JP2021146347A - Sintering raw material, mold powder and method for producing sintering raw material - Google Patents
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- 239000000843 powder Substances 0.000 title claims abstract description 78
- 239000002994 raw material Substances 0.000 title claims abstract description 76
- 238000005245 sintering Methods 0.000 title claims abstract description 31
- 238000004519 manufacturing process Methods 0.000 title claims description 11
- 239000000203 mixture Substances 0.000 claims abstract description 34
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 18
- 239000013078 crystal Substances 0.000 claims abstract description 17
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 8
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 70
- 239000011734 sodium Substances 0.000 claims description 51
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 28
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 20
- 239000004115 Sodium Silicate Substances 0.000 claims description 19
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 claims description 19
- 229910052911 sodium silicate Inorganic materials 0.000 claims description 19
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 18
- 239000000292 calcium oxide Substances 0.000 claims description 15
- 239000010433 feldspar Substances 0.000 claims description 15
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 12
- 239000004575 stone Substances 0.000 claims description 7
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 6
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 6
- 239000010456 wollastonite Substances 0.000 claims description 6
- 229910052882 wollastonite Inorganic materials 0.000 claims description 6
- 239000011398 Portland cement Substances 0.000 claims description 5
- 238000005469 granulation Methods 0.000 abstract description 14
- 230000003179 granulation Effects 0.000 abstract description 14
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract description 3
- 229910052593 corundum Inorganic materials 0.000 abstract 2
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 2
- KKCBUQHMOMHUOY-UHFFFAOYSA-N Na2O Inorganic materials [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 abstract 1
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 230000002349 favourable effect Effects 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 25
- 229910000831 Steel Inorganic materials 0.000 description 22
- 239000010959 steel Substances 0.000 description 22
- 238000002844 melting Methods 0.000 description 21
- 230000008018 melting Effects 0.000 description 21
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 18
- 239000002893 slag Substances 0.000 description 15
- 235000012255 calcium oxide Nutrition 0.000 description 12
- 239000000463 material Substances 0.000 description 10
- 230000015572 biosynthetic process Effects 0.000 description 9
- 239000011775 sodium fluoride Substances 0.000 description 8
- 235000013024 sodium fluoride Nutrition 0.000 description 8
- 238000010304 firing Methods 0.000 description 7
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 6
- 150000001875 compounds Chemical class 0.000 description 6
- 238000001816 cooling Methods 0.000 description 6
- 238000013461 design Methods 0.000 description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 239000002131 composite material Substances 0.000 description 5
- 239000008187 granular material Substances 0.000 description 5
- 239000000378 calcium silicate Substances 0.000 description 4
- 229910052918 calcium silicate Inorganic materials 0.000 description 4
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 4
- 238000009749 continuous casting Methods 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 239000000428 dust Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 238000001354 calcination Methods 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229910001610 cryolite Inorganic materials 0.000 description 2
- -1 etc. are used Substances 0.000 description 2
- 229910052731 fluorine Inorganic materials 0.000 description 2
- 239000006028 limestone Substances 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 238000010583 slow cooling Methods 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- 229910018068 Li 2 O Inorganic materials 0.000 description 1
- 229910000954 Medium-carbon steel Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000003064 anti-oxidating effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000004568 cement Substances 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 229910021540 colemanite Inorganic materials 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000004328 sodium tetraborate Substances 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- 239000007921 spray Substances 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
- Continuous Casting (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
本開示は、鋼の連続鋳造に好適なモールドパウダー、それに含まれる焼結原料及び焼結原料の製造方法に関する。 The present disclosure relates to a mold powder suitable for continuous casting of steel, a sintering raw material contained therein, and a method for producing the sintering raw material.
鋼の連続鋳造プロセスでは、モールド内の溶鋼の表面にモールドパウダーが投入される。モールドパウダーは溶鋼からの熱を受けて溶融して（以下、溶融状態のモールドパウダーを「パウダースラグ」という）溶鋼の表面を覆い、パウダースラグはモールドと凝固シェルの間隙に流れ込んでスラグフィルムとなり、モールド下端から排出されて消費される。このプロセスにおけるモールドパウダーの主な役割は以下のとおりである。
・溶鋼表面の保温
・大気の遮断による溶鋼の酸化防止
・溶鋼から浮上する介在物の溶解及び吸収による溶鋼の浄化
・モールドと凝固シェルの間の潤滑
・凝固シェルの冷却速度のコントロール
In the continuous steel casting process, mold powder is charged onto the surface of the molten steel in the mold. The mold powder receives heat from the molten steel and melts (hereinafter, the molten mold powder is referred to as "powder slag") to cover the surface of the molten steel, and the powder slag flows into the gap between the mold and the solidified shell to form a slag film. It is discharged from the lower end of the mold and consumed. The main roles of the mold powder in this process are as follows.
・ Heat retention of molten steel surface ・ Antioxidation of molten steel by blocking the atmosphere ・ Purification of molten steel by melting and absorption of inclusions floating from molten steel ・ Lubrication between mold and solidified shell ・ Control of cooling rate of solidified shell
モールドパウダーは、主成分としてＳｉＯ２とＣａＯを含み、パウダースラグの特性や溶融速度の調整等のための副成分としてＡｌ２Ｏ３、ＭｇＯ、Ｎａ２Ｏ、Ｌｉ２Ｏ、フッ素（Ｆ）、Ｂ２Ｏ３、炭素（Ｃ）等を含む。 Mold powder contains SiO 2 and CaO as main components, and Al 2 O 3 , MgO, Na 2 O, Li 2 O, fluorine (F), as sub-components for adjusting the characteristics of powder slag and melting rate, etc. Includes B 2 O 3 , carbon (C), etc.
