CA1171663A - Desulphurising agent - Google Patents
Desulphurising agentInfo
- Publication number
- CA1171663A CA1171663A CA000371607A CA371607A CA1171663A CA 1171663 A CA1171663 A CA 1171663A CA 000371607 A CA000371607 A CA 000371607A CA 371607 A CA371607 A CA 371607A CA 1171663 A CA1171663 A CA 1171663A
- Authority
- CA
- Canada
- Prior art keywords
- weight
- agent according
- agent
- quicklime
- diamide lime
- 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 63
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims abstract description 52
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 47
- 229910052742 iron Inorganic materials 0.000 claims abstract description 32
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims abstract description 26
- 235000011941 Tilia x europaea Nutrition 0.000 claims abstract description 26
- 235000012255 calcium oxide Nutrition 0.000 claims abstract description 26
- 239000000292 calcium oxide Substances 0.000 claims abstract description 26
- 239000004571 lime Substances 0.000 claims abstract description 26
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 claims abstract description 21
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 10
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 8
- 239000010959 steel Substances 0.000 claims abstract description 8
- 239000000203 mixture Substances 0.000 claims abstract description 4
- 239000010436 fluorite Substances 0.000 claims abstract 5
- 238000000034 method Methods 0.000 claims description 4
- 239000002245 particle Substances 0.000 claims description 3
- 239000007789 gas Substances 0.000 description 10
- 238000011282 treatment Methods 0.000 description 7
- 238000007664 blowing Methods 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- 239000000155 melt Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 239000005864 Sulphur Substances 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 238000007792 addition Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 235000010216 calcium carbonate Nutrition 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000000428 dust Substances 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 230000009257 reactivity Effects 0.000 description 2
- 239000002671 adjuvant Substances 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 150000002505 iron Chemical class 0.000 description 1
- 229910001338 liquidmetal Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229940088417 precipitated calcium carbonate Drugs 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000002699 waste material Substances 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)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Tea And Coffee (AREA)
- Soy Sauces And Products Related Thereto (AREA)
- Fats And Perfumes (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
- Catalysts (AREA)
Abstract
ABSTRACT
The present invention provides an agent for desulphurising crude iron and raw steel, comprising a mixture of quicklime and diamide lime. The agent preferably comprises 50 to 90% by weight of quicklime and 10 to 50% by weight of diamide lime and may, if desired, also comprise up to 10% by weight of fluor-spar. The diamide lime used preferably has a carbon content of 5 to 50% by weight.
The present invention provides an agent for desulphurising crude iron and raw steel, comprising a mixture of quicklime and diamide lime. The agent preferably comprises 50 to 90% by weight of quicklime and 10 to 50% by weight of diamide lime and may, if desired, also comprise up to 10% by weight of fluor-spar. The diamide lime used preferably has a carbon content of 5 to 50% by weight.
Description
~Y~W 386 ~.~ 7~663 ' -2-~ he present invention is concerned with an agent and a method for desulphurising crude iron and ra~ steel.
It is already known that a desulphuri~ing o crude iron can be accomplished by the addition of quicklime to the iron melt. Thus, for example, in the production of ~teel in an oxygen blow convertor, lime is added in order to bind sulphur.
It i~ also known to blow in quicklime in powdered form~ Thi~ take~ place, for example, in electric arc furnaces, in oxygen blow convertors (LDAC proce~s) and in bottom blow convertors (OBM process). When blowing lime into crude iron transport ladle~, it i~ found to he nece~ary to blow in a large amount of lime in order to achieve the desired desulphuri~ing effec~. Further-more, large amount~ of conveyor gas (about 1 litre of gas per kg. of quicklime) are neces~ary for the pneumatic conveyance of the lime ~ince o~herwise blockages, ~toppage formation~ and non-unifonm pneumatic conveyance would result. ~owever, this i~ unde~irable becau~e it give~
rise to spattering and ejection of metal from the ladle.
