US113584A - Improvement in processes and apparatus for the production of cast-steel from ores - Google Patents

Description

mi@ Q@ III itrrn Stearns QFF.

IMPROVEMENT lN PROCESSES AND APPARATUS 'FORVTHE PRGDUCTION'OF CAST-STEEL FRGM GRES' Speeication forming part of Letters PatentNo. E,s`4t, dated Aprii l1, 1871.

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Be it known that I, CHARLES WILLIAM y SIEMENS, of Westminister, in' the county of Middlesex, England, civil engineer, memberr said invention, and in what manner the sume is to be performed, to be particularly described and ascertained Ain and by the following statement thereof, reference being had to the accompanying drawings, and to the ligures and letters marked tliereon-that 'is t0 say:

In my British Patent of 1866, No. 2,413, I described a process. and apparatus for the. production of cast-steel directly from the ore, witlror without the addition ot' pig-iron, 'and ol' ferro-mangallese or spicgcleisen.

This process consisted, essentially, in cliiccting the reduction or deoiridation ot the orc by' the reaction upon it ot' carbonaceous matter under th'c iniiuence ol" intense' furnace heat, and in effecting the liqnet'action ofthe reduced ore Within the same furnace by the further ad? dition ot'carbouaeeous nmtter. -It was found, however, in practice, that thc deoxidation ot' the ore and `the adjustment ot' the chemical condition of the metallic bath were attended with great diiiculty under thosecircunistances; to remove which I'subsequcntly separated the process ot' deoxidiziug the ore' from that of cffectingits liquet'action and chenical adj ustment bythe introduction ot vertical or other" retorts, or of rotating' milities, as described in my British patents ot' the 21st' of August, 1867, No. 2,395, and of the 10th of June, 1865, No. 1,892, respectively.

Nothwithstamling these'improvements it wasdiicult to realize all rheicomlitions necessary lto insure '-ilsatist'actory result. 'Ihe reduction ot' iron (ire in closefretorts or inutiles is essentially a slow and expensive process, and the pulverulent iron produced thereby, upon being introduced into the melting-furnace, floats upon the. metallic bath tcr a considerable length of time Without being incorporated with it. Being'- exposed, in the mean- -time, t'o the oxidizing and su'lphurizing action 'beds or molds.A JIhislatter door, accorflin ofthe tiame, the metallic oxide thus p* :faced corrodes the banks of the metal bath, and, he ing a non-cox-iductor of heat, causes the duid metal belowto set. l

- According to my Ipresent invention cast steel is produced bythe concerted action ot' two separate processes, the one serving to convert the aw ore into lumps or loaves ot' cnlcined, lux'ed, and partially or whollyv deoxidizcd material, andthe. other to smelt and convert this material, with or without the ad.- dition .of pig metal. .intn cast-steel of any desired temper.

V The first or preparatory process may bc carried outinsevcral diiierent ways. Ac-

cording to one method a furnace is employed (by preference a regenerative gas-furnace) re- 'se'mblinginform a copper-smelters or large puddling-t'urnace, having charging-doors at the sides or in the roofs, and a door in iront, for u fithdrawing the smelted material inte pig to one arrangement, has its sill-plate on ,t level with the bed ot' the furnace, but has mme sills or bricks'placed upon' it for retaining the iiuid material in the furnace until thc completion ot' the operatiomwheu these false sills or the bricks are removed, and the semi-fluid contents ot the furnace are raked forward into veniently ot alui'ninons bricks resting in iron plates; but refractory iron ore, l ,as hematite, may be used with .advantage` in repairing thesides'irom time to time,

The chemical operation performed 1n ,this

yfunction-3 according to one arrangement, is

follows: lhc ore to be operatedlnpon, which I will suppose to be hematite ore con taining ten Vper cent'. ot' silica,'liciifgcrushed to the cxtent that rio-pieces cxceed'thc'size ot' walnuts or apples, is mixed with about tive percent. ot' crushed innestone, (or withy other iiuxi teriah) and with about three. per cent. o coke or anthracite; A ton (oroit'her quanfity) ot' this' batch being prepared,- the i'ur; icois heated to \\'hiteness,'and charged, iirst, with about one `hundredweight of light cokes such` as gascohe i"`charcoal spread. uniformly7 over the bottom, whereupon the batch. is introquired.

2 mariee over the lied of the furnace. The furnacedoors are thereupon closed, and a good welding-heat' is maintained for t-li-ree orfourhours.

