JPH01222013A - Method for dephosphorizing molten chromium-containing iron - Google Patents
Method for dephosphorizing molten chromium-containing ironInfo
- Publication number
- JPH01222013A JPH01222013A JP63046940A JP4694088A JPH01222013A JP H01222013 A JPH01222013 A JP H01222013A JP 63046940 A JP63046940 A JP 63046940A JP 4694088 A JP4694088 A JP 4694088A JP H01222013 A JPH01222013 A JP H01222013A
- Authority
- JP
- Japan
- Prior art keywords
- molten iron
- bao
- flux
- dephosphorization
- naf
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 113
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 56
- 239000011651 chromium Substances 0.000 title claims description 37
- 238000000034 method Methods 0.000 title claims description 18
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 title claims description 12
- 229910052804 chromium Inorganic materials 0.000 title claims description 12
- 230000004907 flux Effects 0.000 claims abstract description 32
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 4
- 239000011574 phosphorus Substances 0.000 claims abstract description 4
- 230000001590 oxidative effect Effects 0.000 abstract description 9
- 229910000831 Steel Inorganic materials 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 239000010959 steel Substances 0.000 abstract description 6
- 229910001634 calcium fluoride Inorganic materials 0.000 abstract description 5
- 230000002829 reductive effect Effects 0.000 abstract description 5
- 229910001220 stainless steel Inorganic materials 0.000 abstract description 5
- 239000010935 stainless steel Substances 0.000 abstract description 4
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 2
- 229910052717 sulfur Inorganic materials 0.000 abstract description 2
- 239000011593 sulfur Substances 0.000 abstract description 2
- 230000003009 desulfurizing effect Effects 0.000 abstract 1
- 239000000203 mixture Substances 0.000 description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 11
- 229910052799 carbon Inorganic materials 0.000 description 11
- 238000002156 mixing Methods 0.000 description 9
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 6
- 229910000423 chromium oxide Inorganic materials 0.000 description 6
- 238000006477 desulfuration reaction Methods 0.000 description 6
- 230000023556 desulfurization Effects 0.000 description 6
- 238000007254 oxidation reaction Methods 0.000 description 5
- 238000002203 pretreatment Methods 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- 230000003647 oxidation Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 229910000975 Carbon steel Inorganic materials 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 229910014813 CaC2 Inorganic materials 0.000 description 1
- 108010062580 Concanavalin A Proteins 0.000 description 1
- XYFCBTPGUUZFHI-UHFFFAOYSA-N Phosphine Chemical compound P XYFCBTPGUUZFHI-UHFFFAOYSA-N 0.000 description 1
- 229910000963 austenitic stainless steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 238000007670 refining Methods 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
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
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。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for dephosphorizing chromium-containing molten iron 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、Ｃａ０−ＦｅＯ系
、ＣａＯ−ＣａＦ２−８ｉ０２−ＦｅＯ系、ＣａＯ−Ｎ
ａ２０−３ ｉ ０２−ＦｅＯ系、又はＮａ２ Ｃｏｎ
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銑中の
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) in stainless steel, high chromium (Cr) steel, etc. deteriorates the mechanical properties of the steel and reduces stress cracking resistance. Furthermore, P deteriorates the hot cracking properties 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, Ca0-FeO system, CaO-CaF2-8i02-FeO system, CaO-N
a20-3 i 02-FeO system or Na2 Con
A method of adding a flux such as a system is known. However, when these fluxes are added to molten iron containing Cr, the oxidation reaction of Cr proceeds preferentially, and the dephosphorization reaction hardly progresses.On the other hand, as a method that can dephosphorize molten iron containing Cr, , CaO-CaF2 system, CaC
Reductive dephosphorization methods using 2-CaF2-based or CaC2-only fluxes are known. In this method, molten iron is dephosphorized by transferring P in the hot metal into the slag as P3- by the reaction shown by the following formula (1).
