JP2003328022A - Desulfurizing agent for molten steel and manufacturing method therefor - Google Patents
Desulfurizing agent for molten steel and manufacturing method thereforInfo
- Publication number
- JP2003328022A JP2003328022A JP2002141705A JP2002141705A JP2003328022A JP 2003328022 A JP2003328022 A JP 2003328022A JP 2002141705 A JP2002141705 A JP 2002141705A JP 2002141705 A JP2002141705 A JP 2002141705A JP 2003328022 A JP2003328022 A JP 2003328022A
- Authority
- JP
- Japan
- Prior art keywords
- desulfurizing agent
- molten steel
- source
- reo
- weight
- 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.)
- Pending
Links
- 230000003009 desulfurizing effect Effects 0.000 title claims abstract description 251
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 137
- 239000010959 steel Substances 0.000 title claims abstract description 137
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 42
- 238000002844 melting Methods 0.000 claims abstract description 75
- 230000008018 melting Effects 0.000 claims abstract description 75
- 239000000203 mixture Substances 0.000 claims abstract description 64
- 238000011282 treatment Methods 0.000 claims abstract description 26
- 238000010298 pulverizing process Methods 0.000 claims abstract description 17
- 238000000034 method Methods 0.000 claims abstract description 15
- 239000012535 impurity Substances 0.000 claims abstract description 14
- 238000010791 quenching Methods 0.000 claims abstract description 14
- 229910052761 rare earth metal Inorganic materials 0.000 claims abstract description 14
- 239000006104 solid solution Substances 0.000 claims abstract description 14
- 230000000171 quenching effect Effects 0.000 claims abstract description 13
- 238000010438 heat treatment Methods 0.000 claims abstract description 6
- 239000002994 raw material Substances 0.000 claims description 42
- 238000002156 mixing Methods 0.000 claims description 34
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 33
- 238000001816 cooling Methods 0.000 claims description 28
- 229910052751 metal Inorganic materials 0.000 claims description 26
- 239000002184 metal Substances 0.000 claims description 26
- 238000005054 agglomeration Methods 0.000 claims description 5
- 230000002776 aggregation Effects 0.000 claims description 5
- 238000005469 granulation Methods 0.000 claims description 5
- 230000003179 granulation Effects 0.000 claims description 5
- 239000003795 chemical substances by application Substances 0.000 abstract description 220
- 238000006477 desulfuration reaction Methods 0.000 abstract description 72
- 230000023556 desulfurization Effects 0.000 abstract description 72
- 230000002829 reductive effect Effects 0.000 abstract description 8
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 6
- 239000010436 fluorite Substances 0.000 abstract description 6
- 239000000243 solution Substances 0.000 abstract 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 88
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 51
- 239000000292 calcium oxide Substances 0.000 description 45
- 235000012255 calcium oxide Nutrition 0.000 description 44
- 239000000395 magnesium oxide Substances 0.000 description 25
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 23
- 239000013078 crystal Substances 0.000 description 19
- 239000002245 particle Substances 0.000 description 18
- 229910052717 sulfur Inorganic materials 0.000 description 16
- 230000005496 eutectics Effects 0.000 description 14
- 239000011593 sulfur Substances 0.000 description 14
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 13
- 238000006243 chemical reaction Methods 0.000 description 13
- 239000011777 magnesium Substances 0.000 description 12
- 239000011734 sodium Substances 0.000 description 11
- 238000005755 formation reaction Methods 0.000 description 9
- 230000015572 biosynthetic process Effects 0.000 description 8
- 239000000843 powder Substances 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 238000007670 refining Methods 0.000 description 7
- 238000005245 sintering Methods 0.000 description 7
- 229910004261 CaF 2 Inorganic materials 0.000 description 6
- XFWJKVMFIVXPKK-UHFFFAOYSA-N calcium;oxido(oxo)alumane Chemical compound [Ca+2].[O-][Al]=O.[O-][Al]=O XFWJKVMFIVXPKK-UHFFFAOYSA-N 0.000 description 6
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 description 6
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 229910052788 barium Inorganic materials 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000002893 slag Substances 0.000 description 5
- 238000005987 sulfurization reaction Methods 0.000 description 5
- 229910018404 Al2 O3 Inorganic materials 0.000 description 4
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- AYJRCSIUFZENHW-UHFFFAOYSA-L barium carbonate Chemical compound [Ba+2].[O-]C([O-])=O AYJRCSIUFZENHW-UHFFFAOYSA-L 0.000 description 4
- 229910052799 carbon Inorganic materials 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 150000003568 thioethers Chemical class 0.000 description 4
- 229910052684 Cerium Inorganic materials 0.000 description 3
- QVQLCTNNEUAWMS-UHFFFAOYSA-N barium oxide Inorganic materials [Ba]=O QVQLCTNNEUAWMS-UHFFFAOYSA-N 0.000 description 3
- 238000007664 blowing Methods 0.000 description 3
- 239000003153 chemical reaction reagent Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000010494 dissociation reaction Methods 0.000 description 3
- 230000005593 dissociations Effects 0.000 description 3
- 230000007613 environmental effect Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000001095 magnesium carbonate Substances 0.000 description 3
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 3
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 3
- 229910052976 metal sulfide Inorganic materials 0.000 description 3
- 229910052698 phosphorus Inorganic materials 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229910020203 CeO Inorganic materials 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- 229910010413 TiO 2 Inorganic materials 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000005280 amorphization Methods 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910002056 binary alloy Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000013329 compounding Methods 0.000 description 2
- 238000007872 degassing Methods 0.000 description 2
- 239000010459 dolomite Substances 0.000 description 2
- 229910000514 dolomite Inorganic materials 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000004484 Briquette Substances 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- ULGYAEQHFNJYML-UHFFFAOYSA-N [AlH3].[Ca] Chemical compound [AlH3].[Ca] ULGYAEQHFNJYML-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 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
- AYJRCSIUFZENHW-DEQYMQKBSA-L barium(2+);oxomethanediolate Chemical compound [Ba+2].[O-][14C]([O-])=O AYJRCSIUFZENHW-DEQYMQKBSA-L 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 229910000420 cerium oxide Inorganic materials 0.000 description 1
- IKNAJTLCCWPIQD-UHFFFAOYSA-K cerium(3+);lanthanum(3+);neodymium(3+);oxygen(2-);phosphate Chemical compound [O-2].[La+3].[Ce+3].[Nd+3].[O-]P([O-])([O-])=O IKNAJTLCCWPIQD-UHFFFAOYSA-K 0.000 description 1
- GHLITDDQOMIBFS-UHFFFAOYSA-H cerium(3+);tricarbonate Chemical compound [Ce+3].[Ce+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O GHLITDDQOMIBFS-UHFFFAOYSA-H 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- -1 conglomerate shale Inorganic materials 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 229910052747 lanthanoid Inorganic materials 0.000 description 1
- 150000002602 lanthanoids Chemical class 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 235000014380 magnesium carbonate Nutrition 0.000 description 1
- 238000007734 materials engineering Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 229910052590 monazite Inorganic materials 0.000 description 1
- BMMGVYCKOGBVEV-UHFFFAOYSA-N oxo(oxoceriooxy)cerium Chemical compound [Ce]=O.O=[Ce]=O BMMGVYCKOGBVEV-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 229910052706 scandium Inorganic materials 0.000 description 1
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 229910052727 yttrium Inorganic materials 0.000 description 1
- VWQVUPCCIRVNHF-UHFFFAOYSA-N yttrium atom Chemical compound [Y] VWQVUPCCIRVNHF-UHFFFAOYSA-N 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)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、溶鋼（例えば、普
通鋼用溶鋼、ステンレス用溶鋼等）の脱硫時に使用する
溶鋼用脱硫剤及びその製造方法に関する。TECHNICAL FIELD The present invention relates to a desulfurizing agent for molten steel used for desulfurizing molten steel (for example, molten steel for ordinary steel, molten steel for stainless steel, etc.) and a method for producing the same.
【０００２】[0002]
【従来の技術】鋼材製造時における精錬は、鋼材の高品
質化、高純度化の要求に対応して、溶銑予備処理、転炉
精錬、溶鋼二次精錬のフローが一般化しており、脱硫処
理はフローの各段階において重要な項目となっている。
そこで、従来、溶銑予備処理段階での脱硫処理では、脱
硫剤としてＣａＯを使用し、溶鋼中の硫黄を３０ｐｐｍ
程度まで低減している。また、溶鋼二次精錬段階では、
脱硫剤としてＣａＯ、Ｎａ2 ＣＯ3 、ＣａＣ2 、Ｍｇ、
カルシウムアルミネート（１２ＣａＯ・７Ａｌ2 Ｏ3 ）
等を溶鋼に添加して、溶鋼中の硫黄を１０ｐｐｍ程度
（例えば、１０ｐｐｍ以下）まで低減している。これに
より、硫黄の濃度が低い低硫鋼を製造している。なお、
脱硫効果を有するＣａＯは、融点が高く、しかも単独で
使用すると脱硫効率が低くなるので、溶鋼には融剤とし
て１０〜４０重量％程度のＣａＦ2 （蛍石）が添加され
ている。ここで、溶鋼二次精錬段階で溶鋼に添加される
脱硫剤は、以下に示すような反応模式で、溶鋼中の硫黄
成分と硫化物を生成する。
ＣａＯ＋Ｓ→ＣａＳ
Ｎａ2 ＣＯ3 ＋Ｓ→Ｎａ2 Ｓ
ＣａＣ2 ＋Ｓ→ＣａＳ
Ｍｇ＋Ｓ→ＭｇＳ
１２ＣａＯ・７Ａｌ2 Ｏ3 ＋Ｓ→ＣａＳ
上記したように、各脱硫剤はＣａＳ、Ｎａ2 Ｓ、ＭｇＳ
等の硫化物をそれぞれ生成し、この生成した硫化物が浮
上して、溶湯（溶鋼）溶面上の溶滓中に吸収される。こ
のとき、溶滓中に一旦分離した硫化物は、溶滓と溶湯と
の界面で解離し、復硫する反応も同時に進行する。この
脱硫と復硫の両作用が反復する中で最終的な脱硫目標が
達成される。2. Description of the Related Art In refining during steel production, the flow of hot metal pretreatment, converter refining, and secondary refining of molten steel has been generalized to meet the demands for high quality and high purity of steel, and desulfurization treatment. Is an important item at each stage of the flow.
Therefore, conventionally, in the desulfurization treatment at the hot metal pretreatment stage, CaO was used as a desulfurizing agent, and the sulfur in the molten steel was 30 ppm.
It has been reduced to some extent. In the molten steel secondary refining stage,
As desulfurizing agent, CaO, Na 2 CO 3 , CaC 2 , Mg,
Calcium aluminate (12CaO / 7Al 2 O 3 )
Etc. are added to the molten steel to reduce the sulfur in the molten steel to about 10 ppm (for example, 10 ppm or less). As a result, low-sulfur steel with a low sulfur concentration is manufactured. In addition,
CaO having a desulfurization effect has a high melting point and, when used alone, has a low desulfurization efficiency, so about 10 to 40% by weight of CaF 2 (fluorite) is added to the molten steel as a fluxing agent. Here, the desulfurizing agent added to the molten steel in the secondary refining stage of the molten steel produces a sulfur component and sulfide in the molten steel in a reaction pattern as shown below. CaO + S → CaS Na 2 CO 3 + S → Na 2 S CaC 2 + S → CaS Mg + S → MgS 12CaO · 7Al 2 O 3 + S → CaS As described above, the desulfurization agents are CaS, Na 2 S, and MgS.
And the like, and the generated sulfide floats and is absorbed in the molten slag on the molten surface of the molten metal (molten steel). At this time, the sulfide once separated in the slag is dissociated at the interface between the slag and the molten metal, and the reaction for re-sulfurization also proceeds at the same time. The final desulfurization target is achieved by repeating the actions of both desulfurization and re-sulfurization.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記し
た脱硫剤には、以下の問題がある。現在、環境に対する
フッ素の排出規制が実施されており、ＣａＦ2 の使用が
制限された場合、ＣａＯでの脱硫効果が低下し、脱硫剤
の使用原単位が大きくなり、溶鋼の温度低下、及び脱硫
スラグの発生量の増大をもたらす。また、Ｎａ2 ＣＯ3
の使用は、脱硫処理中に多量の白煙を発生させるため環
境保全の点で問題があり、またＮａ2 Ｏによる耐火物の
溶損も大きくなる。そして、ＣａＣ2 の使用は、脱硫処
理中にＣ2 Ｈ2 （アセチレン）ガスを発生させるため
に、環境保全策が必要となる。更に、Ｍｇ（金属Ｍｇ）
の使用は、脱硫効率を良好にするものの、高価であるた
め脱硫コストが高くなる。カルシウムアルミネートは、
融点が１３６０℃と低いものの、カルシウムアルミネー
トの生成範囲における低融点の領域が非常に狭く、操業
に難点がある。本発明はかかる事情に鑑みてなされたも
ので、従来使用されている蛍石を軽減もしくは使用する
ことなく、脱硫剤の融点を溶鋼の脱硫処理に使用可能な
温度に調整し、しかも脱硫効率の良好な溶鋼用脱硫剤及
びその製造方法を提供することを目的とする。However, the above desulfurizing agent has the following problems. Currently, there are restrictions on the release of fluorine to the environment, and if the use of CaF 2 is restricted, the desulfurization effect of CaO will decrease, the unit consumption of desulfurizing agents will increase, and the temperature of molten steel will decrease and Increases the amount of slag generated. In addition, Na 2 CO 3
The use of is problematic in terms of environmental protection because it produces a large amount of white smoke during the desulfurization process, and the melting loss of the refractory due to Na 2 O is also large. Further, the use of CaC 2 requires an environmental protection measure in order to generate C 2 H 2 (acetylene) gas during the desulfurization treatment. Furthermore, Mg (metal Mg)
Although it improves the desulfurization efficiency, it is expensive and the desulfurization cost is high. Calcium aluminate
Although the melting point is as low as 1360 ° C., the low melting point region in the production range of calcium aluminate is extremely narrow, which causes a problem in operation. The present invention has been made in view of such circumstances, without reducing or using conventionally used fluorite, the melting point of the desulfurization agent is adjusted to a temperature that can be used for desulfurization treatment of molten steel, and further desulfurization efficiency An object is to provide a good desulfurizing agent for molten steel and a method for producing the same.