By the reaction, under the inllueiice ot' heat, of the three per ceiit.'of earhon mixed with the ore, the peroxide oliron of which it consists is converted i'iito lusiliie magnetic oxide, while the silica which it contains combines with the limestone, forming a fusible shw. This action coiiiiiieuces at the surface and extends down- Award until the layer ol" earlion is reached, when a further reaction upon the tluidore (ac- Vconipaiiied lig.' eliullition) ensues', resulting iii its partial deoxidatioii. l-efore the boiling has quite ceased the mass is stirred, and on the barrier on the Sill of the tapping-door he- 'ing' removed the seii'ii-tluid niass partiall)v ows and is partially raked forward into the molds. Previous to discharging the furnace these liiolds should he charged, iii-st, with a layer of Vprisoned coke, a further deoztida-tion ot' the latter is effected within the molds,`or within a heated chamber or hot-store 'furnace near the melting-furnace, to he presently described, where the loaves Ashould he. kept iii a reducing-atmosphere until they are actuall)y rc- 'lhc process of deoxidation ol' these loaves may thus hecarricd to atri-eater or less degree of completi-on, according1 to the, percentage of carbon eiii.i ilored, and. according to the time of exposure to heat. iii a reducing-at niospuei'e.

lf the available reducing agent is hindiugcoal, containing only a small percentage of sulphur, the operation ol" the preparatoryfur nace may he varied hy mixing` the crushed orc and tlux with from twelve to sixteen per cent. of crushed coal, (according'to the degree ol'- deoxidatiou or carliurization required,) and hy charging this mixture intoA the furnace either continuously or indiatches.- It' fed in continuously, asis preferred, tlie'niixed-ore and coal are charged through a hopper iii a thicli layer down the inclined side of tho furnace, where the flames, in acting' npoii the surface of the layer, cause the reduction of the ore, which runs down in a more or less liquid eoiidi-tioi.i.oiito thc hed of the furnace, and from which it is removed from time to time into the molds, as before described.-

. 1f the ore. is introduced iii hatches, the hed ot' the furnace is dii-idcd into compartments hy putting' tlat iron or steel hars on edge, or hy means of bricks or slabs ot" tire-clay put ou edge. lt' iron or steel here are iised,"t.lie thickness of mixed orc charged should exceed the height ofthe hars, in order to cover them coiiiiinitely and save them from oxidation.

i float heine' applied for several hours, the mixture. will have formed into partiallv or whci umidized linups or loaves, which niar in the inciting-furnace instead of the duced hy fusion of the ores; or, the

ngi; the ore mixed with tlnxiiig' materi- .liinding-coal iiito molds, and by'exposing; the consolidated bricks or lumps to furnacelieatJ iii a closed heated chamber or Yhot-.store t'nriiace, such as before nientioned,' iii'oi'ilci' to effect 'the deoxidation of the ore..

According to another 'incthod,`1` produce,

lumps ol" reduced iron ore. hy placing masses f together with solid fnel'iuto a :store inutile or kiln, heated exter- .atructioii of which will he here- .l,) Idie solid fuel employed iii4 heilig', hy preference, 'placed in `'.aiipaiftmeiit or compartments, by ns the carbonio-oxide gasgeiierated in` the fnst instance from the heatedv fuel is caused to react, upon the heated linups of ore,

taking;l up o,

czirininic-acid thus formed, in returning hy.

a ,frei al circulation of the gases to the. heap of en fuel. takes up another equivalent ot carl?l 'igni'i'ei'lng it hack into carhonic oxide, r la argan attacks the orc, and this action i een until the ore is wholly reduced int c iron, (excepting its earthy coilsizit ,l in which state it may then he nto the steel-melting furnace. Such reduced masses. ot' ore may also he employed for other purpose-s than for making stoel in nii airn-liearrh furnace.

lhe lie'ore-iuentioned hot-store Inutile or hihi la. lv, preference, so arranged as to effect and calcining; of the o`re in a shaft, therewith, preparatory to the .on nl' the orc into the, hotstore', as willv 1-;'trein-.lifter descrilied.

l-ineitiing furnace employed is simifurnace described in my British Pati. YL,8592,.of'lln except that the air and gan are niik'ed diltereiitly, that the furnace bottoni is prepared. iii a manner to he described licreiiial'ter, and that the furnace ispriiridcd 'with a chareine-chamber at the hack. A steellf cat haring heen reached iii this fur- .metal is charged to forni a metallic .e lien the loaves or lumps from the prein-nace. or furnaces, before described, are i n rz poraicd with the nietallichath. rlhe loaves,

consi not, partly ofdeoxidizcd iron and partly of orfiilcs, vili, h y virtue of their gravity, snik to seine. extent below the surface ofthe liquid en from the same, while the hath oli' the -ineltiiig-furnace, and will cause an.

ni'odncing' these luiiipsinay he varied n scribed.

trincee 3 and the dccinhnrizntion otA the liquid hnh to the ieqiiisite degree. 'lihis degree is ii-sccr tained hy taking samples ot' the nietal t'roin time to time, which, when chilled in water :ind broken with a hnniiner, should no longer breuk short, but should show considerable toughness, and :i fractured snri'ace ot' honej-- combed and silky appearance.

