US325293A - Process of smelting ore by means of petroleum - Google Patents

Description

rm Model.) 4 2 Sheets-Shet 1.

P. C. WEBER.

PROCESS OF SMBLTING 0358 BY MEANS OF PETROLEUM 31%. 325 293. Patented Sept. 1 1885,.

ATTORNEY NU Model. T 3 Sheets-Sheet 2 F. G. WIZBEE.

PROCESS OF SMELTING DEBS BY MEANS OF PETROLEUM P10325293. Patented Sept. 1, 1885,

INVENTOR TTORNEY FREDERICK WEBER,

5555 QFSili'iELTiNG Gil-E @Y lr'iEi-ihi CHICAGO, ILLINOIS.

iiPEilUYlliGATIGN forming part of Letters Patent .ii'o. 3.2.5.293, dated September 1, 1&85.

A milicmion Qieil May 1685.

T0 aZZ whom it may con/eerie:

Be it known that l, FREDERICK linnnn, a citizen of the United flutes, residing at Chicago, in the county of Cool; and State of lillinois, have inven'rcfi a certain new a 1d useful Process for Suiclziug Ores by Menus of Petroleum, of which the lollowing is especificution.

The object of my invention is to reduce iron, lend, copper, and other ores byg ascs m l heat produced from the combustion of a mixture of petroleum orhydrocarlsou, and coke, churceal, or coal, as described in my application of June 23, 1884. in doing this 1 feed the perrolcuin'with the hot bios-o in such manner and. in such proportion as to form the require recluction-flmoe, njth excess of air suiiir .ilii to secure lie coinbusbion of and. fully to util 'iize'ilrc fuel fed with the ore charges.

in the accompanying drawings I have shown one form of apparatus with which my process can be curried into effect, and such process will. he described in connection with said apparatus applied to the smelting of iron ore; but it rousibe understood that many variations of the form of upper-ems for intro (lucing the petroleum or carbohydrates on y be made Without effecting the process proper 0r dcmrting from the spirit of my invention.

The apparatus herein shown consists of sundry additions to the mechanism now in use in blastfurnuccs, and such apparatus may lie readily applied to such furnaces.

In the accompanying drawings, Figure l, is a central vertical section or"; a blast-furnace and of my uppzrrums for applying petroleum thereto, this figure beingdesignod to show the relative positions of my apparatus to the furnace. Fig. 2 a central vertical section of part of the furnace, taken through one of the royercs with its blast-pipe through one of my petroleumburners with its supplypipe Fig. 3 is a rear elevation of one of these petroleum-supply pipes, with its stopcochand mechanism for operating the letter. Fig. 4 is an enlarged View in vertical section, taken through one of the tuyercs and through the petroleum-burner and its supply-pipe. Fig. 5 is a rear elevation, partly in secrion, of one of (No model.)

my burners and its snpplypipe; anal Fig. is a section taken on line 6 (i of 2.

In carrying my process into effect; is necessary that the petroleum or hy rocarlimns be introduced with the blast in certain delinezi relative proportions, and for this purpose I provide the mechanism shown in the accompanying drawings. This mechanism consists, essentially, of a reservoir or other suitable provisions for containing one petroleunrsun ply, service-pipes having devices whereby the flow of petroleum may regnluiierlgenrl flevices for properly connecting; the supply-pines with the bless-pipe or tuyerc.

A represents a section of the smeuingrar: 112cc, this furnace being suppliei wish as main water-pipe, B, having branches 31 b, e "ell-ash pipe, (5, inning ore-sch piiics c c, :rni ongreres D. 'lfhetuyere may have r isisiiug in its rear well through "which the emi or" the burner is inserted. i

The burner consists of a. pipe. 333, surrounried by a. Water-jacket, F, and may be helcl either upon said burner or upon the Eeyore. The burner E is provided at its end with suitable orifices through which the petroleum is admit ted lo the blastvfurnacc.

ments, which may he i'orinezl by custiogsrlivid ing-ri'o,f, sons to oriclge thespace between the inner wallof the water-jacket F the outer wall of the burner. This svaierjuclrciif Ell? rounds the burner to the point where the latter is connected wiiil the feedpipe G. 1 pro ferto connect this fecdpipe with a circular underground main,l',als0 under grounc. The nruin 1 leads from a feed-rank, J, the level of the petroleum in which is maintained by flout-. he supply-tank J is connected with a storugetuuk, K, which latter contains the petroleum-supply.

