JPS6319564B2 - - Google Patents
Info
- Publication number
- JPS6319564B2 JPS6319564B2 JP45185A JP45185A JPS6319564B2 JP S6319564 B2 JPS6319564 B2 JP S6319564B2 JP 45185 A JP45185 A JP 45185A JP 45185 A JP45185 A JP 45185A JP S6319564 B2 JPS6319564 B2 JP S6319564B2
- Authority
- JP
- Japan
- Prior art keywords
- slag
- sio
- dephosphorization
- caf
- cao
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002893 slag Substances 0.000 claims description 80
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 34
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 29
- 229910004261 CaF 2 Inorganic materials 0.000 claims description 27
- 239000000203 mixture Substances 0.000 claims description 26
- 229910052742 iron Inorganic materials 0.000 claims description 17
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 28
- 229910052698 phosphorus Inorganic materials 0.000 description 28
- 239000011574 phosphorus Substances 0.000 description 28
- 229910000831 Steel Inorganic materials 0.000 description 21
- 239000010959 steel Substances 0.000 description 21
- 239000011734 sodium Substances 0.000 description 12
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 11
- 239000002184 metal Substances 0.000 description 9
- 229910052751 metal Inorganic materials 0.000 description 9
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 8
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 4
- 239000000292 calcium oxide Substances 0.000 description 4
- 235000012255 calcium oxide Nutrition 0.000 description 4
- 230000004907 flux Effects 0.000 description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical group O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 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 3
- 230000000694 effects Effects 0.000 description 3
- 230000003628 erosive effect Effects 0.000 description 3
- 238000010587 phase diagram Methods 0.000 description 3
- 235000019976 tricalcium silicate Nutrition 0.000 description 3
- 229910021534 tricalcium silicate Inorganic materials 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- KKCBUQHMOMHUOY-UHFFFAOYSA-N sodium oxide Chemical compound [O-2].[Na+].[Na+] KKCBUQHMOMHUOY-UHFFFAOYSA-N 0.000 description 2
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910001948 sodium oxide Inorganic materials 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
- C21C1/025—Agents used for dephosphorising or desulfurising
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Description
［産業上の利用分野］
この発明は、溶銑または溶鋼等の溶鉄に添加し
て溶鉄を脱燐する脱燐スラグに関する。
［従来の技術］
溶鉄の脱燐は、高炉から転炉に運搬される途中
の溶銑、転炉にて脱炭精錬されている溶鋼、又は
転炉から出鋼された取鍋内の溶鋼に対して、脱燐
スラグを添加することによりなされている。
この場合に、脱燐反応を効率的に進行させ、低
燐濃度の溶鉄を得るためには、脱燐スラグの選択
が重要である。スラグの脱燐能が高い程、より低
いスラグ添加原単位で溶鉄の燐濃度を低下させる
ことがきる。従来の脱燐スラグは、転炉にて添加
されるものとして主にCaO―SiO2―FeO系スラ
グ、溶銑及び溶鋼に対して添加されるものとして
CaO―CaF2―SiO2―FeO系スラグ及びNa2O―
SiO2系スラグがある。これらのスラグの脱燐能
を下記第１表に示す。
[Industrial Application Field] The present invention relates to a dephosphorizing slag that is added to molten iron such as hot metal or molten steel to dephosphorize the molten iron. [Prior art] Dephosphorization of molten iron is carried out on molten iron being transported from a blast furnace to a converter, molten steel being decarburized and refined in a converter, or molten steel in a ladle tapped from a converter. This is done by adding dephosphorization slag. In this case, in order to efficiently advance the dephosphorization reaction and obtain molten iron with a low phosphorus concentration, the selection of the dephosphorization slag is important. The higher the dephosphorizing ability of slag, the lower the phosphorus concentration of molten iron can be reduced with a lower unit of slag addition. Conventional dephosphorization slag is mainly CaO-SiO 2 -FeO-based slag added in converters, and added to hot metal and molten steel.
