USRE9833E - siemens - Google Patents

Description

3 Sheath-Shawl. C. W.LSIIMEITS.` `MANERA()TURB` 0F lIRON AND STEEL.

Reissued Aug. 9,1881;

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c. w. SIEMENS. f MANUPAGTURE lO IRON AND STEEL.

Yi `Reiselued Aug. 9, 1.881.

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MANUFAGTURE 0F IRON AND lSTEEL. l No.I 9,833... Ressued Aug. 9,1881.

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UNITED STATES PATENT OFFICIELo CHARLES WILLIAM SIEMENS, OF W'ESTMINSTER, COUNIYIE MIDDLESEX,

ENGLAND.

MANUFACTURE OF IRON AND STEEL.

SPECIFICATION forming part of Reissued Letters Patent No, 9,833, dated August 9, 1881.

Original No. 159,712, dated February 9. 1875. Application for reissue filed December H, 1880.

DIVISION B.

Middlesex,'.Eng'land, have invented certain new and usefulImprovements in eii'ecting the Separation of Metallic Iron from Orcs and the Manufacture ct'Iron and I do hereby declare that the following` is a full, clear, and exact Io description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

It has long been known that oxygen combinedwith iron can be disassociated from the I5 oxides of that metal by placing solid carbon in contact therewith in a heated retort, and excluding` air or other oxygen during the pro? cess of reduction. lron ores have also been reduced in revolving` cylinders, drains, or niutiies.

5o Thus in Letters Patent o' the United States,

issued to me on the 17th day ot' August, 1869, a revolving cylinder lined with tire-brick and heated by means of lues in the lining 'is described as heilig used for this purpose. This furnace consisted of a long cylindrical tube of iron Inountcd upon anti-friction rollers and having a brick lining provided with passages for heating currents. The ore to be reduced, mixed with reducing agents and fluxes, was fed 3o in at one extremity of the rotating cylinder and worked gradually forward by its rotatiomwhile at vthe same time it was heated to redness by the heated lining ot the cylinder. Reducinggas was made to enter the cylinder, and being brought extensively into contact with the heated` and moving orc during the slow rotation of the furnace, ctfeeted its reduction into spongy pulvernlent iron. The methods of eftecting the separation of iron directly from the ores of that 4o metal have, however, heretofore proved com- 4 5 producedto absorb sulphur from the heatinggases, and the impediments to the successful application of the reduced ores after their conversion into spongy metal. -I have found, however, that in melting iron ores no sulphur is absorbed from the fiame, and that by inciting ores mixed with lluxing materials in a furnace so arranged as to accomplish fusion in a continuous manner on a large scale the fused ores may be acted upon by a solid carbonaceous matter, sons to separate the metallic iromwhile the earthy constitue/nts of the orc form a fusible slagwith the fluxingmaterial. 1 have also found. that this reduction by precipitation ofthe iron can only be accomplished at an intense heat, exceeding the welding-heat of iron, but that .the iron so produced is almost chemically pure,

although the ores and the fuel used contain a considerable percentage of sulphur and phosphorus. As, however, the accomplislnnent of these results would require agreat amount of manual labor and involve the exercise ot' care and skill, it is necessary, il' iron is to be pro-' duced largely by this direct process, that some self-acting or mechanical mode ot' working,r it be devised.

The object ot my present invention is the realization, in apraetical and economical man ner, ot' these results g and to that end I eft'ect the separation otmeta-lliciron fromitsore bye-xposin g the ore mingled with iluxing materials and carbonaceous matter to intense heat, while iinparting t0 such mixture the motion incidental. to the revolution of the combustion chambefi` containing;r it. I also expose the ore, mingled with fluxing materials and earbonaceous` mat ter t0 the motion incidental to thc slow revolution of the heated combustion-chamber. containing the mixture until the metallic particles are separated from the ore, and then subject the mixture to a more rapid rotation l'or'the purpose of forming the separated metal into balls. I also expose the oremingled with iuxing materials and carbonaceous matter to Aintense heat while imparting to such mixture the motion incidental to thcvrotation ot the combustion-chamber con tainin g it, and then ct'- i'ect the combustion oi' the carbonio oxide produced by the reaction of the cairbonaceous mafter oII the ore by supplying thereto highlyheated air.