I have contemplaietl locating the storage and feed tanks at such distance from the furnace that all danger of explosion of the petroleum is avoided. The service and supply pipes should also be surrounded with waterjuckete Where there is danger from fire. The petroleum is held at a level above the point where the burner enters the tuycre, and is l preferto mekethe ater-jacket F in two horizontal compar s- 7 o flees. It is evident that the shape or form of maintain the permeability of the descending charge to the ascending gases, and reduce the carbonic acid. in the reduction-flame to car- 7 bonous oxide. The-sum of thc carhonous oxide in the ascending furnace-gases constitutes the principal reducing element in the smelting operations.

In operation the furnace is prepared and 7 charged with the ore, the fluxes, and a limited quantity of solid carbon in the usual way. An important point to consider While blowing in is, that: at the point ofsubstitution of onehalf of petroleum, in usinga hot blast of usual 80 caused toilow through the orifices of the burner by its own weight or by the suction induced by the blast. This level is maintained by the use ot'a float, j, which is soarraugcd as to opcrate a valve in the pipe leading from the storage to thc feed tank, and is such that the head of the liquid shall overcome the presu re in the furnace. The operation of this float will be readily understood from an inspection is of the drawings.

The supply-pipe G and burner E are connected by a coupling, 9. Below this coupling, pipe G is provided with a stop-cock, I, which may be an ordinary plugvalve with an aperr5 ture of any suitable form. The plug of this stop-cock is provided with a lever, M, which.

high unless regulated. This can be readily obviated by gradually lowering the temperais made to swing in front of an arc-dial, O, ture of the blast, and again increasing it as the latter being marked with a graduated the substitution of more than halfprogrcsscs, 3 scale. By means of this lever and arc-dial the I thus maintaining a fairly uniform degree of amonntof hydrocarbons admitted through the heat throughout the hearth during the blowburner may be accurately regulated or deter ing in. When. the furnace is prepared and mined. A ball-valve, P, is placed within the pipejnst above the stopcock, and as the head of oil allows the petroleum to flow up to a 2 stated pressure in the furnace, this ball-valve trolcuni is admitted, as before statcd,,in reguautomatieally checks all flow in excess ofthis latcd quantities, and is forced by its own the charges are being put in, the quantity of l pressure. weight or drawn by the hot blastinto the l l l l l solid fuclmay be gradually reduced and peo,

troleum admitted to take its place. The pe- The part which I have denominated the tuyerc, in which it is converted into gas, in 95 burner(markedEinthedrawings) consists which form it enters the furnace. The sub of a pipe which is cylindrical in form up to stitution ofpetroleum or hydrocarbon forsolid the point where it enters the tuycrc. At this carbon may he carried forward until only such point the form of pipe changes froin' he cylinquantity of olid carbon is retained as will temperature, the heat of the hearth is too drical to the oval. The burner terminates in l carburize the reduced iron and maintain the too a mouth or orifice, N. The castings which form'the walls of the mouth or orifices of the burner may be cored out, and through these chambers thus formed the water flows from the lower to the upper compartment. thus cooling the burner and the walls'ot' the oripermeahility of the descending mass, 850.

In order to i'naintain a uniform flow of potroleum through the stopcock L, therctardation of the flow of the liquid, caused by the friction in the service-pipes, should be coinr05 pensatcd for by making the service-pipes of increased diameter according to their length. the burner and its orifices inay be consider- The fuel and reducing agents now in com' ablyvariedwithoutaffcctingtheresultssought men use to perform the usual operations of to be accomplished bythem. All that is nccblast furnaces are coke, coal, and charcoal. [to essary to be observed in the construction of I These are bin-nod and utilized in such'a way these burners, as well as of the surroumlilw that carbonic acid is nrinci lZLllV formed beh l i l l l l l gs'termlned quantity of petroleum may bc apl acid. The-other half is utilized for adding l l l i lhis carbonic acid is prompt ly reduced to carhonous oxide by coming in contact with incandescent carbon, and then, 115 while ascending through the charges, performs the required operations of reductions, forming slags, X112, by decompositions, recoup binatious, heating, the, as desired. About one half the carbon of the coke furnace passes 120 through the hearth, principally as carbonic water-jackets, is that the construction be such as to permit a regular flowaud avoid the possibility of melting.