CaO―CaF 2 ―SiO 2 ―FeO slag and Na 2 O―
There is SiO2 type slag. The dephosphorizing abilities of these slags are shown in Table 1 below.
【表】
但し、スラグＡは溶銑処理に使用され、Na2O
―SiO2系又はCaO―CaF2―SiO2―FeO系のスラ
グであり、スラグＢは転炉にて添加され、CaO―
SiO2―FeO系のスラグであり、スラグＣは溶鋼
処理に使用され、CaO―CaF2―SiO2―FeO系の
スラグである。また、燐分配値は脱燐処理後のス
ラグ中燐濃度（Ｐ）と、溶鉄中燐濃度［Ｐ］との
比（Ｐ）／［Ｐ］である。
［発明が解決しようとする問題点］
このように、従来のスラグにおいては、脱燐に
有利である低温処理が可能の溶銑添加の場合で
も、燐分配値は高々1000であり、溶鋼添加の場合
は数百にすぎない。このため、所要値に燐濃度を
低下させるためのスラグ原単位が高く、脱燐コス
トが高い。また、操業上、スラグの添加量の増加
には限界がある。このため、極低燐濃度の溶鉄を
得ようとしても脱燐処理により低下させうる燐濃
度には限界がある。
この発明は、かかる事情に鑑がみてなされたも
のであつて、高脱燐能を有し、スラグ原単位を低
下させて脱燐コストを低下させることができ、極
低燐濃度の鋼材を容易に製造することができる溶
鉄の脱燐スラグを提供することを目的とする。
［問題点を解決するための手段］
この発明に係る溶鉄の脱燐スラグは、溶鉄に添
加して溶鉄を脱燐する溶鉄の脱燐スラグにおい
て、下記不等式にて示す組成を有するCaO―
CaF2―SiO2系スラグにNa2Oを３％以下の割合で
含有することを特徴とする。
（SiO2）≧７
10≦（CaF2）≦42
（CaO）≦3.17・（SiO2）
＋1.7・（CaF2）
（CaO）／（SiO2）≧2.1
但し、（ ）はその成分の濃度（重量％）を示
し、
（CaO）＋（CaF2）＋（SiO2）
＝100と規格化する。
［実施例］
以下添付の図面を参照して、この発明について
具体的に説明する。この発明に係る脱燐スラグは
生石灰（CaO）、フツ化カルシウム（CaF2）及び
シリカ（SiO2）からなる３元系スラグをベース
にし、このスラグに酸化ナトリウム（Na2O）を
少量含有させたものである。
本願発明者等は、脱燐能が高いスラグを開発す
べく種々実験研究をかさねた結果、このCaO―
CaF2―SiO2系スラグにおいて、トリカルシウム
シリケート（3CaO・SiO2）及び生石灰が共存す
る領域になるように組成を調整したスラグが高脱
燐能を有していることを見い出した。更に、この
ようなスラグに酸化ナトリウムを含有すると一層
脱燐能が上昇する。また、必要に応じて、酸素ポ
テンシヤルを高めるために酸化鉄（FeO）を含有
させてもよい。
本願発明はこのような知見に基づいてなされた
ものであつて、溶銑又は溶鋼の脱燐処理温度にお
いて以下に規定するような組成範囲になるように
添加スラグ組成をコントロールする。先ず、溶鋼
の脱燐処理に使用するスラグについて、CaO―
CaF2―SiO2三元系スラグの状態図である第１図
に基いて説明する。脱燐処理温度において、スラ
グが溶融している必要があるため、CaO―CaF2
―Sio2の三元系スラグにおいて、その融点が処理
温度より200℃高い温度と200℃低い温度との間に
なるような組成であることが必要がある。溶鋼の
脱燐処理においては、通常処理温度が1575℃であ
るから、上記組成は、第１図において、1775℃と
1375℃の液相線（それぞれ1750℃及び1350℃の液
相線の近傍）に挟まれた領域である。
液相線が1375℃より低い領域は、スラグが溶融
しやすい組成である点で好ましいが、CaF2の濃
度が高くなるので耐火物の溶損が激しくなるとと
もに脱燐能が低くなるという欠点がある。このた
め、この発明においては融点が1375℃以上、つま
り処理温度より200℃低い温度以上になるように
スラグ組成をコントロールする。また、融点が処
理温度より高いと、フラツクスが溶融しないと考
えられるが、この発明に係る脱燐スラグにおいて
は、これらの三成分の外にNa2Oも含有している
ので、CaO―CaF2―SiO2系スラグの状態図にお
いて1775℃の液相線の領域であつても、現実に使
用されるスラグは溶融状態にある。従つて、この
発明においては、三元系スラグのスラグ組成を処
理温度より200℃高い温度以下の融点を有する領
域とする。
この発明においては、トリカルシウムシリケー
トと生石灰との共存領域のスラグを使用するか
ら、2CaO・SiO2が存在する領域はこの発明に係
る脱燐スラグの組成範囲から外れる。
CaOが単体で存在する領域においては、以下の
ように組成範囲が決められる。つまり、処理温度
より200℃高い温度及び200℃低い温度の液相線に
て挟まれた領域であつて、これらの液相線が、
CaO単体領域とトリカルシウムシリケート・生石
灰共存領域との境界線と交差する点X0及びY0か
ら、これらの液相線にそつてCaF2の割合が10％
多い点Ｘ及びＹを結ぶ直線により仕切られた領域
である。脱燐能を高めるためにはCaOの活量を高
めることが望ましいが、CaOの濃度を高めると
CaF2の濃度も高くなつて好ましくないので、
CaF2の濃度が10％増加する領域までをこの発明
に係る脱燐スラグの組成範囲とする。