【０００４】[0004]
【課題を解決するための手段】前記目的に沿う本発明に
係る溶鋼用脱硫剤は、溶鋼の脱硫に使用する脱硫剤であ
って、ＣａＯ：１０〜５５重量％、Ａｌ2 Ｏ3 ：２０〜
５５重量％、ＢａＯ：１〜３５重量％、ＲＥＯn ：１〜
４０重量％の成分を有し、残部が不可避的不純物からな
る。なお、ＲＥは希土類元素を示し、ＲＥＯn はその酸
化物を示す。このＲＥＯn とは、希土類元素（ｒａｒｅ
ｅａｒｔｈ ｅｌｅｍｅｎｔｓ：周期表３Ａ族のうち
スカンジウムとイットリウムにランタノイドを加えた１
７元素の総称）の酸化物の総称である。このように、Ｃ
ａＯとＡｌ2 Ｏ3 にＢａＯ及びＲＥＯn を添加すること
で、従来から溶鋼の脱硫に使用されてきた蛍石を、軽減
もしくは使用することなく、１２ＣａＯ・７Ａｌ2 Ｏ3
系脱硫剤より幅広い領域で低融点化を達成でき、しかも
脱硫剤の融点を、溶鋼の脱硫に使用可能な温度まで低下
させることが可能となる。また、ＣａＯとＡｌ2 Ｏ3 に
ＢａＯ及びＲＥＯn を添加することで、脱硫剤の融点を
更に低下させることが可能となる。そして、高温域での
硫化物の生成自由エネルギーが小さい元素であるＢａ及
びＲＥを有した脱硫剤を使用することで、脱硫剤と溶鋼
中の硫黄成分との結合エネルギーが大きい硫化物を生成
させることが可能となる。The desulfurizing agent for molten steel according to the present invention which meets the above-mentioned object is a desulfurizing agent used for desulfurizing molten steel, wherein CaO is 10 to 55% by weight and Al 2 O 3 is 20 to 20%.
55% by weight, BaO: 1-35% by weight, REO n : 1-
It has a content of 40% by weight and the balance consists of unavoidable impurities. RE represents a rare earth element, and REO n represents an oxide thereof. This REO n is a rare earth element (rare
earth elements: Scandium and yttrium of the Periodic Table 3A group with lanthanoids added 1
It is a general term for oxides of 7 elements). Thus, C
the aO and Al 2 O 3 by adding BaO and REO n, fluorite which has been used in the desulfurization of molten steel from the conventional, reduce or without the use, 12CaO · 7Al 2 O 3
The melting point can be lowered in a wider range than that of the system desulfurizing agent, and further, the melting point of the desulfurizing agent can be lowered to a temperature that can be used for desulfurizing molten steel. Also, by adding BaO and REO n to CaO and Al 2 O 3 , it becomes possible to further lower the melting point of the desulfurizing agent. Then, by using the desulfurizing agent having Ba and RE, which are elements having a small free energy for forming sulfide in a high temperature region, a sulfide having a large binding energy between the desulfurizing agent and the sulfur component in the molten steel is generated. It becomes possible.
【０００５】ここで、本発明に係る溶鋼用脱硫剤におい
て、成分には０を超え２０重量％以下のＭｇＯを有する
ことが好ましい。このように、成分に更にＭｇＯを添加
することで、脱硫剤の融点を更に低下させることが可能
となる。本発明に係る溶鋼用脱硫剤において、ＢａＯと
ＲＥＯn とのモル比がＢａＯ／ＲＥＯn で０．５〜１．
５の範囲であることが好ましい。このように、ＢａＯと
ＲＥＯn との配合比を調整することで、生成物の融点を
ＢａＯ及びＲＥＯn のそれぞれの融点より大幅に降下さ
せることが可能となる。本発明に係る溶鋼用脱硫剤にお
いて、ＲＥＯn はＣｅＯ2 であることが好ましい。この
ように、ＲＥＯn の中でも、特に高温域での硫化物の生
成自由エネルギーが小さい元素であるＣｅを有した脱硫
剤を使用することで、脱硫剤と溶鋼中の硫黄成分との結
合エネルギーが大きい硫化物を生成させることが可能と
なる。Here, in the desulfurizing agent for molten steel according to the present invention, it is preferable that the component contains more than 0 and 20% by weight or less of MgO. Thus, by further adding MgO to the component, the melting point of the desulfurizing agent can be further lowered. In the molten steel for desulfurizing agent according to the present invention, the molar ratio of BaO and REO n is in BaO / REO n 0.5 to 1.
It is preferably in the range of 5. Thus, by adjusting the mixing ratio of the BaO and REO n, it is possible to the melting point of the product is significantly lowered than the respective melting points of BaO and REO n. In the desulfurizing agent for molten steel according to the present invention, REO n is preferably CeO 2 . As described above, by using a desulfurizing agent having Ce, which is an element having a small free energy for forming sulfides particularly in a high temperature region among REO n , the binding energy between the desulfurizing agent and the sulfur component in the molten steel is increased. It becomes possible to generate large sulfides.
【０００６】本発明に係る溶鋼用脱硫剤において、脱硫
剤は、脱硫剤の原料組成物を加熱溶融した後急冷し、破
砕又は粉砕されたものであることが好ましい。この脱硫
剤の原料組成物を加熱溶融して冷却する場合に徐冷する
と、本来この脱硫剤が結晶性化合物であるため、種々の
共晶結晶物が生成し、一般に脱硫剤の融点が高温になる
傾向が生じる。このため、脱硫剤の原料組成物を溶融し
た後、可能な限り急冷することで、共晶結晶物の生成を
阻害し、結晶の微細化、更には非晶質化を図ることが可
能となる。また、急冷により得られた固溶体は、溶鋼に
上置添加する場合、飛散を防止するために粗粒まで破砕
し、また吹込添加する場合、細粉まで粉砕するので、使
用条件に応じてそれぞれ適した粒径に調整することが可
能となる。In the desulfurizing agent for molten steel according to the present invention, it is preferable that the desulfurizing agent is obtained by heating and melting the raw material composition of the desulfurizing agent, followed by rapid cooling, crushing or crushing. When the raw material composition of this desulfurizing agent is heated and melted and gradually cooled, since the desulfurizing agent is originally a crystalline compound, various eutectic crystal products are produced, and the melting point of the desulfurizing agent generally becomes high. Tend to become. Therefore, by melting the raw material composition of the desulfurizing agent and then rapidly cooling it as much as possible, it is possible to inhibit the formation of a eutectic crystal product, and to make the crystal finer and even amorphous. . In addition, the solid solution obtained by quenching is crushed to coarse particles to prevent scattering when added on top of molten steel, and crushed to fine powder when added by blowing, so it is suitable for each use condition. It is possible to adjust to a different particle size.
【０００７】そして、本発明に係る溶鋼用脱硫剤におい
て、脱硫剤は、脱硫剤の原料組成物を、粉砕し混合又は
混合し粉砕した後、造粒又は造塊されたものであること
が好ましい。更に、本発明に係る溶鋼用脱硫剤におい
て、脱硫剤は、脱硫剤の原料組成物を、粉砕し混合又は
混合し粉砕した後、焼結されたものであることが好まし
い。脱硫剤を添加する溶鋼の温度は、１５５０〜１６５
０℃程度で、一般的に溶鋼１０００ｋｇに対して約５〜
１０ｋｇ程度（０．５〜１．０重量％程度）の脱硫剤を
添加する。このとき、粉砕し混合又は混合し粉砕した原
料組成物で構成される脱硫剤は、一度原料組成物を溶解
し固溶体とした脱硫剤よりも多少溶解時間がかかるもの
の溶鋼の持つ顕熱で十分に溶解することが可能である。
また、粉砕し混合又は混合し粉砕した状態（粉体）の原
料組成物は、造粒又は造塊（ブリケット化）するか、も
しくは焼結して造塊化するので、粉体状態での飛散防止
を図ることが可能となる。In the desulfurizing agent for molten steel according to the present invention, it is preferable that the desulfurizing agent is obtained by pulverizing, mixing or mixing and pulverizing the raw material composition of the desulfurizing agent, and then granulating or agglomerating. . Further, in the desulfurizing agent for molten steel according to the present invention, it is preferable that the desulfurizing agent is obtained by pulverizing, mixing or mixing and pulverizing the raw material composition of the desulfurizing agent, followed by sintering. The temperature of the molten steel to which the desulfurizing agent is added is 1550 to 165.
At about 0 ° C, generally about 5 to 1000 kg of molten steel
About 10 kg (about 0.5 to 1.0% by weight) of desulfurizing agent is added. At this time, the desulfurizing agent composed of the raw material composition pulverized and mixed or mixed and pulverized takes a little longer time than the desulfurizing agent which is obtained by dissolving the raw material composition into a solid solution, but the sensible heat of the molten steel is sufficient. It is possible to dissolve.
In addition, the raw material composition in a state of being pulverized and mixed or mixed and pulverized (powder) is granulated or agglomerated (briquetteed), or sintered to be agglomerated, and thus scattered in a powder state. It becomes possible to prevent it.
【０００８】前記目的に沿う第１の発明に係る溶鋼用脱
硫剤の製造方法は、ＣａＯ源、Ａｌ2Ｏ3 源、ＢａＯ
源、ＲＥＯn 源を主体とする原料組成物を加熱溶融して
急冷処理を行う第１工程と、第１工程で得られた固溶体
を破砕及び粉砕のいずれか１の処理をして、ＣａＯ：１
０〜５５重量％、Ａｌ2 Ｏ3 ：２０〜５５重量％、Ｂａ
Ｏ：１〜３５重量％、ＲＥＯn ：１〜４０重量％で、残
部が不可避的不純物からなる脱硫剤を製造する第２工程
とを有する。なお、ＲＥは希土類元素を示し、ＲＥＯn
はその酸化物を示す。このように、脱硫剤の原料組成物
を溶融した後、可能な限り急冷することで、共晶結晶物
の生成を阻害し、結晶の微細化、更には非晶質化を図っ
た脱硫剤を製造できる。また、急冷により得られた固溶
体は、破砕又は粉砕するので、使用条件に応じてそれぞ
れ適した粒径に調整した脱硫剤を製造できる。ここで、
第１の発明に係る溶鋼用脱硫剤の製造方法において、第
１工程での急冷処理は、空冷及び金属板上冷却のいずれ
か一方又は両方を用いた冷却であることが好ましい。こ
のように、空冷及び金属板上冷却のいずれか一方又は両
方を用いた冷却を行うので、大掛かりな設備を使用する
ことなく、共晶結晶物の生成を阻害し、結晶の微細化、
更には非晶質化を図ることが可能となる。The method for producing a desulfurizing agent for molten steel according to the first aspect of the invention, which meets the above-mentioned object, is a CaO source, an Al 2 O 3 source, and a BaO source.
Source, a raw material composition mainly composed of REO n source is heated and melted to perform quenching treatment, and the solid solution obtained in the first step is subjected to any one treatment of crushing and crushing to obtain CaO: 1
0-55 wt%, Al 2 O 3: 20~55 wt%, Ba
The second step is to produce a desulfurizing agent containing O: 1 to 35% by weight, REO n : 1 to 40% by weight, and the balance being unavoidable impurities. RE is a rare earth element, and REO n
Indicates the oxide. Thus, after melting the raw material composition of the desulfurization agent, by quenching as much as possible, to inhibit the production of eutectic crystals, refining the crystal, further desulfurization agent aimed at amorphization Can be manufactured. Further, since the solid solution obtained by quenching is crushed or crushed, it is possible to produce a desulfurizing agent adjusted to have a particle size suitable for each use condition. here,
In the method for producing a desulfurizing agent for molten steel according to the first aspect of the invention, it is preferable that the quenching treatment in the first step is cooling using either one or both of air cooling and cooling on a metal plate. In this way, since cooling is performed using either or both of air cooling and cooling on a metal plate, without using large-scale equipment, the production of eutectic crystals is inhibited, and the crystals are refined,
Furthermore, it becomes possible to make it amorphous.
【０００９】前記目的に沿う第２の発明に係る溶鋼用脱
硫剤の製造方法は、ＣａＯ源、Ａｌ2Ｏ3 源、ＢａＯ
源、ＲＥＯn 源を主体とする原料組成物を、粉砕して混
合する処理、及び混合して粉砕する処理のいずれか１の
処理を行う第１工程と、第１工程で得られた混合物を、
造粒及び造塊処理のいずれか１の処理をして、ＣａＯ：
１０〜５５重量％、Ａｌ2 Ｏ3 ：２０〜５５重量％、Ｂ
ａＯ：１〜３５重量％、ＲＥＯn ：１〜４０重量％で、
残部が不可避的不純物からなる脱硫剤を製造する第２工
程とを有する。なお、ＲＥは希土類元素を示し、ＲＥＯ
n はその酸化物を示す。前記目的に沿う第３の発明に係
る溶鋼用脱硫剤の製造方法は、ＣａＯ源、Ａｌ2Ｏ3
源、ＢａＯ源、ＲＥＯn 源を主体とする原料組成物を、
粉砕して混合する処理、及び混合して粉砕する処理のい
ずれか１の処理を行う第１工程と、第１工程で得られた
混合物を焼結処理して、ＣａＯ：１０〜５５重量％、Ａ
ｌ2 Ｏ3 ：２０〜５５重量％、ＢａＯ：１〜３５重量
％、ＲＥＯn ：１〜４０重量％で、残部が不可避的不純
物からなる脱硫剤を製造する第２工程とを有する。な
お、ＲＥは希土類元素を示し、ＲＥＯn はその酸化物を
示す。このように、粉砕し混合又は混合し粉砕した原料
組成物で構成される脱硫剤は、一度原料組成物を溶解し
固溶体とした脱硫剤よりも多少溶解時間がかかるものの
溶鋼の持つ顕熱で十分に溶解することが可能である。ま
た、粉砕し混合又は混合し粉砕した状態（粉体）の原料
組成物は、造粒又は造塊（ブリケット化）するか、もし
くは焼結して造塊化するので、粉体状態での飛散防止を
図ることが可能となる。A method of manufacturing a desulfurizing agent for molten steel according to the second aspect of the invention, which meets the above object, is a CaO source, an Al 2 O 3 source, and a BaO source.