I have described butone burner; but it will of course be understood that; each tuycre has its burner, and each burner receives its petrolenm'supply from the circular-main ll through pipes similar to pipes By means of the above apparatus a predefore the tuycrcs.

plied to the hot blast in each of the tuycres. The petroleum thus admitted to mingle with the blast is converted into a gaseous form as soon as it enters the tuyerc, and its combos 6o ti n is simultaneous with its volatilization.

the moleculeof free carbon required to reduce carbonicaeid to carbonous oxide, and theheat produced by the combustion of the solid fuel 12;, plus the artificial temperature of the blast performs the operations within the hearth. The amount of solid carbon necessary to be The intensity and quantity oithe heat in the used in the practical operation of a furnace i body of the furnace, and which performs the Wnere petroleum is used as the principal fuel operations there, is that of. the temperature of 1 0 will vary with the character of the or s opcrthe carbononsoxide plus that of the blast not ated upon and the petroleum used; but in all previously consumed in the'hcarth, and also cases such an amount of solid carbon should of the chemical reactions which obtain between be retained as will earburize the reduced iron, l the materials of the charges.

2 from one to the other 0 the lining 6o tied by the pressure,

6'5to carbonic acid in air 10 by just 'so much as the carbon ted with the ore-charges will increase the volume of the carbonic acid by reducing it to earbonous oxide, and this reaction doubles the volume of the carbonic acid so reduced. Allowance 1 must of course be made for varying conditions of the air in making the calculations.

In calculating the relative diameters required oi the hearth and body 01' a petroleum blast-furnace, the volume of the gases passing and the changes in their composition as affecting their volumes must be a governing factor. In a coke-furnace the carbonic acid of the hearth verted to carbonous oxide at and above the 2 boshes, this reaction doubling the volume of.

the carbonic acid, as above stated, and about onehalt'of the carbon goes through the hearth. For this reason the furnace is enlarged at the belly above the hearth; otherwise the tension of the gases would prevent the descent of the charges and choke up the l'nrnace. troleum-l'urnaoe using petroleum principally, about three-fourths 01'. all the fuel passes through the hearth, and threet'ourlhs of the In a pccarbon is carbonous oxide, so that the increase in volume is sc' nuch less.v This will necessitate an increased diameter for the hearth and a more obtuse angle forthe boshes. The bene fits arising 'lromfthis, will be that the wear of of the furnace-walls will be far less, and it will also all'ord a larger space within the hearth for the reduction Jlamesl The furnacelining can be further prcservedby reducing the temperature of the blast, for,-

inasmuch as a coke-furnace works best with a hotblast, and consequently a hot hearth, it does so because that determines a hot body, and so hot ore, upon which. the reducing-gases act most promptly; but asiin a petroleum-tur- 0 nace the heat rendered latent ihrless, the

body is still hotter, even taough the temperature of the blast islowered', which in turn lowcrs the temperature of the hearth.

The burning of the carbon within the cokefurnace hearth to carbonic acid determines and performs the operationsol' I he hearth, and the degree and intensity of the heat in this space is that of burning carbon .to carbonic acid plus the temperature of the blast modilosscs by radiation, (:C.

As a comparison of the heat produced by the different methods of using solid and liquid fuels in combination or solid fuel alone, that degree of heat produced by burning carbon unit, as almost all the carbon of a cokefurnace burned bel'ore the tuycres is burned to rn the petrolcu hi to the is promptly conwill furnish a fair tor;

compounds. These eomhydrocarbons to a rednetion-fiame Having a petroleum containing eighty-tour per cent. carbon, ten percent. h ydrogen,and SIX per cent. impurities, which, burning seventy-five per cent. of the carbonto carbonous oxide,.twentyfive per cent. to carbonic acid, and the hydrogen to water, the sum or degree of heat produced will be that of these elements so bu'rning." Taking-for example, one hundred pounds of such a petroleum, we would have for so burning, twenty-one poun s of carbon for carbonic acid, sixty-three pounds for carbonous oxide, and ten pounds of hydrogen for water, and the impurities modifying the result in a measure. ble of producing an even four times as much heat as an equal weightof carbon, and accept-v ing that carbon burning to is capable ot'produeing a heat of 1,310 centigrade, we would have the following result,

mathematically 2,45S 21:51,6l8.;1,3IOX63,

: 82,530; 2,45S 4 1'0:98,32Q, making ato tal of 232,168 units, which, being divided'by 94, gives 2,558 eentigrade. This calculation Accepting that hydrogen is cap-a earbonous oxide IOC gives centigrade more for the petroleumfurnace, resulting fuel-in the hearth. This is modified, however, being'lower, because hydrogen requires from the combustionof the more air -for combustion than carbon, and so imparts more heat to the increased volume of .the nitrogen oil the blast;

It is plain that as the heat as here calculated is only an approximation, every advantage can be taken ot'raising and lowering the temperature and press ure ol' the blast to attain in the furnace operations.