３Ｃａ＋２Ｐ−（Ｃａ３ Ｐ２ ） −
（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イン（ＰＨ３
）ガスが発生するからである。3Ca+2P-(Ca3P2)-
(1) However, in this reductive dephosphorization method, it is necessary to dephosphorize in a non-oxidizing atmosphere, and it is also necessary to oxidize the slag after the dephosphorization treatment at a high temperature. This is because if the slag after dephosphorization is left unattended, it will react with H2O in the atmosphere through the reaction shown in equation 2 below, resulting in toxic phosphine (PH3).
) This is because gas is generated.
（ｃ ａ３ ｐ２＞ ＋ ３８２０
−３ （Ｃａ Ｏ） ＋ ２ Ｐ Ｈｓ −（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、Ｃ
ａ０−ＦｅＣｊｉ’２系、Ｃａ０−ＣａＣＪ１２系、Ｌ
ｉ２Ｃ○、系、もしくはＬｉ２ＣＯ３を含有するＣａＯ
−ＣａＦ２−Ｆｅ０系フラツグス、又はＢａＯ−ＢａＣ
ｆｆ１２−Ｃｒ２０３系もしくはＮａ４ Ｓ ｉ ０４
−ＮａＦ系フラックスがある。(ca3 p2> + 3820 -3 (CaO) + 2 PHs - (2) Due to these circumstances, in the reductive dephosphorization method, it is difficult to quickly dephosphorize a large amount of molten iron, Practicality is low.On the other hand, in the oxidative dephosphorization method, dephosphorization can be carried out under atmospheric pressure, and oxidation treatment of the slag produced by dephosphorization is not necessary.In this oxidative dephosphorization method, Cr The dephosphorization slag that can dephosphorize the molten iron containing C
a0-FeCji'2 series, Ca0-CaCJ12 series, L
i2C○, system, or CaO containing Li2CO3
-CaF2-Fe0 flags, or BaO-BaC
ff12-Cr203 series or Na4 Si 04
-There is a NaF-based 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者の脱燐
フラックスを使用すると、溶鉄中の炭素濃度［Ｃ％］が
５％以下に低くなり、脱燐反応が進行しないという欠点
があった。又、後者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。[Problem to be solved by the invention] However, in this oxidative dephosphorization method, when the former dephosphorization flux is used, the carbon concentration [C%] in the molten iron becomes low to 5% or less, and the dephosphorization reaction does not proceed. There was a drawback. Also, when using the latter flux,
Since these fluxes are extremely expensive, there is a problem in that the cost of dephosphorization treatment increases.
この発明はかかる事情に鑑みてなされたものであって、
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、Ｃ□ｒ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 was made in view of such circumstances, and
To provide a highly efficient and low-cost method for dephosphorizing chromium-containing molten iron such as stainless steel or high chromium (Cr) steel without causing oxidation loss of C□r regardless of its carbon concentration. With the goal.
［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、Ｃａ０
−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、前記フラックスは、ＢａＯを１０〜９０
重量％、ＮａＦを最大４０重量％、ＣａＯとＢａＯの総
量を６０〜１００重量％とじたものである。[Means for Solving the Problems] The method for dephosphorizing chromium-containing molten iron according to the present invention
- In a method for dephosphorizing chromium-containing molten iron by adding a BaO-NaF-based flux to chromium-containing molten iron to remove phosphorus from the molten iron, the flux contains 10 to 90% of BaO.
NaF is at most 40% by weight, and the total amount of CaO and BaO is 60 to 100% by weight.
［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。[Function] The inventors of the present application have carried out various experimental studies in order to develop a flux that can dephosphorize molten iron with a low carbon concentration with high efficiency without oxidizing Cr while taking advantage of the advantages of oxidative dephosphorization. As a result of repeated studies, it was found that a flux made by mixing CaO, BaO, and CaF2 had a high dephosphorization effect.
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０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。However, this flux cannot be said to have a sufficiently high dephosphorizing ability, especially in the low carbon concentration region of molten iron, and it was necessary to develop a flux with even higher dephosphorizing ability. Focusing on the fact that CaF2 has a complex effect on dephosphorization ability due to its formation as a seed,
It has been found that high dephosphorization ability can be obtained by using NaF as a substitute for NaF. Moreover, this CaO-BaO-
This invention was made based on the knowledge that NaF-based flux is low cost and highly practical. Note that 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。[Example] This invention will be described in detail below. In this invention, BaO is 10 to 90% by weight and NaF is up to 40% by weight.
