US742316A - Electrometallurgy of iron and steel. - Google Patents

Description

PATENTED OCT. 27, 1903. H. HARMBT.

ELEGTROMETALLURGY 0F IRON AND STEEL.

APPLIQA'HON FILED AUGQB, 1902.

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. atented October 27, 1903.-

i PATENT OEEICE.

HENRI HARMET, OF ST. ETIENNE, FRANCE.

ELECTROMETALLURGY oF leonI ANosTEEL..

' SPECIFICATION forming part of Letters Patent.No. 742,316, dated October 27, 1903.

Original application led November 29, 1901, ISerial No. 84,026. Divided and this application led August 6, 1902. Serial i No. 118,578. (No specimens.)

T0 a/Z whom t may concern.-

B'e it known that I, HENRI HAEMET, a'citizen of the Republic of France, residing at St. Etienne, Loire, France, have invented certain new and useful Improvements in the Electrometallurgy of Iron and Steel, of which the following is a specification.

My invention has relation toa method or process whereby the crude ores may be fused, reduced, and refined by al continuons series of electrometallurgicalr operations; and in such connection it relates to the steps embodying such a method or process.

The present application is a division of an application for patent filed by meNovember 29, 1901, under Serial No. 84,026.

In a former application for patent filed by me on September 30, 1901, `under Serial No. 77,012, I- have described a continuous process for converting ores directly into iron and steel by a series of electrometallurgical operations.v In this former process reduction precedes fusion inan electric blast-furnace, and after fusion the crude metal is treatedv as described in a subsequent application for patent filed by me March 20, 1902, Serial No.

99,068, in a refining-oven to purify it. In the present inventiona somewhat similar process is disclosed,diering, however, in two particularsn'namely, that in thepresent process fusion precedes reduction and that after reduction -the crude metal must traversefa column of highly-heated reducing-carbon be-V fore it entersthe reiining-oven or regulator.

The nature and scope of my invention will be more fully understood from thehfollowing description, taken in connection .with the ac-A companying drawings, forming part hereof, inwhich-f.

Figure 1 is a longitudinal sectional view of a complete apparatus for carrying out the process of my-present invention; and Figs. 2, 3, and 4 are detail views in section, illustrating the construction' and arrangement of the reiningfoven wherein the crude metal is refined. f

Referringto the-drawings, it will be found that the complete apparatus for carrying out the process of my present invention comprises three connected parts-namely, iirst, a fusion-chamber, second, a reduction-chamber,

Iclosed by removable bricks 2. l A3 or fusion-hearth of the chamber 1 is preferto heat the same.

and, third, a refining-oven. It will also be observed that the fused materials leave the hearth'v or crucible of the fusion-chamber-to enter directly the hearth or Crucible of the reduction-chamber, pouring or running over an inclined sole in its passage between the two crucibles.

chamber by pouring or running. over an inclined sole and gutter into the refining oven or crucible, traversing in its passage a column of highly-heated reducing-carbon, as will be hereinafter more fully described.

The fusion-chamber 1 is conical and expands at its base into a f iai-ingbell-mouth,

forming the crucible 3 of the fusion-chamber. The top ofthe chamber 1 is preferably open for the ready charging of the ores andfluxes,

as well as for theexit o f gases which are useless in the process. The walls .of the ,chamber 1 are pierced at intervals, as at 2, to permit the entrance of slacking-tools when required; otherwise the holes are bricked up or The crucible ably circular in horizontal section and h'as a sloping sole, upon which are vsupported the inclined electrodes 6, which giveto the crucible 3 the additional heat required for fusion.

The column of the charge in the chamber 1 rests upon thesole 5 in pyramidal form and does not completely fill 'the crucible 3, there being an annular space 4 aroundthe charge, in which combustion and circulation of the gases maytake place and from ,which the gases may pass into and through the mas of oxids After traversin g the charge in` the chamber 1 the gases pass out of tli'e openmouth 5 of the chamber and are dispersed, since after their passage through the fusion-chamber they are burned out and of no value. The fusion of the oxids is caused by gases passing out of the reducing-crucible 7 through the opening 8. These gases are mainly composed of carbonicoxid, and theheatrendered up either by their combustion orby Itheir cooling is ordinarily sufficient to fuse, the, 0X- ids on the sole or hearth of the crueible 3. When the gases pass out through the opening or passage-way 8, they are mixed with air under pressure forced through the twyers or Again, thereduced materials v leave the hearthl or crucible of the reduction- IOO `out of the mouth 5.

blowpipe 9. When so mixed, they play upon the base of the column of oxids, which has already been highly heated, and fuse the oxids upon the base or sole of the crucible 3. The gases then spread around the column in the annular space 4 and complete their combustion. From the space 4 the burned gases lter into and through the porous column of oxids, heating it progressively, and then pass The hot gases from the reducing-crucible 7 are usually sufficient to fuse the oxids in the Crucible 3; but it is preferable to have an auxiliary source of heat in the Crucible 3 in the form of an electric current. This electric heat supplies any heat necessary in addition to the gaseous heat and also regulates the fusion upon the sole of the crucible 3, since said sole being very large and the blowpipe or blowpipes 9 acting mainly upon the base of the column of oxids there may not be sufficient heat to fuse with regularity all portions of the oXids resting upon the sole, and especially the portions farthest away from the blowpipes 9. A current of electricity capable of giving the additional heat required is passed through two electrodes 6, parallel with the sole of the furnace, and passed through openings in the upper surface of the inclined plane forming the sole. The current, however, may be led in through vertical carbons or electrodes, if desired, or in any other manner. It is, however, preferable to so arrange the electrodes that they shall heat those points of the sole remote from the blowpipes 9.