以上の如くして決定されるスラグの組成範囲
は、第１図に斜線にて示す領域である。つまり、
CaO、CaF2及びSiO2が上記組成範囲になるよう
に相対的な割合をきめ、このスラグをベースにし
てNa2Oを３重量％以下の割合で含有させる。
Na2Oが高い程燐分配値が高いが、Na2Oのコス
トが高いこと、Na2Oが多いと耐火物の溶損が激
しくなること、及び粉塵が出やすくなること等の
理由から、Na2Oの濃度は３％以下に設定する。
必要に応じて、酸素ポテンシヤルを維持するため
に、FeOを含有させてもよい。
第２図は、溶銑に添加する場合の脱燐スラグの
組成範囲を斜線領域にて示す。組成範囲の決定方
法は、溶鋼に添加すべきスラグの場合と同様であ
る。溶銑に対して脱燐処理する場合は、処理温度
が通常1300℃と低いので、組成範囲は溶鋼を脱燐
処理する場合に比して、CaF2の割合が高い側に
移動している。
このように脱燐に最適なスラグ組成範囲は処理
温度により異なり、この溶鋼処理及び溶銑処理の
場合を包含する組成範囲（Na2Oを除く）は第３
図のCaO―CaF2―SiO2系スラグの状態図に斜線
領域にて示すようになる。この領域は下記不等式
にて現わされる。
（SiO2）≧７
10≦（CaF2）≦42
（CaO）≦3.17・（SiO2）
＋1.7・（CaF2）
（CaO）／（SiO2）≧2.1
但し、（ ）はその成分の濃度（重量％）を示
す。
また、（CaO）＋（CaF2）＋（SiO2）
＝100と規格化する。
次に、この発明の実施例について具体的に説明
する。まず溶鋼を脱燐処理した場合の実施例につ
いて説明する。５Kgの高周波炉により大気下でマ
グネシアルツボ中で低炭素鋼を溶解した後、上記
組成になるように配合計算したフラツクスを溶鋼
１トンに対して60Kgの割合で添加した。その後、
マグネシア製パイプを溶鋼中に浸漬してアルゴン
ガスを0.5Nl／分の流速で溶鋼中に吹き込み、溶
鋼を撹拌して脱燐反応を促進させた。約20分の反
応期間中、溶鋼及スラグからサンプリングして組
成を分析した。その結果を第２表及第３表に示
す。[Table] However, slag A is used for hot metal processing and contains Na 2 O
-SiO 2 system or CaO-CaF 2 -SiO 2 -FeO system slag, slag B is added in the converter and CaO-
Slag C is a SiO 2 --FeO-based slag, and slag C is used for processing molten steel, and is a CaO--CaF 2 --SiO 2 --FeO-based slag. Further, the phosphorus distribution value is the ratio (P)/[P] of the phosphorus concentration in the slag after dephosphorization treatment (P) and the phosphorus concentration in the molten iron [P]. [Problems to be Solved by the Invention] As described above, in conventional slag, even when hot metal is added, which is advantageous for dephosphorization and allows for low-temperature treatment, the phosphorus distribution value is at most 1000; are only a few hundred. Therefore, the slag consumption rate for reducing the phosphorus concentration to the required value is high, and the dephosphorization cost is high. Additionally, there is a limit to the increase in the amount of slag added due to operational reasons. Therefore, even if it is attempted to obtain molten iron with an extremely low phosphorus concentration, there is a limit to the phosphorus concentration that can be lowered by dephosphorization treatment. This invention was made in view of the above circumstances, and has a high dephosphorization ability, can reduce the slag consumption rate, and reduce the dephosphorization cost, and can easily produce steel materials with extremely