Consequently~ khere is a need for a de~ulphuri~ing agent ba~ed upon quicklime which, with the use of com-paratively ~mall amount~ of conveying gas of, for example, 10 ~l. conveying gas (10 litre~ of ga~ under normal condition~) per ~9. of de~ulphurising agent, can be con-veyed uniformly.
Thu~, it is an object of the pre~ent inventi~n '" ', "' ' , ' "' ~ , .
.
~7~3 to provide a highly ef~ective de~ulphuri3ing ~gent which can be introduced into the crude iron to be treated with the use of a comparatively ~mall amount of conveying ga~, thus making pos~ible ~maller los~e~
of material and a considerable saving of energy due to a reduced cooling of ~he crude iron to be de~ulphurised.
Thus, according to the pre3ent invention, ~here is provided an agent for desulphuri~ing crude iron and raw steel which comprises a mixtura of quicklime (CaO) and diamide lime~
The agent according to the present invention is preferably in powdered form, which can be obtained by grinding the components. The agent according to the present invention preferably has a particle ~i~e suit-able for pneumatic conveying.
The diamide lime u~ed as a com~onent of the agent according to the present invention i~ a chemically produced, precipitated calcium carbonate, which prefer-ably ha~ a car~on content of rom 5 to 4~/0 by weight.
The de~ulphuri~ing agent according to the present invention preferably compri~es 50 to 9~ by weight and, more preferably, 60 to 85% by weight of quicklime and 10 to 50/0 ~y weight and especially 15 to 40% by weight of diamide lime. According to an e~pecially preferred embodiment, the desulphuri~ing agent according to ~he pre~ent invention contains about 40% by weight (40 ~ 3%
by weight) of diamide llme.
.: :
.. , , , ..................... .
.. , :. . ~', ' :' . .
~7~63 The de~ulphurising agent according to ~he present invention with a diamide lime content of about 4~/0 by weight (with a carbon content of 40 to 5~0 by weight) is especially ~uitable for the de~ulphurising of crude iron in torpedo ladles. For desulphurising in open crude iron transport and charging ladle~, the desulphur-iqing agent according to the present invention prefer-ably has a diamide lime content of 15 to 25% by weight.
The diamide lime present in the desulphurising agent according to the pre~ent invention has a carbon content of from 5 to 5~0 by weight and prefarably of 10 to 40% by weight.
Furthermore, the de~ulphurising agent according to the present invention can also contain co~paratively small additions of conventional adjuvant~, or example of fluor3par, of up to loY~ by weight.
Surprisingly, we have found that the desulphur-i~ing agent according to the present invention require~
a substantially 3maller amount of conveying gas than the quicklime previously used for the same purpose.
Thu~, the agent according to the present invention can be uniformly conveyed with an amount of conveyor gas of only 7 Nlo per kg. The calcium carbonate component o the diamide lime, after its emergence from the lance u~ed for the introduction of the agent into the crude iron to be desulphuri3ed, decomposes instantaneouqly and thereby ensures an intensi~e mixing up of the ~olid .
.
.
'' :' ' ~ " ~ ' ' ' ~:3L7~6~
desulphuri~ing agent with the iron melt to ~ de~ulphur~
ised. From the calcium carbonat~ component of the diæmide lime there thereb~ ~ir~t r2sult~ quicklime, which is highly reacti~e because it i~ freshly calcined.
Since thi~ mixture produce~ gaS in the iron melt, very many ga9 bubbleY of small diameter are fonmed. The re~ult of this i~ that only a very small amount of the de3ulphuri~ing agent according to the pre3ent invention i~ su~pended in relatively large bubble~ and is conv~yed through the melt without the agent coming into contact wi~h the iron. This can clearly be een by ob~erving the surface of the iron melt during the desulphurisi~g treatment. Thu~, when blowing quicklime into a molten iron, bubhle~ of the conveying ga~ used reach the sur-face and there burs~ and liberate large amount~ of fine, dust~like ~uicklime~ Thi9 dus~ mu~t be ~ucked off and removed from the waste ga~ with the help of a filter or of a ~crubber, which considerably increase~ the cost of the de~ulphurising treatment. In the case of blowing in the de~ulphurisin~ agent according to the pre~ent invention, no large bubble~ appear on the 9UX-face of the molten iron and only a very ~mall amount of dust formation is ob~erved.