The reducing-furnace is composed of a vertical charging-chamber 10, preferably Circular in Cross-section and adapted to receive the coke, charcoal, or other reducing agent at the top, and a crucible 7, through one end of which the chamber lO, with its charge, extends. The top of the chamber 10 is closed by a charging apparatus 11 of the usual Construction, arranged in such a manner as to prevent the passage of gases out through the mouth or top of the chamber 10 during the charging operation unless it is desired to permit the exit of a portion or all of the gases from said mouth. The crucible or reducer 7 is a horizontally-arranged furnace,preferably circularin cross-section, with its. lateral walls practically vertical. The base or sole of the reducing-crucible 7 is inclined in the direction in which the materials are to ilow--that is to say, from the point of arrival of the fused oxids, as at 8, to the point of the outlets 12 and 13 for the fused and reduced metal and dross-into the regulator or rening-oven 20. The dome of the crucible '7 has the general shape of a portion of a sphere and is provided with a large circular opening above the discharge or outlet 12 of the crucible and permits the charge of carbon in the chamber 10 to descend in the form of a column upon the base or sole of the crucible 7. The dome also has an opening 8, which is the passage-Way for the gases from the reducing-crucible 7 into the fusion-crucible 3. When preferred, the electrodes 14 and 15 also pass through the dome of the crucible 7. The lateral walls of the crucible 7 may, if desired, be provided with doors for examination and inside repairing, and if the carbons or electrodes 14- and 15 are horizontally arranged the walls of the crucible 7 may be perforated to admit these electrodes. The outlet end of the crucible 7 should also be provided with at least two openings or outlets 12 and 13. The outlet 12, as before explained, is for the passage of 'the fused and reduced'metal from the crucible 7, while the outlet 13, situated above the outlet 12, is for the tapping of the slag or dross floating above the fused and reduced metal. The two openings 12 and 13 are situated in the rear yof the column of reducingcarbon, so that the metal and the slag must both traverse this column before bein g tapped or withdrawn from the Crucible 7. Inasmuch as in the crucible 7 the reduction of the oxids absorbs more heat than is produced by the transformation of the carbon or coke reducing agent into carbonic oxid, the crucible is heated by an electric Current. This current is led in through the electrodes 14 and 15, which enter the crucible 7 to a depth so as to reach but not penetrate the dross or slag 18 in the crucible. The reduction in the crucible 7 takes place as follows: After working for some time a first layer of metal 16 Collects upon the sole of the crucible and is surmounted by a layer 17 of incompletely-reduced oxids more or lessl mixed with a top or third layer 18 of dross or slag. The main column of coke in chamber 10 remains resting at its base upon the sole of the crucible, but fragments of the coke are lifted by the metal and dross and oat upon the liquid mass, spreading everywhere until it fills the entire lower portion of the crucible 7, rising to the height 19 19. (Indicated on Figlofthedrawings.) The liquid mass now circulates in the spaces left between the fragments of coke, as in ordinary blast-furnaces. The melted oxids discharged from the fusion-crucible 3 fall upon a mixture of coke and dross and are then reduced under the infiuence of the high temperature produced by the electric current. The freed gases, also highly heated, then pass out through the passage-way Sinto the fusioncrucible to fuse the oxids therein. The reduced metal falls to the sole of the crucible 7 and there collects, and upon this reduced met-al iioats the dross or slag deprived of nearly all of the oxids. Before the reduced metal or the dross can be tapped from the crucible 7 they must both pass through the column of reducingcarbon,which atthe point the metal and dross pass through it is in an incandescent state, and this perfects the reduction. After the reduced metal leaves the crucible 7 it flows into the refining-oven or regulator 20. This regulator 2O is a crucible of preferably circular Cross-section, havinga charging-door 21, a channel ,or passage-way IOO IIC

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22, through which the crude metal enters, a tap-hole 23 for the metal 24, and a tap-hole 25 for the dross or slag 26. The crucible 2O is heated by the electric current through two electrodes 27, which pass either vertically or inclined through the dome or through the lateral wall of the crucible. These electrodes 27 penetrate the liquid in the crucible 20. The refining operation in the regulator-crucible `20 is conducted in a manner analogous to the operation conducted in the Martin reflning-oven. When but one regulator 2O is used to receive the metal, the reduced metal is allowed to accumulate in the reducer 7 and then discharged en bloc into the regulator without disturbing, however,lthe continuous working of the reducer. In many cases, however, it will be found advantageous to have for each reducer two regulators or refiningovens into which the crude metal iows regularly as soon as produced. In this instance one of the regulators receives and becomes charged with the metal while the other is bringing the vrefined metal to the point of hardness and the composition required.

Having thus described the nature and objects of my invention, what I claim as new, and desire to secure by Letters Patent, is-

The continuous conversion of iron ores directly into iron and steel by three electrometallurgical steps, comprising first the fusing of the minerals in the presence of hot gases derived from the second or reducing my signature in the presence of two subscr-ib. 45

ing witnesses.

HENRI I-IARMET. Witnesses:

T. RUSS, F. BEUTHER.

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