A CaO-BaO-NaF flux is used in which the total amount of CaO and BaO is 60 to 100% by weight.
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、Ｃａ０−Ｂ ａｏ−ＮａＦ系フ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。In Figure 1, the horizontal axis shows the NaF blending ratio (wt%), the vertical axis shows the dephosphorization rate, and various BaO and NaF blending ratios (
(wt%), Ca0-B ao-NaF based 90%
%, the dephosphorization rate of molten iron by this flux is significantly reduced. For this reason, the blending ratio of BaO is 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。The numerical values in the graph indicate the blending value of BaO. The composition of molten iron before 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＠ｌ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ＩＫｇ当なり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 this Table 1, the unit is weight%, and the remainder is iron (
Fe) and unavoidable impurities. The dephosphorization rate is 16%
It was determined by melting 5 kg of Cr@l in a high-frequency melting furnace and adding 100 g of flux per I kg of molten iron to the molten iron. As is clear from Figure 1, when the NaF blending ratio is 40% or less, the dephosphorization rate is as high as 70% or more, but this N
When the aF blending ratio exceeds 40%, the dephosphorization rate decreases. Therefore, the blending ratio of NaF is at most 40%, 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（Ｃｒ２０Ｂ
＞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。In addition, as an oxidizing agent, for example, chromium oxide (Cr20B
> by adding 5 to 10% by weight, the dephosphorization rate can be increased. Examples of this invention will be described below.
I will explain in detail.
（実施例１）
この実施例においては、下記の第２表の処理前棚に記載
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２
０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ＩＫｇ当たり１００ｇ投入した。(Example 1) In this example, 5 kg of Cr-containing molten iron having the composition listed on the pre-treatment shelf in Table 2 below was melted in a high frequency furnace, and while this molten iron was maintained at 1400°C, CaO was melted. 2
100 g of a mixed flux having a composition of 0% by weight, 55% by weight of BaO, 20% by weight of NaF, and 5% by weight of chromium oxide was charged per Ikg of molten iron.
（但し、ｔｒは微量を示す）
この結果、第２表の処理後棚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。(However, tr indicates a trace amount.) As a result, molten iron having the composition described in the post-treatment shelf of Table 2 was obtained. In this case, the dephosphorization rate is 93% and the desulfurization rate is 97%. Further, in this dephosphorization treatment, almost no loss of Cr occurs.
（実施例２）
この実施例においては、下記の第３表の処理前棚に記載
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２
０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ＩＫｇ当たり１００ｇ投入した。この結果、第３
表の処理後棚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 Cr-containing molten iron having the composition listed on the pre-treatment shelf in Table 3 below was melted in a high frequency furnace, and while this molten iron was held at 1420°C, CaO was melted. 2
100 g of a mixed flux having a composition of 0% by weight, 55% by weight of BaO, 20% by weight of NaF, and 5% by weight of chromium oxide was charged per Ikg of molten iron. As a result, the third
After the treatment in the table, molten iron having the composition described on the shelf was obtained. In this case, the dephosphorization rate is 93% and the desulfurization rate is 97%. Further, in this dephosphorization treatment, almost no loss of Cr occurs.
（但し、ｔｒは微量を示す）
（実施例３）
この実施例においては、下記の第４表の処理前棚に記載
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２
０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ＩＫｇ当たり１００ｇ投入した。この結果、第４
表の処理後棚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。(However, tr indicates a trace amount.) (Example 3) In this example, 5 kg of Cr-containing molten iron having the composition listed in the pre-treatment shelf of Table 4 below was melted in a high frequency furnace, and this molten iron was When maintained at ℃, CaO is 2
100 g of a mixed flux having a composition of 0% by weight, 55% by weight of BaO, 20% by weight of NaF, and 5% by weight of chromium oxide was charged per Ikg of molten iron. As a result, the fourth
After the treatment in the table, molten iron having the composition described on the shelf was obtained. In this case, the dephosphorization rate is 74% and the desulfurization rate is 97%. Further, in this dephosphorization treatment, almost no loss of Cr occurs.