In comparison with the conventionally u3ed lime, the de3ulphuri~ing agent according to the pre~ent inventlon po~sesse~ the considerable adva~tage of a substantially improved reactivity. Thus, when u~ing ,, ~, . . . . .
.
;3 the agent according to th~ present invention, for obtaining the same desulphuri~ing effect it i~, ~urprisingly, only nece3~ary to use about half the amount which would be necessary if carrying out the treatment with quicklime.
This ~urpri~ing advantage of ~ubstantially better reactivity or of increa~ed degree of action i~
also manife~ted by the fact that, because of the reduction of t~e a~ount of desulphuriqing agent to be blown in, a correspondingly ~maller amount of de~ulphur-i~ing slag i9 obtained. The de~ulphurising ~lag always contain~ a high proportion of metallic iron, which can amount to up to ~OYO by weight. This iron contained in the de~ulphurising 31ag is first 105t from the ladle and can only ~e recovered ~ub~equently ~ro~ the ~olid-ified slag with considerable expen~e. E3pecially when the slag c0019 more considerably, for example ~hen it is not removed immediately after the treatment, ~his can result in a part of it remaining in the treatment ves~el, whereb~ the transport capacity thereof for the liquid metal melt i~ reduced.
In the following Example, which is given for the purpo~e of illu~trating the pr2sent invention, a compari~on i~ made between the use of the agent accord ing to the present invention and the use of the previously conventionally employed quicklime.
.
:
: ' ' ' ' :
.
~7~6~3 ~.
a~ 9b~ L~L~æeaa~
160 Tonne~ crude iron were desulphuri3ed in a torpedo ladle solely wi~h quicklime. The initial ~ulphur content of the crude iron wa~ 0.042% by weight.
A total of 1760 k~. of fine quicklime were blown into the melt with the u~e of a lance which wa~ in~erted into the melt to a depth of 1.6 xetres. In order to be able to achieve a rea-~onably uniform blownng in of the quicklime, 120 ~1. of conveying gas per kg. of quicklime had to be u~ed. Due to this large amount of gas, a violent bubbling of he molten metal occurred, large amount~ of m~tal spattering out of the ladleO
Thick cloud~ of white ~moke th~reby emerged from the mouth of the ladle. In order to prevent the spatter-ing from becoming too violent, only 30 k~. of ~uicklime could be blown in per minute with 3600 ~1. of conveying ga~. The final sulphur content of the crude iron was 0.018% by weight.
b) invention.
Sub~equently, i~ the came plant, the ~ame amount of crude iron was desulphuri~ed using t~e agent accord-ing to the pre~ent invention, w~ich had been produced by grinding 60% by weight of quicklime and 4~% by weight of diamide lime with a carbon content o~ 2~o by weight.
In order to achieve the sæme desulphurising action~ only 1 ,L7~l 6Çi 3 4.8 kg. of desulphurising agent were needed per tonne of crude iron and the mixture could thereby al~o be conveyed with a ~maller amount o~ ga3. For a uniform and di~turbance-free blowing in, it wa~ only neces~ary to use 7 ~1. of conveying ga~ per Xg. o~ desulphurising agent. Therefore, the rate of conveying could be increased to 100 kg. per minute. Even in the case of thi~ higher rate of blowing, only 700 ~1. of conveying gas per minute were needed. Thi9 corresponds to only about one fif~h of the amount per unit time which was needed for conveying the quicklime. There wa~ also a correspondingly lower turbulence of the melt. ~en when the ladle wa~ well filled, no spattering occurred.