low phosphorus concentration. The purpose of the present invention is to provide a molten iron dephosphorization slag that can be produced in the following manner. [Means for Solving the Problems] The molten iron dephosphorization slag according to the present invention is a molten iron dephosphorization slag that is added to molten iron to dephosphorize the molten iron.
It is characterized by containing Na 2 O at a rate of 3% or less in CaF 2 -SiO 2 based slag. (SiO 2 )≧7 10≦(CaF 2 )≦42 (CaO)≦3.17・(SiO 2 ) +1.7・(CaF 2 ) (CaO)/(SiO 2 )≧2.1 However, ( ) indicates the component It shows the concentration (wt%) and is normalized as (CaO) + (CaF 2 ) + (SiO 2 ) = 100. [Example] The present invention will be specifically described below with reference to the attached drawings. The dephosphorization slag according to this invention is based on a ternary slag consisting of quicklime (CaO), calcium fluoride (CaF 2 ), and silica (SiO 2 ), and this slag contains a small amount of sodium oxide (Na 2 O). It is something that The inventors of this application have conducted various experimental studies to develop a slag with high dephosphorization ability, and as a result, the CaO-
It has been found that CaF 2 -SiO 2 based slag whose composition is adjusted so that tricalcium silicate (3CaO.SiO 2 ) and quicklime coexist has high dephosphorizing ability. Furthermore, when such slag contains sodium oxide, the dephosphorization ability is further increased. Moreover, iron oxide (FeO) may be contained in order to increase the oxygen potential, if necessary. The present invention has been made based on such knowledge, and the composition of added slag is controlled so that it falls within the composition range specified below at the dephosphorization treatment temperature of hot metal or molten steel. First, regarding the slag used for dephosphorization of molten steel, CaO-
The explanation will be based on FIG. 1, which is a phase diagram of CaF 2 --SiO 2 ternary system slag. Because the slag must be molten at the dephosphorization treatment temperature, CaO−CaF 2
- The composition of Sio 2 ternary slag must be such that its melting point is between 200°C higher and 200°C lower than the processing temperature. In the dephosphorization treatment of molten steel, the treatment temperature is usually 1575℃, so the above composition is 1775℃ in Figure 1.