主成分の原料としては、一般にモールドパウダーに使用されているものであれば特に制限はなく、ＳｉＯ２−ＣａＯ原料、ＳｉＯ２原料、ＣａＯ原料が使用される。ＳｉＯ２−ＣａＯ原料としては合成珪酸カルシウム、ウォラストナイト、燐スラグ、高炉スラグ、ポルトランドセメント等が使用され、ＳｉＯ２原料としては珪砂、珪石、珪藻土、長石等が使用され、ＣａＯ原料としては石灰石（炭酸カルシウム）、生石灰（酸化カルシウム）等が使用される。 The main component material, generally not particularly limited as long as it is used in the mold powder, SiO 2 -CaO material, SiO 2 material and CaO material is used. Synthetic calcium silicate as SiO 2 -CaO material, wollastonite, phosphorus slag, blast furnace slag, Portland cement, etc. are used, as the SiO 2 raw material silica sand, silica stone, diatomaceous earth, feldspar, etc. are used, limestone as CaO raw material (Calcium carbonate), quicklime (calcium oxide), etc. are used.
副成分の原料としては、アルミナ（酸化アルミニウム）、ＭｇＯ原料（マグネシア）、炭酸ナトリウム、炭酸リチウム、フッ化ナトリウム（ＮａＦ）、フッ化カルシウム（ＣａＦ２）、氷晶石、ホウ酸、ホウ砂、コレマナイト、炭素原料（カーボンブラック、黒鉛、木炭、コークス）等が使用される。 As raw materials for auxiliary components, alumina (aluminum oxide), MgO raw material (magnesia), sodium carbonate, lithium carbonate, sodium fluoride (NaF), calcium fluoride (CaF 2 ), glacial stone, boric acid, borax, etc. Colemanite, carbon raw materials (carbon black, graphite, charcoal, coke), etc. are used.
主成分の原料である合成珪酸カルシウムは、主成分としてＳｉＯ２とＣａＯを含み、必要に応じてＮａ２ＯやＦが添加される。合成珪酸カルシウムの製造方法としては、電気炉やシャフト炉で原料混合物を高温で溶融した後、水中急冷却によりガラス化し、乾燥、粉砕するプリメルトタイプが知られている（特許文献１）。 Synthetic calcium silicate, which is a raw material of the main component, contains SiO 2 and Ca O as the main components, and Na 2 O and F are added as needed. As a method for producing synthetic calcium silicate, a premelt type is known in which a raw material mixture is melted at a high temperature in an electric furnace or a shaft furnace, then vitrified by rapid cooling in water, dried, and crushed (Patent Document 1).
ほぼ全てのモールドパウダーにＦが添加されている。Ｆはモールドパウダーの融点と粘度を低下させ、結晶化挙動を向上させる重要な役割を果たす。Ｆを供給する原料（Ｆ源）としてはフッ化ナトリウム（ＮａＦ）が使用されることが多い。その理由は、Ｎａもモールドパウダーの融点や粘度を下げる等、モールドパウダーの機能を向上させるからである。ＮａＦは工業的に合成されるため、高純度で組成が安定していることも理由である。 F is added to almost all mold powders. F plays an important role in lowering the melting point and viscosity of the mold powder and improving the crystallization behavior. Sodium fluoride (NaF) is often used as a raw material (F source) for supplying F. The reason is that Na also improves the function of the mold powder, such as lowering the melting point and viscosity of the mold powder. Another reason is that NaF is industrially synthesized and therefore has a high purity and a stable composition.
しかし、ＮａＦは健康や環境への有害性が指摘されている。そのため、ＮａＦを使用しないモールドパウダーが設計されている。 However, it has been pointed out that NaF is harmful to health and the environment. Therefore, a mold powder that does not use NaF is designed.
ＮａＦに代わるＦ源としてはフッ化カルシウム（ＣａＦ２）が使用される。また、ＮａＦに代わるＮａ源としては、炭酸ナトリウム（Ｎａ２ＣＯ３）、氷晶石（Ｎａ３ＡｌＦ６）、ソーダ長石（ＮａＡｌＳｉ３Ｏ８）、珪酸ナトリウム（Ｎａ２Ｏ・ｎＳｉＯ２）等が使用される。しかし、これらのＮａ源の含有量が多すぎると、以下のような問題が発生する。 Calcium fluoride (CaF 2 ) is used as an F source instead of NaF. Examples of Na sources that can replace NaF include sodium carbonate (Na 2 CO 3 ), cryolite (Na 3 AlF 6 ), soda valerite (NaAlSi 3 O 8 ), sodium silicate (Na 2 O · nSiO 2 ), and the like. used. However, if the content of these Na sources is too high, the following problems will occur.
・炭酸ナトリウムが多すぎる場合
炭酸ナトリウムが低融点であることからモールドパウダーの溶融性が悪化し、モールド壁面に大きなスラグベアが形成され、連続鋳造の操業トラブルの原因になる。また、炭酸ナトリウムが分解する際、ＣＯ２ガスを放出する。この反応は吸熱反応であるため、溶鋼表面を冷やす。さらに、顆粒タイプのモールドパウダーを造粒するために水を添加すると発熱し、造粒性が悪化する。
・ When too much sodium carbonate is used. Since sodium carbonate has a low melting point, the meltability of the mold powder deteriorates, and a large slug bear is formed on the wall surface of the mold, which causes troubles in continuous casting operation. Also, when sodium carbonate decomposes, it releases CO 2 gas. Since this reaction is an endothermic reaction, it cools the surface of the molten steel. Further, when water is added to granulate the granule type mold powder, heat is generated and the granulation property is deteriorated.
・氷晶石やソーダ長石が多すぎる場合
Ａｌ２Ｏ３の含有量が多くなり、パウダースラグの結晶の生成を阻害してしまう。モールドパウダーの結晶の生成は、凝固シェルの冷却速度の抑制（緩冷却効果）に重要な役割を果たすため、中炭素鋼や珪素鋼等の連続鋳造には強く求められる。したがって、鋼の種類によっては、低Ａｌ２Ｏ３のモールドパウダーが設計しにくい。
-If there are too many cryolites and soda feldspars, the content of Al 2 O 3 will increase, which will hinder the formation of powder slag crystals. Since the formation of mold powder crystals plays an important role in suppressing the cooling rate of the solidified shell (slow cooling effect), it is strongly required for continuous casting of medium carbon steel, silicon steel and the like. Therefore, it is difficult to design a low Al 2 O 3 mold powder depending on the type of steel.
