JPH06256045A - Modification of converter slag - Google Patents
Modification of converter slagInfo
- Publication number
- JPH06256045A JPH06256045A JP19230092A JP19230092A JPH06256045A JP H06256045 A JPH06256045 A JP H06256045A JP 19230092 A JP19230092 A JP 19230092A JP 19230092 A JP19230092 A JP 19230092A JP H06256045 A JPH06256045 A JP H06256045A
- Authority
- JP
- Japan
- Prior art keywords
- slag
- cao
- concentration
- converter
- crystallized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002893 slag Substances 0.000 title claims abstract description 156
- 238000012986 modification Methods 0.000 title abstract description 5
- 230000004048 modification Effects 0.000 title abstract description 5
- 238000001816 cooling Methods 0.000 claims abstract description 43
- 229910044991 metal oxide Inorganic materials 0.000 claims abstract description 42
- 239000006104 solid solution Substances 0.000 claims abstract description 39
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 37
- 229910052742 iron Inorganic materials 0.000 claims abstract description 18
- 238000009628 steelmaking Methods 0.000 claims abstract description 14
- 150000004706 metal oxides Chemical class 0.000 claims description 41
- 238000000034 method Methods 0.000 claims description 25
- 238000002407 reforming Methods 0.000 claims description 10
- 239000002904 solvent Substances 0.000 claims description 7
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 5
- 238000002425 crystallisation Methods 0.000 claims description 2
- 230000008025 crystallization Effects 0.000 claims description 2
- 239000010436 fluorite Substances 0.000 abstract description 12
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 abstract description 10
- 238000010791 quenching Methods 0.000 abstract description 4
- 230000000171 quenching effect Effects 0.000 abstract description 4
- 238000000137 annealing Methods 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 21
- 229910004298 SiO 2 Inorganic materials 0.000 description 20
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 19
- 229910000831 Steel Inorganic materials 0.000 description 15
- 238000006703 hydration reaction Methods 0.000 description 15
- 239000010959 steel Substances 0.000 description 15
- 230000036571 hydration Effects 0.000 description 13
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 10
- 235000011941 Tilia x europaea Nutrition 0.000 description 10
- 239000011575 calcium Substances 0.000 description 10
- 239000004571 lime Substances 0.000 description 10
- 238000010583 slow cooling Methods 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000003287 optical effect Effects 0.000 description 5
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000005260 corrosion Methods 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 4
- 229910052748 manganese Inorganic materials 0.000 description 4
- 239000011572 manganese Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000007704 transition Effects 0.000 description 4
- 238000007664 blowing Methods 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 229910052500 inorganic mineral Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000011707 mineral Substances 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000007711 solidification Methods 0.000 description 3
- 230000008023 solidification Effects 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 229910052918 calcium silicate Inorganic materials 0.000 description 2
- 235000012241 calcium silicate Nutrition 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000029087 digestion Effects 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 101150006573 PAN1 gene Proteins 0.000 description 1
- 238000003723 Smelting Methods 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- JHLNERQLKQQLRZ-UHFFFAOYSA-N calcium silicate Chemical compound [Ca+2].[Ca+2].[O-][Si]([O-])([O-])[O-] JHLNERQLKQQLRZ-UHFFFAOYSA-N 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- BCAARMUWIRURQS-UHFFFAOYSA-N dicalcium;oxocalcium;silicate Chemical compound [Ca+2].[Ca+2].[Ca]=O.[O-][Si]([O-])([O-])[O-] BCAARMUWIRURQS-UHFFFAOYSA-N 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000399 optical microscopy Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 229910021534 tricalcium silicate Inorganic materials 0.000 description 1
- 235000019976 tricalcium silicate Nutrition 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B5/00—Treatment of metallurgical slag ; Artificial stone from molten metallurgical slag
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、製鋼過程で発生する転
炉スラグの改質に関し、より詳しくは、転炉スラグの道
路用路盤材やコンクリート骨材などへの利用を推進する
ために、膨張崩壊性を示さないように改質された転炉ス
ラグと、このような転炉スラグを得るための改質方法と
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reforming of converter slag generated in the steelmaking process, and more specifically, to promote utilization of the converter slag for road roadbed materials, concrete aggregates, etc. The present invention relates to a converter slag modified so as not to exhibit expansion and collapse properties, and a reforming method for obtaining such a converter slag.
【０００２】[0002]
【従来の技術】製鋼においては膨大な量の転炉スラグが
副生するが、転炉スラグは膨張崩壊性を有するため、大
部分が埋め立て用に利用され、一部が仮設道路用材など
として利用されているにすぎない。しかし、わが国では
埋め立て用地も不足してきているので、転炉スラグをよ
り付加価値の高い用途、例えば、道路用路盤材やコンク
リート骨材などとして有効利用するために、転炉スラグ
の膨張崩壊性を抑制するように改質することが強く要望
されていた。BACKGROUND OF THE INVENTION In steelmaking, a huge amount of converter slag is produced as a by-product, but since converter slag has expansive and collapsible properties, most of it is used for landfill and part is used as temporary road material. It is only being done. However, in Japan, there is also a shortage of landfill sites, so in order to effectively use converter slag for higher value-added applications, such as road subbase materials and concrete aggregates, the expansion and disintegration properties of converter slag must be improved. There was a strong demand for modification to suppress it.
【０００３】成田ら, 鉄と鋼, 1978年第10号, p. 1558-
1567によれば、転炉スラグの膨張崩壊の主な原因は、製
鋼時に媒溶剤として添加された石灰に原因がある。即
ち、製鋼過程で溶鋼に添加された石灰の大部分は、鋼中
に溶解し、鋼中の介在物と結合して滓化に寄与し、ダイ
カルシウムシリケート(2CaO-SiO2) 、トリカルシウムシ
リケート(3CaO-SiO2) などとしてスラグ中に移行する
が、一部の石灰は滓化に寄与せず、遊離のCaO のままス
ラグ中に移行する。この遊離CaO が次の(1) 式に示すよ
うに水和 (消化) 反応を受ける時の体積膨張 (体積は約
100 ％膨張) が、転炉スラグの膨張崩壊の主原因であ
り、転炉スラグ中の遊離CaO 量を１重量％以下に制限す
れば崩壊が抑制されると報告されている。Narita et al., Iron and Steel , 1978 No. 10, p. 1558-
According to 1567, the main cause of expansion and collapse of converter slag is due to lime added as a solvent during steelmaking. That is, most of the lime added to the molten steel in the steelmaking process dissolves in the steel and contributes to slag formation by combining with the inclusions in the steel, dicalcium silicate (2CaO-SiO 2 ), tricalcium silicate. Although it migrates into the slag as (3CaO-SiO 2 ), some lime does not contribute to slag formation and migrates into the slag as free CaO. The volume expansion of this free CaO when it undergoes a hydration (digestion) reaction as shown in equation (1)
It is reported that 100% expansion) is the main cause of expansion and collapse of converter slag, and if the amount of free CaO in converter slag is limited to 1% by weight or less, the collapse is suppressed.