This is the region between the liquidus lines of 1375°C (near the liquidus lines of 1750°C and 1350°C, respectively). A region where the liquidus line is lower than 1375℃ is preferable because the slag has a composition that melts easily, but it has the disadvantage that the concentration of CaF 2 increases, which increases the erosion of the refractory and lowers the dephosphorization ability. be. Therefore, in the present invention, the slag composition is controlled so that the melting point is 1375°C or higher, that is, a temperature that is 200°C lower than the processing temperature. Furthermore, if the melting point is higher than the processing temperature, it is thought that the flux will not melt, but the dephosphorization slag according to the present invention also contains Na 2 O in addition to these three components, so CaO-CaF 2 - Even in the liquidus region of 1775℃ in the phase diagram of SiO 2 slag, the slag actually used is in a molten state. Therefore, in the present invention, the slag composition of the ternary slag is set to have a melting point of 200° C. higher than the processing temperature. In this invention, since the slag in the coexistence region of tricalcium silicate and quicklime is used, the region in which 2CaO.SiO 2 exists is outside the composition range of the dephosphorization slag according to the present invention. In the region where CaO exists alone, the composition range is determined as follows. In other words, it is a region sandwiched between liquidus lines 200℃ higher and 200℃ lower than the processing temperature, and these liquidus lines are
From the points X 0 and Y 0 that intersect the boundary between the CaO single region and the tricalcium silicate/quicklime coexistence region, the proportion of CaF 2 is 10% along these liquidus lines.
This is an area partitioned by straight lines connecting many points X and Y. In order to increase the dephosphorization ability, it is desirable to increase the activity of CaO, but increasing the concentration of CaO
The concentration of CaF 2 also increases, which is undesirable.
The composition range of the dephosphorization slag according to the present invention extends up to a region where the concentration of CaF 2 increases by 10%. The composition range of the slag determined as described above is the area shown by diagonal lines in FIG. In other words,
The relative proportions of CaO, CaF 2 and SiO 2 are determined so as to fall within the above composition range, and Na 2 O is contained in a proportion of 3% by weight or less based on this slag.
The higher the Na 2 O content, the higher the phosphorus distribution value, but for reasons such as the high cost of Na 2 O, the high content of Na 2 O, the erosion of refractories will be severe, and the generation of dust will be more likely. The concentration of Na 2 O is set to 3% or less.
If necessary, FeO may be contained in order to maintain the oxygen potential. In FIG. 2, the composition range of dephosphorization slag when added to hot metal is shown in the shaded area. The method for determining the composition range is the same as that for slag to be added to molten steel. When hot metal is dephosphorized, the treatment temperature is usually as low as 1300°C, so the composition range is shifted to the side where the proportion of CaF 2 is higher than when molten steel is dephosphorized. In this way, the optimal slag composition range for dephosphorization differs depending on the processing temperature, and the composition range (excluding Na 2 O) that includes molten steel processing and hot metal processing is the third
The state diagram of the CaO-CaF 2 -SiO 2 system slag in the figure is shown in the shaded area. This region is expressed by the following inequality. (SiO 2 )≧7 10≦(CaF 2 )≦42 (CaO)≦3.17・(SiO 2 ) +1.7・(CaF 2 ) (CaO)/(SiO 2 )≧2.1 However, ( ) indicates the component Concentration (% by weight) is shown. Also, it is normalized as (CaO) + (CaF 2 ) + (SiO 2 ) = 100. Next, embodiments of the present invention will be specifically described. First, an example in which molten steel is subjected to dephosphorization treatment will be described. After melting low carbon steel in a magnesia crucible in the atmosphere using a 5 kg high frequency furnace, a flux calculated to have the above composition was added at a ratio of 60 kg to 1 ton of molten steel. after that,
A magnesia pipe was immersed in molten steel, and argon gas was blown into the molten steel at a flow rate of 0.5 Nl/min to stir the molten steel and promote the dephosphorization reaction. During the approximately 20 minute reaction period, samples were taken from the molten steel and slag and their compositions were analyzed. The results are shown in Tables 2 and 3.
