US1514102A

US1514102A - Process oe treating metal

Info

Publication number: US1514102A
Authority: US
Publication date: 1924-11-04
Anticipated expiration: 1941-11-04

Description

BEST AVAILABLE COP.

Nov. '4 1924.

I R. ROBINSON PROCESVS 0F TREATING METAL Filed D86. 6, 1920 Y Y r J I 9 I /0// &

BEST AVAILABLE cos.

Patented Nov. 4, 1924.

PATENT OFFICE.

UNITED STATES RICHARD ROBINSON, 0F MASURY, O'HIO.

rnoonss or rnnarmemnrnn Application filed December 6, 1920: Serial No. 428,579.

large percentage ofthe ingots made frommetal recovered from open-hearth and other like furnaces are imperfect because of "the piping and segregation of 'the'ingots, because of the presence of impurities such as sulphur and phosphorus in a detrimental proportion,-and because of the uneven distribution of the cleansing, alloying, or modifying agents in and throughout the iron or steel; furthermore, a large proportion of the finished metal from such furnaces isunsuitable for usebecause of the presence of Scams therein' The generalobje'cts of this invention are to provide'a process whereby impurities such as the sulphur and phosphorous constituents of the'molten mass may be completely and quickly removed and whereby the cleansing, alloying, or other modifying agents may be quickly and uniformly incorporated with the metal, with the result that I am enabled, not only to produce metal which is uniform or homogeneous throughout its massand'which is free from the 0bjections above noted','-but to produce the same in a much shorter period of time than is required for the production of the less perfect metal of commerce. I accomplish the objects and results referred to in and through an apparatus'such as shown in the" drawings forming a part hereof, wherein Fig. 1 represents a central transverse sectional view through a furnace capable of realizing my'invention;Fig. 2 a sectional plan 'view of said furnace; and Fig. 3 a diagrammatic view of the electrical apparatus employed in connection with the furnace shown in the preceding views.

Describing'the various parts by reference characters, 1 denotes the bottom, 2 the sides, 3 the ends, and'4 the top of a furnace of the open-hearth type, the bottom being provided with a lining 5 of ganister or other heat resisting-material. The furnace is provided with the tap hole 6 for the removal of metal and with chambers! in' the ends thereof for'the purpose-of heating air and delivering the same above the bath in con- Projecting downwardly into the'ffurnace junction with gas or oil burners l8.

chamber 29 are a plurality-of heat-resistant tubes 10. Four: such tubes are'shown as mounted two in. each of the sides of the chamber and projecting downwardly and 130- ward the center'of the hearth. Adjustably vmounted in .each'ofthe, tubes10 is an electrode 11, the said electrodes being shown'as connected? in.:pairs .to electrical conductors Embedded within the bottom wall of the furnace (which may be 'ofmagnesite brick) are a plurality of electro-magnets, four which 12 extending from opposite sides ofa genermagnets being shown and comprising each a circular core, '14 having a winding '15 therearound. These: magnets areso arranged that, whenithe' electrodes; 11 are in their inwardly adjusted positions, the (lower end ofeach electrode will be above the center ofa'in'agn'et. Ilf

-With the parts constructed and arranged as described the furnace .willibe charged in the usual manner, with the electrodes-11 elevated within their respective tubes. The charge may comprise the ordinary pig iron, scrap iron and limestone and, if desired, one or more modifying agents, such as an alloy or alloys or ascavengingagent: The chamber 9 and the charge 'will be heated by means of the gas or oil burners 18 until the metal is meltedin part at leastand a protecting coating of slag is formed on top of the metal. The supply of fuel to the burners will then be cut off and the electrodes inserted beneath the slag and into the metal, and preferably with their lower ends close to'the bottom of the latter and 'inproximity to one another, as indicated in Figs. 1 and 2. Current will then'be turned on to the electrodes, current also being supplied to thewindings of the'electro-magnets. After the current has been turned on to the electrodes, a. scavenging agent (such as spiegeleisen), a degasifying agent (such as fluor as well as in the molten metal, as indicated BEST AVAILABLE COP.

at 16 can; This diffuses uick? action. The m'olten scavenger acts cas;

electrolyte and affords a whirling path of least resistance along which at least some;

ofithegaseousimpurities move and by which they are delivered to the-appropriate elec.

trodes, risingialong such-electrodes and being: caught and held by the slag, together with i otherzimpuritieswhich have been carried alongi-bymuchugas, the scavengenby this 4 tinfe having-beemgalsi-fiediand caughtiby the 'il Jhr ingi this operation, the metal is pro-2 tectefd from ojxida'tionrby; the-slag coating on 'the-top thereofiiwhileeheated internally at' the bo'ttom ofith'e furnace by the; 818C:

trodes. This lbcatiorr ot-electrodes'preyents'. any adhesion of metal to the bottom (if the" furnace or; to the-elhctrodesi Thismode of treatment enables any limes stone-and othen ingredient's that maybe atthe bottom of the: furnace to be quickly raised;'and-quickly' liberates impurities 1n a: gaseous form, the saidimpurit'iesnbeinga collected by the .slagr, and} where alloying orother modifying agents5 are: employed,-

insures a rapidand 1 uniform: incorporationof the same with the molten metal. A=ll=of thel-gase's will be eliminated; thus avoiding piping and segregation of the:ingots and. seams-in the metal; and the timeirequi'red' fei makii1g the heat will not eitceedhalf the timeordinarily-"required for such pur- At the end of the heating by the elecmelf-jany-slag that may have adhered to the si'des 'of the furnace, so as to enable the latter-to betapped;

While-I havedescribd my process with reference to" the: production of. iron and :.=teel','- I- do not" propose to limit the-scope of my invention to such metals,: as the process-is not only applicable to but valuable in connection with the treatment of other metals, with such variations in amperage suited to the reduction and refining of such metals, respectively.