【０００４】 CaO ＋ H2O → Ca(OH)2 ‥‥ (1) 一方、特開昭51−11011 号公報によれば、転炉スラグ崩
壊の原因は、CaO-10wt％FeO の水和反応と、β−2CaO・
SiO2からγ−2CaO・SiO2への転移による膨張であるとさ
れている。また、特開昭53−149892号公報および特開昭
55−128518号公報によれば、β (α')-2CaO ・SiO2から
γ−2CaO・SiO2への転移が転炉スラグ崩壊の主原因であ
るとされている。CaO + H 2 O → Ca (OH) 2 (1) On the other hand, according to JP-A-51-11011, the cause of converter slag collapse is caused by the hydration reaction of CaO-10wt% FeO. And β-2CaO
It is said that the expansion is caused by the transition from SiO 2 to γ-2CaO · SiO 2 . In addition, JP-A-53-149892 and JP-A-
According to 55-128518, the transition from β (α ′)-2CaO · SiO 2 to γ-2CaO · SiO 2 is the main cause of converter slag collapse.
【０００５】しかし、上記成田らの報告、および水渡
ら, 鉄と鋼, 1977年第14号, p. 2316-2325によれば、転
炉スラグ中に含まれるP2O5が2CaO・SiO2中に固溶される
ため、β−2CaO・SiO2またはα'-2CaO・SiO2からγ−2C
aO・SiO2への転移は起こらない。従って、転炉スラグ膨
張崩壊の主原因は、やはりスラグ中に含まれる遊離CaO
の水和反応による体積膨張であると考えられる。However, according to the above report by Narita et al. And Mizutawa et al., Iron and Steel , No. 14, 1977, p. 2316-2325, P 2 O 5 contained in converter slag is 2CaO.SiO 2 Being a solid solution in, β-2CaO ・ SiO 2 or α'-2CaO ・ SiO 2 to γ-2C
No transition to aO / SiO 2 occurs. Therefore, the main cause of expansion and collapse of converter slag is free CaO contained in slag.
It is considered to be the volume expansion due to the hydration reaction of.
【０００６】成田らは、CaO 相中に固溶している金属酸
化物 (FeO, MnO, MgO など) の量が多くなると、転炉ス
ラグの崩壊性が低下することを報告しているが、定量的
な検討は全く行われていない。[0006] Narita et al. Reported that when the amount of metal oxides (FeO, MnO, MgO, etc.) dissolved in the CaO phase increased, the disintegration property of the converter slag decreased. No quantitative study has been done.
【０００７】膨張崩壊を抑制するための転炉スラグの改
質方法として、前記特開昭53−149892号公報にはフェロ
クロム滓を、特開昭55−128518号公報にはB2O3を、特開
昭60−246246号公報には高炉スラグを、それぞれ出滓後
の転炉スラグに添加する方法が示されている。しかし、
これらは遊離CaO の水和による崩壊性の抑制に着目した
ものではない。As a method for reforming converter slag for suppressing expansion and collapse, ferrochrome slag is disclosed in JP-A-53-149892 and B 2 O 3 is disclosed in JP-A-55-128518. Japanese Patent Laid-Open No. 60-246246 discloses a method of adding blast furnace slag to converter slag after slag slag. But,
These do not focus on the suppression of disintegration due to hydration of free CaO.
【０００８】[0008]
【発明が解決しようとする課題】このように、従来技術
はβ−2CaO・SiO2またはα'-2CaO・SiO2からγ−2CaO・
SiO2への転移の抑制に力点が置かれていたため、遊離Ca
O の水和性に対する検討はほとんどなされてこなかっ
た。上記成田らの報告のように、転炉スラグ中の遊離Ca
O 量を１重量％以下に低減させることは、スラグの崩壊
防止には有効であるかも知れないが、これは製鋼過程で
の石灰の投入量の抑制につながり、肝心の鋼の清浄化が
達成されなくなる恐れが大きいので、採用できない。As described above, according to the prior art, β-2CaO · SiO 2 or α′-2CaO · SiO 2 to γ-2CaO · SiO 2
Since the emphasis was on suppressing the transition to SiO 2 , free Ca
Little consideration has been given to the hydration properties of O 2. As reported by Narita et al. Above, free Ca in converter slag
Reducing the O content to less than 1% by weight may be effective in preventing the collapse of slag, but this leads to a reduction in the amount of lime input during the steelmaking process and the essential steel cleaning is achieved. There is a great risk that they will not be accepted, so it cannot be adopted.
【０００９】本発明の目的は、転炉スラグを多方面で有
効利用するため、スラグ中に含まれる遊離CaO の水和に
起因する膨張崩壊性を抑制するように転炉スラグを改質
することである。具体的には、このように改質された転
炉スラグと、転炉スラグの改質方法とを提供することで
ある。An object of the present invention is to modify converter slag so as to suppress expansion and disintegration due to hydration of free CaO contained in slag in order to effectively use converter slag in various fields. Is. Specifically, it is to provide a converter slag thus modified and a converter slag modifying method.
【００１０】[0010]
【課題を解決するための手段】本発明者らは、転炉スラ
グ中に存在する遊離CaO の水和性について詳しく検討し
た結果、次の知見を得た。[Means for Solving the Problems] As a result of detailed examination of the hydration properties of free CaO 2 present in converter slag, the present inventors have obtained the following findings.
【００１１】即ち、転炉スラグ中の遊離CaO には、溶鋼
に添加された石灰が溶鋼中に溶解せず、そのまま残留し
てスラグ中に移行したCaO(以下、未滓化CaO と称する)
と、溶鋼中に溶解したが、介在物と反応しなかったた
め、スラグ冷却時にそのまま晶出したCaO(以下、晶出Ca
O と称する) の２種類がある。光学顕微鏡や電子顕微鏡
でスラグ組織を観察すると、未滓化CaO は球状で内部に
金属酸化物がないもの、晶出CaO は不定形で内部に粒状
の金属酸化物を含むという形状の相違から、この両者は
判別できる。That is, in free CaO in the converter slag, the lime added to the molten steel was not dissolved in the molten steel, and CaO remained in the molten slag and transferred into the slag (hereinafter referred to as uncast CaO).