Motel present-ing this appearance contains froni 0.1 ,to 0.15 per cente of cnt-bon, :ind in adding spicg'elesen' to the bttth the percentage ot' carbon inny be increased to the extent required tor producing;` the desired temper, while at the saine time manganese is introduced, which is necessary to prevent. red-short ness; or, in place ot' nsinler spiegeloisen, the requisite carbon and manganese may he introdnced in the lforni ol" lumps, nitide accordi ing to one ot' the methods hereinafter dclet'ore addingthe'spieg'eleisen either in the solid or liquid fornn-or the linups ol' reduced ore containing` manganese, it is necessiti-y to stir the inetnliic hath well with an iron hooi-z r' rzilte, which opera-tion is accompanied bj; :in active or even ,riolentehnllition. Care must- :ilso he taken that the cinder covering the ineY tnilic both ncrerexceeds one or two inches in -thickness, that it is always liquid, and that it presents, when cooled and broken, ai glossy light brown appearance,

lt' the slag Should, during the operation ot' melting the loaves, accumulate to ai greaiter thickness, it is removed hy skimming' or disclnirtginic;` it over the sill-pitite ot the front door ot' the furnace, which hitter may he raised or lowered hy phicing'upon it or removing the t'nlse sills, loose liriche, or iron packing-hars, -ll' the cool ind fractured slagl presents n darli or crystalline appearance, time iniist he Q "iien lor its cletnanee, whiehwill henccclernted by stirring th-ctinthz #Shohld the metal becoinc too sott before theshig'is sufficiently clean, it is necessary to edd small quantitiesot' pig;- iron, The hidle slt'nlls and sorti-p from pievi ons nieltings 'unify also be reintroduced into the t'nrnace before the spiegefeisen is added, or pnlveriileni. iron, produced hy other processes, inegi he introduced iii addition to the loaves hereinafter described. The process nia-,ij be varied between wideliinits, nrcording` to thcrehitire nhundnnce and quality ct' the niaterinls used. it' pigI inetnl, of siiiiicient purity t'roin snlphtir and phosphorus, can be had in abundance, :ind rich or pure crc is scarce or expensive, it will be advantageous to de oxidize the ore only pnrtinlly in the prepzirir tory i'iiinzice,' in order that it may retain the pow-ei ot' decarlnirizing' two or three tintes its own wciglitot' pic; inetnl in the nieltingyl'zi nace, whereas it' rich ore (which iiiny heniaitite or spnthic ore or chiy, ironstone, or n. niixtnre ot' several) is cheap, as cnnpiired with lieniatte or other good' descriptions ot' pig; metal, the deoixidiition ot' the orc should he carried further in the preparatory'process, by adding days, land :ire

.ture ol" sands, hnshitherto been nio l snrliiee ot' the nietnl biith, 4in

ii'larger proportion ot carbon in at aireaisonable eost'et 'ooth or either ci' these iii thinA caso inn); he entirely dispensed wi' ii.

three descriptions ofl lumps limites ot' deoxidized ore should be used, irl st containing' u. considerable excess xrond what is necessary for its ni v ,.cii, the second heine; ofthe in'tturt. hetore descrihed, nnd the thi. hig'lily-cnrburized componi iron and manganese, which j be nitide nccording` to one ot 'the following `zpiliods: Ore rich in ninngnncse, titanium, or other oxidizn hleyinetal, intended to be inctn'poratcd with the. lilith, inny be reduced in lumps in proxiinitiF tosolid ctiroonaceons inntter in hot-store furnaces heated to considernole degree, or maybe crushed znid'well inife" r"ih crushed dry clay, and. binding-coal ft e ,n sulphur, in the 'proportions ol about, une, .hundred parts, hy weight, ct' ore, tw( c pin-ts Yot' eozil, and ten parts oi' clay, :,icinponiid is then sprinkled with witter i i mixed till it barely- 4binde in vthe hand, a, which it is iilled into inolds rind consolidated by pressure :is before described, with reference to ordintn)rr iron-ore. These lunips or liriche are stacked iii nl hol; pince (over n furnace) ioi", say, two' then charged into the betiirementioned hentcd chamber er' hot-store 'iirnoce, where they are kept t'in twentr-l'onr honrsor more, and whence tiri, "re tti-hen in a liotstaite to ne charged into the iii-ith ci' the steetnielting furnace, toward lli-e eind of the pc-ration In worlcinf.;V solely .ii'tli these deoridi ineltingturnace is irsb covered 'with a hiycr of coke, charcoal, or anthracite,-npon which che liighly-carbiirized loaves .l

charged in n heated cond inciting will forni n metallic i @li cindennnd forni n i'oiindzit opt-irntion.