9 -Iu reducing my Invention to practice I pre s 9 v 9,sa3

fer to employ a rotative regenerative gas-furnace constructed and arranged as shown in the accompanying drawings, in which- Figure 1 represents alongitudinal section on line a'- :v of Fig. 2. Fig. 2 represents a sectional plan on lines y y y' y of Fig. 1.` Fig. 3 represents, on the left-hand side, a half-transverse section on the line z z of Fig. 1, and on the right-hand side a half-transverse section on the line z' z' of Fig. 1, and Fig. 4 shows a front view.

A is the rotative furnace, in shape cylindrical, with truncated conical ends. Itis mounted on rollers a a, which are caused to revolve by gearing B, driven by any suitable power. The gearing B is arranged with clutch apparatus, so that the furnace can be-rotated at either .the slow or quick speed above referred to, or

brought to rest, while the prime mover continues to work at its regular speed. For this purpose the gearing B consists of a wheel, b", and pinion b, loose en the shaft of the drivingwheel b, and gearing respectively with pinion c' and wheel o on shaft c, which drives the rollers a. By means of a clutch, b, either the wheel b' or the pinion b2 is geared with the vided with a reversing-valve, e, by which the supply can be turned toward either of the chambers D or D4, and the throttle-valve c',

- v whereby the:supply can be regulated.

. In orderto increase the flow of air when intense heat is required in the furnace, a jetrof compressed air, c, is introduced from a blnstfj pipe into the middle ofthe duct E. f

The gas from the main supply-trunk F isi'u-l troduced by a duct,F,which is provided with fa' stop-valve,f, and with a reversing-valve,f,

wherebythe gas can: be directed to either of the chamhersl)z or D3; rlhe air and gas'thus l supplied to the tworegenerative chambers on the one side`of the structure flow thence, heated, into one of the/iluesyC/or C', where theymingle and produ/cca /pow/erfut flame, which plays into and ,sweeps around the furfhace A, the products of combustiXn 'escaping by the other ues, (l or G', throu .i two regenerative chambers, and thence by a i the other Hue, G, to the chimney or other outlet. f When one ofthe two pairs ot' regenerative chambers has been suliciently heated by the escaping.

flowing currents, in the manner well vunderstood in reference to the working of regenerative gas-furnaces.

At the end A* of the furnace opposite the throat is mounted, between the guides a, a vertically-sliding door-,"a, with a counterbalance-weight, a. At the front of the furnace is formed a tap-hole, ct, which can be plugged with refractory material, and under this there is a chute, a5, by which material tapped from the furnace can be run into forms or molds, or into a truck in a pit below the furnace.

The lining of the furnace A may be of any known suitable refractory material that .is not readily affected by scorie; but I prefer to use for it a lining formed in the following manner: I take the mineral ,known as bauxite, cousisting chiefly of alumina,with a proportion ofperoxide of iron. I calcine it and reduce it to powder, and mix with it from ten to fifteen per cent. of powdered plumbago, graphite, or other carbonaceous matter in a dense form, and such a quantity ot' argillaceous clay or other binding material as is necessary to give cohesion. I form this mixture into bricks or blocks of suitable form, and burn them in a kiln in the usual way. In burning such bricks theoxide ot' iron contained in the bauxite is converted by the carbonaceous matter into metallic iron, and a very refractory material isihus produced, capable of resisting the action of scoria for aconsiderable time. These bricks may be built inside the rotating furnacegirith cement 'made from the above-named mixture used in an unburned condition; but I prefer to build them in loosely, and, after heating the furnace to a white heat, to charge it with pure ore or hammer-slag' whilefiotating slowly. The ore or slag is melted'a'nd sinks into thecrevices between' the/bricks, serving as a/ce'ment'wliich binds them firmly together, i

and also as a glaze which prevents accessof aiuto the interiorfof the bricks. A When the bricks are so cemented the excess ot' fused vore for work. v