When it was melted in the molten steel, but did not react with inclusions, CaO that crystallized as it was during slag cooling (hereinafter, crystallized Ca
There are two types). When observing the slag structure with an optical microscope or an electron microscope, unsulfurized CaO is spherical and has no metal oxide in the inside, and crystallized CaO is amorphous and contains granular metal oxide inside. Both can be distinguished.
【００１２】このうち、晶出CaO については、これに金
属酸化物 (FeO, MnO, MgO など) が合計20重量％以上の
濃度で固溶していると、反応性が低下して水和が抑制さ
れる。一方、未滓化CaO は、このような固溶が全くない
ので、水和性が高く、その膨張崩壊を防止することがで
きない。従って、スラグ中の未滓化CaO の含有量を極力
皆無とし、晶出CaO については、金属酸化物が合計20重
量％以上の濃度で固溶したCaO 相が晶出するようにすれ
ば、膨張崩壊性が抑制された転炉スラグが得られること
が判明した。本発明は、この知見に基づき完成したもの
である。Of these, with respect to crystallized CaO, if metal oxides (FeO, MnO, MgO, etc.) are dissolved in solid solution at a total concentration of 20% by weight or more, the reactivity decreases and hydration is reduced. Suppressed. On the other hand, undegreased CaO has no such solid solution, and therefore has high hydration property and cannot prevent its expansion and collapse. Therefore, if the content of undecalcified CaO in the slag is set to a minimum and the CaO crystallized out, if the CaO phase in which the metal oxide is dissolved in a total concentration of 20% by weight or more is crystallized, the expansion will occur. It was found that a converter slag with suppressed disintegration can be obtained. The present invention has been completed based on this finding.
【００１３】ここに、本発明の要旨は、 未滓化CaO を実質的に含まず、晶出CaO 中の固溶全金
属酸化物濃度が20重量％以上あることを特徴とする、改
質された転炉スラグ、 未滓化CaO を実質的に含まない溶融転炉スラグを、出
滓時点から1180〜1050℃まで400 ℃/h以下の冷却速度で
徐冷した後、1200℃/h以上の冷却速度で800 ℃以下まで
急冷することにより、冷却後の晶出CaO 中の固溶全金属
酸化物濃度を20重量％以上とすることを特徴とする、転
炉スラグの改質方法、 転炉製鋼過程で、スラグ中のMnO 濃度を６重量％以上
とするか、および／またはスラグ中の全鉄濃度を20重量
％以上とすることにより、冷却後の晶出CaO 中の固溶全
金属酸化物濃度を20重量％以上とすることを特徴とする
転炉スラグの改質方法、および 転炉製鋼過程でCaF2を主成分とする媒溶剤を添加する
ことにより、溶滓中の未滓化CaO を溶解処理する、上記
または記載の方法、にある。Here, the gist of the present invention is that the content of undissolved CaO is not substantially contained, and the concentration of solid solution total metal oxide in crystallized CaO is 20% by weight or more. The converter slag and the molten converter slag that does not substantially contain unsmelted CaO are gradually cooled from the time of smelting to 1180 to 1050 ° C at a cooling rate of 400 ° C / h or less, and then 1200 ° C / h or more. A method for reforming converter slag, characterized in that the concentration of solid solution total metal oxides in crystallized CaO after cooling is made to be 20% by weight or more by rapidly cooling to 800 ° C or less at a cooling rate. In the steelmaking process, the MnO concentration in the slag is set to 6% by weight or more and / or the total iron concentration in the slag is set to 20% by weight or more, so that solid solution total metal oxidation in crystallized CaO after cooling can be achieved. method of modifying a converter slag, characterized in that the object density and 20 wt% or more, and medium for the CaF 2 as a main component in a converter steelmaking process By adding the agent to dissolve handle non slag formation CaO in 溶滓 method of the above or described, in.
【００１４】なお、「未滓化CaO を実質的に含まず」と
は、顕微鏡 (光学顕微鏡および電子顕微鏡) での観察に
より未滓化CaO が認められないことを意味する。また、
「晶出CaO 中の固溶全金属酸化物濃度」とは、晶出CaO
中に固溶しているFeO, MnOおよびMgO の各濃度の総和を
意味する。晶出CaO 中に固溶しているこれらの金属酸化
物の濃度は、Ｘ線マイクロアナライザにより定量でき
る。The term "substantially free of undegraded CaO" means that undegraded CaO is not observed by observation with a microscope (optical microscope and electron microscope). Also,
"Solid solution total metal oxide concentration in crystallized CaO" means crystallized CaO
It means the sum of the respective concentrations of FeO, MnO and MgO dissolved in the solid solution. The concentrations of these metal oxides which are solid-dissolved in the crystallized CaO can be quantified by an X-ray microanalyzer.
【００１５】[0015]
【作用】本発明による転炉スラグの改質では、スラグが
未滓化CaO を実質的に含有しないようにする。未滓化Ca
O は、溶鋼に石灰を多量に添加した結果、スラグ中の全
CaO 含有量 (遊離CaO および結合CaO の合計量) が多い
場合に生じ易い。そのため、石灰の添加量を変化させ、
場合により蛍石を添加して精錬を行い、転炉スラグ中の
未滓化CaO の有無を、光学顕微鏡および走査型電子顕微
鏡で調べた。結果を、スラグ中の CaO／SiO2重量比 (以
下、塩基度と称する) との関係として、次の表１に示
す。In the reforming of the converter slag according to the present invention, the slag is made substantially free of undegraded CaO. Uncast Ca
O is the total amount of slag in the slag as a result of adding a large amount of lime to the molten steel.
It tends to occur when the CaO content (the total amount of free CaO and bound CaO) is high. Therefore, by changing the amount of lime added,
In some cases, fluorite was added for refining, and the presence or absence of undegreased CaO in the converter slag was examined by an optical microscope and a scanning electron microscope. The results are shown in Table 1 below as a relationship with the CaO / SiO 2 weight ratio in the slag (hereinafter referred to as basicity).
【００１６】[0016]
【表１】 [Table 1]
【００１７】この実験条件下では、塩基度3.5 未満では
未滓化CaO はスラグ中に存在せず、塩基度3.5 以上では
スラグが未滓化CaO を含有していた。従って、未滓化Ca
O の存在が予想されるような塩基度が高めの操業条件に
おいては、製鋼過程で溶鋼に蛍石を媒溶剤として添加す
ることにより、添加した石灰をすべて溶解させ、スラグ
中の未滓化CaO を皆無とする。蛍石は、周知のようにス
ラグの融点を低下させると同時に、石灰の表面に生成し
たカルシウムシリケートの殻の溶解を促進し、石灰の溶
解を容易にする作用がある。Under this experimental condition, unslagged CaO was not present in the slag when the basicity was less than 3.5, and the slag contained unslagged CaO when the basicity was 3.5 or more. Therefore, undecalcified Ca
Under operating conditions with a high basicity such that the presence of O is expected, by adding fluorite to the molten steel as a solvent during the steelmaking process, all of the added lime is dissolved and the undeposited CaO in the slag is dissolved. Is eliminated. As is well known, fluorspar has the effect of lowering the melting point of slag and, at the same time, promoting the dissolution of the calcium silicate shell formed on the surface of lime and facilitating the dissolution of lime.