（但し、ｔｒは微量を示す）
（実施例４）
この実施例においては、下記の第５表の処理前棚に記載
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２
０重量％、ＢａＯが５５重置火、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ＩＫｇ当たり１００ｇ投入した。この結果、第５
表の処理浸種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。(However, tr indicates a trace amount.) (Example 4) In this example, 5 kg of Cr-containing molten iron having the composition listed in the pre-treatment shelf of Table 5 below was melted in a high frequency furnace, and this molten iron was When maintained at ℃, CaO is 2
100 g of a mixed flux having a composition of 0% by weight, 55% by weight of BaO, 20% by weight of NaF, and 5% by weight of chromium oxide was charged per Ikg of molten iron. As a result, the fifth
Molten iron having the composition described in the treatment seed in the table was obtained. In this case, the dephosphorization rate is 56% and the desulfurization rate is 94%. Further, in this dephosphorization treatment, almost no loss of Cr occurs.
（但し、ｔｒは微量を示す）
（実施例５）
この実施例においては、下記の第６表の処理前棚に記載
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２
０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ＩＫｇ当たり１００ｇ投入した。この結果、第６
表の処理浸種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。(However, tr indicates a trace amount.) (Example 5) In this example, 5 kg of Cr-containing molten iron having the composition listed in the pre-treatment shelf of Table 6 below was melted in a high frequency furnace, and this molten iron was When maintained at ℃, CaO is 2
100 g of a mixed flux having a composition of 0% by weight, 55% by weight of BaO, 20% by weight of NaF, and 5% by weight of chromium oxide was charged per Ikg of molten iron. As a result, the 6th
Molten iron having the composition described in the treatment seed in the table was obtained. In this case, the dephosphorization rate is 50% and the desulfurization rate is 94%. Further, in this dephosphorization treatment, almost no loss of Cr occurs.
（但し、ｔｒは微量を示す）
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％コが４％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表かられかるように、Ｃｒの酸化損失は
極めて少ない。(However, tr indicates a trace amount.) As described above, according to the flux defined in the present invention, Cr-containing molten iron can be dephosphorized with high efficiency without causing oxidation loss of Cr. FIG. 2 is a graph showing the relationship between the carbon concentration [C%] in Cr-containing molten iron on the horizontal axis and the dephosphorization rate on the vertical axis. FIG. 2 shows the dephosphorization rates of Examples 1 to 5 in relation to the carbon concentration [C%] in the molten iron, and the composition and amount of added flux are the same for each measured value. As is clear from Figure 2, even if the carbon concentration [C%] in the molten iron is less than 4%, the dephosphorization rate is as high as 50% or more, indicating a high dephosphorization rate over an extremely wide range of carbon concentrations. . Moreover, as can be seen from Tables 2 to 6, the oxidation loss of Cr is extremely small.
［発明の効果コ
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％コが４％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。[Effects of the Invention] According to this invention, while maintaining the advantages of the oxidative dephosphorization method,
Dephosphorization can be performed with high efficiency without substantially oxidizing loss of Cr over a wide range of carbon concentrations, including low carbon steels where the carbon concentration [C%] in molten iron is 4% or less.
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。FIG. 1 is a graph showing the relationship between the NaF blending ratio and the dephosphorization rate, and FIG. 2 is a graph showing the relationship between the carbon concentration [C%] in Cr-containing molten iron and the dephosphorization rate.
Claims (1)
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、前記フラックスは、ＢａＯを１０
〜９０重量％、ＮａＦを最大４０重量％、ＣａＯとＢａ
Ｏの総量を６０〜１００重量％であることを特徴とする
クロム含有溶鉄の脱燐方法。In a method for dephosphorizing chromium-containing molten iron by adding CaO-BaO-NaF-based flux to chromium-containing molten iron to remove phosphorus from the molten iron, the flux contains 10% of BaO.
~90 wt%, up to 40 wt% NaF, CaO and Ba
A method for dephosphorizing chromium-containing molten iron, characterized in that the total amount of O is 60 to 100% by weight.
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 true JPH01222013A (en) | 1989-09-05 |
| JPH0649894B2 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 |
|---|---|
| JPH0649894B2 (en) | 1994-06-29 |
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