A further advantage of the desulphurising agent according to the present invention, which only had to be u~ed in smaller amounts, and of the higher conveying rates which were po~ible, i9 the fact that the treat-ment of 160 tonnes of crude iron i~ inished after about 10 minutes, whereas the de~ulphurisation with quicklime takes practically 1 hour. ~ormally, such a long period of time i~ not available for the desulphur-ing~ A further consequence of the laborious treatment in which large amounts of quicklime are blown in is a considerable cooling of the molten crude iron. Thu~, ~the temperature cf the crude iron melt de~ulphurised with q~icXlime decreased by 42C., whereas the temper-ature losr in the case oE using the dosu1phurising ' ' ~7~63 g agent according to the present invention was only 8C.
Thus, it can be ~een that, in compari~on with the quicklime normall.y used, the desulphurising agent according to the present invention display~ ~urpri3ing advantages.
.
It is already known that a desulphuri~ing o crude iron can be accomplished by the addition of quicklime to the iron melt. Thus, for example, in the production of ~teel in an oxygen blow convertor, lime is added in order to bind sulphur.
It i~ also known to blow in quicklime in powdered form~ Thi~ take~ place, for example, in electric arc furnaces, in oxygen blow convertors (LDAC proce~s) and in bottom blow convertors (OBM process). When blowing lime into crude iron transport ladle~, it i~ found to he nece~ary to blow in a large amount of lime in order to achieve the desired desulphuri~ing effec~. Further-more, large amount~ of conveyor gas (about 1 litre of gas per kg. of quicklime) are neces~ary for the pneumatic conveyance of the lime ~ince o~herwise blockages, ~toppage formation~ and non-unifonm pneumatic conveyance would result. ~owever, this i~ unde~irable becau~e it give~
rise to spattering and ejection of metal from the ladle.
Consequently~ khere is a need for a de~ulphuri~ing agent ba~ed upon quicklime which, with the use of com-paratively ~mall amount~ of conveying gas of, for example, 10 ~l. conveying gas (10 litre~ of ga~ under normal condition~) per ~9. of de~ulphurising agent, can be con-veyed uniformly.
Thu~, it is an object of the pre~ent inventi~n '" ', "' ' , ' "' ~ , .
.
~7~3 to provide a highly ef~ective de~ulphuri3ing ~gent which can be introduced into the crude iron to be treated with the use of a comparatively ~mall amount of conveying ga~, thus making pos~ible ~maller los~e~
of material and a considerable saving of energy due to a reduced cooling of ~he crude iron to be de~ulphurised.
Thus, according to the pre3ent invention, ~here is provided an agent for desulphuri~ing crude iron and raw steel which comprises a mixtura of quicklime (CaO) and diamide lime~
The agent according to the present invention is preferably in powdered form, which can be obtained by grinding the components. The agent according to the present invention preferably has a particle ~i~e suit-able for pneumatic conveying.
The diamide lime u~ed as a com~onent of the agent according to the present invention i~ a chemically produced, precipitated calcium carbonate, which prefer-ably ha~ a car~on content of rom 5 to 4~/0 by weight.
The de~ulphuri~ing agent according to the present invention preferably compri~es 50 to 9~ by weight and, more preferably, 60 to 85% by weight of quicklime and 10 to 50/0 ~y weight and especially 15 to 40% by weight of diamide lime. According to an e~pecially preferred embodiment, the desulphuri~ing agent according to ~he pre~ent invention contains about 40% by weight (40 ~ 3%
by weight) of diamide llme.
.: :
.. , , , ..................... .
.. , :. . ~', ' :' . .
~7~63 The de~ulphurising agent according to ~he present invention with a diamide lime content of about 4~/0 by weight (with a carbon content of 40 to 5~0 by weight) is especially ~uitable for the de~ulphurising of crude iron in torpedo ladles. For desulphurising in open crude iron transport and charging ladle~, the desulphur-iqing agent according to the present invention prefer-ably has a diamide lime content of 15 to 25% by weight.
The diamide lime present in the desulphurising agent according to the pre~ent invention has a carbon content of from 5 to 5~0 by weight and prefarably of 10 to 40% by weight.