Source, a raw material composition mainly composed of a REO n source, a first step of performing any one of a treatment of pulverizing and mixing, and a treatment of mixing and pulverizing, and a mixture obtained in the first step. ,
Any one of the granulation and agglomeration treatments is performed and CaO:
10 to 55 wt%, Al 2 O 3: 20~55 wt%, B
aO: 1 to 35% by weight, REO n : 1 to 40% by weight,
A second step of producing a desulfurizing agent whose balance consists of unavoidable impurities. RE represents a rare earth element, and REO
n represents the oxide. A method for producing a desulfurizing agent for molten steel according to the third aspect of the invention, which meets the above-mentioned object, is a CaO source, Al 2 O 3
Source material, a BaO source, and a REO n source as main components,
CaO: 10-55% by weight, the first step of performing any one of the processing of crushing and mixing, and the processing of mixing and crushing, and sintering the mixture obtained in the first step. A
L 2 O 3 : 20 to 55% by weight, BaO: 1 to 35% by weight, REO n : 1 to 40% by weight, and the second step of producing a desulfurizing agent with the balance being unavoidable impurities. RE represents a rare earth element, and REO n represents an oxide thereof. As described above, the desulfurization agent composed of the raw material composition pulverized and mixed or mixed and pulverized takes a slightly longer melting time than the desulfurization agent which is obtained by once dissolving the raw material composition into a solid solution, but the sensible heat of molten steel is sufficient. It is possible to dissolve in. In addition, the raw material composition in a state of being pulverized and mixed or mixed and pulverized (powder) is granulated or agglomerated (briquetteed), or sintered to be agglomerated, and thus scattered in a powder state. It becomes possible to prevent it.
【００１０】ここで、第１〜第３の発明に係る溶鋼用脱
硫剤の製造方法において、原料組成物にはＭｇＯ源を含
み、脱硫剤には０を超え２０重量％以下のＭｇＯを含む
ことが好ましい。このように、成分に更にＭｇＯを添加
することで、脱硫剤の融点を更に低下させることが可能
となる。第１〜第３の発明に係る溶鋼用脱硫剤の製造方
法において、ＢａＯとＲＥＯn とのモル比がＢａＯ／Ｒ
ＥＯn で０．５〜１．５の範囲であることが好ましい。
このように、ＢａＯとＲＥＯn との配合比を調整するこ
とで、生成物の融点をＢａＯ及びＲＥＯn のそれぞれの
融点より大幅に降下させることが可能となる。第１〜第
３の発明に係る溶鋼用脱硫剤の製造方法において、ＲＥ
Ｏn はＣｅＯ2であることが好ましい。このように、Ｒ
ＥＯn の中でも、特に高温域での硫化物の生成自由エネ
ルギーが小さい元素であるＣｅを有した脱硫剤を使用す
ることで、脱硫剤と溶鋼中の硫黄成分との結合エネルギ
ーが大きい硫化物を生成させることが可能となる。Here, in the method for producing a desulfurizing agent for molten steel according to the first to third inventions, the raw material composition contains a MgO source, and the desulfurizing agent contains more than 0 and 20% by weight or less of MgO. Is preferred. Thus, by further adding MgO to the component, the melting point of the desulfurizing agent can be further lowered. In the method for producing a desulfurizing agent for molten steel according to the first to third inventions, the molar ratio of BaO and REO n is BaO / R.
EO n is preferably in the range of 0.5 to 1.5.
Thus, by adjusting the mixing ratio of the BaO and REO n, it is possible to the melting point of the product is significantly lowered than the respective melting points of BaO and REO n. In the method for producing a desulfurizing agent for molten steel according to the first to third inventions, RE
O n is preferably CeO 2. Thus, R
Among EO n , by using a desulfurizing agent having Ce, which is an element having a small free energy for forming sulfide particularly in a high temperature range, a sulfide having a large binding energy between the desulfurizing agent and the sulfur component in the molten steel can be obtained. It is possible to generate.
【００１１】[0011]
【発明の実施の形態】続いて、添付した図面を参照しつ
つ、本発明を具体化した実施の形態につき説明し、本発
明の理解に供する。ここに、図１は本発明の第１〜第３
の実施の形態に係る溶鋼用脱硫剤に使用するＣａＯとＡ
ｌ2 Ｏ3 の二元系状態の説明図、図２（Ａ）、（Ｂ）は
それぞれ同二元系状態のＣ12Ａ7 近傍の部分拡大図、図
３は本発明の第１〜第３の実施の形態に係る溶鋼用脱硫
剤に使用するＢａ、Ｃｅの硫化物の標準生成自由エネル
ギーと温度との関係を示す説明図である。BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. FIG. 1 shows the first to third aspects of the present invention.
And A used in the desulfurizing agent for molten steel according to the embodiment of
l 2 O 3 Illustration of binary state, 2 (A), (B) is C 12 A 7 partially enlarged view of the vicinity of the same binary state, respectively, first the first through the 3 present invention It is explanatory drawing which shows the relationship between the standard free energy of formation of the sulfides of Ba and Ce used for the desulfurizing agent for molten steel which concerns on 3rd Embodiment, and temperature.
【００１２】本発明の第１の実施の形態に係る溶鋼用脱
硫剤（以下、単に脱硫剤とも言う）は、溶鋼の脱硫に使
用するものであり、ＣａＯ：１０〜５５重量％、Ａｌ2
Ｏ3 ：２０〜５５重量％、ＢａＯ：１〜３５重量％、Ｃ
ｅＯ2 （ＲＥＯn の一例）：１〜４０重量％、ＭｇＯ：
０又は０を超え２０重量％以下の成分を有し、残部が不
可避的不純物からなっており、ＣａＯ源、Ａｌ2 Ｏ3
源、ＢａＯ源、ＣｅＯ2 源（ＲＥＯn 源の一例）、Ｍｇ
Ｏ源を主体とする原料組成物を加熱溶融して急冷処理を
行う第１工程と、第１工程で得られた固溶体を破砕及び
粉砕のいずれか１の処理を行う第２工程とを行って製造
されている。この脱硫剤の融点は、カルシウムアルミネ
ート（１２ＣａＯ・７Ａｌ2 Ｏ3 ）の融点以下で、流動
性も良好である。以下、詳しく説明する。The desulfurizing agent for molten steel according to the first embodiment of the present invention (hereinafter also simply referred to as desulfurizing agent) is used for desulfurizing molten steel, and CaO: 10 to 55% by weight, Al 2
O 3: 20 to 55 wt%, BaO: 1 to 35 wt%, C
eO 2 (an example of REO n ): 1 to 40% by weight, MgO:
It has a component of 0 or more than 0 and 20% by weight or less, and the balance is unavoidable impurities. CaO source, Al 2 O 3
Source, BaO source, CeO 2 source (an example of REO n source), Mg
Performing a first step of heating and melting a raw material composition mainly containing an O source and performing a quenching treatment, and a second step of performing any one treatment of crushing and crushing the solid solution obtained in the first step. Being manufactured. The melting point of this desulfurizing agent is not higher than that of calcium aluminate (12CaO · 7Al 2 O 3 ), and the fluidity is also good. The details will be described below.
【００１３】脱硫剤は、例えば、普通鋼用溶鋼、ステン
レス用溶鋼等で構成される溶鋼の脱硫処理時の温度（例
えば、１５５０〜１６５０℃程度）で使用可能な組成に
調整されたものであり、その結晶形態は、溶融状態とな
った脱硫剤に直接水をかけて冷却を行う水冷方法（以
下、直接水冷とも言う）以外の急冷を行うことで、高融
点の共晶組成物の生成をできるだけ避け、融解熱を取り
込むことにより、溶鋼への添加時にスムーズな溶融を行
うことが可能な形態となっている。また、この脱硫剤の
粒径は、ＲＨ脱ガス槽や取鍋に上置添加する場合には３
〜２５ｍｍ程度の粒状に、インジェクション（吹込方
式）する場合には１ｍｍ以下に、連続鋳造のタンディッ
シュ（投入撹拌方式）に使用する場合には１〜３ｍｍ程
度に、使用条件に応じてそれぞれ粉砕又は破砕し調整さ
れている。なお、この脱硫剤には、不可避的不純物とし
て、例えばＳｉＯ2 、ＴｉＯ2 、Ｆｅ2 Ｏ3 等が含まれ
るが、いずれも脱硫剤中に含まれる量が少ないほど、脱
硫剤の脱硫能が高まることになる。The desulfurizing agent has a composition adjusted so that it can be used at a temperature (for example, about 1550 to 1650 ° C.) at the time of desulfurization of molten steel composed of molten steel for ordinary steel, molten steel for stainless steel and the like. The crystal form of the eutectic composition having a high melting point can be obtained by performing rapid cooling other than a water cooling method in which water is directly applied to a desulfurizing agent in a molten state to cool the desulfurizing agent (hereinafter, also referred to as direct water cooling). By avoiding it as much as possible and taking in the heat of fusion, it is possible to perform smooth melting during addition to molten steel. The particle size of this desulfurizing agent is 3 when it is added to the RH degassing tank or ladle.
Granules of up to about 25 mm, 1 mm or less for injection (blowing method), 1 to 3 mm for continuous casting tundish (charging and stirring method), or crushed or It is crushed and adjusted. This desulfurizing agent contains, for example, SiO 2 , TiO 2 , and Fe 2 O 3 as unavoidable impurities, and the desulfurizing ability of the desulfurizing agent increases as the amount contained in each desulfurizing agent decreases. It will be.
【００１４】ここで、脱硫剤中の各成分を、上記した数
値に限定した理由について説明する。図１に示すよう
に、ＣａＯとＡｌ2 Ｏ3 との反応は共晶反応であり、Ｃ
ａＯとＡｌ2 Ｏ3 との配合比を調整することで、生成物
の融点をＣａＯ及びＡｌ2 Ｏ3 の融点より低下させるこ
とが可能となる。また、図２（Ａ）、（Ｂ）は、それぞ
れカルシウムアルミネート（１２ＣａＯ・７Ａｌ2 Ｏ
3 ）の生成範囲近傍の生成物及びその融点を示してい
る。なお、図１、図２（Ａ）、（Ｂ）は、Ｐｈａｓｅ
Ｄｉａｇｒａｍｓ ｆｏｒＣｅｒａｍｉｓｔｓ（米国セ
ラミックス協会）に記載されたもので、図１、図２
（Ａ）中のＬｉｑ．はＬｉｑｕｉｄの略、ＣはＣａＯ、
ＡはＡｌ2 Ｏ3 をそれぞれ示している。従って、図１中
のＣn Ａm は、ｎＣａＯ・ｍＡｌ2 Ｏ3 を意味する。Now, the reason why each component in the desulfurizing agent is limited to the above-mentioned numerical values will be described. As shown in FIG. 1, the reaction between CaO and Al 2 O 3 is a eutectic reaction, and C
By adjusting the compounding ratio of aO and Al 2 O 3 , the melting point of the product can be made lower than the melting points of CaO and Al 2 O 3 . 2A and 2B show calcium aluminate (12CaO.7Al 2 O), respectively.
It shows the products near the production range of 3 ) and their melting points. In addition, FIG. 1, FIG. 2 (A), and (B) show Phase
It is described in Diagrams for Ceramics (American Ceramic Society).
Liq. In (A). Is an abbreviation for Liquid, C is CaO,
A represents Al 2 O 3 , respectively. Therefore, C n A m in FIG. 1 means nCaO · mAl 2 O 3.
【００１５】ここで、ＣａＯが１０重量％未満では、脱
硫剤の脱硫能が著しく低くなるため、下限値を１０重量
％とした。一方、ＣａＯが多くなると、脱硫剤の融点が
高くなるため、溶鋼中で脱硫剤が容易に軟化、又は溶解
しなくなり、迅速で高い脱硫効率を達成できなくなるの
で、上限値を５５重量％とした。しかし、十分な脱硫能
を有し、しかもより高い脱硫効率を有するためには、脱
硫剤中のＣａＯを２０〜５０重量％、更には３０〜４５
重量％とすることが好ましい。また、Ａｌ2 Ｏ3 が２０
重量％未満では、脱硫剤の融点が高くなるため、溶鋼中
で脱硫剤が容易に軟化、又は溶解しなくなり、迅速で高
い脱硫効率を達成することができなくなるので、脱硫剤
中のＡｌ2 Ｏ3 量の下限値を２０重量％とした。一方、
Ａｌ2 Ｏ3 が多くなると、脱硫剤中に含まれるＣａＯ、
ＢａＯ、ＣｅＯ2等が減少し、脱硫剤の脱硫能が著しく
低くなり、しかも溶鋼の清浄化作用の主たる機構である
Ａｌ2 Ｏ3 の吸収能も急激に低下するため上限値を５５
重量％とした。しかし、十分な脱硫能を有し、しかもよ
り高い脱硫効率を有するためには、脱硫剤中のＡｌ2 Ｏ
3 を３０〜５５重量％、更には３５〜５０重量％とする
ことが好ましい。When CaO is less than 10% by weight, the desulfurizing ability of the desulfurizing agent is remarkably reduced, so the lower limit is set to 10% by weight. On the other hand, when the amount of CaO increases, the melting point of the desulfurizing agent increases, so that the desulfurizing agent is not easily softened or melted in molten steel, and rapid desulfurization efficiency cannot be achieved. Therefore, the upper limit is set to 55% by weight. . However, in order to have sufficient desulfurization ability and higher desulfurization efficiency, CaO in the desulfurization agent should be 20 to 50% by weight, and further 30 to 45% by weight.
