Claims
- 1. A process for producing ductile iron in which a separate heat-resistant capsule mounted from its top on the lower end of a plunging rod and enclosed except for side and floor openings to permit controlled entry of molten metal and escape of reaction products and containing pure magnesium is plunged into a body of molten iron in the ladle under surrounding atmospheric pressure, comprising,
- providing a magnesium charge in the form of a plurality of shaped solid pieces of pure magnesium,
- providing an open topped capsule and a solid plunging rod removably mounted thereto and closing the top in which one side opening is a single upper filling passage of a size to receive the individual pieces one by one and to permit controlled entry of molten metal but to prevent escape of said pieces and a floor to receive the solid pieces and provided with a lower passage of a size effective of bar escape of the solid pieces and to allow entry of molten metal and escape of reaction products and drainage of molten metal,
- providing a vertically elongated open topped ladle,
- filling the ladle with a body of molten iron having a volume several times that of the capsule to a level leaving an overlying space above the molten metal of a size to accommodate the capsule,
- loading said plurality of pieces into the capsule through the upper filling passage one by one to fall on the floor forming a pile, with the capsule mounted on the plunging rod,
- bringing the ladle and capsule together and lowering the capsule into the overlying space in the ladle,
- after so placing the capsule, capping the ladle by seating a hood thereon, to limit the slopping of molten metal agitated by the reaction, and to allow the escape of gases from the top of the ladle,
- lowering the plunging rod relative to the ladle and plunging the capsule into the body of molten iron thereby causing the molten iron to flow through the openings into contact with the pile of magnesium pieces to produce a volatile reaction forcing reaction products to pass outward through the openings into the body of molten iron,
- controlling the escape of solid reaction products,
- conducting away escaping gases,
- uncapping the ladle and withdrawing the capsule from the molten iron and draining it of molten metal,
- and recovering the treated molten iron from the ladle.
- 2. A process, as defined in claim 1, in which a capsule and a plurality of ladles are provided,
- one ladle containing molten iron is brought together with the capsule and the plunging operation performed,
- then said one ladle and the capsule are separated and the processed molten iron recovered from said one ladle,
- the capsule is cleaned and recharged and another ladle charged with molten iron and the capsule are brought together and the plunging operation repeated, and so on, with further ladles in a semi-continuous process.
- 3. A process, as defined in claim 1, in which the chamber of the capsule has a volume of at least 80 cubic inches per pound of said charge.
- 4. A process, as defined in claim 1, in which the capsule is provided with a sidewall opening having a maximum cross-sectional area not greater than 3 square inches.
- 5. A process, as defined in claim 1, in which the capsule is provided with a sidewall opening having a cross-sectional area within the range from about 1.5 square inches to about 3 square inches.
- 6. A process, as defined in claim 1, in which the pieces are elongated bars.
- 7. A process, as defined in claim 1, in which said pieces are in the form of elongated bars and the side filling opening in the capsule is of a size and shape just larger than the cross-section of a bar.
- 8. A process, as defined in claim 1, in which the capsule is cylindrical.
- 9. A process, as defined in claim 1, in which the capsule has a cylindrical sidewall and a floor having a surface sloping downwards from the sidewall towards a central opening.
- 10. A process, as defined in claim 7, in which the bars are substantially rectangular in cross-section.
- 11. A process, as defined in claim 1, in which the lower and upper passage means are spaced apart at least about 10 inches.
- 12. A process, as defined in claim 1, in which the effective total cross-section of the passage means is from 2 to 5 sq. inches with any single passage having a maximum effective cross-section of 3 sq. inches.
- 13. A process, as defined in claim 11, in which the bottom passage means is at least 11/4 inches across.
- 14. A process, as defined in claim 11, in which the upper passage means is at least one inch across.
- 15. A process, as defined in claim 11, in which the lower passage means is at least 11/4 inches across and the upper passage means is at least one inch across.
- 16. A process, as defined in claim 11, wherein the access means includes an opening not more than about 11/2 inches from the top of the reaction zone.
- 17. A process, as defined in claim 1, in which the height of the ladle is at least three times its lateral dimension.
- 18. A process, as defined in claim 1, in which the capsule is immersed to near the bottom of the melt-confining zone.
- 19. A process, as defined in claim 18, in which the capsule is immersed to within 21/2 inches from the bottom of the melt-confining zone.
- 20. A process, as defined in claim 1, wherein the additive is in the form of a pile of solid metal bars.
- 21. A process, as defined in claim 1, wherein the additive is in the form of a pile of solid metal bars, wherein the bars are loaded one by one through the upper passage means, and the cross-section of the upper passage means is related to that of each bar so that the bar can only be inserted when the passage is unfouled.
Priority Claims (1)
Number |
Date |
Country |
Kind |
269973 |
Jan 1977 |
CAX |
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Parent Case Info
This is a division of application Ser. No. 806,094 filed June 13, 1977 which in turn issued as U.S. Pat. No. 4,199,353, on Apr. 22, 1980.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
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Parent |
806094 |
Jun 1977 |
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