CA1139568A - Method for the desulfurization of molten metal - Google Patents
Method for the desulfurization of molten metalInfo
- Publication number
- CA1139568A CA1139568A CA000347048A CA347048A CA1139568A CA 1139568 A CA1139568 A CA 1139568A CA 000347048 A CA000347048 A CA 000347048A CA 347048 A CA347048 A CA 347048A CA 1139568 A CA1139568 A CA 1139568A
- Authority
- CA
- Canada
- Prior art keywords
- desulfurizing
- agent
- aluminium
- metallic aluminium
- desulfurization
- 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
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
-
- 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)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
A METHOD FOR THE DESULFURIZATION
OF MOLTEN METAL
ABSTRACT OF THE DISCLOSURE:
A desulfurizing method of molten pig iron comprising co-using 1-30% by weight of metallic aluminium to the total weight of a desulfurizing agent of alkali metal oxide type.
OF MOLTEN METAL
ABSTRACT OF THE DISCLOSURE:
A desulfurizing method of molten pig iron comprising co-using 1-30% by weight of metallic aluminium to the total weight of a desulfurizing agent of alkali metal oxide type.
Description
~f~3~
~ 2 -Thi~ invention relate~ to an improvement in a method for the desulfurization of mol-ten metal, particularly of molten pig iron.
Easy and convenient method is regarded a~ important for u~ing a desulfuri3ing agent o~ molten metal~. A~ the most suitable desul~urizing agents used in pre~etting method there are mentioned dasulfurizing agents o~ alkali metal oxide type, which have quick raaction and a low melting point of slag, i.e. agents such a~ sodium carbonate~ caustic soda, pota~ium carbonate and caustic potae~ium or mixtures thereof with ~mall amount~ o~ calcium -fluorideS ~odium ~luoride, iron oxide, aluminium fluoride, ~odium aluminium fluoride, potassium aluminium fluoride and magnesium fluoride.
Known de~ul~urizing agents ~uch a~ lime, calcium carbonate, lime nitrogen and metallic magne~ium are not suitable ~or the d~ulfurizing operation by presetting method becauæe they are active either too ~lowly or too quickl~, and they mu~t be added into hot melt by using a large-sized apparatu~ ~o that they are not economical de~ulfurizing agent~. ~ desulfurizing reaction of moten metal in the case of using a desulfurizing agent ~f alkali metal o~ide type is carried out theoretically in the co-e~i~tence with reduclng element. That i~7 it can be presum~d from reaction ~ormula that frea alkali metal i~ formed ~rom alkali oxide by mean3 of the reducing agent~ ~uch a~ carbon9 silicon, alwminium~
magne~ium, tltanium and zirconium, it i~ bonded with ~ul~ur ~ ,, ' - ' :
in metal sulfide thereby to become alkali sulfide, and then the alkali sulfide is solved in slag when it is ~eparated from metal. It is e~ident from the phase diagram o~ ~e-Aæ
that aluminium is the very element which is meltable in molten iron and has the maximuM chance o~ exhibiting a desulfurizing action until its extinction. Magnesium which is a highl~ reactive metal on the other hand melts in less amount in molten iron 90 that it~ reactivitg is ~ubstantially infsrior. ~urther, as an advantage of aluminium when used for the desulfurization of molten pig iron, it does not lower the basicity of slag whereby the desulfuri~ing reaction is carried ou-t continuousl~ under the same condition~.
The present invention is to provide a de~ulfurizing agent most suitable ~or the pre~etting method which is easy and convenient for the desulfurization of molten metals, particularly of molten pig iron7 and a method suitable for the addition of said desulfurizing agent. That is, the desulfurizing method is either to previously melt aluminium into molten pig iron and then react the pig iron with a desulfurizing agent or to simultaneously add aluminium and the de~lfurizing agent into the molten pig iron. Preferably, however, aluminium is added to the molten pig iron before the desulfurizing agent~
As a desulfurizing agent of alkali metal oxide type, which exhibits effects for ~aid pre~stting method, there is u~ed, in the form of powder, grain~ mass or flake~ any of anhydrous substance, ~alt hydrate and hydrogencarbonate , .
, ~3 of one or more of potas~ium carbonate, sodium carbonate, cau~tic soda, caus-tic pota~sium and pota~sium ~odium carbo-nate. ~urthermore, when the desulfurizing agent is used in the form of grain or mas~ it may be added with an organlc binder of a small amount of 3tarch, de~trin, glue, natural resin or synthetic resin, or an inorganic binder of cement, water glass, clay, colloidal silica or aluminium phosphate.