・珪酸ナトリウムが多すぎる場合
他の原料より低融点であることからモールドパウダーの溶融性が悪化し、モールド壁面に大きなスラグベアが形成され、連続鋳造の操業トラブルの原因になる。
-When too much sodium silicate has a lower melting point than other raw materials, the meltability of the mold powder deteriorates, and large slug bears are formed on the wall surface of the mold, which causes troubles in continuous casting operations.
さらに、Ｆの含有量が少ない又は含まないモールドパウダーは、Ｆの代わりに粘度や融点を調整するため、通常のＦを含むモールドパウダーより多量のＮａを含有することがある。氷晶石はＦを含むため、Ｎａ源は実質的に炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムに限られる。それらはより多くの含有量が必要とされるが、多すぎる場合の問題は上記のとおりであるから、モールドパウダーの設計はより一層困難になる。 Further, a mold powder having a low or no F content may contain a larger amount of Na than a normal mold powder containing F in order to adjust the viscosity and melting point instead of F. Since cryolite contains F, the Na source is substantially limited to sodium carbonate, soda feldspar and sodium silicate. They require a higher content, but the problem with too much is as described above, making the design of the mold powder even more difficult.
Ｎａ源として、Ｎａ化合物を添加した合成珪酸カルシウムのプリメルトを使用することがある（例えば、特許文献２）。プリメルトは溶融性が良好でＣＯ２ガスを放出せず、造粒性も良好である。しかし、プリメルトの製造過程で溶融が必要であり、融液からＮａ化合物が揮発し、歩留まりや周囲の環境を悪化させることがある。 As the Na source, a premelt of synthetic calcium silicate to which a Na compound is added may be used (for example, Patent Document 2). Premelt has good meltability, does not emit CO 2 gas, and has good granulation properties. However, melting is required in the premelt manufacturing process, and the Na compound volatilizes from the melt, which may deteriorate the yield and the surrounding environment.
本開示は上記実状を鑑みてなされたものであり、本開示のいくつかの態様は、溶鋼の表面に投入される際に溶融性が良好でＣＯ２ガスを放出せず、造粒性が良好で、Ａｌ２Ｏ３の含有量を低減しやすく、Ｆの含有量が少ない又は含まない場合でも炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムが多すぎる場合の問題を生じず、さらに、Ｎａ源を製造する際にＮａ化合物を揮発させないモールドパウダー、それに含まれる焼結原料及び焼結原料の製造方法を提供することを目的とする。 The present disclosure has been made in view of the above circumstances, and some aspects of the present disclosure have good meltability when put into the surface of molten steel, do not emit CO 2 gas, and have good granulation property. Therefore, it is easy to reduce the content of Al 2 O 3 , and even if the content of F is low or not contained, the problem of too much sodium carbonate, sodium feldspar and sodium silicate does not occur, and a Na source is produced. It is an object of the present invention to provide a mold powder that does not volatilize a Na compound, a sintering raw material contained therein, and a method for producing the sintering raw material.
（１）本開示の第１の態様は、酸化物換算の組成として１０〜４０質量％のＮａ２Ｏ、２５〜６０質量％のＣａＯ、２０〜４５質量％のＳｉＯ２及び６％以下（０％を含む）のＡｌ２Ｏ３を含み、かつ、主たる結晶はａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）であることを特徴とする焼結原料に関する。 (1) A first aspect of the present disclosure, Na 2 O 10 to 40 wt% as the composition of the oxide equivalent, 25 to 60 wt% of CaO, 20 to 45 wt% of SiO 2 and 6% or less (0 A sintering raw material containing Al 2 O 3 ( containing%), and the main crystal being aNa 2 O · bCaO · cSiO 2 (a, b, c are arbitrary integers 1 to 8). Regarding.
Ｎａ源としてこの焼結原料を使用すると、溶融性が良好でＣＯ２ガスを放出せず、また、造粒性が良好で、ＮａＦ原料を必要としないモールドパウダーや、高Ｎａ、低Ｆ、低Ａｌ２Ｏ３組成のモールドパウダーを提供することができる。 When this sintered raw material is used as the Na source, mold powder that has good meltability and does not emit CO 2 gas, has good granulation property and does not require a NaF raw material, or high Na, low F, low A mold powder having an Al 2 O 3 composition can be provided.
（２）本開示の第２の態様は、第１の態様の焼結原料と、合計含有量が２０質量％以下（０質量％を含む）の炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムとを含むことを特徴とするモールドパウダーに関する。 (2) The second aspect of the present disclosure includes the sintering raw material of the first aspect, and sodium carbonate, soda feldspar and sodium silicate having a total content of 20% by mass or less (including 0% by mass). Regarding mold powder characterized by.
Ｎａ源の焼結原料はＮａの含有量（１０〜４０質量％）は多いが、主たる結晶はａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）であるため、融点が１２００℃以上であり、炭酸ナトリウムや珪酸ナトリウムほど低くない。したがって、Ｎａ源としてこの焼結原料を含み、他のＮａ源である炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムが少ない（合計含有量が２０質量％以下）モールドパウダーは、溶鋼の表面に投入される際の溶融性が良好である。また、炭酸成分を含まないためＣＯ２ガスを放出しない。さらに、高Ｎａ組成の焼結原料を使用すると炭酸ナトリウムを過剰に添加する必要がないことからモールドパウダーの造粒性を悪化させない。 Sintering material of Na source is the content (10-40 wt%) is often of Na, main crystal is a aNa 2 O · bCaO · cSiO 2 (a, b, c are arbitrary integers of 1-8) Therefore, the melting point is 1200 ° C. or higher, which is not as low as sodium carbonate or sodium silicate. Therefore, when the mold powder containing this sintered raw material as an Na source and having a small amount of other Na sources such as sodium carbonate, soda feldspar and sodium silicate (total content is 20% by mass or less) is put into the surface of molten steel. Has good meltability. Moreover, since it does not contain a carbonic acid component, it does not emit CO 2 gas. Further, when a sintered raw material having a high Na composition is used, it is not necessary to add an excessive amount of sodium carbonate, so that the granulation property of the mold powder is not deteriorated.