instead ol" using tiny lieiinitit'flrft i processor-i, lf prefer to inix the lneeons or spathc orc in snel: pwyrorl the tongue ot' both ores torn; wherehy the use of linie is nrt o Titanic iroirsand may :ilse lic nsed with advinitsige. lliersiiccess ot' this process dep nds greatly npon the foundation ol" a sono terence bottoni in the meltiiig-fornace.` -wand, or a. inixstty ein. these .lo the i cose the thickness ol' the slag.;` is greatly incr" .anni the niet-nl frequently sets77 I opened hottoinfc-t' the furnace. lhene ilitlicnlties are, in n ir/itt monitore, tivoided hy 'forming the furnace bottoni. in the fiilioiving' manner: Pore silicicns sand is oh,

veretl wi th the nt'ter `ile slag,

oloyed to forni such bottoms, onently ineltor rise. in largo r i :fied and carliiirized ores, the hed ot' the 4 n' 'masse a great measure 'avoided by forming the fur nace-bottoni'in the following nianner:7j

Pure silicious'sand is obtained, 'which isty baked, in -order to destroy any organicf'mat-.-

U', three percent. of' 'tine glass powder by passing both together `through a sieve, and the mixture is put aside for use.

iiunakiiig a'new bottom, the iron-.plated furnace-botl`em is rst covered with bricks, and the heat of the furnaceV is raised to whitefness'. .A layer of the dry mixtuiieof sand and glass powder isthereupon spread over the brick bottom tothe thickness of about two inches, after which time is allowed until the surface has commenced to hardeinin consequence of the particles of glass inciting, and thus binding` adjacent particles of the white '..sand together without being sufficient in quantity to ,fuse them; Another andl somewhat thinner layer of the dry powder is next applied, andthe heat is raised, so as to produce amore' complete fusion of theglass powder, and\eonsequeiitly a greater degree of hardness and cohesion of the mass. A still thinner layerof the 'mixture is then applied, and thisprocess is repeated until a bottom ot' the requisite form and thickness is obtained Ilie- 'furnace-doors are thereupon thrown open, and

the admission of gas and air from the regenerato'rs, is reduced, in'order to allow'the bottom to set hard, when itis ready for receiving its charge of pig metal and reduced ore.- The same method of charging the dry mixture is resorted to for mending the bottombetween, the charges.

. The meltingfurnaee which I employ is, as l'ieforeetated, similar to those I have described insoine of l myformer .British patents; but I improve'tlie arrangement for mixing the heat- 'ed-combustible gases 'and the heated air aris-` ing frointhe. regenerators by raising the ver-f t-iealair-ports verynearly to ,the root1 of the furnace, audby bringing the side walls of the ,dues forward toward the heated chamber in a convergent manner .l'pitil they meet. By this arrangement thel gas is introduced into the heated chamber'below the air through channels increasing iii width toward the furnace,

I' where-jt is met by the ain passing in indiverse directions, etfectiiig its thorough combustion -whlle traversing the heated chamber, the iincombined air being l.tt-'the saine ti me prevented from coming into Vcontact with the metal 'in 'thebed' of the furnace. 4

In r'ranging steel-.works I placesreveral melting-furnaces side by side, with tlieir'froiits or'tapping-holes facing the foundry; or I place two such rowsopposite to cach other,

vwith the foundry between them'. 4Iiroin'eaclr center of the furnace or tapping-hole a trench extends at rightl angles to the line of furnaces -out the before-i intoawideranddeepertrenclnrunningthrough theimiddle of the foundry, parallel with the `line of furnaces.

line oi`-rails is laid upon' the edges-ot the crosstrenclies, and across the central trench,

upon girders, which line of rails carries the ladle-carriages, by which a' ladle, when suitably lined and heated, may be drawn lclose up g to the tappinghclc to. receive a charge of steel, -and be moved by a wheel and pinion or other agency over the central trench. 'A lineof -A rails at the bottom. of this latter carries trucks,

upon which the molds to receive lthe fluid metal are arranged. lThese mold-trucks may be conveniently moved. toand fro by an endle'ss traveling chain passing over pulleys at the bottom of the pit, and being actuated --by inea'ns of a small winding-engine fitted with reversing-gear. opening thestopper in the bottom of the ladle these molds are filled', and the tri-'ick nnen 'which they are mounted 4 is moved out of the vfoundry to a crane, or intov an annealingstove, .if the castings are not to be hammered or rolled. By thisgcneral arrangement tlie preparation ot' the molds and the removal of the cast ingots or castings isV greatly facilitated'. l' .y