It is preferably set to wt%. Also, Al 2 O 3 is 20
In less than wt%, the melting point of the desulfurizing agent is increased, the desulfurization agent is easily softened in molten steel, or no longer dissolve, since it is not possible to achieve a rapid and high desulfurization efficiency, Al 2 O in the desulfurizing agent The lower limit of the amount of 3 was set to 20% by weight. on the other hand,
When the amount of Al 2 O 3 increases, CaO contained in the desulfurizing agent,
BaO, CeO 2, etc. are decreased, the desulfurization ability of the desulfurization agent is remarkably lowered, and the absorption ability of Al 2 O 3 , which is the main mechanism of the cleaning action of molten steel, is drastically reduced.
It was set to% by weight. However, in order to have sufficient desulfurization ability and higher desulfurization efficiency, Al 2 O in the desulfurization agent should be used.
3 is preferably 30 to 55% by weight, more preferably 35 to 50% by weight.
【００１６】次に、脱硫剤中のＢａＯ及びＣｅＯ2 量
を、上記した数値に限定した理由について説明する。ま
ず、図３について詳しく説明する。金属（Ｍｅ）と硫化
物（ＭｅＳ2 ）との反応式を以下のように考える。
Ｍｅ（固体、液体）＋Ｓ2 （気体）＝ＭｅＳ2 （固体、
液体）
ここで金属と硫化物に相互溶解度がないとみなせる場
合、標準（生成）自由エネルギーΔＧ°は以下の式で示
すことが可能となる。
ΔＧ°＝Ｒ×Ｔ×（ｌｎ（ＰS2,e））
ここで、Ｒは気体定数、Ｔは温度、ＰS2,eは平衡時での
Ｓ2 （気体）の分圧を示す。即ち、このΔＧ°−Ｔの関
係図を表すため、縦軸にＲ×Ｔ×（ｌｎ（ＰS2））、横
軸にＴをとったものが図３に示すエリンガム図である。
なお、図３は、金属の硫化物生成反応のΔＧ°と温度Ｔ
との関係が、相変態を生じない温度範囲において直線と
みなせることを利用したものである。Next, the reason why the amounts of BaO and CeO 2 in the desulfurizing agent are limited to the above numerical values will be explained. First, FIG. 3 will be described in detail. The reaction formula of metal (Me) and sulfide (MeS 2 ) is considered as follows. Me (solid, liquid) + S 2 (gas) = MeS 2 (solid,
Liquid) If it can be considered that the metal and the sulfide do not have mutual solubility, the standard (formation) free energy ΔG ° can be expressed by the following formula. ΔG ° = R × T × (ln (P S2, e )) where R is the gas constant, T is the temperature, and P S2, e is the partial pressure of S 2 (gas) at equilibrium. That is, in order to express this ΔG ° -T relationship diagram, the ordinate represents R × T × (ln (P S2 )) and the abscissa represents T in the Ellingham diagram shown in FIG.
Note that FIG. 3 shows ΔG ° and temperature T of the metal sulfide formation reaction.
The relationship between and can be regarded as a straight line in the temperature range where phase transformation does not occur.
【００１７】ここで、ΔＧ°−Ｔ直線上のＰS2の値はＰ
S2,eであるため、ΔＧ°−Ｔ直線上においては、金属と
硫化物とが共存できる。しかし、ΔＧ°−Ｔ直線より上
の領域では、ＰS2＞ＰS2,eであるため、以下の式で示さ
れる。
ΔＧ＝Ｒ×Ｔ×（ｌｎ（ＰS2,e／ＰS2））＜０
これにより、反応は順反応、即ち前記した反応式の右方
向に進むこととなるため、ΔＧ°−Ｔ直線より上のＰS2
領域の金属は不安定で、硫化物は安定となる。上記した
ことから、図３に示すように、ＢａＯ中のアルカリ土類
金属であるＢａ、及びＣｅＯ2 中の希土類Ｃｅは、それ
ぞれ高温域（例えば、１５５０〜１６５０℃程度）での
硫化物の生成自由エネルギーが他の金属と比較して小さ
いため、脱硫剤と硫黄との結合エネルギーが大きい硫化
物を生成させることが可能な元素となることが分かる。
従って、脱硫剤による脱硫反応を、復硫反応よりも速く
進行させた状態で、平衡状態を維持させることが可能と
なるので、表面的には生成した硫化物の解離を阻止する
ことができ、最終的な脱硫効率を向上させることが可能
となる。Here, the value of P S2 on the ΔG ° -T straight line is P
Since S2, e , the metal and the sulfide can coexist on the ΔG ° -T straight line. However, since P S2 > P S2, e in the region above the ΔG ° -T straight line , it is expressed by the following equation. ΔG = R × T × (ln (P S2, e / P S2 )) <0 As a result, the reaction proceeds in the forward reaction, that is, to the right of the above-mentioned reaction formula, and therefore above the ΔG ° -T straight line. Of P S2
The region metal is unstable and the sulfide is stable. From the above, as shown in FIG. 3, Ba, which is an alkaline earth metal in BaO, and rare earth, Ce, in CeO 2 are each formed of a sulfide in a high temperature range (for example, about 1550 to 1650 ° C.). Since the free energy is smaller than that of other metals, it is understood that the element becomes an element capable of forming a sulfide having a large binding energy between the desulfurizing agent and sulfur.
Therefore, the desulfurization reaction by the desulfurization agent can be maintained in an equilibrium state in a state where the desulfurization reaction is allowed to proceed faster than the re-sulfurization reaction. It is possible to improve the final desulfurization efficiency.
【００１８】このように、復硫反応を抑制し、脱硫剤の
脱硫性を高めるため、脱硫剤中のＢａＯとＣｅＯ2 の量
の下限値を、それぞれ１重量％とした。なお、ＢａＯ
（融点１９２３℃）、ＣｅＯ2 （融点１９５０℃）は共
に高融点化合物であるが、ＢａＯとＣｅＯ2 がモル比で
ＢａＯ：ＣｅＯ2 ＝１：１付近に共融点降下現象がある
ため、モル比をＢａＯ／ＣｅＯ2 で０．５〜１．５の範
囲にして脱硫剤に添加することにした。しかし、融点を
より降下させ、しかも製造可能な範囲を確保するため、
モル比をＢａＯ／ＣｅＯ2 で０．６〜１．４、更には
０．７〜１．３とすることが好ましい。In this way, in order to suppress the desulfurization reaction and enhance the desulfurization ability of the desulfurization agent, the lower limit values of the amounts of BaO and CeO 2 in the desulfurization agent were each 1% by weight. In addition, BaO
(Melting point 1923 ° C.) and CeO 2 (melting point 1950 ° C.) are both high melting point compounds, but since BaO and CeO 2 have a eutectic melting point lowering in the molar ratio of BaO: CeO 2 = 1: 1, Was added to the desulfurization agent in the range of 0.5 to 1.5 with BaO / CeO 2 . However, in order to further lower the melting point and to secure a manufacturable range,
The molar ratio of BaO / CeO 2 is preferably 0.6 to 1.4, and more preferably 0.7 to 1.3.
【００１９】ここで、ＣａＯ及びＡｌ2 Ｏ3 に、等モル
比で混合したＢａＯとＣｅＯ2 を添加し、各配合値での
融点を実測したところ、ＣａＯ＋Ａｌ2 Ｏ3 ＝（Ａ）、
ＢａＯ＋ＣｅＯ2 ＝（Ｂ）が、（Ａ）：（Ｂ）＝９９：
１〜５０：５０程度の範囲で、カルシウムアルミネート
（１２ＣａＯ・７Ａｌ2 Ｏ3 、融点１３６０℃）より低
融点組成物になることを発見した。しかしながら、Ｃａ
Ｏと比較した場合の産出量や経済性を考慮することで、
脱硫剤中のＢａＯの上限値を３５重量％、ＣｅＯ 2 の上
限値を４０重量％とした。なお、脱硫反応を復硫反応よ
りも十分に速くし、脱硫剤の脱硫能を更に高め、しかも
経済性を考慮した場合、脱硫剤中のＢａＯを２〜２０重
量％、更には４〜１６重量％とすることが好ましく、ま
た脱硫剤中のＣｅＯ2 を３〜３０重量％、更には５〜１
８重量％とすることが好ましい。Here, CaO and Al2 O3 To equimolar
BaO and CeO mixed in ratio2 Is added, and
When the melting point was measured, CaO + Al2 O3 = (A),
BaO + CeO2 = (B) is (A) :( B) = 99:
Calcium aluminate in the range of 1 to 50:50
(12CaO / 7Al2 O3 , Melting point 1360 ° C)
It has been found to be a melting point composition. However, Ca
By considering the output and economic efficiency when compared with O,
The upper limit of BaO in the desulfurization agent is 35% by weight, CeO 2 upon
The limit value was 40% by weight. The desulfurization reaction is called the re-sulfurization reaction.
Faster enough to further improve the desulfurization ability of the desulfurization agent, and
Considering economy, 2 to 20 layers of BaO in the desulfurizing agent is used.
%, More preferably 4 to 16% by weight,
In desulfurizing agent2 3 to 30% by weight, further 5 to 1
It is preferably 8% by weight.
【００２０】ＭｇＯは、鋼の溶解時に使用する耐火物
（例えば、マグネシアカーボン、マグネシアクロム等）
中に含まれるマグネシア（ＭｇＯ）が脱硫剤中へ溶解
し、耐火物が損傷する現象を抑制する効果を有する。ま
た、ＭｇＯを有する脱硫剤の融点は、無添加の脱硫剤の
融点よりも約５０℃低下することを発見した。また、脱
硫剤としての脱硫特性にもプラスの影響があるが、無添
加でも１２ＣａＯ・７Ａｌ2Ｏ3 と比較して脱硫能力が
理論値で約１８％程度高いため、脱硫剤中のＭｇＯの下
限値を０重量％、又は０重量％を超えた量とした。一
方、上限値は、脱硫剤中のＭｇＯの固溶限界と融点降
下、脱硫能力向上効果を考慮して２０重量％とした。し
かし、耐火物の損傷をより効果的に抑制し、しかもＭｇ
Ｏの固溶限界を考慮すれば、脱硫剤中のＭｇＯを、２〜
１５重量％、更には４〜１０重量％とすることが好まし
い。これにより、耐火物中のマグネシウムの溶損損失を
低減すると共に、脱硫剤の融点降下、更には脱硫能力の
向上を図ることができるため、従来よりも耐火物の寿命
を伸ばすことが可能となり、経済性が良好となる。な
お、この脱硫剤には、不可避的不純物として、例えばＳ
ｉＯ2 、ＴｉＯ2 、ＦｅＯ、Ｆｅ2 Ｏ3 等が含まれる
が、いずれも脱硫剤中に含まれる量が少ないほど、脱硫
剤の脱硫能が高まることとなる。MgO is a refractory used when melting steel (eg, magnesia carbon, magnesia chromium, etc.)
Magnesia (MgO) contained therein dissolves in the desulfurizing agent and has an effect of suppressing the phenomenon that the refractory is damaged. Further, it has been discovered that the melting point of the desulfurizing agent having MgO is about 50 ° C. lower than the melting point of the desulfurizing agent containing no additive. Although it has a positive effect on the desulfurization characteristics as a desulfurization agent, the desulfurization capacity is higher by about 18% in theory than 12CaO · 7Al 2 O 3 even without addition, so the lower limit of MgO in the desulfurization agent The value was defined as 0% by weight or an amount exceeding 0% by weight. On the other hand, the upper limit is set to 20% by weight in consideration of the solid solution limit of MgO in the desulfurizing agent, the melting point drop, and the effect of improving the desulfurizing ability. However, it effectively suppresses damage to refractories, and
Considering the solid solution limit of O, MgO in the desulfurizing agent
It is preferably 15% by weight, more preferably 4 to 10% by weight. With this, it is possible to reduce the melting loss of magnesium in the refractory, as well as to lower the melting point of the desulfurizing agent and further improve the desulfurizing ability, so that it is possible to extend the life of the refractory as compared with the conventional one. Economic efficiency is improved. The desulfurizing agent contains, for example, S as an unavoidable impurity.
Although iO 2 , TiO 2 , FeO, Fe 2 O 3 and the like are contained, the desulfurizing ability of the desulfurizing agent is enhanced as the amount of each of them is smaller in the desulfurizing agent.
【００２１】続いて、本発明の第１の実施の形態に係る
溶鋼の脱硫剤の製造方法について説明する。まず、前記
した各成分を、前記した割合にそれぞれ配合して原料組
成物を製造する。ここで使用する原料は、ＣａＯ源とし
て、例えば生石灰、石灰石、ドロマイト等、Ａｌ2 Ｏ3
源として、例えばボーキサイト、礬土頁岩、アルミナ
等、ＢａＯ源として、例えば毒重石、炭酸バリウム等、
ＣｅＯ2 源として、例えばバストネサイト、モナザイ
ト、酸化セリウム、炭酸セリウム等、ＭｇＯ源として、
例えばマグネシア、マグネサイト、ドロマイト等であ
る。従って、配合時においては、上記したＣａＯ源、Ａ
ｌ2 Ｏ3 源、ＢａＯ源、ＣｅＯ2 源、ＭｇＯ源を、それ
ぞれＣａＯ、Ａｌ2 Ｏ3 、ＢａＯ、ＣｅＯ2 、ＭｇＯに
換算して配合する。なお、ＣａＯ源、Ａｌ2 Ｏ3 源、Ｂ
ａＯ源、ＣｅＯ2 源としては、例えば試薬であるＣａ
Ｏ、Ａｌ2 Ｏ3 、ＢａＯ、ＣｅＯ2 をそれぞれ使用する
ことも勿論可能である。Next, a method for producing a desulfurizing agent for molten steel according to the first embodiment of the present invention will be described. First, the above-mentioned components are blended in the above-mentioned proportions to produce a raw material composition. The raw material used here is, as a CaO source, for example, quick lime, limestone, dolomite, etc., Al 2 O 3
As a source, for example, bauxite, conglomerate shale, alumina, etc. As a BaO source, for example, poisonous weights, barium carbonate, etc.