【００１８】この目的で添加する媒溶剤は、蛍石に限定
されず、CaF2を主成分とする (即ち、CaF2を50重量％以
上含有する) ものであればよい。CaF2を主成分とする媒
溶剤の添加量は、未滓化CaO の残留を皆無にするのに必
要な量であればよく、精錬条件によって異なるが、一般
には溶鋼１トンあたり蛍石として 0.3〜10 kg の範囲内
が好ましい。この量が0.3 kg未満では、表１に示したよ
うに未滓化CaO が残存し、10 kg を超えると、スラグの
腐食性が強くなって、転炉耐火物の損耗が著しくなる。The solvent added for this purpose is not limited to fluorite, and may be any solvent containing CaF 2 as a main component (that is, containing 50% by weight or more of CaF 2 ). The amount of the solvent containing CaF 2 as a main component may be the amount necessary to completely eliminate the unreacted CaO remaining, and it varies depending on the refining conditions, but generally 0.3 ton of fluorite per ton of molten steel is used. A range of up to 10 kg is preferred. When the amount is less than 0.3 kg, undegraded CaO remains as shown in Table 1, and when it exceeds 10 kg, the corrosiveness of the slag becomes strong and the wear of the converter refractory becomes remarkable.
【００１９】ただし、後述するように、スラグ中のMnO
濃度が６重量％以上または全鉄濃度が20重量％以上と高
い場合には、塩基度が3.5 以上と高くなっても、未滓化
CaOは残存しない。これは、スラグの粘度が低くなるこ
とによって流動性が良くなり滓化が促進するためであ
る。However, as will be described later, MnO in the slag is
When the concentration is 6% by weight or more or the total iron concentration is 20% by weight or more, even if the basicity is 3.5 or more, it is not slag.
CaO does not remain. This is because the fluidity of the slag is improved and the slag is promoted as the viscosity of the slag is reduced.
【００２０】このように、必要に応じて蛍石を主成分と
する媒溶剤の添加によりスラグが未滓化CaO を含まない
ようにした上で、スラグ中の晶出CaO 相の全金属酸化物
濃度が20重量％以上となるように改質する。このように
スラグを改質する手段としては、スラグ冷却時の冷却
速度調整による方法と、転炉操業時のスラグ組成調整
による方法の、２種類の方法が可能である。以下、これ
らの方法について順に説明する。Thus, if necessary, the medium solvent containing fluorite as a main component is added so that the slag does not contain undeposited CaO, and the total metal oxide of the crystallized CaO phase in the slag is added. Modify so that the concentration becomes 20% by weight or more. As the means for reforming the slag in this way, two types of methods are possible: a method by adjusting the cooling rate during slag cooling and a method by adjusting the slag composition during converter operation. Hereinafter, these methods will be described in order.
【００２１】スラグ冷却時の冷却速度調整 未滓化CaO を実質的に含まない転炉スラグを、出滓温度
(1630℃) から800 ℃まで1150〜6000℃/hの冷却速度で
急冷した場合と、 180〜400 ℃/hの冷却速度で徐冷した
場合について、冷却中の鉱物相の変化と冷却中に析出し
た晶出CaO 中に固溶した全金属酸化物濃度 (晶出CaO 中
のFeO, MnO, MgO の各濃度 <wt％> の総和) を、光学顕
微鏡、走査型電子顕微鏡およびＸ線マイクロアナライザ
で調べた。結果を表２（鉱物相の変化）および図１（晶
出CaO 中の全金属酸化物濃度) に示す。Adjustment of cooling rate during slag cooling The converter slag substantially free of unslagged CaO was discharged at the slag temperature.
(1630 ° C) to 800 ° C, the rapid cooling at a cooling rate of 1150 to 6000 ° C / h and the slow cooling at a cooling rate of 180 to 400 ° C / h show changes in the mineral phase during cooling and during cooling. The concentration of all metal oxides dissolved in the precipitated crystallized CaO (sum of FeO, MnO, and MgO concentrations <wt%> in the crystallized CaO) was determined by optical microscope, scanning electron microscope, and X-ray microanalyzer. I looked it up. The results are shown in Table 2 (change of mineral phase) and Figure 1 (concentration of all metal oxides in crystallized CaO).
【００２２】[0022]
【表２】 [Table 2]
【００２３】表２に示すように、未滓化CaO を含まない
転炉スラグを1630℃から800 ℃まで急冷した場合には、
５〜30μｍ程度の晶出CaO が析出するが、800 ℃までそ
の量はほとんど変化しない。一方、図１からわかるよう
に、この急冷中、転炉スラグにおいて析出した晶出CaO
中における固溶全金属酸化物濃度はほとんど変化しな
い。As shown in Table 2, when the converter slag containing no undegraded CaO was rapidly cooled from 1630 ° C to 800 ° C,
Crystallized CaO of about 5 to 30 μm is deposited, but its amount hardly changes up to 800 ° C. On the other hand, as can be seen from Fig. 1, crystallized CaO precipitated in the converter slag during the rapid cooling.
The solid solution total metal oxide concentration in the solution hardly changes.
【００２４】これに対して、1630℃から800 ℃まで転炉
スラグを徐冷した場合には、表２に示すように、温度降
下に伴ってカルシウム・フェライト量が減少し、晶出Ca
O 量が増大する。この際、カルシウム・フェライトの分
解による酸化鉄分およびウスタイトからもたらされたFe
O が晶出CaO 中に固溶するため、晶出CaO 量の増大にも
かかわらず、図１に示すごとく、1180〜1050℃までは晶
出CaO 中における固溶全金属酸化物濃度が上昇する。一
方、1180〜1050℃より低温では、晶出CaO 中で高濃度と
なった固溶FeO が析出し始めるため、図１に示すよう
に、固溶全金属酸化物濃度は逆に低下する。さらに、次
の(2) 式で示される３CaO-SiO2の分解反応が起こり、２
CaO-SiO2相中に１〜３μｍの幅を持つ縞状のCaO が析出
する。On the other hand, when the converter slag is gradually cooled from 1630 ° C. to 800 ° C., as shown in Table 2, the amount of calcium / ferrite decreases as the temperature drops, and crystallized Ca
O amount increases. At this time, the iron oxide content from the decomposition of calcium and ferrite and the Fe derived from wustite
Since O 2 forms a solid solution in the crystallized CaO, the solid solution total metal oxide concentration in the crystallized CaO increases from 1180 to 1050 ° C as shown in Fig. 1, despite the increase in the amount of crystallized CaO. . On the other hand, at a temperature lower than 1180 to 1050 ° C, the solid solution FeO 3 having a high concentration in the crystallized CaO starts to precipitate, so that the solid solution total metal oxide concentration decreases conversely, as shown in FIG. Further, the decomposition reaction of 3CaO-SiO 2 represented by the following formula (2) occurs, and 2
Striped CaO having a width of 1 to 3 μm is precipitated in the CaO-SiO 2 phase.