Having thus described the nature of my invention, and in what, manner the'same'is t0 be performed, I will now proceed lmore particularly to describe the arrangement of furnaces which I i r to employ.forearrying .,rihed. processes, for which purpose I shall. reten to the Vaccompanying drawings. Figure l shows sectional elevations, respect4 ivel y, ot' the preparatory furnace at X, for preparing the lumps or loaves, as before described, and the heated chamber or hot-'store furnace at Y, for .maintaining the lumps or loaves vina heated redncing-atmosphere until required for conversion in the steel-melting fur-l nace'at Z. The f ,instruction of each ot' these furnaces is show-xn more 4clearly to an enlarged' 2 showsa longil' scale in Figs. i. in lil. tiidinal section of the preparatory'furnace on line 2 2, Fig. e.. lfig. 3 shows a transversesection of the saine on lineB 3, Fig. 2; and Fig. 4 shows a sectional plan on line 'a 4,

In this furnace the crushed ore A A, mixed with the requisite percentage of flux and carbonaceous matter, as before described, is fed continuously onto the bed B through the hopper C, into which it is charged from trucks W, running on rails, as shown at Fig. 1,'. The ore is caused to pass gradually from the hopper ina tliic; iryer dowli the inclined side D'ofthe furnace, situated lopposite the gas and air ports, which are all placed'on one and the saine side of vthe furnace, in a. similar manner to arrangements already patented by me both in England and lin the United States. The bed Band inclined side'D ofthe furnace are construct-ed of strong metal plates b d, covered with bi icl; b' d', the 'plat-es being entirely open tu ne air, so as .to be kept cool;

masse 5 purpose below tliebed by the formation oi' a` chimney-flue, E, passing Ithrough the partitionwall E between the two sets ot' gas and air passages F G F il', and communicating' with a chimney, E2, above the furnace, as shown. rlhe bed of the iin-nace is inclosed on the inner side by means ot' a waierbridge or box, H, through which cold water is made to circulate bymeans of the pipes h h', Fig. 4, in order to keep the bridge ot' the furnace cool. The combustible gas and air rise from the regenerator's below the furnace respectively through, say, the passages F and G, the airpassage G being raised somewhat above the gas-passage F, as shown, and in entering; into combustion in the passage J the resulting flames are caused to impinge in a downward direction upon the layer A ot' mixed ore, coal, and iiuxing material. j After acting upon this compound the products ot' combustion escape through the passagesJ, F', and G into the other set of regenerators, in a manner well understood. lhe heat thus produced in tliefurnace 'eiects the before-,described partial reduction and fusion of a portion of the ore.

When a sutiicient quantity ot" ore has thus been acted upon, the more'or less liquid mass is stirred up bymwans of toolsv introduced through the side' doors L L, after which one or both ot' the side apertures K, below the doors L, are opened; by removingthe ore or slag with. which they are closed up, as shown in Fig. 1, and the liquid mass is raked out through them into the boxes or. molds M, brought up to the spouts ofthe apertures upon the trucks N.

The construction of these molds is shown in enlarged longitudinal and transverse .sections at Figs. 11 and 12. rllhey are open at top and bottom, and are made to rest with the grooved `laiige mi upon a layer of sand, clay, orcarbon upon the'table of the truck N.. Before filling them with the partielly-conyerted ore, they receive layers oi' debrisof partially-reduced yore, and ot colte orcha-rcoal, as Vbefore dej scribed. The tluid portion of the ore, on ilowfinginto the molds, fills the iuterstiees and ,binds the whole together into lumps or loaves 1 0. When the mass has solidified, itl is removed from the mold, the ribs m m of which ,form deep grooves iuV the loaves 0, as indi- .'.cated at Fig. l, iu order' that the whole mass inlay be more uniformly, acted upon in the 'subsequent processes. These loaves are then removed to the reducing oren or Inutile at Y, .Fig. 1, the construction ot' which is shown, to an enlarged scale, at Figs. 5 to 7. tshows a longitudinal section on line 5 5, Fig. 7. Fig. @shows atransverse section ou line 6 6, Fig. 5, and Fig. 7` shows a sectional plan on line 7 7, Fig. 5. Y

, This furnace consists ot' a series of inclosed chambers, P l? l?, accessible through doors Q Q, which chambers are contained Within the furnace E, in which a full red-heat-is nia-intaiued by the combustion of air and gas pass Fig. o'

ing in. through the passages d 5% at. the one end or the other iroin the regenr. tors '1 if l '1, in the usual manner. The tops oi-- the chambers l are i'ormed, by proies-ence, of hollow iirebriclcs, as shown, in order' that the' heat oi" the furnace may be readily transmitted to the interior ot' the chambers. Into theseebainbers the lumps or loaves ,of partiallvconvcrtod ore mixed with carbon, or the consolidated and unconverted lumps oi` ore inixedwith carbon and liuxing materials, as beibrc described, are introducedi and maiutuined at a i'ull red-heat. in a reducing-atmosphere, so as to promote their Y'rducioin for which purpose either solid or gaseous carbonaceous matter may be introduced into the chambers. In either case the chambers are entirely inclosed so as to exclude any sulphurous gases arising from the combustion takingfplace in the surrounding furnace. ,As

Ythe lumps or loaves are required t'or use they are removed from the heated chambers or h ot store furnace and carried tothc steel-n1elt1ng i'urnace'at Z, Fig. 1.