As the CeO 2 source, for example, bastnasite, monazite, cerium oxide, cerium carbonate, etc., as the MgO source,
For example, magnesia, magnesite, dolomite, etc. Therefore, at the time of compounding, the above-mentioned CaO source, A
An l 2 O 3 source, a BaO source, a CeO 2 source, and an MgO source are converted into CaO, Al 2 O 3 , BaO, CeO 2 , and MgO, respectively, and mixed. In addition, CaO source, Al 2 O 3 source, B
Examples of the aO source and the CeO 2 source include Ca that is a reagent.
Of course, it is also possible to use O, Al 2 O 3 , BaO and CeO 2 , respectively.
【００２２】この原料組成物を構成する各成分を、粒径
が例えば、いずれも約５０ｍｍ以下となるまで粉砕し、
できるだけ均一になるように混合した後、溶解炉に投入
する。溶解炉は、平炉、竪型炉、電気炉等のいずれも使
用できるが、不純物のＳ、Ｐ等の混入を避けるため、好
ましくは炉の内張材質がカーボンで構成される電気炉が
好適である。電気炉の一例であるアーク式電気炉で溶解
した溶解物は、溶解量によっても差があるが、熟成時間
として一定時間（例えば、５〜２０分程度）放置し、直
接水冷以外の方式を用いて急冷する。Each component constituting this raw material composition is pulverized to a particle size of, for example, about 50 mm or less,
Mix so as to be as uniform as possible, and then put in the melting furnace. As the melting furnace, any of a flat furnace, a vertical furnace, an electric furnace and the like can be used. However, in order to avoid mixing of impurities such as S and P, it is preferable to use an electric furnace whose carbon lining material is carbon. is there. The melted material melted in an arc type electric furnace, which is an example of an electric furnace, is left to stand for a certain period of time (for example, about 5 to 20 minutes) as the aging time, though a method other than direct water cooling is used. To quench.
【００２３】脱硫剤の製造時において、溶融後の冷却速
度が脱硫剤の性能に大きな影響を及ぼす。これは、脱硫
剤が基本的に結晶性化合物であることに起因しており、
溶融後の冷却、特に徐冷をした場合に、種々の共晶結晶
物が生成される。この共晶結晶物の融点は、一般に高温
になる傾向があり、共晶結晶物を有する脱硫剤を溶融金
属に添加した場合、脱硫剤の溶融速度が遅延し、脱硫剤
の脱硫性能が低下する。従って、加熱溶融後の冷却速度
は、直接水冷以外の方式を用いて、できるだけ急冷と
し、冷却時に脱硫剤中に生成する高融点である共晶化合
物の結晶の粗大化を防止、更には、生成する結晶を微細
化し、非晶質化するようにする。ここで、急冷方法とし
ては、例えば空冷、金属板上の冷却、内部水冷の金属ロ
ール冷却等のいずれか１つを行う場合、又は２つ以上を
組合せて行う場合が考えられ、金属板上の冷却として
は、熱伝導性の良好な金属材（例えば、鉄、銅、銅合金
等）を使用した急冷方法が好適である（以上、第１工
程）。During the production of the desulfurizing agent, the cooling rate after melting has a great influence on the performance of the desulfurizing agent. This is because the desulfurizing agent is basically a crystalline compound,
Various eutectic crystal products are produced when cooling after melting, particularly when gradually cooled. The melting point of this eutectic crystal generally tends to be high, and when a desulfurizing agent having a eutectic crystal is added to molten metal, the melting speed of the desulfurizing agent is delayed and the desulfurizing performance of the desulfurizing agent is reduced. . Therefore, the cooling rate after heating and melting should be as rapid as possible using a method other than direct water cooling to prevent coarsening of crystals of the eutectic compound having a high melting point that is generated in the desulfurizing agent during cooling, and further The crystals to be refined are made to be amorphous. Here, as the rapid cooling method, for example, any one of air cooling, cooling on a metal plate, internal water cooling of a metal roll, etc., or a combination of two or more may be performed. As the cooling, a quenching method using a metal material having good thermal conductivity (for example, iron, copper, copper alloy, etc.) is preferable (the above is the first step).
【００２４】この冷却されて生成した固溶体、即ち脱硫
剤の塊を、使用用途に応じて、例えば２５ｍｍより大き
く１００ｍｍ以下程度に粉砕、又は２５ｍｍ程度以下に
粉砕する。なお、この脱硫剤の粒径は、ＲＨ脱ガス槽や
取鍋に上置添加する場合には３〜２５ｍｍ程度の粒状
に、インジェクション（吹込方式）する場合は１ｍｍ以
下に、連続鋳造のタンディッシュ（投入撹拌方式）に使
用する場合は１〜３ｍｍ程度に、使用条件に応じてそれ
ぞれ調整される（以上、第２工程）。The solid solution produced by cooling, that is, the mass of the desulfurizing agent is crushed to a size of, for example, more than 25 mm and 100 mm or less, or crushed to 25 mm or less, depending on the intended use. The particle size of this desulfurizing agent is about 3 to 25 mm when it is added to the RH degassing tank or ladle, and 1 mm or less when the injection (blowing method) is used. When it is used in the (charging / stirring method), it is adjusted to about 1 to 3 mm depending on the usage conditions (the above is the second step).
【００２５】次に、本発明の第２の実施の形態に係る溶
鋼用脱硫剤について説明する。この脱硫剤は、前記第１
の実施の形態に係る溶鋼用脱硫剤と同じ成分、同じ配合
量を有するものであり、ＣａＯ源、Ａｌ2 Ｏ3 源、Ｂａ
Ｏ源、ＣｅＯ2 源（ＲＥＯn 源の一例）を主体とする原
料組成物を粉砕して混合する処理、及び混合して粉砕す
る処理のいずれか１の処理を行う第１工程と、第１工程
で得られた混合物を、造粒及び造塊処理のいずれか１の
処理を行って製造されたものである。これにより、溶鋼
への脱硫剤の容易な溶解を達成し、しかも溶鋼への添加
時の飛散を防止できるので、作業性が良好となる。ま
た、本発明の第２の実施の形態に係る溶鋼用脱硫剤の製
造方法は、まず原料組成物を構成する各成分を、粒径が
例えば、いずれも約５ｍｍ以下程度となるまでそれぞれ
粉砕し、前記した配合割合に調整して、できるだけ均一
になるように混合する。なお、各成分の粒径が細かけれ
ば、各成分をできるだけ均一になるように混合して使用
することも、また混合した後所定の粒径まで粉砕して使
用することも可能であり、この後更に混合することもで
きる（以上、第１工程）。Next, a desulfurizing agent for molten steel according to a second embodiment of the present invention will be described. This desulfurizing agent is the first
Of the desulfurizing agent for molten steel according to the embodiment of the present invention, which has the same components and the same blending amount, and has a CaO source, an Al 2 O 3 source, and a Ba.
A first step of performing any one of a treatment of pulverizing and mixing a raw material composition mainly composed of an O source and a CeO 2 source (an example of REO n source); and a first step, The mixture obtained in the step is manufactured by performing any one of granulation and agglomeration treatments. This makes it possible to easily dissolve the desulfurizing agent in the molten steel and prevent the desulfurization agent from being scattered during addition to the molten steel, resulting in good workability. Further, in the method for producing a desulfurizing agent for molten steel according to the second embodiment of the present invention, first, each component constituting the raw material composition is pulverized to a particle size of, for example, about 5 mm or less. Then, adjust the mixing ratio as described above and mix so as to be as uniform as possible. In addition, if the particle size of each component is small, it is possible to mix and use each component so as to be as uniform as possible, or it is possible to use after mixing and pulverizing to a predetermined particle size. After that, it is possible to further mix (the above is the first step).
【００２６】次に、第１工程で得られた混合物を造粒処
理又は造塊（ブリケット）処理する。ここで、造粒処理
又は造塊処理は、混合した原料組成物に接着剤を使用し
て行ってもよく、また接着剤を使用することなく加圧す
ることも、更には従来公知の造粒機（例えば、ドラムミ
キサー、パンペレタイザー、アイリッヒミキサー等）を
使用して行うことも可能である。この脱硫剤の造粒又は
造塊処理後の粒径は、前記した使用条件に応じてそれぞ
れ調整されることが好ましい（以上、第２工程）。Next, the mixture obtained in the first step is subjected to a granulating process or a lump (briquette) process. Here, the granulation treatment or the agglomeration treatment may be carried out by using an adhesive in the mixed raw material composition, or by applying pressure without using the adhesive, or by using a conventionally known granulator. It is also possible to use (for example, a drum mixer, a pan pelletizer, an Erich mixer, etc.). The particle size of the desulfurizing agent after granulation or agglomeration is preferably adjusted according to the above-mentioned use conditions (above, second step).
【００２７】次に、本発明の第３の実施の形態に係る溶
鋼用脱硫剤について説明する。この脱硫剤は、前記第１
の実施の形態に係る溶鋼用脱硫剤と同じ成分、同じ配合
量を有するものであり、ＣａＯ源、Ａｌ2 Ｏ3 源、Ｂａ
Ｏ源、ＣｅＯ2 源（ＲＥＯn 源の一例）を主体とする原
料組成物を粉砕して混合する処理、及び混合して粉砕す
る処理のいずれか１の処理を行う第１工程と、第１工程
で得られた混合物を焼結処理して製造されたものであ
る。これにより、溶鋼への脱硫剤の容易な溶解を達成
し、しかも溶鋼への添加時の飛散を防止できるので、作
業性が良好となる。また、本発明の第３の実施の形態に
係る溶鋼用脱硫剤の製造方法は、まず原料組成物を構成
する各成分を、粒径が例えば、いずれも約５ｍｍ以下程
度となるまでそれぞれ粉砕し、前記した配合割合に調整
して、できるだけ均一になるように混合する。なお、各
成分の粒径が細かければ、各成分をできるだけ均一にな
るように混合して使用することも、また混合した後所定
の粒径まで粉砕して使用することも可能であり、この後
更に混合することもできる（以上、第１工程）。Next, a desulfurizing agent for molten steel according to a third embodiment of the present invention will be described. This desulfurizing agent is the first
Of the desulfurizing agent for molten steel according to the embodiment of the present invention, which has the same components and the same blending amount, and has a CaO source, an Al 2 O 3 source, and a Ba.
A first step of performing any one of a treatment of pulverizing and mixing a raw material composition mainly composed of an O source and a CeO 2 source (an example of REO n source); and a first step, It is manufactured by sintering the mixture obtained in the process. This makes it possible to easily dissolve the desulfurizing agent in the molten steel and prevent the desulfurization agent from being scattered during addition to the molten steel, resulting in good workability. Further, in the method for producing a desulfurizing agent for molten steel according to the third embodiment of the present invention, first, each component constituting the raw material composition is pulverized until the particle size becomes about 5 mm or less, respectively. Then, adjust the mixing ratio as described above and mix so as to be as uniform as possible. In addition, if the particle size of each component is small, it is possible to mix and use each component so as to be as uniform as possible, or it is possible to use after mixing and pulverizing to a predetermined particle size. After that, it is possible to further mix (the above is the first step).
【００２８】次に、第１工程で得られた混合物を焼結処
理する。ここで、焼結は、混合物を焼結炉に投入して行
う。この焼結に使用する燃料としては、不純物のＳ、Ｐ
等が脱硫剤中に混入することを避けるため、低燐、低硫
黄系の燃料を使用することが好ましい。この脱硫剤の焼
結処理後の粒径は、前記した使用条件に応じてそれぞれ
調整されることが好ましい（以上、第２工程）。Next, the mixture obtained in the first step is sintered. Here, the sintering is performed by charging the mixture into a sintering furnace. The fuel used for this sintering is impurities S, P
It is preferable to use a low phosphorus and low sulfur fuel in order to prevent the above substances from being mixed in the desulfurizing agent. The particle size of the desulfurizing agent after the sintering treatment is preferably adjusted according to the above-mentioned use conditions (above, the second step).
【００２９】[0029]
【実施例】本発明に係る前記第１〜第３の実施の形態に
係る溶鋼用脱硫剤を使用し、試験を行った結果について
説明する。まず、本発明例１〜６、及び比較例の脱硫剤
中に占める各成分の割合を、表１にそれぞれ示す。EXAMPLES The results of tests conducted using the desulfurizing agent for molten steel according to the first to third embodiments of the present invention will be described. First, Table 1 shows the proportions of the respective components in the desulfurizing agents of Examples 1 to 6 of the present invention and Comparative Example.
【００３０】[0030]
【表１】 [Table 1]
【００３１】表１に示すように、本発明例１、２の脱硫
剤は、前記第１の実施の形態に係る溶鋼用脱硫剤であ
り、しかも各成分が表１の配合割合となったものであ
る。この脱硫剤は、ＣａＯ源としてＣａＣＯ3 を、Ａｌ
2 Ｏ3 源としてＡｌ2 Ｏ3 を、ＢａＯ源としてＢａＣＯ
3 を、ＣｅＯ2 源としてＣｅＯ2 をそれぞれ使用した原
料組成物を、高周波誘導炉で約１６００℃に加熱溶融
し、鉄板上で急冷して製造した固溶体を破砕機で粉砕し
て、粒径を１０ｍｍ以下として製造したものである。な
お、本発明例１の脱硫剤中にはＭｇＯが添加されてな
く、本発明例２の脱硫剤中にはＭｇＯ源としてＭｇＣＯ
3 が添加されている。また、脱硫剤中のＢａＣＯ 3 に含
まれるＢａＯとＣｅＯ2 とのモル比は、発明例１、２共
に、ＢａＯ／ＣｅＯ2 で１．０となっている。As shown in Table 1, desulfurization of Examples 1 and 2 of the present invention
The agent is the desulfurizing agent for molten steel according to the first embodiment.
