US627855A - Process of refining iron. - Google Patents

Description

No. 627,855. Pat ented June 27, I899.

a. F. KEY. Y rnocass 0F BEFINING mun;

(Application filed Mar. 10, 1898;)

2 Sheets-Shoet I.

(No Model.)

PROCESS OF BEFINING IRON.

(Application filed Mar. 10, 1898.)

(No Modal.) I 2 Sheats Sheet 2.

Patented June 27, I899.

ATENT GEORGE F. KEY, or ANN ARBOR, MIGHIGAN.

PROCESS OF REFINlNG IRON.

SPECIFICATIGN forming part of Letters Patent No. 627,855, dated June 27, 1899.

Application filed March 10, 1898. Serial No. 673,311. (Nospeoimens) To all whom it may concern:

Be it known that I, GEORGE F. KEY, a citizen of the United States, residing at Ann Arbor, in the count-y of VVashtenaw and State of Michigan, have invented certain new and useful Improvements in Processes of Refining Iron, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention isespecially designed for the purification of iron rich in phosphorus; and the object is to makeiron manufactured from so-called non-Bessemer ores equally commercially available for the manufacture of steel as iron made from Bessemer ores and which is convertible into steel by the Bessemer process.

To this end my improvement is based upon the general conclusions obtained in the practice of different processes that when phosphorus is present in a melted mixture of iron, iron oxid and ferrous silicate, orany suitable basic material, the tendency of the phosphorus is to become oxidized and converted into phosphate, which separates in the slag, leav: ing a purer iron, while on the other hand if the cinder is mainly silicate or of an acid type the tendency is the other waythat is, part of the metallic iron becomes oxidized while the phosphate is reduced, thus increasing the amount of phosphorus in the iron. Thus when plenty of ferric oxid is present and the mixture has a strong basic character phosphorus is largely removed from the molten metal, while on the other hand in the ordinary Bessemer blowing process the first action of the oxygen of the blast acts on the silicon rather than on the iron, and in consequence a highly-silicious conder results, so

steam, and into the bath resulting from this treatment air is then blown for about the same period as in the converter treatment.

is in contact with the steam and with a highly oxidizing atmosphere, which is maintained by injecting preheated air through a bunch of twyers.

The introduction of the basic material is preferably accomplished by mixing powdered limestone directly into the stream of molten metal as it flows into the atomizing-chamber.

The effect of atomizing the molten metal in a highly-oxidizing atmosphere is that a considerable portion of the metal is oxidized, the presence-of steam contributing to make ferrous oxid, (which makes a more fusible slag,) and the bath resulting therefrom becomes thus intimately mixed with these oxids and with the basic material introduced with the molten metal, and in the subsequent blowing instead of oxids being formed (as in the converter) the oxids already present react not only to acertain extent upon the silicon, but mostly upon the phosphorus, and silicates and phosphates are formed separate with the slag, while the carbon burns out. manner the eliminations of phosphorus from molten metal not too highly phosphorized can be satisfactorily and speedily accomplished in one operation, and the metal will be found surprisingly homogeneous.

If necessary, the operation can be repeated, (in the presence of heat to keep the metal fluid,) or for the further treatment the openhearth process may be more or less closely followed, according to the desired quality of steel, thereby shortening the time to onefourth .the time of what the process now requires. Besides the saving in time the result is superior, as. the prolonged treatment by the open-hearth process alone results in loss of metal and the introduction of. certain im- In this purities from the lining and from the fu rnacegases.

To carry out my process in the best manner, I have devised the following apparatus, as shown in the drawings, in which- Figure l is a vertical longitudinal section of the furnace. Fig. 2 is a front elevation thereof with the cupola and rotary screen removed, and Fig, 3 is an inner face view of the gaschamber.

Ais the reducing-chamber,having the usual basic lining and formed with a forwardly-inclined bottom and communicating at the rear end into a suitable stack B for the exit of the waste gases. In the front end is arranged the chamber 0, which communicates through a suitable pipe D with a supply of air under-pressure and preferably through a pipe D with a supply of gas. The chamber 0 com municates by a series of openings or twyers E into the furnace-chamber, and above the same is arranged a blast-nozzle P, through which a current of steam of suitable volume and force may be introduced. In the top of the chamber, above this blast-pipe, is placed a hopper G, terminating in an orifice II. The front end of the furnace has a trap-door J, in which is a tap-hole I. This door may be used forcleaning out the furnace. In the top is a suitable feed-opening K, provided with a removable door D. Near the bottom, in one orboth sides, are arranged a series of twyers M, suitably inclined to discharge into the bath of metal collected at the bottom of the furnace.

N is a rotary screen placed above the hopper G and serving to receive the powdered limestone or other basic material used by my process and which by agitating the screen is made to drop through a slot in the outer casing into the hopper G.

Ialso preferably provide means for introducing heat into the furnace, which may be accomplished by providing an aperture 0 in the face-plate, through which an oil-burner may be introduced.

In carrying out my process with this apparatus I preferably locate the furnace in such relation to the cupola or blast furnace that the molten metal may be run directly into the hopper G, from whence it flowsin a thin stream through the orifice H directly across the path of the steam from the nozzle F, the blast of which strikes the liquid metal and completely atomizes it and disperses it through the whole extent of the chamber in the furnace, which to this end is largely extended in the direction in which the blast strikes. At the same time preheated air is injected through the twyers E, so that in the whole interior of the furnace a highly-oxidizing atmosphere is maintained. Simultaneously with the introduction of the metal into the hopper G the screen is agitated, and the powdered basic material dropping into the vortex of the metal in the hopper is drawn in with it and becomes intimatelymixed with it and equally atomized with the metal. As soon as the metal has collected again the bath is then blown the usual time required 'to effeet the reaction, after which the metal is drawn off. During the treatment a rise in temperature takes place, and as the operation is quickly accomplished no extra heat is ordinarily required, except that at the start the furnace should be preheated, which can be accomplished with the means described. providing the chamber 0 with a separate connection for gas the furnace can be readily connected to one of the character of the openhearth furnace, if desired, for a further treatment of the metal.

\Vhat I claim as my invention is The herein-described process of refining pig-iron which consists in intimately mixing the molten metal with finely-divided limestone or other basic material, atomizing this mixture in a highly-oxidizing atmosphere of air and steam, collecting the atomized mixture into a bath and then blowing the same with air, or other refining purifying-gas.

In testimony whereof I affix my signature in presence of two witnesses.

' GEORGE F. KEY.

Witnesses:

M.B. ODOGI-IERTY, OTTO F. BARTHEL.

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