Figs. 14., 15, and 16 show my; rotore-meuv tioned hot-store furnace, inutile, or liilinior reducing the linups of ore entirely by means of carbonaceous gases, according' to the last process hereinbetore described. if* gie shows a transverse section through the hot-store on line 14 14, Fig. 15. Fig. 15 shows a iongitudi nal' section on line 15 15, Fig. il, and Fig.. 16 shows a part sectional plan ou line. 1li lo, Fig. 1li.

rEhe reducing inuftle or kiln constructed 'in duplicate, tl muiiies being employed either one and the same kind ot' om. eut kinds of ore, as hereina'i is here shown f separate reducing l evplained.

The mufde consists ofa chemin d., oi' tirebrick, with a discharging-oitoning, li 18,211: each end, which, when the inufiie is in operation, are eit'ectually closed against the ent-rance ofair.' On each side of the chamber A sepa rate spaces U C are formed, by means. ot longitudinal bars D D, which .sp-.tees

provided to receive the carbonaceous ma* niais serving to act upon the orc, and r i are charged into such. spaces through the doors B. The ore is introduced into the e ral part ot the chamber A through the t' shafts E, which are charged from a sta r v the opening F at the top, lpi d with a slide, Gr, The chambers A are i.. .Y d in. the furnace H--by preference a regenerative gas-fura. @,as sbown--iuto which the heated gas and air rise through the passage l, communicating with the rcgenerators below, arranged and operating as ordinary regenerative gas-fur- 113.685.

lhe operation of these reducingmufiies is as follows: Assuming the "mi .e ,er to be is rst generated from the the spaces l, through 's Haasse iiiipcri'cci' combustion with thc air contained in the chambers. This carbonio-oxide gas passesainong the heated luinps ot ore, and, in taking up oxygen therefrom, is converted into (':arhonic-acid gas, which r"again passes to the fucl, where, 'taking up another,equivalent of' carbon, it is converted into carbonio oiiide,l

which again attacks the ore; and this actionA continues iintil the charge ot' ore has becoine entirely reduced. lliis reduction takes place voiyifhorouglily and at a quick rate, inasniiich as the circulating carbonio-oxide gas is virtually free f'roiii nitrogen, wliichlattei retards the operation of reduction in ordinary kilns or,blast-furnaces. vVhile this operation is going on the excessof carbonic'oxide .quoiitly enters into combustion therewith, the

gaseous products of' this'coiiibustiou beingallowed to escape at the top by partially opening the slide Gr. By this means the ore, in gradually desceiidiii g in the vertical shaft, b econies incre and more heated, aiid is thus deprived of its volatile constituents, including Iwater and sulphur, until it reaches the'airholes L, whence downward it passes, through a gaseous red uciiig-atniosphcre, `into the heated chainbe'iI A. ll" necessary, the heatiii the shaft E may be fui-ther increased, either by the admission ot' -combustible gases, separatei y generated, or by mixing solid f'uel with the ore charged in at the top, or by heating' tlieshatt externally. The Isolid fuel eiii'ployed in the reducing-chambers A inight also (butI iiotso advantageously) he inixed with the orc.

The construction of these hoppers and hot stores may be iiaterially modified. rllius the I lioppers may be inclined, auth-instead of' being in the ii'i'iddle of the hot-chanibers, may be placed at one end, and may, moreover, be arranged in forni to resenibleaklii, with asta-ging and valve arrangement at the top, onto which the ore is lifted iii the usual manner.

When the reduction ot' the ore in the chain bers A has been completed, the doors at B B l are opened, and the charge is 'drawn out 'into scoops oirwlicelsor pivots., to be introduced into the steel ineltii'igfurnace, or to be einployed f'or other purposes. A fresh charge of ca-lciiied and partiallyredneed ore then descends into the chambers A from the shalt E, which is filled up f'roiii tiii'ie to time with raw ore at the top. As before stated, the two or more' separate vchambers may with advantage. be charged with ores of' different descriptions. Thus, if' three reducing-chambers are provided, andthe oiie'is charged with iii \.iiiatite,'the second with spathic ore, and lthe third with clay ironstone, it will be possible to use so niuch of' the reduced orc f'i'oui the one and the other that the earthy matters contained in tl'ieiu -f'orin a 'fusible slag in the.steel-incitingfur;4

nace, and render tho use ofseparate lluxiiig materials unnecessary; ori-lic masses of ijeduced 4ore .inay be charged coiijointly with'v lumps produced hy fusion of ores with linie or other liuxing inaterial, as hcrcinbefore described, which lumps .or loaves inay conveniently be contained in the hot-store M at the.