Moreover, the composition ratios of each component are shown in Table 1.
It This desulfurizing agent uses CaCO as a CaO source.3 Is Al
2 O3 Al as a source2 O3 As a BaO source is BaCO
3 To CeO2 CeO as a source2 Used with each
Melts the composition to about 1600 ℃ in a high frequency induction furnace
Then, the solid solution produced by quenching on an iron plate was crushed with a crusher.
The particle size is 10 mm or less. Na
Note that MgO was not added to the desulfurizing agent of Inventive Example 1.
In the desulfurizing agent of Inventive Example 2, MgCO was used as a MgO source.
3 Has been added. In addition, BaCO in the desulfurizing agent 3 Included in
BaO and CeO2 The molar ratio of
And BaO / CeO2 Is 1.0.
【００３２】また、本発明例３、４の脱硫剤は、前記第
２の実施の形態に係る溶鋼用脱硫剤であり、しかも各成
分（試薬）が表１の配合割合となったものである。な
お、本発明例３の脱硫剤は、ＣａＯ源としてＣａＣＯ3
を、Ａｌ2 Ｏ3 源としてＡｌ2 Ｏ 3 を、ＢａＯ源として
ＢａＣＯ3 を、ＣｅＯ2 源としてＣｅＯ2 をそれぞれ使
用した原料組成物を、また本発明例４の脱硫剤は、本発
明例３の脱硫剤に更にＭｇＯ源としてＭｇＣＯ3 を添加
した原料組成物を、それぞれ均一になるように混合した
後、１０ｍｍの粒径に造粒したものである。表１中の本
発明例３にはＣａＣＯ3 量を記載し、本発明例４にはＣ
ａＣＯ3 量とＭｇＣＯ3 量を記載しているため、共に合
計量が１００ｗｔ％を超えている。ここで、このＣａＣ
Ｏ3 、ＭｇＣＯ3 をそれぞれＣａＯ、ＭｇＯとして換算
（本発明例３：ＣａＯは３８．８ｗｔ％、本発明例４：
ＣａＯは３６．６ｗｔ％、ＭｇＯは５．７ｗｔ％）する
ことで、合計量は１００ｗｔ％となる。The desulfurizing agents of Examples 3 and 4 of the present invention are
2 is a desulfurizing agent for molten steel according to the second embodiment.
Minutes (reagents) have the blending ratios shown in Table 1. Na
The desulfurizing agent of Inventive Example 3 was CaCO as a CaO source.3
Is Al2 O3 Al as a source2 O 3 As a BaO source
BaCO3 To CeO2 CeO as a source2 Respectively
The raw material composition used and the desulfurizing agent of Inventive Example 4 were
In addition to the desulfurizing agent of Example 3, MgCO was used as a MgO source.3 Add
The raw material compositions were mixed so as to be uniform.
Then, it is granulated to have a particle size of 10 mm. Books in Table 1
Inventive Example 3 includes CaCO3 The amount of C
aCO3 Amount and MgCO3 The amount is listed, so
The weighing exceeds 100 wt%. Where this CaC
O3 , MgCO3 Are converted as CaO and MgO respectively
(Invention Example 3: CaO is 38.8 wt%, Invention Example 4:
CaO is 36.6 wt% and MgO is 5.7 wt%)
Therefore, the total amount becomes 100 wt%.
【００３３】そして、本発明例５、６の脱硫剤は、前記
第３の実施の形態に係る溶鋼用脱硫剤であり、しかも各
成分（試薬）が表１の配合割合となったものである。こ
の脱硫剤は、ＣａＯ源としてＣａＣＯ3 を、Ａｌ2 Ｏ3
源としてＡｌ2 Ｏ3 を、ＢａＯ源としてＢａＣＯ3 を、
ＣｅＯ2 源としてＣｅＯ2 をそれぞれ使用した原料組成
物を、それぞれ均一になるように混合した後造粒し、こ
れをシリコニット発熱電気炉で約１２００℃に加熱焼結
したものである。なお、本発明例５の脱硫剤中にはＭｇ
Ｏが添加されてなく、本発明例６の脱硫剤中にはＭｇＯ
源としてＭｇＣＯ 3 が添加されている。この本発明例
５、６の脱硫剤中に占める各成分の割合は、本発明例
１、２の脱硫剤中に占める各成分の割合にそれぞれ対応
している。なお、比較例は、８５％カルシウムアルミネ
ート（１２ＣａＯ・７Ａｌ2 Ｏ3 ）＋１５％ＣａＯを加
熱溶融して製造したものである。The desulfurizing agents of Examples 5 and 6 of the present invention are the same as those described above.
The desulfurizing agent for molten steel according to the third embodiment,
The components (reagents) have the blending ratios shown in Table 1. This
Desulfurization agent of CaCO as a source of CaO3 Is Al2 O3
Al as a source2 O3 As a BaO source is BaCO3 To
CeO2 CeO as a source2 Raw material composition using each
The ingredients are mixed so that they are even, and then granulated.
This is heated and sintered at approximately 1200 ° C in a siliconit exothermic electric furnace.
It was done. In addition, in the desulfurizing agent of Inventive Example 5, Mg was used.
O was not added, and MgO was included in the desulfurizing agent of Inventive Example 6.
MgCO as a source 3 Has been added. This invention example
The proportions of the respective components in the desulfurizing agents 5 and 6 are the same as those of the present invention.
Corresponds to the proportion of each component in the desulfurizing agent
is doing. The comparative example is 85% calcium aluminum.
(12CaO / 7Al)2 O3 ) + 15% CaO added
It is manufactured by heat melting.
【００３４】上記した本発明例１〜６、及び比較例の脱
硫剤をそれぞれ使用し、溶銑（普通鋼用溶鋼）の脱硫試
験を以下の方法により行った。まず、黒鉛坩堝（外径４
５ｍｍ、内径３５ｍｍ、深さ１５０ｍｍ）を使用し、円
筒形シリコニット電気炉内でアルゴンガス気流（５００
ｍＬ／分）中、溶銑を１５００℃に加熱昇温した。次
に、溶銑温度を１５００℃に保持した状態で、母材とな
る溶銑上に前記した脱硫剤を、それぞれ３０〜４１ｇ上
置きし、静置した状態で１２０分間保持した。そして、
１２０分間経過後、溶銑をアルゴンガス中で自然冷却し
て、溶銑の冷却を行った。この試験結果を表２に示す。Using the desulfurizing agents of Examples 1 to 6 of the present invention and Comparative Example described above, a desulfurization test of hot metal (molten steel for ordinary steel) was conducted by the following method. First, graphite crucible (outer diameter 4
5 mm, inner diameter 35 mm, depth 150 mm) and argon gas flow (500) in a cylindrical silicon knit electric furnace.
(mL / min), the hot metal was heated to 1500 ° C. and heated. Next, while maintaining the hot metal temperature at 1500 ° C., 30 to 41 g of each of the above desulfurizing agents was placed on the hot metal serving as the base material, and the hot metal was held for 120 minutes in a static state. And
After 120 minutes, the hot metal was naturally cooled in argon gas to cool the hot metal. The test results are shown in Table 2.
【００３５】[0035]
【表２】 [Table 2]
【００３６】表２から分かるように、各溶銑中の初期Ｓ
濃度は、３０５ｐｐｍである。一方、溶銑中の終期Ｓ濃
度は、比較例の場合２２ｐｐｍであるが、本発明例１〜
６の脱硫剤を使用することで、１５〜１７ｐｐｍまで低
減できていることが分かる。ここで、比較例のスラグ中
の初期Ｓ濃度は３５８ｐｐｍとなっており、本発明例１
〜６（３７７〜４００ｐｐｍ）より低いにも関らず、終
期Ｓ濃度は本発明例１〜６（１３３７〜１３７２ｐｐ
ｍ）の方が比較例（１３００ｐｐｍ）よりも高く、本発
明例１〜６の脱硫剤の方がＳの吸収能力が高いことが分
かる。なお、脱硫能力の実測値からも明らかなように、
本発明例１〜６の脱硫剤は、比較例よりも大きな脱硫能
力を備えていることが分かる。As can be seen from Table 2, the initial S in each hot metal is
The concentration is 305 ppm. On the other hand, the final S concentration in the hot metal is 22 ppm in the case of the comparative example, but
By using the desulfurizing agent of No. 6, it can be seen that the amount can be reduced to 15 to 17 ppm. Here, the initial S concentration in the slag of the comparative example is 358 ppm, and the invention example 1
~ 6 (377 to 400 ppm), the final S concentration was inferior to the invention examples 1 to 6 (1337 to 1372 pp).
It is understood that m) is higher than that of Comparative Example (1300 ppm), and that the desulfurizing agents of Inventive Examples 1 to 6 have higher S absorption capacity. As is clear from the actual measurement of desulfurization capacity,
It can be seen that the desulfurizing agents of Examples 1 to 6 of the present invention have a larger desulfurizing ability than the comparative examples.
【００３７】以上、本発明を、実施の形態を参照して説
明してきたが、本発明は何ら上記した実施の形態に記載
の構成に限定されるものではなく、特許請求の範囲に記
載されている事項の範囲内で考えられるその他の実施の
形態や変形例も含むものである。例えば、前記したそれ
ぞれの実施の形態や変形例の一部又は全部を組合せて本
発明の溶鋼用脱硫剤及びその製造方法を構成する場合に
も本発明は適用される。また、前記実施の形態において
は、製造した脱硫剤を、溶鋼の脱硫剤として使用した場
合について説明したが、溶鋼の脱燐剤として利用するこ
とも可能である。Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the configurations described in the above embodiments, and is described in the scope of claims. Other embodiments and modifications that are conceivable within the scope of the matters mentioned above are also included. For example, the present invention is also applied to the case where the desulfurizing agent for molten steel and the method for producing the same of the present invention are configured by combining some or all of the above-described respective embodiments and modified examples. Further, in the above embodiment, the case where the produced desulfurizing agent is used as a desulfurizing agent for molten steel has been described, but it is also possible to use it as a dephosphorizing agent for molten steel.
【００３８】そして、前記実施の形態においては、希土
類元素の酸化物（ＲＥＯn ）としてＣｅＯ2 を使用した
場合について説明したが、硫化物の生成自由エネルギー
が他の金属と比較して小さい他の希土類元素、例えば、
Ｌａ、Ｎｄ等の酸化物を使用することも可能である。更
に、本発明の溶鋼用脱硫剤にＣａＦ2 を混合して使用す
ることも可能であり、又は脱硫効果を有するＣａＯ、Ｎ
ａ2 ＣＯ3 、ＣａＣ2 、Ｍｇのいずれか１又は２以上を
混合して使用することも可能である。また、この脱硫剤
にＣａＦ2 を混合し、更に脱硫効果を有するＣａＯ、Ｎ
ａ2 ＣＯ3 、ＣａＣ2 、Ｍｇのいずれか１又は２以上を
混合して使用することも可能である。このように、脱硫
剤にＣａＦ2 を混合することで、脱硫剤の融点を、溶鋼
の脱硫に使用可能な温度まで容易に低下させることがで
きる。また脱硫剤に脱硫効果を有する物質を混合するこ
とで、脱硫剤の脱硫効率を更に向上させることができ
る。なお、この場合、脱硫剤を破砕又は粉砕した後、必
要に応じて、脱硫剤の融点を低下させる効果を有するＣ
ａＦ2 や、脱硫効果を有するＣａＯ、Ｎａ2 ＣＯ3 、Ｃ
ａＣ2 、Ｍｇを混合したり、例えばＣａＯ、Ｎａ2 ＣＯ
3 、ＣａＣ2 、Ｍｇの粒径が大きい場合には、ＣａＯ、
Ｎａ2 ＣＯ3 、ＣａＣ2 、Ｍｇを脱硫剤に混合した後、
脱硫剤と共に破砕又は粉砕することも可能である。In the above-described embodiment, the case where CeO 2 is used as the oxide (REO n ) of the rare earth element has been described. However, the free energy of sulfide formation is smaller than that of other metals. Rare earth elements, for example,
It is also possible to use an oxide such as La or Nd. Furthermore, it is also possible to use CaF 2 mixed with the desulfurizing agent for molten steel of the present invention, or CaO, N having a desulfurizing effect.
It is also possible to use any one of a 2 CO 3 , CaC 2 , and Mg or a mixture thereof. In addition, CaF 2 which has a desulfurizing effect is obtained by mixing CaF 2 with this desulfurizing agent.
It is also possible to use any one of a 2 CO 3 , CaC 2 , and Mg or a mixture thereof. Thus, by mixing CaF 2 with the desulfurizing agent, the melting point of the desulfurizing agent can be easily lowered to a temperature that can be used for desulfurizing molten steel. Further, by mixing the desulfurizing agent with a substance having a desulfurizing effect, the desulfurizing efficiency of the desulfurizing agent can be further improved. In this case, after crushing or crushing the desulfurizing agent, C having an effect of lowering the melting point of the desulfurizing agent, if necessary.
aF 2 and, CaO having a desulfurizing effect, Na 2 CO 3, C
Mixing aC 2 and Mg, for example CaO, Na 2 CO
When the particle size of 3 , CaC 2 and Mg is large, CaO,
After mixing Na 2 CO 3 , CaC 2 , and Mg with the desulfurizing agent,
It is also possible to crush or grind with a desulfurizing agent.