（３）本開示の第２の態様のモールドパウダーは、Ｆを含まなくてもよい。第１の態様の焼結原料をＮａ源として使用すると、炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムが少量でよい、又は、必要ないため、それらが多すぎる場合の問題を回避することができる。したがって、ＮａＦやＦを含まないモールドパウダーの設計が可能になる。また、Ａｌ２Ｏ３の含有量が比較的少ない（酸化物換算の組成として５質量％以下）モールドパウダーを設計することもできる。このようにモールドパウダーの設計自由度を高めることができる。 (3) The mold powder of the second aspect of the present disclosure does not have to contain F. When the sintered raw material of the first aspect is used as a Na source, a small amount of sodium carbonate, soda feldspar and sodium silicate may or is not required, so that the problem of too much of them can be avoided. Therefore, it is possible to design a mold powder that does not contain NaF or F. It is also possible to design a mold powder having a relatively low content of Al 2 O 3 (5% by mass or less as an oxide-equivalent composition). In this way, the degree of freedom in designing the mold powder can be increased.
（４）本開示の第２の態様のモールドパウダーは、酸化物換算の組成として４質量％以下（０質量％を含む）のＡｌ２Ｏ３を含むことが好ましい。パウダースラグの結晶の生成が阻害されないため、幅広い種類の鋼に使用することができる。 (4) The mold powder of the second aspect of the present disclosure preferably contains Al 2 O 3 of 4% by mass or less (including 0% by mass) as an oxide-equivalent composition. Since the formation of powder slag crystals is not inhibited, it can be used for a wide variety of steels.
（５）本開示の第３の態様は、本開示の第１の態様の焼結原料の製造方法であって、ウォラストナイト、ポルトランドセメント、珪石及び炭酸カルシウムから選ばれる２種以上と、炭酸ナトリウムと、３質量％以下（０質量％を含む）の酸化アルミニウムとを含む原料混合物を８００〜１２００℃で焼成する工程を含むことを特徴とする焼結原料の製造方法に関する。 (5) The third aspect of the present disclosure is the method for producing a sintered raw material according to the first aspect of the present disclosure, which comprises two or more kinds selected from wollastonite, Portland cement, silica stone and calcium carbonate, and carbonic acid. The present invention relates to a method for producing a sintered raw material, which comprises a step of firing a raw material mixture containing sodium and 3% by mass or less (including 0% by mass) of aluminum oxide at 800 to 1200 ° C.
原料混合物を８００〜１２００℃で焼成し、Ｎａ源の炭酸ナトリウムを高温で溶融しないので、Ｎａ化合物が揮発せず、歩留まりや周囲の環境を悪化させることなく焼結原料を製造することができる。 Since the raw material mixture is fired at 800 to 1200 ° C. and the sodium carbonate as the Na source is not melted at a high temperature, the Na compound does not volatilize, and the sintered raw material can be produced without deteriorating the yield or the surrounding environment.
以下、本開示の好適な実施形態について詳細に説明する。なお、以下に説明する本実施形態は、特許請求の範囲に記載された本開示の内容を不当に限定するものではなく、本実施形態で説明される構成のすべてが本開示の解決手段として必須であるとは限らない。 Hereinafter, preferred embodiments of the present disclosure will be described in detail. It should be noted that the present embodiment described below does not unreasonably limit the content of the present disclosure described in the claims, and all the configurations described in the present embodiment are essential as a means of solving the present disclosure. Is not always the case.
＜焼結原料＞
本実施形態の焼結原料は、酸化物換算の組成として１０〜４０質量％のＮａ２Ｏ、２５〜６０質量％のＣａＯ、２０〜４５質量％のＳｉＯ２及び６質量％以下（０質量％を含む）のＡｌ２Ｏ３を含み、かつ、焼結原料の主たる結晶はａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）である。
<Sintering material>
Sintering material of the present embodiment, Na 2 O 10 to 40 wt% as the composition of the oxide equivalent, 25 to 60 wt% of CaO, 20 to 45 wt% of SiO 2 and 6 wt% or less (0 wt% includes Al 2 O 3 of the included), and a main crystal of the sintering raw material aNa 2 O · bCaO · cSiO 2 (a, b, c is any integer from 1 to 8).
焼結原料は酸化物換算の組成として、Ｎａ２Ｏの含有量は１０〜４０質量％が好ましく、１２〜３５質量％がより好ましく、１５〜３０質量％がさらに好ましい。Ｎａ２Ｏの含有量がこの範囲を満たすと、モールドパウダーの溶融性が良好である。Ｎａ２Ｏの含有量が多すぎると目的のＮａ２Ｏ−ＣａＯ−ＳｉＯ２複合酸化物の融点が低くなりすぎ、この焼結原料を含むモールドパウダーは溶融性が悪化し、操業トラブルの原因になる。 The content of Na 2 O in the sintered raw material is preferably 10 to 40% by mass, more preferably 12 to 35% by mass, and further preferably 15 to 30% by mass in terms of oxide composition. When the Na 2 O content satisfies this range, the meltability of the mold powder is good. Na 2 O having a melting point too low for when the content is too large Na 2 O-CaO-SiO 2 composite oxide purposes, the mold powder meltability deteriorates including the sintering material, causing the operation troubles Become.