Furthermore, the de~ulphurising agent according to the present invention can also contain co~paratively small additions of conventional adjuvant~, or example of fluor3par, of up to loY~ by weight.
Surprisingly, we have found that the desulphur-i~ing agent according to the present invention require~
a substantially 3maller amount of conveying gas than the quicklime previously used for the same purpose.
Thu~, the agent according to the present invention can be uniformly conveyed with an amount of conveyor gas of only 7 Nlo per kg. The calcium carbonate component o the diamide lime, after its emergence from the lance u~ed for the introduction of the agent into the crude iron to be desulphuri3ed, decomposes instantaneouqly and thereby ensures an intensi~e mixing up of the ~olid .
.
.
'' :' ' ~ " ~ ' ' ' ~:3L7~6~
desulphuri~ing agent with the iron melt to ~ de~ulphur~
ised. From the calcium carbonat~ component of the diæmide lime there thereb~ ~ir~t r2sult~ quicklime, which is highly reacti~e because it i~ freshly calcined.
Since thi~ mixture produce~ gaS in the iron melt, very many ga9 bubbleY of small diameter are fonmed. The re~ult of this i~ that only a very small amount of the de3ulphuri~ing agent according to the pre3ent invention i~ su~pended in relatively large bubble~ and is conv~yed through the melt without the agent coming into contact wi~h the iron. This can clearly be een by ob~erving the surface of the iron melt during the desulphurisi~g treatment. Thu~, when blowing quicklime into a molten iron, bubhle~ of the conveying ga~ used reach the sur-face and there burs~ and liberate large amount~ of fine, dust~like ~uicklime~ Thi9 dus~ mu~t be ~ucked off and removed from the waste ga~ with the help of a filter or of a ~crubber, which considerably increase~ the cost of the de~ulphurising treatment. In the case of blowing in the de~ulphurisin~ agent according to the pre~ent invention, no large bubble~ appear on the 9UX-face of the molten iron and only a very ~mall amount of dust formation is ob~erved.
In comparison with the conventionally u3ed lime, the de3ulphuri~ing agent according to the pre~ent inventlon po~sesse~ the considerable adva~tage of a substantially improved reactivity. Thus, when u~ing ,, ~, . . . . .
.
;3 the agent according to th~ present invention, for obtaining the same desulphuri~ing effect it i~, ~urprisingly, only nece3~ary to use about half the amount which would be necessary if carrying out the treatment with quicklime.
This ~urpri~ing advantage of ~ubstantially better reactivity or of increa~ed degree of action i~
also manife~ted by the fact that, because of the reduction of t~e a~ount of desulphuriqing agent to be blown in, a correspondingly ~maller amount of de~ulphur-i~ing slag i9 obtained. The de~ulphurising ~lag always contain~ a high proportion of metallic iron, which can amount to up to ~OYO by weight. This iron contained in the de~ulphurising 31ag is first 105t from the ladle and can only ~e recovered ~ub~equently ~ro~ the ~olid-ified slag with considerable expen~e. E3pecially when the slag c0019 more considerably, for example ~hen it is not removed immediately after the treatment, ~his can result in a part of it remaining in the treatment ves~el, whereb~ the transport capacity thereof for the liquid metal melt i~ reduced.
In the following Example, which is given for the purpo~e of illu~trating the pr2sent invention, a compari~on i~ made between the use of the agent accord ing to the present invention and the use of the previously conventionally employed quicklime.
.
:
: ' ' ' ' :
.
~7~6~3 ~.
a~ 9b~ L~L~æeaa~
160 Tonne~ crude iron were desulphuri3ed in a torpedo ladle solely wi~h quicklime. The initial ~ulphur content of the crude iron wa~ 0.042% by weight.
A total of 1760 k~. of fine quicklime were blown into the melt with the u~e of a lance which wa~ in~erted into the melt to a depth of 1.6 xetres. In order to be able to achieve a rea-~onably uniform blownng in of the quicklime, 120 ~1. of conveying gas per kg. of quicklime had to be u~ed. Due to this large amount of gas, a violent bubbling of he molten metal occurred, large amount~ of m~tal spattering out of the ladleO
Thick cloud~ of white ~moke th~reby emerged from the mouth of the ladle. In order to prevent the spatter-ing from becoming too violent, only 30 k~. of ~uicklime could be blown in per minute with 3600 ~1. of conveying ga~. The final sulphur content of the crude iron was 0.018% by weight.
b) invention.
Sub~equently, i~ the came plant, the ~ame amount of crude iron was desulphuri~ed using t~e agent accord-ing to the pre~ent invention, w~ich had been produced by grinding 60% by weight of quicklime and 4~% by weight of diamide lime with a carbon content o~ 2~o by weight.
In order to achieve the sæme desulphurising action~ only 1 ,L7~l 6Çi 3 4.8 kg. of desulphurising agent were needed per tonne of crude iron and the mixture could thereby al~o be conveyed with a ~maller amount o~ ga3. For a uniform and di~turbance-free blowing in, it wa~ only neces~ary to use 7 ~1. of conveying ga~ per Xg. o~ desulphurising agent. Therefore, the rate of conveying could be increased to 100 kg. per minute. Even in the case of thi~ higher rate of blowing, only 700 ~1. of conveying gas per minute were needed. Thi9 corresponds to only about one fif~h of the amount per unit time which was needed for conveying the quicklime. There wa~ also a correspondingly lower turbulence of the melt. ~en when the ladle wa~ well filled, no spattering occurred.
A further advantage of the desulphurising agent according to the present invention, which only had to be u~ed in smaller amounts, and of the higher conveying rates which were po~ible, i9 the fact that the treat-ment of 160 tonnes of crude iron i~ inished after about 10 minutes, whereas the de~ulphurisation with quicklime takes practically 1 hour. ~ormally, such a long period of time i~ not available for the desulphur-ing~ A further consequence of the laborious treatment in which large amounts of quicklime are blown in is a considerable cooling of the molten crude iron. Thu~, ~the temperature cf the crude iron melt de~ulphurised with q~icXlime decreased by 42C., whereas the temper-ature losr in the case oE using the dosu1phurising ' ' ~7~63 g agent according to the present invention was only 8C.
Thus, it can be ~een that, in compari~on with the quicklime normall.y used, the desulphurising agent according to the present invention display~ ~urpri3ing advantages.
.
Claims (15)
1. An agent for desulphurising crude iron and raw steel, comprising a mixture of quicklime and diamide lime.
2. An agent according to claim 1, which comprises, by weight, 50 to 90% of quicklime and 10 to 50% of diamide lime.
3. An agent according to claim 2, which comprises, by weight, 60 to 85% of quicklime and 15 to 40% of diamide lime.
4. An agent according to claim 1, wherein the diamide lime has a carbon content of from 5 to 50% by weight.
5. An agent according to claim 1, wherein the diamide lime has a carbon content of from 10 to 40% by weight.
6. An agent according to claim 1, 2 or 3, which additionally contains up to 10% by weight of fluorspar.
7. An agent according to claim 4 or 5, which addi-tionally contains up to 10% by weight of fluorspar.
8. An agent according to claim 1, 2 or 3, wherein it has a particle size appropriate for pneumatic conveying.
9. An agent according to claim 4 or 5, wherein it has a particle size appropriate for pneumatic conveying.
10. An agent according to claim 2 or 3, wherein the diamide lime has a carbon content of from 5 to 50% by weight.
11. An agent according to claim 2 or 3, wherein the diamide lime has a carbon content of from 10 to 40% by weight.
12. An agent according to claim 2 or 3, wherein the diamide lime has a carbon content of from 5 to 50% by weight and additionally contains up to 10% by weight of fluorspar.
13. An agent according to claim 2 or 3, wherein the diamide lime has a carbon content of from 10 to 40% by weight and additionally contains up to 10% by weight of fluorspar.
14. A method of desulphurising crude iron and raw steel, wherein an agent as defined in claim 1, 2 or 3, is blown into molten crude iron or into molten raw steel.
15. A method of desulphurising crude iron and raw steel, wherein an agent as defined in claim 4 or 5, is blown into molten crude iron or into molten raw steel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3015024.4 | 1980-04-18 | ||
| DE3015024A DE3015024C2 (en) | 1980-04-18 | 1980-04-18 | Desulphurising agents for pig iron |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1171663A true CA1171663A (en) | 1984-07-31 |
Family
ID=6100415
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000371607A Expired CA1171663A (en) | 1980-04-18 | 1981-02-24 | Desulphurising agent |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0038417B1 (en) |
| JP (1) | JPS56158807A (en) |
| AT (1) | ATE10650T1 (en) |
| CA (1) | CA1171663A (en) |
| DE (2) | DE3015024C2 (en) |
| ES (1) | ES8205867A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6989040B2 (en) | 2002-10-30 | 2006-01-24 | Gerald Zebrowski | Reclaimed magnesium desulfurization agent |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56158827A (en) * | 1980-05-10 | 1981-12-07 | Nippon Carbide Ind Co Ltd | Powdered composition for desulfurizing agent |
| JPS58204119A (en) * | 1982-05-25 | 1983-11-28 | Nippon Carbide Ind Co Ltd | Desulfurizing agent for molten iron |
| ATE37902T1 (en) * | 1984-06-28 | 1988-10-15 | Thyssen Stahl Ag | PIG IRON DESULPHURIZATION PROCESS. |
| LU86689A1 (en) * | 1985-12-03 | 1987-05-04 | Centro Speriment Metallurg | CONTINUOUS PURIFICATION PROCESS OF MOLTEN CAST IRON |
| DE4242328C2 (en) * | 1992-12-15 | 1995-06-08 | Alfred Dipl Ing Dr Freissmuth | Means for desulfurization, dephosphorization, desiliconization and denitrification of pig iron and cast iron melts |
| JP5653741B2 (en) | 2010-12-15 | 2015-01-14 | タカタ株式会社 | Buckle and seat belt device provided with the same |
| DE102011116501C5 (en) * | 2011-10-20 | 2018-05-24 | Almamet Gmbh | Bitumen-containing desulphurising agent |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1583268B1 (en) * | 1967-12-29 | 1971-08-05 | Konink Nl Hoogovens En Staalfa | Means for the desulphurisation of liquid iron based on technical calcium cyanamide and a process for the desulphurisation of iron |
-
1980
- 1980-04-18 DE DE3015024A patent/DE3015024C2/en not_active Expired
-
1981
- 1981-02-24 CA CA000371607A patent/CA1171663A/en not_active Expired
- 1981-03-10 DE DE8181101765T patent/DE3167539D1/en not_active Expired
- 1981-03-10 AT AT81101765T patent/ATE10650T1/en not_active IP Right Cessation
- 1981-03-10 EP EP81101765A patent/EP0038417B1/en not_active Expired
- 1981-04-07 ES ES501153A patent/ES8205867A1/en not_active Expired
- 1981-04-14 JP JP5518581A patent/JPS56158807A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6989040B2 (en) | 2002-10-30 | 2006-01-24 | Gerald Zebrowski | Reclaimed magnesium desulfurization agent |
Also Published As
| Publication number | Publication date |
|---|---|
| ES501153A0 (en) | 1982-07-01 |
| DE3015024A1 (en) | 1981-10-29 |
| ES8205867A1 (en) | 1982-07-01 |
| JPS56158807A (en) | 1981-12-07 |
| DE3015024C2 (en) | 1982-12-23 |
| ATE10650T1 (en) | 1984-12-15 |
| EP0038417A1 (en) | 1981-10-28 |
| DE3167539D1 (en) | 1985-01-17 |
| EP0038417B1 (en) | 1984-12-05 |
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