The blast will be heated with t-llB'WtlStG gases of the petroleum-furnace just in the the required results same manner as from a coke or charcoal furnaee. The same plant as now used for a furnace using coke or charcoal may be used to utilize petroleum with simply the addition of prope'r tanks and attachments as required by the altered conditions. The-furnice-g ases of apetroleum blast-furnace will vary in composition and in volume from a coke-furnace in that they will contain more nitrogen and war but'this will be immaterial when taking into considerationthat but a Fraction of the sum of the fuel can be replaced, and that coke and charcoal also contain hydrogen and water, while petroleum contains practically no water as such. 'The hydrogen products, of combustion being water are practically neutral in the chemical'rcactions of reduction of I more heatingeleroent and as affect. ing the rel ed capacity of the furnace and size of the tuyeres, burners, and. blow-pipes.

temperature oi the petroleum-furnace ahorethe hearth will be higher than in a cokefurnace, because the amount of heat rendered latent by converting the fully amount of car tonic acid to carbonous oxide of the solid fuel greater, the amount iron of hygroscopic water and moisture, and one to twelve per cent of combined hydrogen and oxygen. ihen the ash oi the solid fuel must be fluxed and melted and the moisture volatilized, so that from ten to twenty per cent. of

the value of the solid fuel is consumed in get ting rid of the contained impurities. Consequently only from sixty to eighty per cent, by weight, of the solid fuelis'utilized in the furnace economy. Petroleum contains as impurities only a little dirt and water, with. some sulphur. The water and dirt, settling to the bottom of the storage-tanks, are mostly removed, and do not go through the furnace at all, so that petroleum may be considered as being practically a pure fuel. As a very lio- 8 5 oral general estimate, a colrciurnace now requiring one and one-half ton of coke to make one ton of pig-iron would require about one third ton of coke and about three-fourths ton of petroleum.

in making the various grades of pig-iron, similar methods as now employed will apply. The quality of the iron from a petroleunriuu' nace will be most excellent, as the higher temperature of the zone of carbonization will fa- 5 vor iull carbonization. Then the reduced iron, because of falling through a mixture of gases in which there is a larger quantity of the redusing-gas carbonous oxide, it will not lose its carbon; and, further, the slags will be more basiewith the iron more fully carburized, a smaller amount of silica will be reduced to contaminate the iron with silicon. As petroleum contains scarcely a trace of phosphorus,

this element will be present in less quantity in the iron. The sulphur will be for less because of the large quantity 0!: hydrogen present in the furnaoegnses. This will tend to form sulphureted hydrogen, which will go oil with the waste gases, as will also the phosphorus. The datrl contained in the above will furnish the formula; for determining the relative di' mensions of'a furnace and its parts, the size of the tuyercs required and their burners, the

just the diil'e rencc between F to carbonic acid or carbonous LGf furnaces, which obwhere the reduction to can oe 1 ace, being highest in z-etroleo. nrna Above these zones it uin hes in the petroleurn-furna 2e, nearer to that of a colic-fun are continuhea to the descending losses by radiation. The perrill. have the advantage of a tion of heat from. the bottom furnace, and will be ind ecially with benefit in the zones of cartonisation and reduction. "he ultimate a is obtained from like amounts carbon alilcemhether obtained no echo, 2 rcoai, or petroleum. The heat o "ulated and utilized from these Various es oxide at and above the reduction to carhonous oxide within *e. The carbon almost completely to aside in both classes the same within ng only in the manner.

will have to be al.- changed conditions. The V of furnace being let be rendered more basic es the fact that the "h will have to enter,

tered to thercixture to produce the desired The petroleum-blastfurnace process l proceed more regularly and rapidly, tocause there will he slag and slagiorsn lug route l to'mechanically interfere with the r on of reducing-gases on the ore, and no guid fuel beingfully under control quired mixtures for conducting smelting operations.

in blowing iu a petroleum blast-furnace the same precautions of properly preparing the the cunt of fuel required per ton of iron 7 A l. l more nearly correspond with furnace must be taken aswith a coke-furnace.