Metallic aluminium in the form of mass, grain or granulated article of powder is charged or inqerted into the hot melt, but to delay the reaction it i~ possible to provide at the outer periphery of ~aid mass, grain or granulated article a receptacle, coating or carrier con-sisting of a material which may not reversely af~ect the hot melt or the inner wall refractory of hot melt vessel.
In the pre~ent de~ulfurizing method, a desulfurizi~g agent of alkali metal oxide type and metallic aluminium is either mixed ju~t before use or simultaneously charged as separate packages. Alternately there may be adopted a method in which the hot melt is poured after metallic aluminium has previously been arranged in a treating vessel, and a desul~urizing agent of aIkali metal oxide type is charged and added towards the pouring flow, in the mid-cour~e of the melt pouring. The u~e ratio of metallic aluminium to the whole weight of said desulfurizing agent is $n the range 1-30~ by weight. With less than 1% of metallic aluminium the reducingr action does not affect the desulfuri~ingr agent~ and with more than 30% the desulfurizing , ~
g~
agent is decreased in quantity thereby requiring use of same in large quantity. As a result, aluminium oxide is produced so much that the fluidity of slag is impeded, and therefore ~uch an excess is not desirable.
The desulfurizing method of the invention will now be described below in compari~on with comparative example~.
In each of the examples, desulfurizing effects of addition or non-addition of a:Luminium were compared by using pig iron of same component and a hot-metal ladle of ~ame capacity and carrying out a presetting method. The capacity of the hot-metal ladle is 250 ton, and molten pig iron of 240 ton wa~ poured into said ladle by means of a pig iron mixing car thereby to carry out a desulfurizing treatment.
It will be understood from the comparison that the desulfurizing agent in co-use of metallic aluminium di~plays a higher desulfurizing rate by 5-12~ than the agent not in co-uee.
. .
.
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~ 2 -Thi~ invention relate~ to an improvement in a method for the desulfurization of mol-ten metal, particularly of molten pig iron.
Easy and convenient method is regarded a~ important for u~ing a desulfuri3ing agent o~ molten metal~. A~ the most suitable desul~urizing agents used in pre~etting method there are mentioned dasulfurizing agents o~ alkali metal oxide type, which have quick raaction and a low melting point of slag, i.e. agents such a~ sodium carbonate~ caustic soda, pota~ium carbonate and caustic potae~ium or mixtures thereof with ~mall amount~ o~ calcium -fluorideS ~odium ~luoride, iron oxide, aluminium fluoride, ~odium aluminium fluoride, potassium aluminium fluoride and magnesium fluoride.
Known de~ul~urizing agents ~uch a~ lime, calcium carbonate, lime nitrogen and metallic magne~ium are not suitable ~or the d~ulfurizing operation by presetting method becauæe they are active either too ~lowly or too quickl~, and they mu~t be added into hot melt by using a large-sized apparatu~ ~o that they are not economical de~ulfurizing agent~. ~ desulfurizing reaction of moten metal in the case of using a desulfurizing agent ~f alkali metal o~ide type is carried out theoretically in the co-e~i~tence with reduclng element. That i~7 it can be presum~d from reaction ~ormula that frea alkali metal i~ formed ~rom alkali oxide by mean3 of the reducing agent~ ~uch a~ carbon9 silicon, alwminium~
magne~ium, tltanium and zirconium, it i~ bonded with ~ul~ur ~ ,, ' - ' :
in metal sulfide thereby to become alkali sulfide, and then the alkali sulfide is solved in slag when it is ~eparated from metal. It is e~ident from the phase diagram o~ ~e-Aæ
that aluminium is the very element which is meltable in molten iron and has the maximuM chance o~ exhibiting a desulfurizing action until its extinction. Magnesium which is a highl~ reactive metal on the other hand melts in less amount in molten iron 90 that it~ reactivitg is ~ubstantially infsrior. ~urther, as an advantage of aluminium when used for the desulfurization of molten pig iron, it does not lower the basicity of slag whereby the desulfuri~ing reaction is carried ou-t continuousl~ under the same condition~.
The present invention is to provide a de~ulfurizing agent most suitable ~or the pre~etting method which is easy and convenient for the desulfurization of molten metals, particularly of molten pig iron7 and a method suitable for the addition of said desulfurizing agent. That is, the desulfurizing method is either to previously melt aluminium into molten pig iron and then react the pig iron with a desulfurizing agent or to simultaneously add aluminium and the de~lfurizing agent into the molten pig iron. Preferably, however, aluminium is added to the molten pig iron before the desulfurizing agent~
As a desulfurizing agent of alkali metal oxide type, which exhibits effects for ~aid pre~stting method, there is u~ed, in the form of powder, grain~ mass or flake~ any of anhydrous substance, ~alt hydrate and hydrogencarbonate , .