【００２５】 ３CaO-SiO2 → ２CaO-SiO2 ＋ CaO ‥‥ (2) この縞状CaO は、固溶した金属酸化物を含んでおらず、
従って、水和による膨張崩壊を受けやすい。3CaO-SiO 2 → 2CaO-SiO 2 + CaO (2) This striped CaO contains no solid solution metal oxide,
Therefore, it is susceptible to expansion and collapse due to hydration.
【００２６】冷却凝固させた転炉スラグを鏡面研磨した
ものを、水あるいはエチレングリコールに浸漬し、晶出
CaO 相中の水およびエチレングリコールに対する耐食性
を光学顕微鏡により調べた。その結果を表３に示す。表
３において、「消化」とは浸漬により晶出CaO がCa(OH)
2 化した場合であり、安定とはCaO のままであった場合
を意味する。The cooled and solidified converter slag mirror-polished is crystallized by immersing it in water or ethylene glycol.
The corrosion resistance to water and ethylene glycol in CaO phase was investigated by optical microscopy. The results are shown in Table 3. In Table 3, "digestion" means that the crystallized CaO is Ca (OH) upon immersion.
A case in which two However, the stability means the case remained of CaO.
【００２７】[0027]
【表３】 [Table 3]
【００２８】表３において、水およびエチレングリコー
ルによってCa(OH)2 化せず、安定であった晶出CaO 相中
の固溶全金属酸化物濃度を図１により調べたところ、い
ずれも20重量％以上であった。即ち、晶出CaO 中の固溶
全金属酸化物濃度が20重量％以上であると、晶出CaO は
安定化され、水和による膨張崩壊性を示さなくなること
が確認された。In Table 3, the solid solution total metal oxide concentration in the crystallized CaO phase, which was stable without being Ca (OH) 2 conversion with water and ethylene glycol, was examined by FIG. % Or more. That is, it was confirmed that when the concentration of the solid solution total metal oxide in the crystallized CaO was 20% by weight or more, the crystallized CaO was stabilized and did not exhibit the expansion and disintegration property due to hydration.
【００２９】従って、転炉スラグの冷却を、凝固後の晶
出CaO 中の固溶全金属酸化物濃度が20重量％以上となる
ように行えばよいわけである。このような晶出CaO 相を
得るために、先に述べた、転炉スラグの急冷中および徐
冷中における鉱物相の変化と晶出CaO 中の固溶全金属酸
化物濃度の変化に関する挙動の差異を利用する。Therefore, the converter slag may be cooled so that the solid solution total metal oxide concentration in the crystallized CaO after solidification is 20% by weight or more. In order to obtain such a crystallized CaO phase, the difference in the behavior related to the change of the mineral phase during the rapid cooling and slow cooling of the converter slag and the change of the solid solution total metal oxide concentration in the crystallized CaO was described above. To use.
【００３０】即ち、出滓時点から1180〜1050℃までは40
0 ℃/h以下の冷却速度で徐冷することにより、晶出CaO
中の固溶全金属酸化物濃度を上昇させた後、800 ℃以下
まで1200℃/h以上の冷却速度で急冷することにより、晶
出CaO 中におけるFeO の析出と３CaO-SiO2相の分解反応
（縞状CaO の生成）とを抑制して、徐冷中に上昇した晶
出CaO 中の固溶全金属酸化物濃度を高いまま維持するの
である。こうして、晶出CaO 中の固溶全金属酸化物濃度
が20重量％以上ある、CaO の水和による膨張崩壊が抑制
された改質転炉スラグが得られる。That is, 40 from the time of slag to 1180 to 1050 ° C.
By gradually cooling at a cooling rate of 0 ° C / h or less, crystallized CaO
After increasing the concentration of solid solution total metal oxide in the solution, it is rapidly cooled to 800 ℃ or less at a cooling rate of 1200 ℃ / h or more to precipitate FeO 2 in the crystallized CaO and decompose the 3CaO-SiO 2 phase. By suppressing the (formation of striped CaO), the concentration of the total dissolved solid metal oxide in the crystallized CaO increased during the slow cooling is maintained at a high level. In this way, a reformed converter slag having a solid solution total metal oxide concentration of 20% by weight or more in crystallized CaO and in which expansion and collapse due to hydration of CaO is suppressed can be obtained.
【００３１】転炉操業時のスラグ組成調整 晶出CaO 中の固溶全金属酸化物濃度の増大は、スラグ中
のMnO 濃度または全鉄濃度を増大させることによっても
可能である。Adjustment of slag composition during converter operation The concentration of solid solution total metal oxide in crystallized CaO can be increased by increasing the concentration of MnO 2 or total iron in the slag.
【００３２】スラグ中のMnO 濃度を増大させた時の晶出
CaO 中の固溶全金属酸化物濃度の変化を図２に示す。 1
80〜6000℃/hの冷却速度で800 ℃まで冷却した場合、ス
ラグ中のMnO 濃度が６重量％以上の時に、晶出CaO 中の
固溶全金属酸化物濃度が20重量％以上となり、転炉スラ
グの改質に有効であることが判明した。Crystallization when increasing MnO concentration in slag
Figure 2 shows the changes in the concentration of solid solution total metal oxides in CaO. 1
When cooled to 800 ℃ at a cooling rate of 80 to 6000 ℃ / h, when the MnO concentration in the slag is 6 wt% or more, the concentration of solid solution total metal oxide in crystallized CaO becomes 20 wt% or more, It has been found to be effective in reforming furnace slag.