Having thus described my invention, what I'claim is;

1. The process of treating metal which comprises reducing or melting the metal and maintaining the same in a molten condition by means of heat applied thereto from above, providing a protecting coat-- ing'of slag for such molten metal, and subjecting;- the molten metal to the action of an electric current supplied through electi o n:b-y the combustion of .mctal with a protecting coating of slag, and SLIbJGCtlIIgJ the molten metal to the action of an electric current flowing therethrough beneath the slag coating.

.3. The process of treating molten metal a which comprises forming a p rotecting coat ing of slag, for such metal and subjecting the metal thus protected to a lcieading action by means of an electric current passingtherethrough beneath the saidcoating and adjacent to the-bottom of the. mass of .such,metal and in the presence of one or more modifying agents.

4; The process of treatinginolten metal which comprises providing the same with anoxygen or airrexcludingcoating and;subjecting the metal below such coating to the action of electrical heating means operating adjacentto the hottompf the m e tal mass below the said coating and operating to stirand knead the molten metal charge.

5. The process of treating moltenmetal which comprises providing the sam with an oxygen or air-excluding coating and subjecting the metal below such coatingv to the action of electric current supplied through the metal by electrodes operating adjacent to the bottom of the metal mass.

6. The process of treating molten metal in a furnace which comprises providing a mass of such metal with an air or oxygenexcluding coating, and subjecting the molten massbelow such coating to the action ofan electric current supplied therethrough by electrodes located within and adjacent tothe bottom of such mass, whereby ad hesion of such metal to the bottom of the furnace or tothe electrodes is prevented and themolten metal charge is kneaded. g

7. The process of treatingmetal which comprises preliminarily tusingsuch metal with slagg-ing material toprovide a protecting coating of slag, supplying electric current to and between electrodes extending into the metal below such coating and through the metal interposed between such electrodes, and imparting to the current flowing through such mass. a whirling motion whereby the mass is kneaded and rendered uniform in composition.

8. The process of'treating metalv which comprises preliminarily fusing such metal with slagging material-to provide a-protecting coating of slag, supplying electric current to and between electrodes extending BEST AVAILABLE into the metal below such coating and through the metal interposed between such electrodes, and subjecting the current flowing through such mass to the action of an electro-magnet, whereby the current is deflected and the mass is kneaded and rendered uniform in composition.

9. The process of treating metal which comprises preliminarily fusing the upper portion of a charge of such metal with slag producing material, thereby to produce a protecting coating of such slag, supplying electric current to and between electrodes extending into the metal below such coating and through the metal interposed between such electrodes, and subjecting the current thus supplied to the action of magnetic excitation, thereby to impart a whirling motion to the current-in such metal and to the metal itself.

10. The process of treating metal which comprises providing the same with a protecting coating of slag, supplying electric current to and between electrodes extending into the metal below such coating and through the metal interposed between such electrodes, in the presence of a scavenger, and subjecting the current thus supplied to the action of magnetic excitation, thereby to impart a whirling motion to the current in such metal and to the metal itself.

11. The process of treating metal which comprises providing the same with a protecting coating of slag, subjecting the mass of metal beneath such coating to the action of electricity supplied at the bottom of the metal mass through electrodes and in the presence of a scavenger, and subjecting the current passing between such electrodes and through the metal to the action of one or more electro-magnets thereby to deflect such current and impart a whirling motion thereto and to the molten metal.

12. The process of treating metal which comprises providing the same with a protecting coating of slag, supplying electric current to and between electrodes extending into the mass of metal below such coating and through the metal interposed between such electrodes in the presence of a scavenging agent and a degasifying agent, and subjecting the current thus supplied to the action of one or more electro-magnets serving to deflect the current and to produce a whirling motion in the same and in the molten metal.

13. The process of treating metal which comprises providing the same with a protecting coating of slag, supplying electric current to and between electrodes extending into the mass of metal below such coating and through the metal interposed between such electrodes in the presence of one or more modifying agents, and discharging impurities in the form of gases along one or more of said electrodes.

14. The process of treating molten metal which comprises providing the same with a protecting coating of slag, and supplying electric current to and between electrodes extending into the mass of metal below such coating and through the metal interposed between such electrodes in the presence of deoxidizing and degasifying agents, whereby the impurities are discharged in the form of gases along one or more of said electrodes.

In testimony whereof, I hereunto aflix my signature.

RICHARD ROBINSON.