焼結原料は酸化物換算の組成として、ＣａＯの含有量は２５〜６０質量％が好ましく、３０〜５０質量％がより好ましく、３５〜４７質量％がさらに好ましい。ＳｉＯ２の含有量は２０〜４５質量％が好ましく、２５〜４０質量％がより好ましく、２８〜３８質量％がさらに好ましい。ＣａＯ及びＳｉＯ２の含有量がこの範囲を満たすと目的のＮａ２Ｏ−ＣａＯ−ＳｉＯ２複合酸化物の合成が進み、未反応の原料が残りにくい。 As the composition of the sintered raw material in terms of oxide, the CaO content is preferably 25 to 60% by mass, more preferably 30 to 50% by mass, still more preferably 35 to 47% by mass. The content of SiO 2 is preferably 20 to 45% by mass, more preferably 25 to 40% by mass, and even more preferably 28 to 38% by mass. When the contents of CaO and SiO 2 satisfy this range, the synthesis of the target Na 2 O-CaO-SiO 2 composite oxide proceeds, and unreacted raw materials are unlikely to remain.
焼結原料は酸化物換算の組成として、Ａｌ２Ｏ３の含有量は６％以下（０％を含む）が好ましく、３質量％以下がより好ましく、１質量％以下がさらに好ましい。Ａｌ２Ｏ３の含有量がこの範囲であれば、焼結原料の原料として安価なソーダ長石等を使用することもできる。一方、Ａｌ２Ｏ３の含有量が多すぎると目的の低Ａｌ２Ｏ３、高Ｎａ２Ｏの焼結原料が得られない。 As the composition of the sintered raw material in terms of oxide, the content of Al 2 O 3 is preferably 6% or less (including 0%), more preferably 3% by mass or less, and further preferably 1% by mass or less. If the content of Al 2 O 3 is within this range, inexpensive soda feldspar or the like can be used as a raw material for the sintering raw material. On the other hand, if the content of Al 2 O 3 is too large, the desired low Al 2 O 3 and high Na 2 O sintered raw materials cannot be obtained.
焼結原料の主たる結晶はａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）である。この結晶は融点が１２００℃以上であり、炭酸ナトリウムや珪酸ナトリウムほど低くない。したがって、Ｎａ源としてこの焼結原料を含み、他のＮａ源である炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムが少ない（合計含有量が２０質量％以下）モールドパウダーは造粒性に優れ、溶鋼の表面に投入される際の溶融性も良好である。また、炭酸成分を含まないためＣＯ２ガスを放出しない。 The main crystals of the sintering raw material are aNa 2 O, bCaO, and cSiO 2 (a, b, and c are arbitrary integers of 1 to 8). The crystals have a melting point of 1200 ° C. or higher, not as low as sodium carbonate or sodium silicate. Therefore, the mold powder containing this sintered raw material as an Na source and containing a small amount of other Na sources such as sodium carbonate, soda feldspar and sodium silicate (total content is 20% by mass or less) has excellent granulation properties and is a surface of molten steel. The meltability when it is put into the water is also good. Moreover, since it does not contain a carbonic acid component, it does not emit CO 2 gas.
焼結原料の強熱減量（Ｌｏｓｓ ｏｎ Ｉｇｎｉｔｉｏｎ：ＬＯＩ）は５質量％以下が好ましく、３質量％以下がより好ましく、１質量％以下がさらに好ましい。ＬＯＩは脱ＣＯ２反応に起因し、ＣＯ２反応は吸熱反応であるため、ＬＯＩが少ないほど、溶鋼の表面に投入する際、吸熱反応に伴う溶鋼表面の冷却を抑制することができる。 The loss on ignition (LOI) of the sintered raw material is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less. Since LOI is caused by the de-CO 2 reaction and the CO 2 reaction is an endothermic reaction, the smaller the LOI, the more the cooling of the molten steel surface due to the endothermic reaction can be suppressed when the LOI is put into the surface of the molten steel.
＜モールドパウダー＞
本実施形態のモールドパウダーは、本実施形態の焼結原料と、合計含有量が２０質量％以下（０質量％を含む）の炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムとを含む。
<Mold powder>
The mold powder of the present embodiment contains the sintered raw material of the present embodiment and sodium carbonate, soda feldspar and sodium silicate having a total content of 20% by mass or less (including 0% by mass).
モールドパウダーの原料の割合としては、焼結原料の含有量は０質量％超が好ましく、１０質量％以上がより好ましく、２０質量％以上がさらに好ましく、２５質量％以上が特に好ましい。一方、炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムの合計含有量は２０質量％以下（０質量％を含む）が好ましく、１５質量％以下がより好ましく、１０質量％以下がさらに好ましい。また、炭酸ナトリウム及び珪酸ナトリウムの合計含有量は１５質量％以下（０質量％を含む）が好ましく、１０質量％以下がより好ましく、７質量％以下がさらに好ましい。モールドパウダーは、融点が１２００℃以上の焼結原料をＮａ源として含むことによって融点が過度に低いＮａ源の含有量を抑えられるため、溶融性が良好である。また、ＣＯ２ガスを放出するＮａ源の含有量を抑えられるため、溶鋼の表面に投入すると、溶鋼表面の冷却を抑制し、綱の品質を維持することができる。さらに、Ｎａ含有量が多い焼結原料を含むことによって炭酸ナトリウムを過剰に添加する必要がないため、造粒性を悪化させない。 As for the ratio of the raw material of the mold powder, the content of the sintered raw material is preferably more than 0% by mass, more preferably 10% by mass or more, further preferably 20% by mass or more, and particularly preferably 25% by mass or more. On the other hand, the total content of sodium carbonate, soda feldspar and sodium silicate is preferably 20% by mass or less (including 0% by mass), more preferably 15% by mass or less, still more preferably 10% by mass or less. The total content of sodium carbonate and sodium silicate is preferably 15% by mass or less (including 0% by mass), more preferably 10% by mass or less, and further preferably 7% by mass or less. The mold powder has good meltability because the content of the Na source having an excessively low melting point can be suppressed by containing a sintered raw material having a melting point of 1200 ° C. or higher as the Na source. Further, since the content of the Na source that emits CO 2 gas can be suppressed, when it is put into the surface of the molten steel, the cooling of the surface of the molten steel can be suppressed and the quality of the rope can be maintained. Further, since it is not necessary to add sodium carbonate excessively by containing the sintering raw material having a high Na content, the granulation property is not deteriorated.