【００３９】[0039]
【発明の効果】請求項１〜７記載の溶鋼用脱硫剤におい
ては、ＣａＯとＡｌ2 Ｏ3 にＢａＯ及びＲＥＯn を添加
することで、従来から溶鋼の脱硫に使用されてきた蛍石
を、軽減もしくは使用することなく、１２ＣａＯ・７Ａ
ｌ2 Ｏ3 系脱硫剤より幅広い領域で低融点化を達成で
き、しかも脱硫剤の融点を、溶鋼の脱硫に使用可能な温
度まで低下させることが可能となる。従って、排出され
るフッ素の量が環境基準を満足し、しかも脱硫剤が容易
に軟化、又は溶解するため、迅速で高い脱硫効率を達成
できる脱硫剤を提供できる。また、ＣａＯとＡｌ2 Ｏ3
にＢａＯ及びＲＥＯn を添加することで、脱硫剤の融点
を更に低下させることができるので、脱硫時における作
業性が良好となる。そして、高温域での硫化物の生成自
由エネルギーが小さい元素であるＢａ及びＲＥを有した
脱硫剤を使用することで、脱硫剤と溶鋼中の硫黄成分と
の結合エネルギーが大きい硫化物を生成させることが可
能となる。従って、脱硫反応を復硫反応よりも速く進行
させた状態で、平衡状態を維持させることが可能となる
ので、表面的には生成した硫化物の解離を阻止すること
ができ、最終的な脱硫効率を向上させる脱硫剤を提供で
きる。In the desulfurizing agent for molten steel according to claims 1 to 7, by adding BaO and REO n to CaO and Al 2 O 3 , fluorite which has been conventionally used for desulfurizing molten steel, 12CaO / 7A without reducing or using
A lower melting point can be achieved in a wider range than that of the l 2 O 3 -based desulfurizing agent, and further, the melting point of the desulfurizing agent can be lowered to a temperature that can be used for desulfurizing molten steel. Therefore, the amount of fluorine discharged satisfies the environmental standard, and the desulfurizing agent is easily softened or dissolved, so that it is possible to provide a desulfurizing agent capable of achieving rapid and high desulfurization efficiency. In addition, CaO and Al 2 O 3
Since the melting point of the desulfurizing agent can be further lowered by adding BaO and REO n to the, the workability during desulfurization becomes good. Then, by using the desulfurizing agent having Ba and RE, which are elements having a small free energy for forming sulfide in a high temperature region, a sulfide having a large binding energy between the desulfurizing agent and the sulfur component in the molten steel is generated. It becomes possible. Therefore, it is possible to maintain the equilibrium state in the state where the desulfurization reaction proceeds faster than the re-sulfurization reaction, and thus it is possible to prevent dissociation of the generated sulfide on the surface, and to achieve the final desulfurization. A desulfurizing agent that improves efficiency can be provided.
【００４０】特に、請求項２記載の溶鋼用脱硫剤におい
ては、成分に更にＭｇＯを添加することで、脱硫剤の融
点を更に低下させることができるので、脱硫時における
作業性が更に良好となる。請求項３記載の溶鋼用脱硫剤
においては、ＢａＯとＲＥＯn との配合比を調整するこ
とで、生成物の融点をＢａＯ及びＲＥＯn のそれぞれの
融点より大幅に降下させることが可能となる。従って、
融点が溶鋼の脱硫に使用可能な温度まで低下した脱硫剤
を提供できるので、更に迅速で高い脱硫効率を達成でき
る。請求項４記載の溶鋼用脱硫剤においては、ＲＥＯn
の中でも、特に高温域での硫化物の生成自由エネルギー
が小さい元素であるＣｅを有した脱硫剤を使用すること
で、脱硫剤と溶鋼中の硫黄成分との結合エネルギーが大
きい硫化物を生成させることが可能となる。従って、表
面的には生成した硫化物の解離を阻止することができ、
最終的な脱硫効率を更に向上させることが可能な脱硫剤
を提供できる。Particularly, in the desulfurizing agent for molten steel according to the second aspect, by further adding MgO to the component, the melting point of the desulfurizing agent can be further lowered, so that workability during desulfurization is further improved. . In claim 3 the molten steel for desulfurizing agent according, by adjusting the mixing ratio of the BaO and REO n, it is possible to the melting point of the product is significantly lowered than the respective melting points of BaO and REO n. Therefore,
Since it is possible to provide a desulfurizing agent having a melting point lowered to a temperature at which it can be used for desulfurizing molten steel, it is possible to achieve a quicker and higher desulfurization efficiency. In the desulfurizing agent for molten steel according to claim 4, REO n
Among them, by using a desulfurizing agent having Ce, which is an element having a small free energy for forming sulfide in a high temperature range, a sulfide having a large binding energy between the desulfurizing agent and the sulfur component in the molten steel is generated. It becomes possible. Therefore, it is possible to prevent dissociation of the generated sulfide on the surface,
A desulfurizing agent capable of further improving the final desulfurization efficiency can be provided.
【００４１】請求項５記載の溶鋼用脱硫剤においては、
脱硫剤の原料組成物を溶融した後、可能な限り急冷する
ことで、共晶結晶物の生成を阻害し、結晶の微細化、更
には非晶質化を図ることが可能となる。従って、脱硫剤
を溶鋼に添加した際に、脱硫剤が容易に軟化、又は溶解
し、良好な溶融特性を発現できるので、更に迅速で高い
脱硫効率を達成する脱硫剤を提供できる。また、急冷に
より得られた固溶体は、使用条件に応じてそれぞれ適し
た粒径に調整されるので、作業性が良好な脱硫剤を提供
できる。請求項６及び７記載の溶鋼用脱硫剤において
は、粉砕し混合又は混合し粉砕した脱硫剤が溶鋼の持つ
顕熱で十分に溶解可能である。また、請求項６において
はこの原料組成物を造粒又は造塊し、請求項７において
はこの原料組成物を焼結して、粉体状態での飛散防止を
図るので、取扱いが容易で、しかも使用時における作業
性が良好な脱硫剤を提供できる。In the desulfurizing agent for molten steel according to claim 5,
By melting the raw material composition of the desulfurizing agent and then rapidly cooling it as much as possible, it is possible to inhibit the formation of a eutectic crystal product, and to make the crystal finer and even amorphous. Therefore, when the desulfurizing agent is added to the molten steel, the desulfurizing agent can be easily softened or melted, and good melting characteristics can be exhibited, so that the desulfurizing agent that achieves even higher desulfurization efficiency can be provided. Further, the solid solution obtained by quenching is adjusted to have a particle size suitable for each use condition, so that a desulfurizing agent having good workability can be provided. In the desulfurizing agent for molten steel according to claims 6 and 7, the desulfurizing agent pulverized and mixed or mixed and pulverized can be sufficiently dissolved by the sensible heat of the molten steel. Further, in claim 6, the raw material composition is granulated or agglomerated, and in claim 7, the raw material composition is sintered to prevent scattering in a powder state, so that the handling is easy. Moreover, it is possible to provide a desulfurizing agent having good workability during use.
【００４２】請求項８及びこれに従属する請求項９、１
２、１３、１４記載の溶鋼用脱硫剤の製造方法において
は、脱硫剤の原料組成物を溶融した後、可能な限り急冷
することで、共晶結晶物の生成を阻害し、結晶の微細
化、更には非晶質化を図った脱硫剤を製造できる。従っ
て、脱硫剤を溶鋼に添加した際に、脱硫剤が容易に軟
化、又は溶解し、良好な溶融特性を発現できるので、更
に迅速で高い脱硫効率を達成する脱硫剤を容易に製造で
きる。また、急冷により得られた固溶体は、破砕又は粉
砕するので、使用条件にそれぞれ適した粒径の脱硫剤を
容易に製造できる。特に、請求項９記載の溶鋼の脱硫剤
の製造方法においては、大掛かりな設備を使用すること
なく、共晶結晶物の生成を阻害し、結晶の微細化、更に
は非晶質化を図ることができるので、経済的に脱硫剤の
製造を行うことができる。Claim 8 and claims 9 and 1 subordinate thereto.
In the method for producing a desulfurizing agent for molten steel according to 2, 13, and 14, the raw material composition of the desulfurizing agent is melted and then rapidly cooled as much as possible, thereby inhibiting the formation of a eutectic crystal and refining the crystal. Further, it is possible to produce a desulfurization agent aiming at amorphization. Therefore, when the desulfurizing agent is added to the molten steel, the desulfurizing agent can be easily softened or melted and good melting characteristics can be exhibited, so that the desulfurizing agent that achieves even higher desulfurization efficiency can be easily manufactured. Further, since the solid solution obtained by quenching is crushed or crushed, it is possible to easily produce a desulfurizing agent having a particle size suitable for each use condition. Particularly, in the method for producing a desulfurizing agent for molten steel according to claim 9, the production of a eutectic crystal is inhibited without using large-scale equipment, and the crystal is refined and further amorphized. Therefore, the desulfurizing agent can be economically produced.
【００４３】請求項１０及びこれに従属する請求項１
２、１３、１４記載の溶鋼用脱硫剤の製造方法において
は、粉砕し混合又は混合し粉砕した原料組成物で構成さ
れる脱硫剤を、溶鋼の持つ顕熱で十分に溶解することが
できるので、製造時における溶融に必要なエネルギーコ
ストを低減でき経済的である。また、この原料組成物を
造粒又は造塊し、粉体状態での飛散防止を図るので、脱
硫剤の取扱いが容易で、しかも使用時における作業性が
良好な脱硫剤の製造を行うことが可能となる。請求項１
１及びこれに従属する請求項１２、１３、１４記載の溶
鋼用脱硫剤の製造方法においては、粉砕し混合又は混合
し粉砕した原料組成物で構成される脱硫剤を、溶鋼の持
つ顕熱で十分に溶解することができるので、製造時にお
ける溶融に必要なエネルギーコストを低減でき経済的で
ある。また、この原料組成物を焼結し、粉体状態での飛
散防止を図るので、脱硫剤の取扱いが容易で、しかも使
用時における作業性が良好な脱硫剤の製造を行うことが
可能となる。Claim 10 and claim 1 subordinate thereto
In the method for producing a desulfurizing agent for molten steel according to 2, 13, and 14, the desulfurizing agent composed of the raw material composition that is pulverized and mixed or mixed and pulverized can be sufficiently dissolved by the sensible heat of the molten steel. It is economical because the energy cost required for melting during manufacturing can be reduced. In addition, since the raw material composition is granulated or agglomerated to prevent scattering in a powder state, it is possible to easily produce a desulfurizing agent that is easy to handle and has good workability during use. It will be possible. Claim 1
In the method for producing a desulfurizing agent for molten steel according to claim 1 or claim 12, 13 or 14, which is dependent on this, a desulfurizing agent composed of a raw material composition that is pulverized and mixed or mixed and pulverized by sensible heat of molten steel. Since it can be sufficiently dissolved, the energy cost required for melting during manufacturing can be reduced, which is economical. In addition, since the raw material composition is sintered to prevent scattering in the powder state, it is possible to manufacture a desulfurizing agent that is easy to handle and has good workability during use. .
【００４４】特に、請求項１２記載の溶鋼用脱硫剤の製
造方法においては、成分にＭｇＯを添加することで、脱
硫剤の融点を更に低下させることができるので、脱硫時
における作業性が更に良好となる。請求項１３記載の溶
鋼用脱硫剤の製造方法においては、ＢａＯとＲＥＯn と
の配合比を調整することで、生成物の融点をＢａＯ及び
ＲＥＯn のそれぞれの融点より大幅に降下させることが
可能となる。従って、融点が溶鋼の脱硫に使用可能な温
度まで低下することができるので、更に迅速で高い脱硫
効率を達成可能な脱硫剤を製造できる。請求項１４記載
の溶鋼用脱硫剤の製造方法においては、ＲＥＯn の中で
も、特に高温域での硫化物の生成自由エネルギーが小さ
い元素であるＣｅを有した脱硫剤を使用することで、脱
硫剤と溶鋼中の硫黄成分との結合エネルギーが大きい硫
化物を生成させることが可能となる。従って、表面的に
は生成した硫化物の解離を阻止することができ、最終的
な脱硫効率を更に向上させることが可能な脱硫剤を提供
できる。Particularly, in the method for producing a desulfurizing agent for molten steel according to the twelfth aspect, the melting point of the desulfurizing agent can be further lowered by adding MgO to the component, so that workability during desulfurization is further improved. Becomes In the method according to claim 13 of molten steel for desulfurizing agent according, BaO and by adjusting the mixing ratio of the REO n, the melting point of the product can be greatly lowered than the respective melting points of BaO and REO n Becomes Therefore, the melting point can be lowered to a temperature that can be used for desulfurization of molten steel, so that it is possible to manufacture a desulfurizing agent that can achieve more rapid and high desulfurization efficiency. In the method for producing a desulfurizing agent for molten steel according to claim 14, a desulfurizing agent having Ce, which is an element having a small free free energy of sulfide formation in a high temperature range among REO n , is used. It becomes possible to generate a sulfide having a large binding energy between the sulfur component in the molten steel and the sulfur component in the molten steel. Therefore, it is possible to provide a desulfurizing agent capable of preventing dissociation of the generated sulfide on the surface and further improving the final desulfurization efficiency.
【図１】本発明の第１〜第３の実施の形態に係る溶鋼用
脱硫剤に使用するＣａＯとＡｌ2Ｏ3 の二元系状態の説
明図である。FIG. 1 is an explanatory diagram of a binary system state of CaO and Al 2 O 3 used in a desulfurizing agent for molten steel according to first to third embodiments of the present invention.
【図２】（Ａ）、（Ｂ）はそれぞれ同二元系状態のＣ12
Ａ7 近傍の部分拡大図である。[FIG. 2] (A) and (B) are C 12 of the same binary system state, respectively.
It is a partially expanded view of the vicinity of A 7 .