【００３３】即ち、転炉操業時あるいは出滓時にマンガ
ン鉱石を添加して、スラグ中のMnO濃度を６重量％以
上、好ましくは６〜10重量％に調整した場合には、冷却
速度に関係なく、徐冷、急冷のいずれの場合にも、晶出
CaO 中の固溶全金属酸化物濃度が20重量％の以上の転炉
スラグを得ることができる。こうして得られた転炉スラ
グは、良好な耐水・耐エチレングリコール性を示すこと
が確認され、CaO の水和によるスラグの膨張崩壊が抑制
される。That is, when manganese ore is added at the time of converter operation or slag to adjust the MnO concentration in the slag to 6% by weight or more, preferably 6 to 10% by weight, regardless of the cooling rate. Crystallized in both slow cooling and rapid cooling
A converter slag having a solid solution total metal oxide concentration in CaO of 20% by weight or more can be obtained. It was confirmed that the converter slag thus obtained exhibits good water resistance and ethylene glycol resistance, and expansion and collapse of the slag due to hydration of CaO are suppressed.
【００３４】一方、全鉄濃度の高い転炉スラグを光学顕
微鏡、走査型電子顕微鏡で観察した結果、カルシウム・
フェライト量が増大し、晶出CaO 量は減少した。Ｘ線マ
イクロアナライザによれば、晶出CaO 中のFeO 濃度が高
かった。晶出CaO 中の固溶全金属酸化物濃度が20重量％
以上となるためには、スラグ中のMnO 濃度が４重量％以
下の場合、20重量％以上の全鉄濃度が必要であることが
判明した。スラグ中の全鉄濃度は、例えば、転炉吹錬操
業において、酸素の流量を少なくしてソフトブローする
方法がある。従って、このような手段により、スラグ中
の全鉄濃度を20重量％以上、好ましくは20〜35重量％と
することは、CaO の水和による膨張崩壊を抑制するため
の転炉スラグの改質に有効である。この場合も、スラグ
の冷却速度には制限はなく、徐冷、急冷のいずれであっ
てもよい。On the other hand, as a result of observing the converter slag having a high total iron concentration with an optical microscope and a scanning electron microscope, it was found that
The amount of ferrite increased and the amount of crystallized CaO decreased. According to an X-ray microanalyzer, the FeO 2 concentration in the crystallized CaO was high. 20% by weight of solid solution total metal oxide concentration in crystallized CaO
In order to become the above, it was found that when the MnO 2 concentration in the slag is 4% by weight or less, a total iron concentration of 20% by weight or more is necessary. The total iron concentration in the slag can be soft-blown by reducing the flow rate of oxygen in a converter blowing operation, for example. Therefore, the total iron concentration in the slag is set to 20% by weight or more, preferably 20 to 35% by weight by such means, so that the reforming of the converter slag for suppressing the expansion and collapse due to the hydration of CaO is performed. Is effective for. In this case as well, the cooling rate of the slag is not limited and may be slow cooling or rapid cooling.
【００３５】マンガン鉱石の添加とスラグ全鉄濃度の増
大を併用すると、スラグの膨張崩壊の抑制に関して相乗
効果が得られることも確認された。前述したように、ス
ラグ中のMnO 濃度および／または全鉄濃度をこのように
高めた場合には、スラグ塩基度が高くても未滓化CaO は
残らないので、未滓化CaOを生じないようにするための
蛍石の添加は必要ない。It was also confirmed that the combined use of the addition of manganese ore and the increase of the total iron concentration in the slag have a synergistic effect in suppressing the expansion and collapse of the slag. As described above, when the MnO concentration and / or total iron concentration in the slag are increased in this way, no undegraded CaO will be produced because undegraded CaO does not remain even if the slag basicity is high. It is not necessary to add fluorspar to achieve
【００３６】[0036]
【実施例】以下、実施例により本発明の効果を例証す
る。EXAMPLES The effects of the present invention will be illustrated by the following examples.
【００３７】実施例１ 図３(a) に示す作業工程図により転炉スラグを本発明の
方法により冷却した。製鋼工場のドライピット内に、幅
５ｍ、長さ６ｍの矩形を囲うように高さ1.2 ｍの堤防３
を転炉スラグを用いて構築し、この堤防内に滓鍋１から
溶滓２を100 トン流し込み、８時間徐冷して温度が1180
〜1050℃まで低下した後、固化スラグ４をブルドーザ５
でリッピングし、ホッパ６を介してコンベア７に薄層状
に乗せ、上部配管８から水を吹き付けることによりスラ
グを急冷し、改質スラグ９を得た。なお、スラグ塩基度
が3.5 以上となりそうな場合に、製鋼過程で蛍石を添加
して、未滓化CaO の残留を防止した。図３(b) は、図３
(a) でのＡ矢視図、すなわち堤防内の溶滓の様子を示す
平面図である。 Example 1 Converter slag was cooled by the method of the present invention according to the work process diagram shown in FIG. 3 (a). A dike 3 with a height of 1.2 m that encloses a rectangle with a width of 5 m and a length of 6 m in the dry pit of a steelmaking plant.
Was constructed by using converter slag, 100 tons of slag 2 was poured from the slag pan 1 into this bank, and the temperature was gradually cooled to 1180 for 8 hours.
After cooling down to ~ 1050 ° C, solidified slag 4 and bulldozer 5
Then, the slag was rapidly cooled by spraying water from the upper pipe 8 onto the conveyor 7 through the hopper 6 in a thin layer, and the modified slag 9 was obtained. If the slag basicity is likely to be 3.5 or more, fluorite was added during the steelmaking process to prevent the undegraded CaO from remaining. 3 (b) is shown in FIG.
It is the arrow A view in (a), ie, the top view which shows a mode of the molten slag in a bank.
【００３８】得られた改質スラグをランダムに採取し
て、スラグの各成分を蛍光Ｘ線分析法により、またスラ
グの晶出CaO 中の固溶全金属酸化物濃度をＸ線マイクロ
アナライザにより定量した。次に、スラグを鏡面研磨し
た後、エチレングリコールに浸漬し、耐食性[Ca(OH)2化
による浸食の有無] を調べた。The obtained modified slag was sampled at random, and each component of the slag was determined by a fluorescent X-ray analysis method, and the concentration of the solid solution total metal oxide in the crystallized CaO of the slag was determined by an X-ray microanalyzer. did. Next, the slag was mirror-polished and then immersed in ethylene glycol to examine the corrosion resistance [presence or absence of corrosion due to Ca (OH) 2 conversion].
【００３９】一方、膨張試験は次の方法で行った。改質
スラグからランダムに50 kg 採取し、クラッシャを用い
て25 mm 以下に破砕した。次いで、篩分けにより、−25
mmで中央粒度12.5 mm となるように粒度調整した。こ
れを路床土支持力比(CBR) 試験法 (JIS A-1211) に従っ
て、直径150 mm、高さ125 mmのモールドに突き固めて供
試体を作製し、水浸膨張試験 (鉄鋼連盟法) およびオー
トクレーブ試験(200℃、４時間) を行った。これらの試
験結果は、いずれも、試験前の供試体の高さに対する試
験前後の高さの差の比率で示す。On the other hand, the expansion test was conducted by the following method. Randomly 50 kg of the modified slag was sampled and crushed to 25 mm or less using a crusher. Then, by sieving, -25
The particle size was adjusted so that the median particle size was 12.5 mm in mm. According to the subgrade soil bearing capacity ratio (CBR) test method (JIS A-1211), it was compacted into a mold with a diameter of 150 mm and a height of 125 mm to prepare a test piece, and a water immersion expansion test (steel federation method). And an autoclave test (200 ° C., 4 hours) was performed. Each of these test results is shown by the ratio of the difference in height before and after the test to the height of the specimen before the test.
【００４０】操作条件 (冷却速度および蛍石添加量) 、
改質スラグの組成 (塩基度、未滓化CaO の有無、全鉄濃
度 <%T.Fe>、MnO 濃度<%MnO>、晶出CaO 中の固溶全金属
酸化物濃度) 、および試験結果をまとめて次の表４に示
す。Operating conditions (cooling rate and fluorite addition amount),
Composition of modified slag (basicity, presence or absence of undecalcified CaO, total iron concentration <% T.Fe>, MnO concentration <% MnO>, solid solution total metal oxide concentration in crystallized CaO), and test results Are summarized in Table 4 below.
【００４１】実施例２ 製鋼過程でマンガン鉱石を添加して、スラグ中のMnO 濃
度を高め、出滓したスラグを、図３に示した工程図にお
いて、堤防３内で800 ℃以下まで徐冷してから、コンベ
ア上での急冷を行った。堤防内での徐冷は13時間かけて
行った。 Example 2 Manganese ore was added in the steelmaking process to increase the MnO concentration in the slag, and the slag that had been slagged was gradually cooled to 800 ° C. or less in the embankment 3 in the process chart shown in FIG. After that, quenching was performed on the conveyor. Slow cooling in the embankment took 13 hours.
【００４２】実施例３ 転炉吹錬操業時に酸素をソフトブローすることにより、
スラグ中の全鉄濃度を高めた以外は、実施例２と同様に
スラグを処理した。 Example 3 By soft-blowing oxygen during converter blowing operation,
The slag was treated as in Example 2 except that the total iron concentration in the slag was increased.
【００４３】実施例２および実施例３の操作条件、改質
スラグの組成、および試験結果も、表４に併せて示す。
なお、実施例２および３のように、スラグ中のMnO 濃度
および／または全鉄濃度を高めた場合には、スラグ塩基
度が3.5 以上となっても未滓化CaO は残留しないので、
蛍石は添加しなかった。Table 4 also shows the operating conditions of Examples 2 and 3, the composition of the modified slag, and the test results.
When the MnO 2 concentration and / or the total iron concentration in the slag were increased as in Examples 2 and 3, undegraded CaO did not remain even when the slag basicity was 3.5 or more.
Fluorite was not added.
【００４４】比較のために、特開昭51−11011 号公報に
記載の方法に準じて、出滓した転炉スラグを鋼板床上に
流し、散水急冷した場合 (特開昭51-11011号公報記載の
方法) および鋼板製スラグパン (１ｍ幅×３ｍ長×0.2
ｍ高で80mm厚) に50〜100 mm厚となるように流しこみ、
断続散水して急冷した場合の結果も、表４に示す。For comparison, according to the method described in JP-A-51-11011, the slag-converted converter slag is poured onto a steel plate floor and water-spray-quenched (described in JP-A-51-11011). Method) and steel plate slag pan (1m width x 3m length x 0.2
(80 mm thick at m height) to 50 to 100 mm thick,
Table 4 also shows the results when intermittent watering and quenching were performed.
【００４５】[0045]
【表４】 [Table 4]
【００４６】表４からわかるように、徐冷→急冷により
晶出CaO 中の固溶全金属酸化物濃度を20重量％以上とす
る場合、徐冷時の冷却速度が400 ℃/hより速いか、急冷
時の冷却速度が1200℃/hより遅いと、晶出CaO 中の固溶
全金属酸化物濃度が20重量％を下回り、スラグはエチレ
ングリコールに対する耐食性を失ない、膨張崩壊が起こ
り易く、改質の目的が達成されない。これに対し、本発
明の範囲内の条件で冷却を行った場合には、晶出CaO 中
の固溶全金属酸化物濃度が20重量％以上となり、エチレ
ングリコールに対して安定で、膨張崩壊も抑制され、水
浸膨張試験およびオートクレーブ試験の結果がいずれも
１％未満 (ほとんどは0.5 ％以下) であった。一方、特
開昭51−11011 号公報に記載のような急冷のみによる方
法では、スラグの改質は全く不十分であった。As can be seen from Table 4, when the solid solution total metal oxide concentration in the crystallized CaO is set to 20% by weight or more by slow cooling → rapid cooling, is the cooling rate during slow cooling faster than 400 ° C./h? When the cooling rate during quenching is slower than 1200 ° C / h, the concentration of solid solution total metal oxides in crystallized CaO falls below 20% by weight, the slag does not lose the corrosion resistance to ethylene glycol, and expansion collapse easily occurs, The purpose of modification is not achieved. On the other hand, when the cooling is carried out under the conditions within the scope of the present invention, the concentration of the solid solution total metal oxide in the crystallized CaO is 20% by weight or more, which is stable to ethylene glycol and expands and collapses It was suppressed, and the results of both the water immersion expansion test and the autoclave test were less than 1% (mostly 0.5% or less). On the other hand, with the method described in JP-A No. 51-11011, which uses only rapid cooling, modification of the slag is completely insufficient.
【００４７】マンガン鉱石を添加した場合には、スラグ
中のMnO 濃度が６重量％以上になれば、晶出CaO 中の固
溶全金属酸化物濃度が20重量％以上となり、改質の目的
が達成された。同様に、スラグの全鉄濃度を20重量％以
上とした場合にも、晶出CaO中の固溶全金属酸化物濃度
が20重量％以上となり、スラグが改質された。When manganese ore is added, if the MnO 2 concentration in the slag is 6% by weight or more, the solid solution total metal oxide concentration in the crystallized CaO is 20% by weight or more. Achieved Similarly, when the total iron concentration in the slag was set to 20% by weight or more, the solid solution total metal oxide concentration in the crystallized CaO was 20% by weight or more, and the slag was reformed.