モールドパウダーの原料は、既述のものを含め、一般にモールドパウダーに用いられ、かつ、上記の組成や特性を満足するものであれば特に制限はなない。 The raw material of the mold powder, including the above-mentioned ones, is not particularly limited as long as it is generally used for the mold powder and satisfies the above composition and characteristics.
モールドパウダーはＦを含まなくてもよい。本実施形態の焼結原料をＮａ源として使用すると、炭酸ナトリウム、ソーダ長石及び珪酸ナトリウムが少量でよい、又は、必要ないため、それらが多すぎる場合の問題を回避することができる。したがって、ＮａＦやＦを含まないモールドパウダーの設計が可能になる。また、Ａｌ２Ｏ３の含有量が比較的少ない（酸化物換算の組成として５質量％以下）モールドパウダーを設計することもできる。このようにモールドパウダーの設計自由度を高めることができる。 The mold powder does not have to contain F. When the sintered raw material of the present embodiment is used as a Na source, a small amount of sodium carbonate, soda feldspar and sodium silicate may or is not required, so that the problem of too much of them can be avoided. Therefore, it is possible to design a mold powder that does not contain NaF or F. It is also possible to design a mold powder having a relatively low content of Al 2 O 3 (5% by mass or less as an oxide-equivalent composition). In this way, the degree of freedom in designing the mold powder can be increased.
モールドパウダーは酸化物換算の組成としてＡｌ２Ｏ３の含有量が６質量％以下（０質量％を含む）であることが好ましく、４質量％以下であることがより好ましい。パウダースラグの結晶の生成が阻害されないため、幅広い種類の鋼に使用することができる。 The composition of the mold powder in terms of oxide is preferably such that the content of Al 2 O 3 is 6% by mass or less (including 0% by mass), and more preferably 4% by mass or less. Since the formation of powder slag crystals is not inhibited, it can be used for a wide variety of steels.
モールドパウダーの形態は、一般にモールドパウダーに用いられる形態であれば特に制限はなく、例えば、粉末、押し出し成形顆粒、中空スプレー顆粒、撹拌造粒等を用いることができる。 The form of the mold powder is not particularly limited as long as it is a form generally used for the mold powder, and for example, powder, extruded granules, hollow spray granules, agitated granules and the like can be used.
＜焼結原料の製造方法＞
本実施形態の焼結原料の製造方法は、ウォラストナイト、ポルトランドセメント、珪石及び炭酸カルシウムから選ばれる２種以上と、炭酸ナトリウムと、３質量％以下（０質量％を含む）の酸化アルミニウムとを含む原料混合物を、８００〜１２００℃で焼成する工程を含む。
<Manufacturing method of sintered raw material>
The method for producing the sintered raw material of the present embodiment includes two or more kinds selected from wollastonite, Portland cement, silica stone and calcium carbonate, sodium carbonate, and 3% by mass or less (including 0% by mass) of aluminum oxide. Including a step of calcining a raw material mixture containing Calcium at 800 to 1200 ° C.
原料混合物は、ＣａＯやＳｉＯ２の供給原料としてウォラストナイト、ポルトランドセメント、珪石及び炭酸カルシウム（石灰石）から選ばれる２種以上を含むことが好ましいが、これらに限定されることはなく、他に高炉スラグ、燐スラグ等を含んでもよい。Ｎａ源としては炭酸ナトリウムが好ましいが、珪酸ナトリウム等他のＮａ源を含んでもよい。原料混合物は酸化アルミニウムの含有量が３質量％以下であることが好ましく、１質量％以下がより好ましく、０質量％がさらに好ましい。焼結原料の主たる結晶として融点が適度に低いａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）を得ることができるため、モールドパウダーの溶融性を良好にすることができる。 The raw material mixture preferably contains, but is not limited to, two or more selected from wollastonite, Portland cement, silica stone and calcium carbonate (limestone) as a feedstock for CaO and SiO 2. It may contain blast furnace slag, phosphorus slag and the like. Sodium carbonate is preferable as the Na source, but other Na sources such as sodium silicate may be contained. The raw material mixture preferably has an aluminum oxide content of 3% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass. Sintering material having a melting point moderately low, as a main crystal of aNa 2 O · bCaO · cSiO 2 (a, b, c are arbitrary integers of 1-8) it is possible to obtain, in good meltability of mold powder can do.
焼成温度は８００〜１２００℃が好ましく、９００〜１１００℃がより好ましく、９５０〜１０５０℃がさらに好ましい。８００℃以上で焼成することによりＮａ２Ｏ−ＣａＯ−ＳｉＯ２複合酸化物の合成、即ち、焼結が進むとともに、ＣＯ２ガスが放出され、炭酸成分が残りにくい。また、複合酸化物は融点が１２００℃以上のため、１２００℃以下の焼成では溶融しない。したがって、Ｎａ化合物が揮発せず、歩留まりや周囲の環境を悪化させないとともに、焼成設備を痛めない。さらに、燃料コストを抑制することができる。焼成時間はＮａ２Ｏ−ＣａＯ−ＳｉＯ２複合酸化物の合成が進行すればよく、合成完了以降まで長くする必要はない。後述の実施例では１時間に設定した。加熱方法は一般に焼成を行うことができれば特に限定されず、例えば、内燃式ロータリーキルン、外熱式ロータリーキルン、トンネルキルン、バッチ式焼成炉等を用いることができる。 The firing temperature is preferably 800 to 1200 ° C., more preferably 900 to 1100 ° C., and even more preferably 950 to 1050 ° C. By firing at 800 ° C. or higher, the synthesis of Na 2 O-CaO-SiO 2 composite oxide, that is, sintering proceeds, CO 2 gas is released, and the carbonic acid component is unlikely to remain. Further, since the composite oxide has a melting point of 1200 ° C. or higher, it does not melt by firing at 1200 ° C. or lower. Therefore, the Na compound does not volatilize, does not deteriorate the yield and the surrounding environment, and does not damage the firing equipment. Further, the fuel cost can be suppressed. The calcination time may be as long as the synthesis of the Na 2 O-CaO-SiO 2 composite oxide proceeds, and it is not necessary to lengthen the firing time until after the synthesis is completed. In the examples described later, it was set to 1 hour. The heating method is generally not particularly limited as long as it can be fired, and for example, an internal combustion type rotary kiln, an externally heated rotary kiln, a tunnel kiln, a batch type firing furnace, or the like can be used.