Havingvthus` described 4a rotative regenerative furnace which may be employed, I will proceed to explain my improvements in the manufacture of iron. n

The ore to be treated is crushed and mixed with a suitable proportion of lime, manganese, or other iiuxin g material, according to t-,he`relative amount and nature of .the gangne which the ore contains, in order tol form a fluid scoria; or a mixture of ores may be employed which produces a thsibleslag without admixture .of lime vor other iluxing material. The mixed material. is introduced into the sl/,owlyrotating furmace Aby way of the ydoor-la' and heated nearly to th/c fusing-point/fnthe ore, hereupou is added a quantity of the reducing agent, such as coal or anthracite or coke, previously crushed but not ground ine,'or charcoal or vwood previously dried and cut into pieces. The

the conversion of a certain quantity of ore depends upon the richness of the ore and upon the nature of the carbonaceous matter employed, as well as on the nature of the iron to be produced. In each case the proportions should be determined by experience, but under ordinary circumstances about half a ton of solid carbonaceous matter to a ton of metal to be produced would'be suficient. If the reducing agent employed be anthracite or hard coke, it may be crushed moderately ne and chargedinto the furnace with the ore and heated simultaneously therewith. By the slow rotation of the furnace the carbonaceous matter becomes covered rby the heated ore, with which it is gradually mingled, while fresli intensely-heated surface is being continually presented to the mixture. A very powerful reaction is thus produced, and a quantity of carbonio oxide is evolvcd,which, in burning with the highly-heated air supplied from the regenerator, nearly'sutiices to maintain intense heat in the furnace without necessitating the admission of additional gaseous fuel.. The reduction ot' the ore under these conditons is effected rapidly,the gangue combin` ing with the fluxing material so as to form a fusible slag, and the rotation of the furnace being very slow, (from t'onr to revolutions per hour,) the particles of metallic iron in the course of separation are not prematurely aggmelfatcd. When the reaction is complete ""rtnton ofthe furnace is stopped and the -scoria is tapped otl', so as io liberate the metalliciron resultingfrom the reaction. Afuller supply ot gaseous fuel is then turned on, and the furnace is caused to rotate five or six times more rapidly than before. This more rapid rotation has the eli'ect of agglomerating the iron into balls, which may be taken ont ofthe furnace and subjected to the action ot' squeezers, hammers,or rolls for the production otwroughtiron or puddled steel.

In order to produce several balls ot moderate size,instead of one large ball, which would be inconvenient to handle, l form internallyprojecting circular ribs R. in the lining ot' the furnace, which have the eeet of dividing the mass during balling into several portions. A portion of these ribs is omitted in line of the tap-holes, (shown in Fig. 2,) so that there may be a clear passage for material to tlow toward `the front of the furnace when the tap-hole is hole is opened.

Having thus described the nature of my invention, I claim and desire to secure by Letters Patentl. The process of eti'ecting the separation of metallic iron from its ore, which consists in exposing tbe ore mingled with uxing materials and carbonaceous matter to intense heat while imparting to such mixture the motion incidental to the revolution of the combustion-chamber containing it, as herein described.

2. The improvement in the process of effecting the separation of metallic `iron from its ore, which consists in exposing the ore mingled with iinxing materials and carbonaeeous mat-- ter to the motion incidental to the slow revolution ot' the heated combustion-chamber containing the mixture until the metallic particles are separated from the ore and then subjecting the mixture to a more rapid rotation for the purpose of forming the separated metal into balls, as herein described.

3. The improvement in the process of ei'ect ing the separation of metallic iron from its ore, which consists in exposing the ore mingled with tlnxing materials and carbonaceous Inatter to intense heat while imparting to such mixture the motion incidental to the rotation of the combustion chamber containing it and then effecting the combustion of the carbonio oxide produced by the reaction of the carbona ceous matter on the ore by supplying thereto highly-heated air, as herein described.

(1.,WILllIAM SIEMENS.

lWitnesses GEO. WooLLETT, H. T."I.HRUPP, Both clerks lo Ridgway Bros., 2 lflraterloo Place,

Iall Mall, London, Notaries.

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