The charging can begin either wholly with solid fuel, the petroleum flow not being turned on until the furnace is fully under way, and l or i do about four times the petroleum gradually substituted until the J neating' theme-charges, practical limit is reached; or-the petroleum :25 ng siege and reduced iron, keeping orumay be used in part at once and the limit oi le hot. (366., and leave the carbonous oxide its most advantageous substitution gradually formed from the carbon of the petroleum and reached That this can be done is seen from the free carbon fed with the charges to perthe feet that in either case all the carbon from sat called for theoretically. The ten per (or more) of ydrogen of the petroleum cing four times as niuch heat amount of blast-power and blast, and the re- :15

form their proper work of reducing iron oxide the petroleum is burned to carbonic acid until 1 0 excess in the blast. After that itgoes throughcarbons, and burning the hydrocarbon to car to carbonic acid and. water.

. fraction al in part as carbonous oxide, and the solid carbon is of course diminished in proportion.

In thus using hydrocarbons the proportions of the charge will vary according to, the charaeter of the petroleum, the kind of ore used, and of her specialcircumstances, as explained above; but as an example for an iron ore charge having a fifty-five per cent. ore with silicious gangne I give the following: two hundred parts of iron ore, one hundred and twenty parts petroleum, forty parts coke, and fifty parts limestone. A fraction of the solid fuel is also replaced in smelting by crude petroleum or other hydrocarbons for the purpose of desnl phurizing and dephospl-iorizing the ores. This does not apply to smelting pure snlphurets, like iron pyrites, but only to such ores as charged for smelti ng in blast-furnaces, innvhich sulphur and phosphorus are present as im purities up to a few percent. 'ihis is accomplished by using onehalf or less of hydro bonie acid and water, these gases being formed and introduced with the blast, and l'erminga portion of the furnace-gases, and thesmclting, desulphu'rizing, and dephosphor izing being performed during nus one operation of smelting. The effective agent performing the desnlphnrivzizg and dcphosphorizin is thowatcrof the burned hydroca *bons, this water acting either as superheated steam or as nascent hydrogen formed, owing to its decomposition, by incandescent carbon. This desulphnrizing and dephosphorizing obtains when substituting crude petroleum in any pro portion whatever for solid fuel.

The reasons for these reactions is the varying chemical affinities of the elements, the ex.- planation being about as follows: Pure hydrogen gas will promptly reduce iron oxides, the oxides being heated; but it will not do so if there is present in the hydrogen any of the carbon oxides. Carbonous oxide will reduce oxides-of iron promptly in. presence of hydrogen gas or water-vapor, thccxides being heated. Carbonous oxidewill also reduce iron oxide l1l-1)lQStllC0 of. carbonic acid if the carbonons oxide is in excess.- \Vatcnva poi-as superheated steam, ordeeomposed, having formed nascenthydrogen, will decompose compounds of sulphur or phosphorus, form-' ing sulphureted and phosphoreted hydrogcns, respectively, in thepresenccof carbon oxides. Now, these conditions are present 'while partially substituting hydrocarbons for solid fuel with the blast and. burning th hydrocarbons All hydrocarbons can be so burned,whether solid, liquid, orgasc ens. They can be burned to carbonic acid, water, and carbonons oxide, or to carbonir. acid and water, but can in no case whatever be burned to earbonons oxide and water, because of the difference in t-heailinity between the carbon and oxygen, and the carbon and hydrogen, and the hydrogen and oxygen. For this reason, complete substitution of petroleum or hydrocarbons for solid fuel is a practical impos sibility, and this because the ever-present carbonic acid is an oxidizing agent, and so retards all reduction.

tVhen smelting with the object of making better iron, less than half of liquidfnel should be used and enough free carbon additional be fed with the ore-charges to utilize the carbonic acid as earbonons oxide, the carbonic acid taking part in'thcse operations the same as if formed from solid fuel within the hearth of the furnace. The temperature of the blast must also be regulated to suit the requirements of each individual case, according to the amountof hydrocarbon substituted, so as to avoid wasting the furnace-lining. In thus using hydrocarbons the proportions of the charge will vary according to the character of the petroleum, the kind of ore used. and other special circumstances, as explained above; but as an example for an iron-ore charge, having a fifty-five per centore with silicious gangue, I give the following: Two

hundred parts of iron ore, one hundred and twenty parts coke, twenty-five parts'petro- 'lcum, fifty partslimestone.