以下、本開示の実施例について詳細に説明する。 Hereinafter, examples of the present disclosure will be described in detail.
（１）焼結原料
ウォラストナイト、ポルトランドセメント、珪石及び炭酸カルシウムから選ばれる２種以上と、炭酸ナトリウムとを含む原料混合物に焼結助剤として珪酸ソーダを添加し、１０００℃で１時間焼成、粉砕し、焼結原料を得た。実験に用いた原料の配合と、酸化物換算の組成（焼結原料の組成）を表１に示す。
実施例１〜３は本開示の実施例である。比較例は６質量％の酸化アルミニウムを含む。 Examples 1 to 3 are examples of the present disclosure. The comparative example contains 6% by mass of aluminum oxide.
得られた焼結原料について、生成した結晶をＸ線回折法により同定した。同定結果を表１に示す。結晶の「＋」記号の数が多いほど生成量が多いことを意味する。 For the obtained sintered raw material, the produced crystals were identified by X-ray diffraction. The identification results are shown in Table 1. The larger the number of "+" symbols in the crystal, the larger the amount produced.
実施例１〜３で得られた焼結原料の主たる結晶はいずれもａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）であった。一方、比較例はＮａＡｌＳｉ２Ｏ６、Ａｌ２Ｃａ２Ｏ１５Ｓｉ５が晶出した。これらはパウダースラグの緩冷却効果を阻害するおそれがある。 The main crystals of the sintering raw materials obtained in Examples 1 to 3 were aNa 2 O, bCaO, and cSiO 2 (a, b, and c are arbitrary integers of 1 to 8). On the other hand, in Comparative Example, NaAlSi 2 O 6 and Al 2 Ca 2 O 15 Si 5 were crystallized. These may interfere with the slow cooling effect of the powder slag.
本開示では原料混合物を溶融することなく、主たる結晶がａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）の焼結原料を得ることができる。即ち、Ｎａ化合物が揮発せず、歩留まりや周囲の環境を悪化させることがなく、Ｎａ源の焼結原料を製造することができる。 In the present disclosure, it is possible to obtain a sintered raw material in which the main crystals are aNa 2 O, bCaO, and cSiO 2 (a, b, and c are arbitrary integers of 1 to 8) without melting the raw material mixture. That is, the Na compound does not volatilize, and the yield and the surrounding environment are not deteriorated, and the sintered raw material of the Na source can be produced.
（２）モールドパウダー
表２に示す原料の配合に基づき、焼結原料を含むモールドパウダーを得た。焼結原料は表１の実施例２を用いた。各モールドパウダーの酸化物換算の組成を表２に示す。組成の単位は質量％だが、「質量比（ＣａＯ／ＳｉＯ２）」はＣａＯのＳｉＯ２に対する質量比であり、他成分の質量％表示と単位が異なるためカッコ書きとした。
実施例１〜６は本開示の実施例であって焼結原料を含み、比較例１〜３は焼結原料を含まない。モールドパウダーの組成として実施例１〜４はＦを含み、実施例５〜６はＦを含まない（フッ素レス）。また、実施例１〜５はＡｌ２Ｏ３の含有量が少なく、実施例６はＡｌ２Ｏ３の含有量が多い。 Examples 1 to 6 are examples of the present disclosure and include a sintering raw material, and Comparative Examples 1 to 3 do not contain a sintering raw material. As the composition of the mold powder, Examples 1 to 4 contain F, and Examples 5 to 6 do not contain F (fluorine-less). Further, Examples 1 to 5 have a low content of Al 2 O 3 , and Example 6 has a high content of Al 2 O 3.
得られたモールドパウダーについて、以下の評価を行った。 The obtained mold powder was evaluated as follows.
＜造粒性＞
モールドパウダーの造粒性について、粒強度が高く、粉塵がほとんど発生しないものを優（◎）、許容できる粒強度を持ち、粉塵を若干発生するものの作業上問題のないレベルのものを良（○）、粒強度がほとんどなく、粉塵を多く発生するものを不可（×）と評価した。
<Granulation>
Regarding the granulation property of the mold powder, the one with high grain strength and almost no dust is excellent (◎), and the one with acceptable grain strength and some dust is generated but there is no problem in work is good (○). ), Those with almost no grain strength and generating a lot of dust were evaluated as impossible (x).
＜溶融性＞
高周波誘導炉で１５００℃に加熱した溶鉄の表面にモールドパウダーを投入し、その溶融性を以下のように評価した。溶融からパウダースラグの生成が円滑に進むものを優（◎）、多少焼結や溶融遅れが見られるものの問題のないレベルのものを良（○）、焼結やパウダースラグの粘り等が発生し溶融性状が悪いものを不良（△）、焼結やパウダースラグの粘り等が発生し溶融性状が著しく悪いものを不可（×）とした。
<Melting property>
Mold powder was put into the surface of molten iron heated to 1500 ° C. in a high-frequency induction furnace, and its meltability was evaluated as follows. The one in which the formation of powder slag proceeds smoothly from melting is excellent (◎), the one in which there is some sintering or melting delay but there is no problem (○), and the stickiness of sintering or powder slag occurs. Those with poor melt properties were marked as defective (Δ), and those with extremely poor melt properties due to sintering or stickiness of powder slag were marked as unacceptable (x).
実施例及び比較例の評価結果を表２に示す。 Table 2 shows the evaluation results of Examples and Comparative Examples.
