、この脱燐処理においては、Ｃｒの損失はほとん
ど生じていない。 (Example 3) In this example, 5 kg of molten iron containing Cr having the composition described in the column before treatment in Table 4 below was melted in a high-frequency furnace, and CaO was dissolved in a state where the molten iron was held at 1470 ° C. 20 wt%, BaO 55 wt%, NaF 20 wt%
Then, 100 g of a mixed flux having a composition of 5% by weight of chromium oxide was added per 1 kg of molten iron. As a result, molten iron having the composition shown in the column after treatment in Table 4 was obtained.
In this case, the dephosphorization rate is 74% and the desulfurization rate is 97%. Further, in this dephosphorization treatment, there is almost no loss of Cr.
（実施例４） この実施例においては、下記の第５表の処理前欄に記載
の組成を有するＣｒ含有溶鉄を高周波炉で５Ｋｇ溶解
し、この溶鉄を１５２０℃に保持した状態で、ＣａＯが
２０重量％、ＢａＯが５５重量％、ＮａＦが２０重量％
及び酸化クロムを５重量％の組成を有する混合フラック
スを溶鉄１Ｋｇ当たり１００ｇ投入した。この結果、第
５表の処理後欄に記載の組成を有する溶鉄が得られた。
この場合の脱燐率は５６％であり、脱硫率は９４％であ
る。又、この脱燐処理においては、Ｃｒの損失はほとん
ど生じていない。 (Example 4) In this example, 5 kg of molten iron containing Cr having the composition described in the column before treatment in Table 5 below was melted in a high-frequency furnace, and CaO was dissolved in the molten iron held at 1520 ° C. 20 wt%, BaO 55 wt%, NaF 20 wt%
Then, 100 g of a mixed flux having a composition of 5% by weight of chromium oxide was added per 1 kg of molten iron. As a result, molten iron having the composition shown in the post-treatment column of Table 5 was obtained.
In this case, the dephosphorization rate is 56% and the desulfurization rate is 94%. Further, in this dephosphorization treatment, there is almost no loss of Cr.
（実施例５） この実施例においては、下記の第６表の処理前欄に記載
の組成を有するＣｒ含有溶鉄を高周波炉で５Ｋｇ溶解
し、この溶鉄を１５５０℃に保持した状態で、ＣａＯが
２０重量％、ＢａＯが５５重量％、ＮａＦが２０重量％
及び酸化クロムを５重量％の組成を有する混合フラック
スを溶鉄１Ｋｇ当たり１００ｇ投入した。この結果、第
６表の処理後欄に記載の組成を有する溶鉄が得られた。
この場合の脱燐率は５０％であり、脱硫率は９４％であ
る。又、この脱燐処理においては、Ｃｒの損失はほとん
ど生じていない。 (Example 5) In this example, 5 kg of molten iron containing Cr having the composition described in the column before treatment in Table 6 below was melted in a high frequency furnace, and CaO was dissolved in the molten iron held at 1550 ° C. 20 wt%, BaO 55 wt%, NaF 20 wt%
Then, 100 g of a mixed flux having a composition of 5% by weight of chromium oxide was added per 1 kg of molten iron. As a result, molten iron having the composition shown in the column after treatment in Table 6 was obtained.
In this case, the dephosphorization rate is 50% and the desulfurization rate is 94%. Further, in this dephosphorization treatment, there is almost no loss of Cr.
このように、本願発明にて規定したフラックスによれ
ば、Ｃｒ含有溶鉄を、Ｃｒを酸化損失させることなく、
高効率で脱燐することができる。第２図は横軸にＣｒ含
有溶鉄中の炭素濃度［Ｃ％］をとり、縦軸に脱燐率をと
った、両者の関係を示すグラフ図である。第２図は、前
記実施例１〜実施例５における脱燐率を溶鉄中の炭素濃
度［Ｃ％］について整理したものであり、添加フラック
スの組成及び添加量は各測定値でも同一である。第２図
から明らかなように溶鉄中の炭素濃度［Ｃ％］が５％以
下であっても、脱燐率は５０％以上と高く、極めて広い
炭素濃度範囲にわたって高い脱燐率を示している。しか
も、第２表〜第６表からわかるように、Ｃｒの酸化損失
は極めて少ない。 As described above, according to the flux defined in the present invention, molten Cr-containing iron does not cause oxidation loss of Cr,
Dephosphorization can be performed with high efficiency. FIG. 2 is a graph showing the relationship between the carbon concentration [C%] in the molten iron containing Cr on the horizontal axis and the dephosphorization rate on the vertical axis. FIG. 2 shows the dephosphorization rate in Examples 1 to 5 with respect to the carbon concentration [C%] in the molten iron, and the composition and the amount of the added flux are the same in each measured value. As is clear from FIG. 2, even if the carbon concentration [C%] in the molten iron is 5% or less, the dephosphorization rate is as high as 50% or more, showing a high dephosphorization rate over an extremely wide carbon concentration range. . Moreover, as can be seen from Tables 2 to 6, the oxidation loss of Cr is extremely small.