, ~3 of one or more of potas~ium carbonate, sodium carbonate, cau~tic soda, caus-tic pota~sium and pota~sium ~odium carbo-nate. ~urthermore, when the desulfurizing agent is used in the form of grain or mas~ it may be added with an organlc binder of a small amount of 3tarch, de~trin, glue, natural resin or synthetic resin, or an inorganic binder of cement, water glass, clay, colloidal silica or aluminium phosphate.
Metallic aluminium in the form of mass, grain or granulated article of powder is charged or inqerted into the hot melt, but to delay the reaction it i~ possible to provide at the outer periphery of ~aid mass, grain or granulated article a receptacle, coating or carrier con-sisting of a material which may not reversely af~ect the hot melt or the inner wall refractory of hot melt vessel.
In the pre~ent de~ulfurizing method, a desulfurizi~g agent of alkali metal oxide type and metallic aluminium is either mixed ju~t before use or simultaneously charged as separate packages. Alternately there may be adopted a method in which the hot melt is poured after metallic aluminium has previously been arranged in a treating vessel, and a desul~urizing agent of aIkali metal oxide type is charged and added towards the pouring flow, in the mid-cour~e of the melt pouring. The u~e ratio of metallic aluminium to the whole weight of said desulfurizing agent is $n the range 1-30~ by weight. With less than 1% of metallic aluminium the reducingr action does not affect the desulfuri~ingr agent~ and with more than 30% the desulfurizing , ~
g~
agent is decreased in quantity thereby requiring use of same in large quantity. As a result, aluminium oxide is produced so much that the fluidity of slag is impeded, and therefore ~uch an excess is not desirable.
The desulfurizing method of the invention will now be described below in compari~on with comparative example~.
In each of the examples, desulfurizing effects of addition or non-addition of a:Luminium were compared by using pig iron of same component and a hot-metal ladle of ~ame capacity and carrying out a presetting method. The capacity of the hot-metal ladle is 250 ton, and molten pig iron of 240 ton wa~ poured into said ladle by means of a pig iron mixing car thereby to carry out a desulfurizing treatment.
It will be understood from the comparison that the desulfurizing agent in co-use of metallic aluminium di~plays a higher desulfurizing rate by 5-12~ than the agent not in co-uee.
. .
.
,9 ,~ ~ ~,~ C^~
_ ~0 ~rl ~ ~ ~ ~ ~ t~
_ r~ rl a~Lt~~ t~`\ 1~ ~ ~I
s~ h ~ ~ o o o o ol o ~
~4 r~l ~ O O O O O O
O c~ ~ ~
I bO _ _ r~ r~ +~ ~ ~ ~ ~ ~ t~
U~ O ~ td O O O O r~ O
4~ O O O O O O
_ R ~rlbO ~rl O ~r O
rl rd $ 1:> $ ~ b~1 ~ ~P
o Q) a~~I) ~D r~-r~ I ~-r~
,~,~ ~ m ~q ~q a~ $~ 3 I a) h :3:
rd Y a) a) a~ a) rd ,~ O ~I) rd ;S O
~ E~ h h h h ~ O r d O r~ O O O
_ _ C~
~ K o a o u~ o o o o g $ g .r ~ r~
r-- ~ ~ cr~ r-l l N 0~ ~r~ h~o _ O ~ r~
_ ~ ~ r~ ~ r-l ~0^ ~0^ ~ ~0 O c) ~
~:1 01:) ~o ~_ O , ~ * _, ~ h ~ r~
l t~ O ~ r~ Fd ~ ~ h _~
sD ~ ~ ~ O ~ O ~ O ~ ~5 r~ _ ~rl r~ ~rN rd ~ O ~ r~ u~ O O ~ O a~ O
~H~r~ O ~d u~ C~ b ~rl ~rl r~ d c) ~rl h~a~ 5: +~ ~ ~1 +~ +~ Q~ ~ h rl (D rl h ~d ~ 3 ~ o bO ~ rl 3 3 ~ r-l r-l 3 ~ ~ *
V c~ 1~1 V ~ V ¢I c~ F`~ V ~c H ~ H g r O r ~D~ ~r~td (D ~ rl ~ a) +~ rl cd r~d ;l ~ Pd d h ~ ~ d E3 ~q a) P~ ~ u~ ~ P~ ~ ~ a) ~ ~1 oh ~.1 O ~ ~1 ~1 H O ~ h ~i ~ r ~ p .