【図３】本発明の第１〜第３の実施の形態に係る溶鋼用
脱硫剤に使用するＢａ、Ｃｅの硫化物の標準生成自由エ
ネルギーと温度との関係を示す説明図である。FIG. 3 is an explanatory diagram showing a relationship between standard free energy of formation of sulfides of Ba and Ce used in the desulfurizing agent for molten steel according to the first to third embodiments of the present invention and temperature.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 伊藤 秀行 福岡県北九州市戸畑区仙水町１番１号 九 州工業大学 工学部 物質工学科内 (72)発明者 柴田 悦郎 宮城県仙台市青葉区片平２丁目１−１ 東 北大学内 (72)発明者 久松 國男 神奈川県横浜市保土ヶ谷区峰沢町207番地 ６ (72)発明者 遠藤 光範 福岡県北九州市小倉北区馬借３丁目６番42 号 日本磁力選鉱株式会社内 (72)発明者 西田 武司 福岡県北九州市小倉北区馬借３丁目６番42 号 日本磁力選鉱株式会社内 Ｆターム(参考） 4K013 BA05 CB09 EA01 EA03 EA05 EA39 4K014 AA02 AB02 AB03 4K070 AB05 AC13 AC14 AC16 AC34 EA02 ─────────────────────────────────────────────────── ─── Continued front page (72) Inventor Hideyuki Ito 9-9 Sensui-cho, Tobata-ku, Kitakyushu, Fukuoka Department of Materials Engineering, Faculty of Engineering, State Institute of Technology (72) Inventor, Etsuro Shibata 2-1-1, Katahira, Aoba-ku, Sendai City, Miyagi Prefecture North University (72) Inventor Kunio Hisamatsu 207 Minezawa-cho, Hodogaya-ku, Yokohama-shi, Kanagawa 6 (72) Inventor Mitsunori Endo Fukuoka Prefecture Kitakyushu City Kokurakita Ward No. Japan Magnetic Separation Co., Ltd. (72) Inventor Takeshi Nishida Fukuoka Prefecture Kitakyushu City Kokurakita Ward No. Japan Magnetic Separation Co., Ltd. F-term (reference) 4K013 BA05 CB09 EA01 EA03 EA05 EA39 4K014 AA02 AB02 AB03 4K070 AB05 AC13 AC14 AC16 AC34 EA02
Claims (14)
ＣａＯ：１０〜５５重量％、Ａｌ2 Ｏ3 ：２０〜５５重
量％、ＢａＯ：１〜３５重量％、ＲＥＯn ：１〜４０重
量％の成分を有し、残部が不可避的不純物からなること
を特徴とする溶鋼用脱硫剤。なお、ＲＥは希土類元素を
示し、ＲＥＯn はその酸化物を示す。1. A desulfurizing agent used for desulfurizing molten steel, comprising:
CaO: 10 to 55% by weight, Al 2 O 3 : 20 to 55% by weight, BaO: 1 to 35% by weight, REO n : 1 to 40% by weight, with the balance being inevitable impurities. A characteristic desulfurizing agent for molten steel. RE represents a rare earth element, and REO n represents an oxide thereof.
成分には０を超え２０重量％以下のＭｇＯを有すること
を特徴とする溶鋼用脱硫剤。2. The desulfurizing agent for molten steel according to claim 1, wherein
A desulfurizing agent for molten steel, characterized in that it contains more than 0 and 20% by weight or less of MgO.
溶鋼用脱硫剤において、前記ＢａＯと前記ＲＥＯn との
モル比がＢａＯ／ＲＥＯn で０．５〜１．５の範囲であ
ることを特徴とする溶鋼用脱硫剤。3. A molten steel desulfurizing agent according to any one of claims 1 and 2, in the range molar ratio of 0.5 to 1.5 in BaO / REO n of the said BaO REO n A desulfurizing agent for molten steel, characterized by being present.
鋼用脱硫剤において、前記ＲＥＯn はＣｅＯ2 であるこ
とを特徴とする溶鋼用脱硫剤。4. The desulfurizing agent for molten steel according to claim 1, wherein the REO n is CeO 2 .
鋼用脱硫剤において、前記脱硫剤は、該脱硫剤の原料組
成物を加熱溶融した後急冷し、破砕又は粉砕されたもの
であることを特徴とする溶鋼用脱硫剤。5. The desulfurizing agent for molten steel according to any one of claims 1 to 4, wherein the desulfurizing agent is obtained by heating and melting the raw material composition of the desulfurizing agent, followed by rapid cooling, crushing or crushing. Is a desulfurizing agent for molten steel.
鋼用脱硫剤において、前記脱硫剤は、該脱硫剤の原料組
成物を、粉砕し混合又は混合し粉砕した後、造粒又は造
塊されたものであることを特徴とする溶鋼用脱硫剤。6. The desulfurizing agent for molten steel according to any one of claims 1 to 4, wherein the desulfurizing agent is formed by pulverizing and mixing or mixing and pulverizing a raw material composition of the desulfurizing agent, and then granulating. Alternatively, a desulfurizing agent for molten steel, which is an ingot.
鋼用脱硫剤において、前記脱硫剤は、該脱硫剤の原料組
成物を、粉砕し混合又は混合し粉砕した後、焼結された
ものであることを特徴とする溶鋼用脱硫剤。7. The desulfurizing agent for molten steel according to any one of claims 1 to 4, wherein the desulfurizing agent is a raw material composition of the desulfurizing agent, which is ground and mixed or mixed and ground, and then sintered. A desulfurizing agent for molten steel, characterized in that
ＥＯn 源を主体とする原料組成物を加熱溶融して急冷処
理を行う第１工程と、前記第１工程で得られた固溶体を
破砕及び粉砕のいずれか１の処理をして、ＣａＯ：１０
〜５５重量％、Ａｌ2 Ｏ3 ：２０〜５５重量％、Ｂａ
Ｏ：１〜３５重量％、ＲＥＯn ：１〜４０重量％で、残
部が不可避的不純物からなる脱硫剤を製造する第２工程
とを有することを特徴とする溶鋼用脱硫剤の製造方法。
なお、ＲＥは希土類元素を示し、ＲＥＯn はその酸化物
を示す。8. A CaO source, Al 2 O 3 source, BaO source, R
CaO: 10 is obtained by performing a first step of heating and melting a raw material composition mainly composed of an EO n source and quenching it, and crushing or crushing the solid solution obtained in the first step to obtain CaO: 10.
55 wt%, Al 2 O 3: 20~55 wt%, Ba
A second step of producing a desulfurizing agent having O: 1 to 35% by weight, REO n : 1 to 40% by weight, and the balance being an unavoidable impurity, and a second step for producing a desulfurizing agent for molten steel.
RE represents a rare earth element, and REO n represents an oxide thereof.
において、前記第１工程での急冷処理は、空冷及び金属
板上冷却のいずれか一方又は両方を用いた冷却であるこ
とを特徴とする溶鋼用脱硫剤の製造方法。9. The method for producing a desulfurizing agent for molten steel according to claim 8, wherein the quenching treatment in the first step is cooling using one or both of air cooling and cooling on a metal plate. And a method for producing a desulfurizing agent for molten steel.
ＲＥＯn 源を主体とする原料組成物を、粉砕して混合す
る処理、及び混合して粉砕する処理のいずれか１の処理
を行う第１工程と、前記第１工程で得られた混合物を、
造粒及び造塊処理のいずれか１の処理をして、ＣａＯ：
１０〜５５重量％、Ａｌ2 Ｏ3 ：２０〜５５重量％、Ｂ
ａＯ：１〜３５重量％、ＲＥＯn ：１〜４０重量％で、
残部が不可避的不純物からなる脱硫剤を製造する第２工
程とを有することを特徴とする溶鋼用脱硫剤の製造方
法。なお、ＲＥは希土類元素を示し、ＲＥＯn はその酸
化物を示す。10. A CaO source, an Al 2 O 3 source, a BaO source,
A first step of performing any one of a treatment of pulverizing and mixing a raw material composition mainly composed of a REO n source, and a treatment of mixing and pulverizing, and a mixture obtained in the first step,
Any one of the granulation and agglomeration treatments is performed and CaO:
10 to 55 wt%, Al 2 O 3: 20~55 wt%, B
aO: 1 to 35% by weight, REO n : 1 to 40% by weight,
A second step of producing a desulfurizing agent, the balance of which is an unavoidable impurity, and a method for producing a desulfurizing agent for molten steel, the method comprising: RE represents a rare earth element, and REO n represents an oxide thereof.
ＲＥＯn 源を主体とする原料組成物を、粉砕して混合す
る処理、及び混合して粉砕する処理のいずれか１の処理
を行う第１工程と、前記第１工程で得られた混合物を焼
結処理して、ＣａＯ：１０〜５５重量％、Ａｌ2 Ｏ3 ：
２０〜５５重量％、ＢａＯ：１〜３５重量％、ＲＥＯ
n ：１〜４０重量％で、残部が不可避的不純物からなる
脱硫剤を製造する第２工程とを有することを特徴とする
溶鋼用脱硫剤の製造方法。なお、ＲＥは希土類元素を示
し、ＲＥＯn はその酸化物を示す。11. A CaO source, an Al 2 O 3 source, a BaO source,
A first step of performing any one of a treatment of pulverizing and mixing a raw material composition mainly composed of a REO n source and a treatment of mixing and pulverizing, and baking the mixture obtained in the first step. After binding treatment, CaO: 10 to 55% by weight, Al 2 O 3 :
20-55% by weight, BaO: 1-35% by weight, REO
n : 1 to 40% by weight, and the second step of producing a desulfurizing agent in which the balance consists of unavoidable impurities, and a second step of producing a desulfurizing agent for molten steel. RE represents a rare earth element, and REO n represents an oxide thereof.
の溶鋼用脱硫剤の製造方法において、前記原料組成物に
はＭｇＯ源を含み、前記脱硫剤には０を超え２０重量％
以下のＭｇＯを含むことを特徴とする溶鋼用脱硫剤の製
造方法。12. The method for producing a desulfurizing agent for molten steel according to claim 8, wherein the raw material composition contains a MgO source, and the desulfurizing agent exceeds 0 to 20% by weight.
A method for producing a desulfurizing agent for molten steel, comprising the following MgO.
の溶鋼用脱硫剤の製造方法において、前記ＢａＯと前記
ＲＥＯn とのモル比がＢａＯ／ＲＥＯn で０．５〜１．
５の範囲であることを特徴とする溶鋼用脱硫剤の製造方
法。13. 0.5 The method of manufacturing a molten steel for desulfurizing agent according to any one of claims 8 to 12, the molar ratio of the said BaO REO n is in BaO / REO n.
5. The method for producing a desulfurizing agent for molten steel, which is in the range of 5.
の溶鋼用脱硫剤の製造方法において、前記ＲＥＯn はＣ
ｅＯ2 であることを特徴とする溶鋼用脱硫剤の製造方
法。14. The method for producing a desulfurizing agent for molten steel according to claim 8, wherein the REO n is C
A method for producing a desulfurizing agent for molten steel, which is eO 2 .
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2864551A1 (en) * | 2003-12-24 | 2005-07-01 | Lafarge Sa | DESULFURATION AGENT FOR STEELS AND ITS USE FOR THE DESULFURATION OF STEEL |
| JP2008063600A (en) * | 2006-09-05 | 2008-03-21 | Nippon Steel Corp | Desulfurization method for chromium-containing molten iron |
| JP2013036062A (en) * | 2011-08-04 | 2013-02-21 | Nippon Steel & Sumitomo Metal Corp | Method of desulfurizing molten steel and molten iron alloy |
| CN106521093A (en) * | 2016-12-08 | 2017-03-22 | 桂林加宏汽车修理有限公司 | Industrial desulfurizing agent |
| CN115161435A (en) * | 2022-07-05 | 2022-10-11 | 鞍钢股份有限公司 | A method for controlling sulfur and sulfide inclusions in heavy rail steel |
| CN115627322A (en) * | 2022-10-31 | 2023-01-20 | 河南少林特材有限公司 | Desulfurizer for RH furnace and preparation method thereof |
| CN116875769A (en) * | 2023-08-08 | 2023-10-13 | 河南少林特材有限公司 | Barium calcium aluminate desulfurizing agent and preparation method thereof, and preparation method of steel |
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2002
- 2002-05-16 JP JP2002141705A patent/JP2003328022A/en active Pending
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2864551A1 (en) * | 2003-12-24 | 2005-07-01 | Lafarge Sa | DESULFURATION AGENT FOR STEELS AND ITS USE FOR THE DESULFURATION OF STEEL |
| WO2005064022A1 (en) * | 2003-12-24 | 2005-07-14 | Lafarge | Steel desulphurating agent and use thereof in the desulphuration of steel |
| US7563303B2 (en) | 2003-12-24 | 2009-07-21 | Lafarge | Steel desulphurating agent and use thereof in the desulphuration of steel |
| JP2008063600A (en) * | 2006-09-05 | 2008-03-21 | Nippon Steel Corp | Desulfurization method for chromium-containing molten iron |
| JP2013036062A (en) * | 2011-08-04 | 2013-02-21 | Nippon Steel & Sumitomo Metal Corp | Method of desulfurizing molten steel and molten iron alloy |
| CN106521093A (en) * | 2016-12-08 | 2017-03-22 | 桂林加宏汽车修理有限公司 | Industrial desulfurizing agent |
| CN115161435A (en) * | 2022-07-05 | 2022-10-11 | 鞍钢股份有限公司 | A method for controlling sulfur and sulfide inclusions in heavy rail steel |
| CN115627322A (en) * | 2022-10-31 | 2023-01-20 | 河南少林特材有限公司 | Desulfurizer for RH furnace and preparation method thereof |
| CN115627322B (en) * | 2022-10-31 | 2023-12-12 | 河南少林特材有限公司 | Desulfurizing agent for RH furnace and preparation method thereof |
| CN116875769A (en) * | 2023-08-08 | 2023-10-13 | 河南少林特材有限公司 | Barium calcium aluminate desulfurizing agent and preparation method thereof, and preparation method of steel |
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