［発明の効果］ この発明によれば、酸化脱燐方法の利点を維持しつつ、
溶鉄中の炭素濃度［Ｃ％］が５％以下の低炭素鋼を含む
広範囲の炭素濃度にわたり、Ｃｒを実質的に酸化損失さ
せることなく、高効率で脱燐することができる。According to the present invention, while maintaining the advantages of the oxidative dephosphorization method,
Dephosphorization can be performed with high efficiency over a wide range of carbon concentrations including low carbon steel in which the carbon concentration [C%] in molten iron is 5% or less, without substantially oxidizing loss of Cr.
【図面の簡単な説明】 第１図はＮａＦ配合比と脱燐率との関係を示すグラフ
図、第２図はＣｒ含有溶鉄中の炭素濃度［Ｃ％］と脱燐
率の関係を示すグラフ図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing the relationship between the NaF compounding ratio and the dephosphorization rate, and FIG. 2 is a graph showing the relationship between the carbon concentration [C%] in molten Cr-containing iron and the dephosphorization rate. It is a figure.
Claims (1)
ロムを含有する溶鉄に添加して溶鉄中の燐を除去するク
ロム含有溶鉄の脱燐方法において、ＢａＯを１０〜９０
重量％、ＮａＦを最大４０重量％、ＣａＯとＢａＯの総
量を６０〜１００重量％にした組成のフラックスを、ク
ロムを含有し且つ炭素濃度が５％以下の溶鉄に添加する
ことを特徴とするクロム含有溶鉄の脱燐方法。1. A method for dephosphorizing chromium-containing molten iron by adding a CaO-BaO-NaF flux to molten iron containing chromium to remove phosphorus in the molten iron.
%, NaF at a maximum of 40% by weight, and a flux having a composition in which the total amount of CaO and BaO is 60 to 100% by weight is added to molten iron containing chromium and having a carbon concentration of 5% or less. Method for dephosphorizing molten iron containing iron.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63046940A JPH0649894B2 (en) | 1988-02-29 | 1988-02-29 | Method for dephosphorizing molten iron containing chromium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63046940A JPH0649894B2 (en) | 1988-02-29 | 1988-02-29 | Method for dephosphorizing molten iron containing chromium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01222013A JPH01222013A (en) | 1989-09-05 |
| JPH0649894B2 true JPH0649894B2 (en) | 1994-06-29 |
Family
ID=12761314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63046940A Expired - Lifetime JPH0649894B2 (en) | 1988-02-29 | 1988-02-29 | Method for dephosphorizing molten iron containing chromium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0649894B2 (en) |
-
1988
- 1988-02-29 JP JP63046940A patent/JPH0649894B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01222013A (en) | 1989-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3003865A (en) | Decarburizing process for alloy steels containing chromium | |
| JPS63481B2 (en) | ||
| JPH0649895B2 (en) | Method for dephosphorizing molten iron containing chromium | |
| JP4753504B2 (en) | Method for producing high purity Fe-Cr, Fe-Cr-Ni alloy | |
| JP2897640B2 (en) | Dephosphorization method of high chromium high manganese molten alloy iron | |
| JPH0649894B2 (en) | Method for dephosphorizing molten iron containing chromium | |
| JPH058251B2 (en) | ||
| JPH058250B2 (en) | ||
| JPS61153225A (en) | Method for dephosphorizing chromium-containing molten iron | |
| JPS61149422A (en) | Dephosphorization method for chromium-containing molten iron | |
| JP3221812B2 (en) | Low oxygen steel smelting method | |
| JP2607337B2 (en) | Method for dephosphorizing chromium-containing steel | |
| JP3169275B2 (en) | Dephosphorization of chromium-containing steel | |
| JPS6315965B2 (en) | ||
| JPS5856005B2 (en) | High chromium steel melting method | |
| JPH01215920A (en) | Method for dephosphorizing and desulfurizing molten iron alloy containing chromium | |
| JPH0676613B2 (en) | Dephosphorization method of high manganese molten iron | |
| JPS62224625A (en) | Dephosphorization method for chromium-containing molten iron | |
| JP2802799B2 (en) | Dephosphorization and desulfurization method for crude molten stainless steel and flux used for it | |
| JPS6254165B2 (en) | ||
| JPS6237686B2 (en) | ||
| JPS6214210B2 (en) | ||
| JPS6212300B2 (en) | ||
| JPS6157371B2 (en) | ||
| JPS61149421A (en) | Dephosphorizing method of chromium-containing molten iron |