【００４８】[0048]
【発明の効果】以上に述べた通り、本発明によれば、必
要により蛍石を添加して転炉スラグ中の未滓化CaO を溶
解して実質的に皆無とした上で、冷却・凝固時に晶出す
るCaOについては、冷却条件の制御あるいは転炉スラグ
中のMnO および／または全鉄濃度を一定以上に高めるこ
とにより、晶出CaO 中の固溶全金属酸化物濃度を20重量
％とすれば、晶出CaO の水和性が抑えられ、転炉スラグ
の膨張崩壊が効果的に抑制される。従って、本発明の改
質スラグは、道路用路盤材やコンクリート骨材などの高
付加価値用途に十分に使用できる。それにより、転炉ス
ラグの埋め立てが必要なくなるので、本発明は転炉スラ
グという資源の有効利用に加えて、環境の保全にも役立
つ技術である。As described above, according to the present invention, if necessary, fluorite is added to dissolve undeposited CaO in the converter slag to substantially eliminate it, and then cooling and solidification are performed. For CaO that crystallizes at times, the solid solution total metal oxide concentration in the crystallized CaO is set to 20 wt% by controlling the cooling conditions or increasing the MnO and / or total iron concentration in the converter slag above a certain level. If so, the hydration property of crystallized CaO is suppressed, and expansion and collapse of converter slag is effectively suppressed. Therefore, the modified slag of the present invention can be sufficiently used for high value-added applications such as roadbeds and concrete aggregates. As a result, there is no need to reclaim the converter slag, so the present invention is a technique that is useful for environmental conservation in addition to effective use of the resource of converter slag.
【図１】凝固中に晶出したCaO 中の固溶全金属酸化物濃
度におよぼす冷却条件の影響を示す図である。FIG. 1 is a diagram showing the influence of cooling conditions on the concentration of solid solution total metal oxides in CaO crystallized during solidification.
【図２】晶出CaO 中の固溶全金属酸化物濃度とスラグ中
MnO 濃度との関係を示すグラフである。[Fig.2] Concentration of solid solution total metal oxide in crystallized CaO and in slag
5 is a graph showing the relationship with MnO 2 concentration.
【図３】図３(a) は実施例で採用した転炉スラグの冷却
処理工程図、図３(b) は図３(a) でのＡ矢視図、すなわ
ち堤防内の溶滓の様子を示す平面図である。FIG. 3 (a) is a cooling treatment process diagram of the converter slag used in the embodiment, and FIG. 3 (b) is a view taken along the arrow A in FIG. 3 (a), that is, a state of the slag inside the embankment. FIG.
１ 滓鍋, ２ 溶滓, ３ 堤防, ４ 固化スラグ, ５
ブルドーザ ６ ホッパ, ７コンベア, ８ 散水配管1 slag pan, 2 slag, 3 levees, 4 solidified slag, 5
Bulldozer 6 hoppers, 7 conveyors, 8 sprinkler pipes
───────────────────────────────────────────────────── フロントページの続き (72)発明者 牧野 芳久 大阪市中央区北浜４丁目５番33号 住友金 属工業株式会社内 (72)発明者 井上 亮 仙台市青葉区川内（無番地）川内住宅３の 203 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Makino 4-53 Kitahama, Chuo-ku, Osaka City Sumitomo Metal Industries Co., Ltd. (72) Inventor Ryo Inoue Kawauchi, Aoba-ku, Sendai-shi Kawauchi Housing 3 of 203
Claims (4)
中の固溶全金属酸化物濃度が20重量％以上あることを特
徴とする、改質された転炉スラグ。1. Crystallized CaO that does not substantially contain undegraded CaO
Modified converter slag, characterized in that the solid solution total metal oxide concentration therein is 20% by weight or more.
スラグを、出滓時点から1180〜1050℃まで400 ℃/h以下
の冷却速度で徐冷し、しかる後に1200℃/h以上の冷却速
度で800 ℃以下まで急冷することにより、冷却後の晶出
CaO 中の固溶全金属酸化物濃度を20重量％以上とするこ
とを特徴とする、転炉スラグの改質方法。2. A molten converter slag substantially free of unsmelted CaO is gradually cooled from the time of slagging to 1180 to 1050 ° C. at a cooling rate of 400 ° C./h or less, and then 1200 ° C./h or more. Crystallization after cooling is achieved by rapidly cooling to 800 ° C or less at the cooling rate of
A method for reforming converter slag, which comprises setting the concentration of solid solution total metal oxides in CaO to 20% by weight or more.
６重量％以上とするか、および／またはスラグ中の全鉄
濃度を20重量％以上とすることにより、冷却後の晶出Ca
O 中の固溶全金属酸化物濃度を20重量％以上とすること
を特徴とする、転炉スラグの改質方法。3. Crystallized Ca after cooling by setting the MnO 2 concentration in the slag to 6 wt% or more and / or the total iron concentration in the slag to 20 wt% or more in the converter steelmaking process.
A method for reforming converter slag, characterized in that the concentration of solid solution total metal oxides in O is 20% by weight or more.
剤を添加することにより、溶滓中の未滓化CaO を溶解処
理する、請求項２または３記載の方法。4. The method according to claim 2 or 3, wherein unsolvated CaO in the slag is dissolved by adding a solvent containing CaF 2 as a main component in the converter steelmaking process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19230092A JP2636641B2 (en) | 1992-07-20 | 1992-07-20 | Converter slag reforming |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19230092A JP2636641B2 (en) | 1992-07-20 | 1992-07-20 | Converter slag reforming |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06256045A true JPH06256045A (en) | 1994-09-13 |
| JP2636641B2 JP2636641B2 (en) | 1997-07-30 |
Family
ID=16288987
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19230092A Expired - Lifetime JP2636641B2 (en) | 1992-07-20 | 1992-07-20 | Converter slag reforming |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2636641B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100406370B1 (en) * | 1998-12-24 | 2004-02-14 | 주식회사 포스코 | A method of preventing ld slag from expanding |
| KR100821045B1 (en) * | 2001-10-17 | 2008-04-08 | 주식회사 포스코 | method of preventing a hydration for BOF slag |
| JP2015105873A (en) * | 2013-11-29 | 2015-06-08 | 濱田重工株式会社 | Determination method of free lime in converter slag |
-
1992
- 1992-07-20 JP JP19230092A patent/JP2636641B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100406370B1 (en) * | 1998-12-24 | 2004-02-14 | 주식회사 포스코 | A method of preventing ld slag from expanding |
| KR100821045B1 (en) * | 2001-10-17 | 2008-04-08 | 주식회사 포스코 | method of preventing a hydration for BOF slag |
| JP2015105873A (en) * | 2013-11-29 | 2015-06-08 | 濱田重工株式会社 | Determination method of free lime in converter slag |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2636641B2 (en) | 1997-07-30 |
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