It has long been known that superheated steam would desulphurizc and dephosphorize iron ores, and also dephosphorizc molten iron in the Bessemer converter,.bnt owing to diffieul-ties experienced in introducing the steam into the converter, or with the blast, it has been only a partial success. Introducing steam directly into an iron blast-furuacc in this way causes large losses of heat, and so seriously interferes by retarding operations that it has been abandoned. Recently, also, L am informed, iron ores have been subjected to the action of superheated steam in reverberatory furnaces, and then smelting the so-treated ores. This necessitates two operations, and has the further disadvantage of again introducing the same impurities by means of the solid fuel and fluxes now used in smelting, which, during the one operation, while formingsteam from the crude pretrolcum or hydrocarbons by-their burning, are expelled not only from the ores but from both the fluxes and solid fuel. In utilizing crude petroleum as last above described, it is burned to'a mixture of water and carbonic acid with such excess of blast as will utilize the solid fuel fed with the ore. The water formed during this combustion does not cause a loss of heat, but, on the contrary, is a source ofheat and aids the furnace operations by so much. The proportion of hydrocarbons 'and 'solid fuel to be used, while using principally solid fuel, will vary-with the eharacterofthe ores, lluxes, and solid fuel of each case.

I do not consider that ten per cent. or less of solid fuel can be used practically in my process, because of thevaitinities of the different elements: hence the proportions will always be more than ten per cent. of solid to less than ninety per cent. ofliquid fuel. iron contains from five to eight per cent. of carbon, which iscalculated as coming from Pigsolid fuel, and this alone calls for over ten per cent. of solid fuel A s above sh own, I am ewareihai: eziperi menis have bceninnrle to reduce iron and other ores by means ofe finnie ofpeivrcleum orhydrocnrbon vapor; also thnmsmell ofcarhon has been mixed Wi th iron ore 2m (1 th e charge red need by means of peirolenm; hut these instances the amount of solid fuel has not ceen sufficientto perform the reducing operations of she blush furnace process; nor do I claim the mere nee of petroleum us a fuel for the smelt ing oi. ore, only when used in connection with soliii or ee carbon and in such relative proporiiims thethe burning of the hue will i'urnish iiiiQ-Efhfll red reuncing-guses, lnlso discinimilie oi 65 earn es an aid in the combushe peiroienin, and my process is also u the coin piete burning of the petroso as to produce n mini-ureof carbonic an cnrhonous oxides, vapor of water, and other gases, anal so to utilize these gases by the nddihion or use of the proper amount of or free carbon to furnish flrue reducrequired in the li ing of ores; i now disclaim nil processes operating w or on different principles i 'nrenc. to cover ihe use of gas only as efuel, hut-only petroleum or liquid rocerhons when inizrcii with. soliri fuel in such n array that ilheliquill fuel will be volatiliizeci simultaneously, and 1106 first ertcii into n ilo nfierwnrl used as afnel; and I also disclaim thcusc of wood as a solid fuel.

I do not now claim the uppnruius shown for carrying out my process, the some being the subjechinatber of an upplicni-ion iiled by me January 1?), 1855.

I clnin l. The process of smelting ore, which consists in charging the furnace with one hundred parts of ore, proper fluxes, 21116 from sixteen to forty parts of free carbon, and injecting from sixty-five to forty parts of crude petroleum with, air, and regulating the amount of air to produce a, non-oxidizing flanie,the proportions of free carbon and petroleum varying relatively within said limits as required by the varying compositions of the petroleum or 0thcr circumstances, substantinllyus described.

53. The process of smelting iron ore, which consists in charging hundred parts of ore, proper fluxes, and from fifteen to sixty parts of free carbon, and re ducing the mass by a flenic produced by the burning of crude petroleum or liquid hydrocarbons injected with sufficient air to produce a. non-oxidizing flame, the amount of the liqu'ni zuel being determined and regulated by the varying composition of the ore, solid and liquid fuehor other circumstzuiecs, substantially as described.

FREDERICK C. VVEBEE.

Witnesses:

EPHRAIM EARNING, THOMAS A. BANNINU.

the furnace with one- V

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