【表】【table】
【表】
この第２表及び第３表に示すようにフラツクス
添加後、10分経過すると、溶鋼中の燐濃度が
10ppm以下になり、燐分配値が1000を超え、従来
の脱燐スラグでは得られない高脱燐能で溶鋼が脱
燐された。
第４表は、第１図（溶鋼脱燐処理）の斜線領域
に示す範囲にコントロールされたこの発明に係る
スラグの燐分配値を、第１図の斜線領域から外れ
る組成のスラグの燐分配値と比較して示す。な
お、燐分配値は脱燐スラグを添加した後、20分経
過して得られた燐分配値である。また、第１図の
，，，は夫々第４表の比較例１，２，
３，４のスラグの組成を示す。[Table] As shown in Tables 2 and 3, 10 minutes after adding flux, the phosphorus concentration in molten steel decreases.
The phosphorus distribution value exceeded 1000, and the molten steel was dephosphorized with a high dephosphorizing ability that could not be obtained with conventional dephosphorizing slag. Table 4 shows the phosphorus distribution value of the slag according to the present invention, which was controlled within the range shown in the shaded area in FIG. A comparison is shown below. Note that the phosphorus distribution value is the phosphorus distribution value obtained 20 minutes after adding the dephosphorization slag. In addition, , , in Fig. 1 are Comparative Examples 1 and 2 in Table 4, respectively.
The composition of slag No. 3 and 4 is shown below.
【表】
但し、各スラグの組成は下記第５表に示すとお
りである。[Table] However, the composition of each slag is as shown in Table 5 below.
【表】
この第４表及び第１図から明らかなように、こ
の発明にて規定される組成範囲から外れるスラグ
（比較例１，２，３，４）は、Na2Oを含有して
いても、この発明に係るスラグよりも燐分配値が
極めて低い。比較例１のスラグは他の比較例のス
ラグよりも燐分配値が多少高いが、CaF2の濃度
が高いため、耐火物の浸食が激しいので実用的で
はない。
一方、第４図はこの発明に係るスラグの燐分配
値Lpを、従来の脱燐スラグの燐分配値と比較し
て示すグラフである。燐分配値は温度に依存する
ため、図の横軸には温度をとつている。図中破線
はCaO―CaF2系、一点鎖線はNa2O―SiO2系スラ
グのLpを示し、破線にて囲む領域はCaO―Na2O
―SiO2系スラグのLpを示す。この第４図から明
らかなように、この発明に係るスラグは全ての温
度において、従来のスラグよりも数倍乃至数十倍
高い燐分配置を有している。
次に、溶銑に対して脱燐処理した場合の実施例
について説明する。第６表はこの発明に係る脱燐
スラグの燐分配値をこの発明にて規定する組成か
ら外れるスラグの燐分配値と比較して示し、第７
表は各スラグの組成を示す。[Table] As is clear from this Table 4 and FIG. Also, the phosphorus distribution value is much lower than that of the slag according to the present invention. Although the slag of Comparative Example 1 has a somewhat higher phosphorus distribution value than the slags of other comparative examples, the high concentration of CaF 2 causes severe erosion of refractories, making it impractical. On the other hand, FIG. 4 is a graph showing the phosphorus distribution value Lp of the slag according to the present invention in comparison with the phosphorus distribution value of the conventional dephosphorization slag. Since the phosphorus distribution value depends on temperature, temperature is plotted on the horizontal axis of the figure. In the figure, the broken line shows the CaO--CaF 2 system, the dashed line shows the Lp of the Na 2 O--SiO 2 -based slag, and the area surrounded by the broken line is the CaO--Na 2 O
- Indicates Lp of SiO 2 -based slag. As is clear from FIG. 4, the slag according to the present invention has a phosphorus content several to several tens of times higher than that of the conventional slag at all temperatures. Next, an example in which hot metal is dephosphorized will be described. Table 6 shows the phosphorus distribution value of the dephosphorization slag according to the present invention in comparison with the phosphorus distribution value of the slag that deviates from the composition specified in the present invention.
The table shows the composition of each slag.