Claims (3)
PROPERTY OR PRIVILEGE IS CLIAMED ARE DEFINED AS FOLLOWS:
1. A desulfurizing method of molten pig iron comprising co-using 1-30% by weight of metallic aluminium to the total weight of a desulfurizing agent of alkali metal oxide type.
2. A desulfurizing method according to Claim 1 wherein said desulfurizing agent and said metallic aluminium are previously arranged within a treating vessel before hot metal is poured.
3. A desulfurizing method according to Claim 1 wherein said metallic aluminium is previously arranged within the treating vessel before the hot metal is poured, and said desulfurizing agent is added to the pouring flow of the hot metal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP36987/79 | 1979-03-30 | ||
| JP3698779A JPS55131112A (en) | 1979-03-30 | 1979-03-30 | Molten metal desulfurizing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1139568A true CA1139568A (en) | 1983-01-18 |
Family
ID=12485091
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000347048A Expired CA1139568A (en) | 1979-03-30 | 1980-03-05 | Method for the desulfurization of molten metal |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS55131112A (en) |
| AU (1) | AU524961B2 (en) |
| BE (1) | BE881916A (en) |
| CA (1) | CA1139568A (en) |
| DE (1) | DE3009477A1 (en) |
| FR (1) | FR2452521A1 (en) |
| GB (1) | GB2050430A (en) |
| IT (2) | IT8009395A1 (en) |
| LU (1) | LU82305A1 (en) |
| NL (1) | NL8001834A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63145707A (en) * | 1986-12-08 | 1988-06-17 | Nisshin Steel Co Ltd | Desulfurizing agent of molten iron |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR573866A (en) * | 1923-11-28 | 1924-07-02 | Desulphurizing agent for iron and steel | |
| DE881797C (en) * | 1949-11-30 | 1953-07-02 | Solvay Werke Gmbh | Desulfurization and deoxidization of an iron melt |
| FR1125154A (en) * | 1955-04-28 | 1956-10-25 | Siderurgie Fse Inst Rech | Process for desulphurizing molten metals and in particular cast iron |
| FR1168646A (en) * | 1957-02-21 | 1958-12-11 | Siderurgie Fse Inst Rech | Insufflation process for desulphurizing molten metals, in particular cast iron and steel |
| CH363670A (en) * | 1962-01-11 | 1962-08-15 | Technochemie Ets | Means for desulphurisation and / or dephosphorization of iron and steel melts and processes for their production |
| LU65436A1 (en) * | 1971-06-07 | 1972-08-24 | ||
| DE2730016C3 (en) * | 1977-07-02 | 1984-05-30 | Stahlwerke Peine-Salzgitter Ag, 3150 Peine | Process for soda desulphurization of iron melts |
-
1979
- 1979-03-30 JP JP3698779A patent/JPS55131112A/en active Pending
-
1980
- 1980-02-26 BE BE2/58428A patent/BE881916A/en not_active IP Right Cessation
- 1980-03-05 CA CA000347048A patent/CA1139568A/en not_active Expired
- 1980-03-11 GB GB8008110A patent/GB2050430A/en not_active Withdrawn
- 1980-03-12 DE DE19803009477 patent/DE3009477A1/en not_active Ceased
- 1980-03-25 AU AU56802/80A patent/AU524961B2/en not_active Ceased
- 1980-03-28 FR FR8006932A patent/FR2452521A1/en active Pending
- 1980-03-28 LU LU82305A patent/LU82305A1/en unknown
- 1980-03-28 IT IT1980A09395A patent/IT8009395A1/en unknown
- 1980-03-28 IT IT09395/80A patent/IT1153795B/en active
- 1980-03-28 NL NL8001834A patent/NL8001834A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| BE881916A (en) | 1980-06-16 |
| NL8001834A (en) | 1980-10-02 |
| DE3009477A1 (en) | 1980-10-09 |
| JPS55131112A (en) | 1980-10-11 |
| LU82305A1 (en) | 1980-07-01 |
| GB2050430A (en) | 1981-01-07 |
| AU5680280A (en) | 1980-10-02 |
| IT8009395A0 (en) | 1980-03-28 |
| FR2452521A1 (en) | 1980-10-24 |
| IT8009395A1 (en) | 1981-09-28 |
| IT1153795B (en) | 1987-01-21 |
| AU524961B2 (en) | 1982-10-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |