[go: up one dir, main page]

US3918963A - Addition agent for molten metals and process for making the same - Google Patents

Addition agent for molten metals and process for making the same Download PDF

Info

Publication number
US3918963A
US3918963A US481546A US48154674A US3918963A US 3918963 A US3918963 A US 3918963A US 481546 A US481546 A US 481546A US 48154674 A US48154674 A US 48154674A US 3918963 A US3918963 A US 3918963A
Authority
US
United States
Prior art keywords
metal
weight
porous material
binder
particle size
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 - Lifetime
Application number
US481546A
Inventor
Luigi Palumbo
Raffaele Tarozzi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3918963A publication Critical patent/US3918963A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00Refining of pig-iron; Cast iron
    • C21C1/02Dephosphorising or desulfurising
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C1/00Refining of pig-iron; Cast iron
    • C21C1/10Making spheroidal graphite cast-iron

Definitions

  • An addition agent for adding an alkali metal or alkaline earth metal to a molten metal bath for example for the addition of magnesium to a molten iron bath in the production of nodular cast iron in which the graphite is spheroidal in the as-cast condition, comprises briquettes of 5-50 percent by weight of the inoculant metal of a particle size 0.1 to 3 mm.. 50-80 percent by weight of a porous material such as semicoke, coke or graphite having a particle size of 0.1 to 3 mm., and l025 percent by weight of a binder such as coal-tar pitch, coal-tar. or petrochemical pitch or bitumen.
  • the inoculant metal and porous material are first admixed and then homogenized with the binder at a temperature of 80130C.. after which briquetting is conducted.
  • the briquettes are then heated from ISO-250C for 15 to 90 minutes to harden them. and 11121:" be further heated for that period of time at 250990C to bake them 7 Claims, N0 Drawings ADDITION AGENT FOR MOLTEN METALS AND PROCESS FOR MAKING THE SAME addition agents and processes, for the addition in a conl0 trolled manner to a molten metallic bath, of metals which are relatively volatile and/or easily oxidized and- /or violently reactive with the metal bath.
  • Another object of the present invention is the provision of such addition agents which will be relatively simple and inexpensive to produce and reliable in result when used, and to provide such processes for the production thereof which will be easy to practice and dependable in result.
  • the objects of the present invention are achieved by providing an addition agent and a process for producing the same, usable in various pyrometallurgical operations such as hot metal desulfurization and the nodularization of cast iron, in which particles of the reactive metal and particles of a porous material are admixed with each other and then with a binder, and then heated.
  • the resulting product is uniform both dimensionally and compositionally and is not subject to the drawbacks and disadvantages recited above.
  • the invention comprises the formation of a mixture consisting essentially of particles of the active material and particles of the porous support material which is then admixed with a binder, followed by briquetting of the mixture. The briquetted mixture is then heated. Thereafter, if required, the briquettes are baked.
  • composition by weight of the product can be as follows:
  • Metal S50% Porous material 50-80Z Binder l0-25k Homogenization and briquetting of the mixture can be conducted between and 130C; Subsequent heating of the briquettes takes place between [50 and 250 C. and for a time between 15 and minutes. Baking of the briquettes, if carried out, can be performed at a temperature in a range of 250-900C. and for the same time period.
  • the metal may be alkali metal or alkaline earth metal, or in general, any metal which is added to a molten metal bath and which has, relative to the bath, great volatility and/or a high tendency toward oxidization and/or violent reactivity with the bath. Examples are sodium, potassium, magnesium, calcium and strontium.
  • the metal may be in the form of pure metal or an alloy thereof.
  • the particle size is between 0.1 and 3 mm.
  • the bath itself may be any of the molten metal baths encountered in pyrometallurgy, and will ordinarily be ferrous, e.g., iron, nickel, cobalt or an alloy thereof.
  • the porous material may be semi-coke, coke, graphite, or any similar compound or substance which has sufficient porosity and mechanical strength.
  • the particle size may be 0.1 to 3 mm.
  • the binder may be coal tar pitch, coal tar, pitch or bitumen of petrochemical origin or mixtures of these in various proportions.
  • Horn genization with the mixed particles of the active metal and the porous material is carried out for example in a masticator at a temperature between 80 and C. but which ordinarily will not exceed by more than 50C. the softening temperature of the binder.
  • a mixture is formed of 60 parts by weight of semicoke of particle size from 0.3 to 1 mm. and 20 parts by weight of magnesium particles of particle size from 0.1 to 0.3 mm. it is admixed in a masticator with 20 parts by weight of coal tar pitch having a softening point of 435C, at a temperature of 90C. for 10 minutes.
  • the mixture thus obtained was briquetted in a press to obtain spherical briquettes 32 mm. in diameter.
  • the briquettes were then hardened by exposure for 30 minutes in a current of air at 200C. with a flow rate of Nl/h.
  • the hardened briquettes were then baked by exposure for 30 minutes in a current of hydrogen having a temperature of 700C. and a flow rate of 150 Nl/h.
  • the briquettes obtained showed the following properties at various stages:
  • the briquetted addition agent thus obtained is useful in ferrous metallurgy as an addition agent for inoculating a bath of molten iron in a production of cast iron containing nodular or spheroidal graphite in the as-cast condition.
  • An addition agent for the inoculation of a molten metal bath consisting essentially of to 50 percent by weight of a metal selected from the group consisting of alkali metal and alkaline earth metal having a particle size 0.l to 3 mm., 50 to 80 percent by weight of a porous material having a particle size of 0.1 to 3 mm., said porous material being selected from the group consist- 4 ing of semi-coke, coke and graphite, and l0 to 25 percent by weight of a binder which secures said metal particles and said porous material particles together in a briquette.
  • a method of producing an addition agent for inoculation of a molten metal bath comprising admixing 5 to 50 parts by weight of a metal selected from the group consisting of alkali metal and alkaline earth metal having a particle size of O.l to 3 mm., 50 to parts by weight of a porous mate rial having a particle size of 0. l to 3 mm., said porous material being selected from the group consisting of semi-coke, coke and graphite, and 10 to 25 parts by weight of a thermoplastic binder, at a temperature of 80 to C, briquetting the mixture to form solid bodies thereof, and heating the briquettes at a temperature from about to about 250C. for a time from about 15 minutes to about 90 minutes.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Manufacture Of Alloys Or Alloy Compounds (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

An addition agent for adding an alkali metal or alkaline earth metal to a molten metal bath, for example for the addition of magnesium to a molten iron bath in the production of nodular cast iron in which the graphite is spheroidal in the as-cast condition, comprises briquettes of 5-50 percent by weight of the inoculant metal of a particle size 0.1 to 3 mm., 50-80 percent by weight of a porous material such as semi-coke, coke or graphite, having a particle size of 0.1 to 3 mm., and 10-25 percent by weight of a binder such as coal-tar pitch, coal-tar, or petrochemical pitch or bitumen. The inoculant metal and porous material are first admixed and then homogenized with the binder at a temperature of 80-130*C., after which briquetting is conducted. The briquettes are then heated from 150-250*C. for 15 to 90 minutes to harden them, and may be further heated for that period of time at 250-990*C. to bake them.

Description

United States Patent Palumbo et al.
[ ADDITION AGENT FOR MOLTEN METALS AND PROCESS FOR MAKING THE SAME [76) inventors: Luigi Palumbo, via Eusebio Chini 22; Raffaele Tarozzi, via Marangoni N. 1. both of Rome, Italy [22] Filed: June 20. 1974 [21] Appl. No.: 481,546
[30] Foreign Application Priority Data June 20. 1973 ital 50929/73 [52} US. Cl 75/130; 75/53; 252/475; 264/1 17 {51] Int. Cl.'-. C22C 33/08; B01] 23/02; CO9C 1/56 [58] Field of Search 75/53 130; 252/475. 476; 264/1 17 {56] References Cited UNITED STATES PATENTS 2.881.068 4/1959 Bergh 75/53 1656989 4/1972 Layland 75/130 R [451 Nov. 11, 1975 Fri/mm Bummer-Peter D, Rosenberg Attorney. Agent. or Firm-Young A: Thompson ABSTRACT An addition agent for adding an alkali metal or alkaline earth metal to a molten metal bath. for example for the addition of magnesium to a molten iron bath in the production of nodular cast iron in which the graphite is spheroidal in the as-cast condition, comprises briquettes of 5-50 percent by weight of the inoculant metal of a particle size 0.1 to 3 mm.. 50-80 percent by weight of a porous material such as semicoke, coke or graphite having a particle size of 0.1 to 3 mm., and l025 percent by weight of a binder such as coal-tar pitch, coal-tar. or petrochemical pitch or bitumen. The inoculant metal and porous material are first admixed and then homogenized with the binder at a temperature of 80130C.. after which briquetting is conducted. The briquettes are then heated from ISO-250C for 15 to 90 minutes to harden them. and 11121:" be further heated for that period of time at 250990C to bake them 7 Claims, N0 Drawings ADDITION AGENT FOR MOLTEN METALS AND PROCESS FOR MAKING THE SAME addition agents and processes, for the addition in a conl0 trolled manner to a molten metallic bath, of metals which are relatively volatile and/or easily oxidized and- /or violently reactive with the metal bath.
For example, in the production of nodular cast iron, in which spheroidal graphite is produced in the as-cast fonn by the inoculation of the bath with small amounts of magnesium, a difficulty arises from the fact that the boiling point of magnesium is below the melting point of iron. Similar problems arise in steelmaking in connection with ladle desulfurization of the hot metal prior to refining.
In the past, a number of techniques and products for the inoculation of baths such as ferrous metal baths have been proposed, among them being the use of aporous support material as a vehicle for the inoculant metal. Such a porous support has been for example coke, impregnated with the desired metal in the molten state. Techniques for the production of such additives are disclosed for example in Italian Pat. Nos. 743,720 and 904,658, and comprise immersion of the porous material in the molten inoculant metal, followed by rapid cooling to solidify the metal which has penetrated the pores of the support.
However, such techniques and the resulting products have drawbacks by virtue of the high reactivity and temperature of the inoculant metal. Thus, carbides form by the partial reaction of the metal with the carbon of the coke, and these carbides in the presence of moisture react to emit flammable gases. Moreover, the surface mechanical properties of the finished product correspondingly deteriorate. If the cooling medium is oil, then this can ignite. The active metal can oxidize when the cooling medium contains oxygen; and nitrides can form when the cooling medium contains nitrogen.
Accordingly, it is an object of the present invention to provide an addition agent as defined above and a process for producing the same, which will overcome the foregoing difficulties and disadvantages.
Another object of the present invention is the provision of such addition agents which will be relatively simple and inexpensive to produce and reliable in result when used, and to provide such processes for the production thereof which will be easy to practice and dependable in result.
Briefly, the objects of the present invention are achieved by providing an addition agent and a process for producing the same, usable in various pyrometallurgical operations such as hot metal desulfurization and the nodularization of cast iron, in which particles of the reactive metal and particles of a porous material are admixed with each other and then with a binder, and then heated. The resulting product is uniform both dimensionally and compositionally and is not subject to the drawbacks and disadvantages recited above.
Further objects, features and advantages of the present invention will become apparent from a consideration of the following more detailed description of the invention.
ln greater detail, the invention comprises the formation of a mixture consisting essentially of particles of the active material and particles of the porous support material which is then admixed with a binder, followed by briquetting of the mixture. The briquetted mixture is then heated. Thereafter, if required, the briquettes are baked.
The composition by weight of the product can be as follows:
Metal S50% Porous material 50-80Z Binder l0-25k Homogenization and briquetting of the mixture can be conducted between and 130C; Subsequent heating of the briquettes takes place between [50 and 250 C. and for a time between 15 and minutes. Baking of the briquettes, if carried out, can be performed at a temperature in a range of 250-900C. and for the same time period.
The metal may be alkali metal or alkaline earth metal, or in general, any metal which is added to a molten metal bath and which has, relative to the bath, great volatility and/or a high tendency toward oxidization and/or violent reactivity with the bath. Examples are sodium, potassium, magnesium, calcium and strontium. The metal may be in the form of pure metal or an alloy thereof. The particle size is between 0.1 and 3 mm.
The bath itself may be any of the molten metal baths encountered in pyrometallurgy, and will ordinarily be ferrous, e.g., iron, nickel, cobalt or an alloy thereof.
The porous material may be semi-coke, coke, graphite, or any similar compound or substance which has sufficient porosity and mechanical strength. The particle size may be 0.1 to 3 mm.
The binder may be coal tar pitch, coal tar, pitch or bitumen of petrochemical origin or mixtures of these in various proportions. Horn) genization with the mixed particles of the active metal and the porous material is carried out for example in a masticator at a temperature between 80 and C. but which ordinarily will not exceed by more than 50C. the softening temperature of the binder.
To enable those skilled in this art to practice the invention, the following illustrative example is given:
A mixture is formed of 60 parts by weight of semicoke of particle size from 0.3 to 1 mm. and 20 parts by weight of magnesium particles of particle size from 0.1 to 0.3 mm. it is admixed in a masticator with 20 parts by weight of coal tar pitch having a softening point of 435C, at a temperature of 90C. for 10 minutes. The mixture thus obtained was briquetted in a press to obtain spherical briquettes 32 mm. in diameter. The briquettes were then hardened by exposure for 30 minutes in a current of air at 200C. with a flow rate of Nl/h. The hardened briquettes were then baked by exposure for 30 minutes in a current of hydrogen having a temperature of 700C. and a flow rate of 150 Nl/h. The briquettes obtained showed the following properties at various stages:
Hardened briquettes l .03 I20 -continued Compressive Density Strength gicm" kg Baked briquettes 93 300 The yield after baking is 90 percent.
The briquetted addition agent thus obtained is useful in ferrous metallurgy as an addition agent for inoculating a bath of molten iron in a production of cast iron containing nodular or spheroidal graphite in the as-cast condition.
From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.
Although the present invention has been described and illustrated in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invvention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.
Having described our invention we claim:
I. An addition agent for the inoculation of a molten metal bath, consisting essentially of to 50 percent by weight of a metal selected from the group consisting of alkali metal and alkaline earth metal having a particle size 0.l to 3 mm., 50 to 80 percent by weight of a porous material having a particle size of 0.1 to 3 mm., said porous material being selected from the group consist- 4 ing of semi-coke, coke and graphite, and l0 to 25 percent by weight of a binder which secures said metal particles and said porous material particles together in a briquette.
2. An agent as claimed in claim 1, in which said selected metal is magnesium.
3. An agent as claimed in claim 1, in which said binder is selected from the group consisting of coal tar, coal tar pitch, petrochemical pitch and petrochemical bitumen.
4. A method of producing an addition agent for inoculation of a molten metal bath, comprising admixing 5 to 50 parts by weight of a metal selected from the group consisting of alkali metal and alkaline earth metal having a particle size of O.l to 3 mm., 50 to parts by weight of a porous mate rial having a particle size of 0. l to 3 mm., said porous material being selected from the group consisting of semi-coke, coke and graphite, and 10 to 25 parts by weight of a thermoplastic binder, at a temperature of 80 to C, briquetting the mixture to form solid bodies thereof, and heating the briquettes at a temperature from about to about 250C. for a time from about 15 minutes to about 90 minutes.
5. A process as claimed in claim 4, and further heating the briquettes at a temperature from about 250 to about 900C. for a time from about 15 minutes to about 90 minutes.
6. A process as claimed in claim 4, in which said metal is magnesium.
7. A process as claimed in claim 4, in which said binder is selected from the group consisting of coal tar, coal tar pitch, petrochemical pitch and petrochemical bitumen.

Claims (7)

1. AN ADDITION AGENT FOR THE INOCULATION OF A MOLTEN METAL BATH, CONSISTING ESSENTIALLY OF 5 TO 50 PERCENT BY WEIGHT OF A METAL SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND ALKALINE EARTH METAL HAVING A PARTICLE SIZE 0.1 TO 3 MM., 50 TO 80 PERCENT BY WEIGHT OF A POROUS MATERIAL HAVING A PARTICLE SIZE OF 0.1 TO 3 MM., SAID POROUS MATERIAL BEING SELECTED FROM THE GROUP CONSISTING OF SEMI-COKE AND GRAPHITE, AND 10 TO 25 PERCENT BY WEIGHT OF A BINDER WHICH SECURES SAID METAL PARTICLES AND SAID POROUS MATERIAL PARTICLES TOGETHER IN A BRIQUETTE.
2. An agent as claimed in claim 1, in which said selected metal is magnesium.
3. An agent as claimed in claim 1, in which said binder is selected from the group consisting of coal tar, coal tar pitch, petrochemical pitch and petrochemical bitumen.
4. A method of producing an addition agent for inoculation of a molten metal bath, comprising admixing 5 to 50 parts by weight of a metal selected from the group consisting of alkali metal and alkaline earth metal having a particle size of 0.1 to 3 mm., 50 to 80 parts by weight of a porous material having a particle size of 0.1 to 3 mm., said porous material being selected from the group consisting of semi-coke, coke and graphite, and 10 to 25 parts by weight of a thermoplastic binder, at a temperature of 80* to 130*C., briquetting the mixture to form solid bodies thereof, and heating the briquettes at a temperature from about 150* to about 250*C. for a time from about 15 minutes to about 90 minutes.
5. A process as claimed in claim 4, and further heating the briquettes at a temperature from about 250* to about 900*C. for a time from about 15 minutes to about 90 minutes.
6. A process as claimed in claim 4, in which said metal is magnesium.
7. A process as claimed in claim 4, in which said binder is selected from the group consisting of coal tar, coal tar pitch, petrochemical pitch and petrochemical bitumen.
US481546A 1973-06-20 1974-06-20 Addition agent for molten metals and process for making the same Expired - Lifetime US3918963A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT50929/73A IT988276B (en) 1973-06-20 1973-06-20 PROCEDURE FOR THE PRODUCTION OF COMPOSITE MATERIALS FOR THE TREATMENT OF MOLTEN METALS