【表】【table】
【表】
なお、この第６表における燐分配値は、フラツ
クス添加後30分経過したときの燐分配値であり、
この発明に係るスラグにおいては約10000という
極めて高い値が得られている。このように、この
発明に係るスラグにおいては、処理温度に拘ら
ず、従来のスラグでは得られない極めて高い燐分
配値が得られる。
［発明の効果］
以上詳細に説明したように、この発明によれ
ば、スラグの脱燐能が極めて高いから、スラグの
添加原単位を低下させ、脱燐コストを低下させる
ことがきる。また、この発明によれば、従来の脱
燐スラグでは得られない極低燐濃度の鋼材を容易
に製造することができる。[Table] In addition, the phosphorus distribution value in this Table 6 is the phosphorus distribution value when 30 minutes have passed after adding flux,
The slag according to this invention has an extremely high value of about 10,000. As described above, the slag according to the present invention provides an extremely high phosphorus distribution value that cannot be obtained with conventional slags, regardless of the treatment temperature. [Effects of the Invention] As described above in detail, according to the present invention, since the dephosphorizing ability of slag is extremely high, the unit of addition of slag can be reduced, and the dephosphorization cost can be reduced. Further, according to the present invention, it is possible to easily produce a steel material with an extremely low phosphorus concentration that cannot be obtained with conventional dephosphorization slag.
第１図乃至第３図はこの発明に係るスラグの組
成範囲を示す状態図、第４図はこの発明の効果を
示すグラフ図である。
1 to 3 are phase diagrams showing the composition range of the slag according to the present invention, and FIG. 4 is a graph diagram showing the effects of the present invention.
Claims (1)
ラグにおいて、下記不等式にて示す組成を有する
CaO―CaF2―SiO2系スラグにNa2Oを３％以下の
割合で含有することを特徴とする溶鉄の脱燐スラ
グ。 （SiO2）≧７ 10≦（CaF2）≦42 （CaO）≦3.17・（SiO2） ＋1.7・（CaF2） （CaO）／（SiO2）≧2.1 但し、（ ）はその成分の濃度（重量％）を示
し、 （CaO）＋（CaF2）＋（SiO2） ＝100と規格化する。[Claims] 1. Molten iron dephosphorization slag added to molten iron to dephosphorize the molten iron, having a composition represented by the following inequality:
A molten iron dephosphorization slag characterized by containing Na 2 O in a CaO-CaF 2 -SiO 2 -based slag at a ratio of 3% or less. (SiO 2 )≧7 10≦(CaF 2 )≦42 (CaO)≦3.17・(SiO 2 ) +1.7・(CaF 2 ) (CaO)/(SiO 2 )≧2.1 However, ( ) indicates the component It shows the concentration (wt%) and is normalized as (CaO) + (CaF 2 ) + (SiO 2 ) = 100.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP45185A JPS61159506A (en) | 1985-01-08 | 1985-01-08 | Slag for dephosphorizing molten iron |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP45185A JPS61159506A (en) | 1985-01-08 | 1985-01-08 | Slag for dephosphorizing molten iron |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4006373A Division JPH0711020B2 (en) | 1992-01-17 | 1992-01-17 | Dephosphorization method for molten steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61159506A JPS61159506A (en) | 1986-07-19 |
| JPS6319564B2 true JPS6319564B2 (en) | 1988-04-23 |
Family
ID=11474151
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP45185A Granted JPS61159506A (en) | 1985-01-08 | 1985-01-08 | Slag for dephosphorizing molten iron |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61159506A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103205533B (en) * | 2012-01-13 | 2014-12-03 | 宝山钢铁股份有限公司 | Torpedo tank car deslagging material and preparation method thereof |
| JP6594644B2 (en) * | 2015-04-03 | 2019-10-23 | 旭ファイバーグラス株式会社 | Glass fiber insulation sound absorber and method of using the same |
| US20230357075A1 (en) * | 2022-05-06 | 2023-11-09 | Mexichem Fluor S.A. De C.V. | Fluorite synthetic stones and method of making fluorite synthetic stones |
-
1985
- 1985-01-08 JP JP45185A patent/JPS61159506A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61159506A (en) | 1986-07-19 |
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