' side 0fl -the reducing-inutiles, as shown at Fig.

15; or these reduced niasses may be used together v i metallic luiiips produced in any other way. ln workingupon only 'oncdescription ot' ore the solid luinpsl inay be picked out and reduced by the process above described, whereas the sniall ore may be consolidated and mixed with the necessary' uxing agents by the methods previously described.

The construction of' the steel-melting furnace is shown to an enlarged scale at Figs. 8 to 10. Fi shows a longitudinal section on liiie 8 8, fig. l0. Fig. 9 shows a transverse sectionon liuc S) 9,' Fig. 8, and Fig. 10 shows 1 a sectional 'ilaii on line l0 l0, Fig. 8.. This furnace n iiiily of the saine construction as those previously described by nie in the specifications to iny fornier patents. The principal difference consists, first, in the addition thereto ot the heating-chamber A, for thereception ofthe lninps or loaves of'V more 0r less convert-ed ore before introduction into the melting-chamber l ofthe furnace; and, secondly, in the peculiar construction of the combusti; ble gasanii air passages G D UQ D', for effecting the mixture ot' the heated combustible gases and F F F' Ff. lhe airfpassages D D are raised I,very nearly te the roof of' the furnace, while the gaspassages C U open linto the chamber B ata considerably lower point, as s hown at Fig. 8, and the side walls G G of the air-fues are brought forward toward the chamber Bin a con verging manner until they meet, as shown atiFig. 10, thus f'orining widening passages E E- for the gas to issue through, the gases, on l their asc-ent, being deflected and directed' into such widening i'iassages by means .of the slabs N, xed over the vertical passages 0.0', while the air is caused to enter the furnacefinzdr f verse directions, above the combustible gases., f

so that these gases, in rising,becoine thoroughly` mixed with the air, and thus their complete combustion is eected', while any unconibiii edl air, ii-i remaining at the root' of' the furiia'c'e?, is

prevented froin coming into contact y"witlrthe' inetalon the bed H of' this furnace. This heid] 4 is f'ornied ci pure silicious sand, prepared and` mixed with glass powder, and then laid in, layers upon the fire-bricklining I'of' the iron 'bed J, in the inaiiiier as fully hereinbefore del scribed.

The iron hed J is open to the surrounding air, in order to cool the saure, asl informer constructions ot' niy furnaces.

For tapping oftithe bath of'v steel when ready for use-a hole is .torn'ied in the san'd bottom by t-hc introduction of' a tool through the spout) rising up fronithe regciierators other ca'rbonneeoue metter.

,fthe beth oi steel when ready for use, e, hole .is "termed in the sand bottom by theintrodnetion' of e tool through the spout/gli', through which hole and spout the ete-el t' ien ,iiows od' into the hulle .L on the carriage M, shown in Fig'. l. The deoxidized endcarbonized loaves 0,

having been introduced into the charging-- clmn'iberA, through the door A1, are there hearted to the requisite deg-ree by the radiated heat orby dame troni the nielting-ehznnber, n portion ot' sueh thune or hot gases being caused to enter the chamber A through the aperture B', and to circulatethrough the saine by men-ns et' the chimneys A2, the -t'ops of which :ire provided with sla-hs A for regulating' the draft., When sutiiciently heated, the iomes nre eneeeesivey pushed forward through the hperl ture B', into the beth of molten nie'tni in the Vehninher B, Where theynre melted, land the proeees of preiitning the beth is eaiiried on in the manner hereinbet'ore describedn A charge of molten steel furnace in the indie L, the :gerrie-ge M is run upon the/miie P, either ore-r e mold-carriage running upon miie in elongitudinel trench, ns-

hereinhei'bre described', or veyed to wherever required.

Fi ilshows n planet' the before-mentioned .arrangement ot' steeiielting furnaces with tmnsveii'seii-nd lengitndinel trenches :and trainvm-ys'. 55 Z are the furnaces, arranged in, two opposite rows, from the dieohnrging-sponts K et' which rails l P, inid along the sides oiI trnnsverse trenches ig, Q, extend toward nud across e -longitudiin-ii trench, H, so that the ladle-trucks L M can be run oi'er the hitter.. In the iongitudinni trench is the mold-carriage En', moved along upon the rnile T, either by a chain, U, driven hy no engine, or by any other sniinble menne. Aohnrge ot' liquideteel inw ing been run into the .indie L, the carriage M in moved over the treneh R, und the moldear ringe is run underneath it, so' as to enebie the inetnl to be discharged from the indie inioihe molds. These are then conveyed bythe the `ladle is,v ooncarriage "t'o wherever required.