実施例１〜６は造粒性が良好であった。これは造粒時に水と反応して発熱する炭酸ナトリウムが少ないためと考えられる。また、実施例１〜６は溶融性が良好であった。実施例１〜６の焼結原料はＮａの含有量は多いが、主たる結晶はａＮａ２Ｏ・ｂＣａＯ・ｃＳｉＯ２（ａ，ｂ，ｃは１〜８の任意の整数）であるため、融点が１２００℃以上であり、比較的融点が低い炭酸ナトリウムやソーダ長石、珪酸ナトリウムが少ないためと考えられる。一方、比較例１〜３は炭酸ナトリウムやソーダ長石、珪酸ナトリウムの含有量が過剰であるため造粒性、溶融性が実施例より劣る結果となった。 Examples 1 to 6 had good granulation properties. It is considered that this is because there is little sodium carbonate that reacts with water and generates heat during granulation. In addition, Examples 1 to 6 had good meltability. Although the sintered raw materials of Examples 1 to 6 have a high Na content , the melting point is high because the main crystals are aNa 2 O, bCaO, and cSiO 2 (a, b, and c are arbitrary integers of 1 to 8). It is considered that this is because there are few sodium carbonate, soda feldspar, and sodium silicate having a relatively low melting point of 1200 ° C. or higher. On the other hand, Comparative Examples 1 to 3 were inferior in granulation property and meltability as in Examples because the contents of sodium carbonate, soda feldspar, and sodium silicate were excessive.
本開示の焼結原料を用いると、モールドパウダーの組成として、Ｆの有無やＡｌ２Ｏ３の多少によらず、造粒性、溶融性が良好なモールドパウダーを得ることができる。即ち、モールドパウダーの設計自由度が高く、多様なモールドパウダーを製造することができる。さらに、本開示のモールドパウダーは、焼結原料が炭酸成分を含まないため、溶鋼の表面に投入される際にＣＯ２ガスを放出しない。ＣＯ２反応は吸熱反応であるため、吸熱反応に伴う溶鋼表面の冷却を抑制することができる。 By using the sintered raw material of the present disclosure, it is possible to obtain a mold powder having good granulation property and meltability regardless of the presence or absence of F and the amount of Al 2 O 3 as the composition of the mold powder. That is, the degree of freedom in designing the mold powder is high, and various mold powders can be produced. Further, the molded powder of the present disclosure does not emit CO 2 gas when it is put into the surface of molten steel because the sintering raw material does not contain a carbonic acid component. Since the CO 2 reaction is an endothermic reaction, it is possible to suppress the cooling of the molten steel surface due to the endothermic reaction.
なお、上記のように本実施形態について詳細に説明したが、本開示の新規事項及び効果から実体的に逸脱しない多くの変形が可能であることは当業者には容易に理解できるであろう。したがって、このような変形例はすべて本開示の範囲に含まれる。例えば、明細書において、少なくとも一度、より広義又は同義な異なる用語とともに記載された用語は、明細書のいかなる箇所においても、その異なる用語に置き換えられることができる。 Although the present embodiment has been described in detail as described above, those skilled in the art will easily understand that many modifications that do not substantially deviate from the new matters and effects of the present disclosure are possible. Therefore, all such variations are within the scope of the present disclosure. For example, in the specification, a term described at least once with a different term having a broader meaning or a synonym may be replaced with the different term at any part of the specification.
Claims (5)
Ｆを含まないことを特徴とするモールドパウダー。 The mold powder according to claim 2.
A mold powder characterized by not containing F.
酸化物換算の組成として４質量％以下（０質量％を含む）のＡｌ２Ｏ３を含むことを特徴とするモールドパウダー。 The mold powder according to claim 2 or 3.
A mold powder containing 4% by mass or less (including 0% by mass) of Al 2 O 3 as an oxide-equivalent composition.
ウォラストナイト、ポルトランドセメント、珪石及び炭酸カルシウムから選ばれる２種以上と、炭酸ナトリウムと、３質量％以下（０質量％を含む）の酸化アルミニウムとを含む原料混合物を８００〜１２００℃で焼成する工程を含むことを特徴とする焼結原料の製造方法。 The method for producing a sintered raw material according to claim 1.
A raw material mixture containing two or more selected from wollastonite, Portland cement, silica stone and calcium carbonate, sodium carbonate and 3% by mass or less (including 0% by mass) of aluminum oxide is calcined at 800 to 1200 ° C. A method for producing a sintered raw material, which comprises a step.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61115695A (en) * | 1984-11-09 | 1986-06-03 | Nittetsu Mining Co Ltd | Manufacture of granular sintering type flux |
| JPH0538560A (en) * | 1991-08-05 | 1993-02-19 | Shinagawa Refract Co Ltd | Molding powder for continuous casting of steel |
| JP2000169136A (en) * | 1998-12-07 | 2000-06-20 | Shinagawa Refract Co Ltd | Synthetic calcium silicate and mold powder for continuous casting of steel using the same |
| JP2005169488A (en) * | 2003-12-15 | 2005-06-30 | Shinagawa Refract Co Ltd | High viscosity mold powder for continuous casting of steel |
| JP2011245503A (en) * | 2010-05-25 | 2011-12-08 | Sumitomo Metal Ind Ltd | Mold flux for continuously casting steel |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61115695A (en) * | 1984-11-09 | 1986-06-03 | Nittetsu Mining Co Ltd | Manufacture of granular sintering type flux |
| JPH0538560A (en) * | 1991-08-05 | 1993-02-19 | Shinagawa Refract Co Ltd | Molding powder for continuous casting of steel |
| JP2000169136A (en) * | 1998-12-07 | 2000-06-20 | Shinagawa Refract Co Ltd | Synthetic calcium silicate and mold powder for continuous casting of steel using the same |
| JP2005169488A (en) * | 2003-12-15 | 2005-06-30 | Shinagawa Refract Co Ltd | High viscosity mold powder for continuous casting of steel |
| JP2011245503A (en) * | 2010-05-25 | 2011-12-08 | Sumitomo Metal Ind Ltd | Mold flux for continuously casting steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115319038A (en) * | 2022-07-22 | 2022-11-11 | 中南大学 | Novel ultra-low carbon steel covering slag |
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