Publications (1)

Publication Number Publication Date
US3918963A true US3918963A (en) 1975-11-11

Family

ID=11274105

Family Applications (1)

Application Number Title Priority Date Filing Date
US481546A Expired - Lifetime US3918963A (en) 1973-06-20 1974-06-20 Addition agent for molten metals and process for making the same

Country Status (9)

Country Link
US (1) US3918963A (en)
JP (1) JPS5033111A (en)
AT (1) AT352156B (en)
BE (1) BE816473A (en)
DE (2) DE2429487B2 (en)
FR (1) FR2234372B1 (en)
GB (1) GB1428320A (en)
IT (1) IT988276B (en)
NL (1) NL180234C (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1156708B (en) * 1978-04-21 1987-02-04 Italsider Spa Nuova IMPROVEMENT IN THE PROCESS OF PREPARATION OF COMPOSITE MATERIALS FOR THE TREATMENT OF MELTED AND MANUFACTURED METALS SO OBTAINED
JPS6367121U (en) * 1986-10-21 1988-05-06
ES2249172B1 (en) * 2004-09-06 2007-05-01 Batz, S. Coop. PARKING HAND BRAKE FOR VEHICLES WITH FOLDING LEVER.

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2881068A (en) * 1952-04-28 1959-04-07 Wargons Ab Method of treating a ferrous melt with a porous sintered metal body impregnated with a treating agent
US3656989A (en) * 1969-03-19 1972-04-18 Foseco Int Production of metal-impregnated porous coke materials

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1012529A (en) * 1952-07-22
FR1077890A (en) * 1952-05-29 1954-11-12 Improvements in processes for the manufacture of briquettes, in particular those used for the addition of easily oxidizable or volatile metals to baths of molten metals

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2881068A (en) * 1952-04-28 1959-04-07 Wargons Ab Method of treating a ferrous melt with a porous sintered metal body impregnated with a treating agent
US3656989A (en) * 1969-03-19 1972-04-18 Foseco Int Production of metal-impregnated porous coke materials

Also Published As

Publication number Publication date
FR2234372B1 (en) 1977-10-07
JPS5033111A (en) 1975-03-31
AT352156B (en) 1979-09-10
IT988276B (en) 1975-04-10
NL180234C (en) 1987-01-16
DE2429487A1 (en) 1975-03-27
DE7421011U (en) 1978-05-03
ATA512574A (en) 1979-02-15
DE2429487B2 (en) 1977-03-24
GB1428320A (en) 1976-03-17
BE816473A (en) 1974-10-16
NL7408091A (en) 1974-12-24
FR2234372A1 (en) 1975-01-17
NL180234B (en) 1986-08-18

Similar Documents

Publication Publication Date Title
US3829295A (en) Sintered iron based articles infiltrated with copper based metals
US3847601A (en) Reduced pellets for making alloys containing nickel and chromium
US2881068A (en) Method of treating a ferrous melt with a porous sintered metal body impregnated with a treating agent
US1922037A (en) Treatment of metals
US2726152A (en) Addition agent and method for treating cast iron
US3782930A (en) Graphite-containing ferrous-titanium carbide composition
US4545817A (en) Alloy useful for producing ductile and compacted graphite cast irons
US3918963A (en) Addition agent for molten metals and process for making the same
US4225343A (en) Addition agent for molten metals
US4472197A (en) Alloy and process for producing ductile and compacted graphite cast irons
US3459541A (en) Process for making nodular iron
US2988445A (en) Method for making briquettes for the treatment of molten metals and alloys
US3321304A (en) Materials for and methods of treating molten ferrous metals to produce nodular iron
US3507644A (en) Titanium additive and method of use thereof
US3902892A (en) Porous ferrous metal impregnated with magnesium metal
US2999777A (en) Antimonide coated magnetic materials
US2874038A (en) Method of treating molten metals
US3336118A (en) Magnesium alloy for cast iron
US3314787A (en) Method for producing an mg addition agent
CA1174854A (en) Production of abrasion-resistant pressed articles mainly consisting of metal
US2762701A (en) Carburizing molten ferrous metal
US3393068A (en) Manufacture of ferro alloys containing silicon
US3945819A (en) Ferrous metal network impregnated with magnesium metal
US3146090A (en) Process of producing nodular iron using group iii metal hydride
US2839393A (en) Addition agent and method for treating cast iron