Hering thus described the nature otn'iy invention, und the beet with for carrying' Elusznne into prnetice, ,l wish it to he understood that Whnt i claim 1sl. Producing oneteteel by first converting ferruginonsI ore' into innips or loaves of partially or Wholly reduced inetnl, either with 'or without adniixture ot' flexing materials, and. by then charging these lumps in e heated oondition into nn open-heerth steel-melting tornnee, to be there iiqneticd by being brought into contact with :L bet-h oi" enst-iron or with substantially es hereinbetbie described, I

2. The method ofreducing messes of iron zure, whereby the ore of carbonio-oxide gas, generated from carbon-- eceous materiels contained with theiore inside' '1, close eheinber heated externaiiy,

- resulting carbonio-froid gas is n having been received from the menne l. nin acquainted is subjected to the notion .or other materiele .to

while the I dition, into the melting-chalutier, en

into eerhouie oxide by Contact fuel, substantially as set forth.

Preparing loaves ot' Wholig,j er Wirtin-lig' reduced viron ore, oy meiting'fthe ore or mixtiirevoffOles Withuxing inaterinie in contact 'with cerbon, and by charging thi finid mess into molds containing coke, clinreoel, or other solidea-rboneceone metter, which iozwee ere thereupon maintained for some ha, ad; n t'nii lrtsdiefnt in a redncing-ntniosnhe within. n hearted -ehainb-er or hot-Store i ce h-efore they nre charged into the eteei-n -nmg ter ence, substantially es described lFi-epnring' loaves similar Seid ivy ernehing the ore, by ni mnteiy with liuxing 'materiels and with binditin-mainly forcing or pinning the mixture in" gooide, Aind exposing the shinefcr n oonsiderohie nnenher ot' hours to a, t'uii reti-heet in` aJ closed heated chamber or snhetnntielly es deecribed.

hot-store hermine,

ihiepnring' loaveereimilnr' t one et'oret'roni ores rieb in mangeur e er other Yvolent eeeilymxidizehle in .il Wit.M eireitoess of Carbon, to be en the 'timid beth ot' theeteelhlelti Yed into nce telwerd 'the endet each operatioinnu einer to ini ,mrt those metals eribed. jonetruoting hotistore farne tothe both, A,f tntieilg;

or kilns-tor reducing iron ore, where] the ore ie eonta-iued together with carhoi me nieterinhi inside e closed chamber f there nitnnted ineiden regenerative ge other i'urnfiee, substantially as d i?, tionstrueting hot-store t'nrnn.l or hiine for enleining or redneii".l 'ii-'herein the ore, 'in the form et' l" caused to descend through a verticali or 'inclined shaft, on tothe bed ot'l a close chamber hr f* te`i'nn1 l y,in Which'chztmi Y ier iaerbonenenne nntterinls ere placed, the excuse et' eerbonneeous gases being' enused to rise through the-vertien1 shaft, Where they nre in to enter into combustion with ntnioepifx treduced throisgh side npertnri ett'cot the eiiieinattioii ot the deseo,

hei'fiutinily hereinbefore'deseJ reierenee to 14, l5, :uid 16 inge.

8. Arrnngingin hot-store redLining-furnaces, es deecribedfin the sixth e nepnlrnte receptacle or receptneif or the eerbonneeone intimidatie, so es to brine theore only-1n Contact with the carbone 't-eee generated from sli'eh cnrboneceons nie-towels,

substantially ne described.

Si, Conetrneting .the steelin e1tin with e. charging-ehember,'throng portion of 'the hot gaseous produr hustion een' he nitide" to circulate, 'l the etereenid lumps, as Well as the nig. iii-edd be' used, -ore intzcidtieed to he mee-"pushed tbrwerd' in if ,heee-1i. non"N i hented together and seventh eleime,v

vsfeelhieliing fnl-nace in such manuel-,that the vertical nir-ports rise nearly to the root'of the furnace, while the side wells 'ot' the lines are extended forward in n convergent manner un til they meer, in order'thzit the ir may issue Into the furnace in diverse directions above the `combustible gays, substantially as hereinheforedescribed with reference to Fins. 8 to 10 o' the accomlmnying drawings.l

12, Arranging one or more rows steel'- meltlng furnaces with their t'uppingholes fucin g a longitudinal trench, with luterul trenches l *MN i leading to each ol the iur-neces, upon the edges ing the main trench, ladle-carriages being arranged to run over the lateral trenches, in 0rder that the linid metal nnry he discharged into molds carried upon rails in the central trench, i'nciiit-ating' their preparation und removal, hereinhel'ore described.

In testimony whereof I have signed my name to this specification in the presence of two sul)` scribing witnesses this 23d day of December,

C, TILLAM SEMENS. Witnesses L. Cown, l EDWD. W. PACE.

of' or over which 'rrenches rails are fixed, cross-

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