US1051494A - Apparatus for treating ores in preparation for magnetic separation. - Google Patents

Description

J. B. ETHBRINGTON. APPARATUS FOR TREATING ORES IN PREPARATION FOR MAGNETIC SEPARATION.

APPLICATION FILED JAN.12, 1911.

- Patented J an. 28, 1913.

2 sHEETs-sHnBT 1.

j m Q E v w QM mm L w Wm D g M %N x mm v w m Y MN 7.x. 1 -1 1 *N MN X. J Q $N QM RN wa k Q\ Q Q Q w 1 Q Q QM. mm l. Nm

J. B; ETHERINGTON.

TION.

Patented Jan. 28, 1913.

APPARATUS FOR TREATING ORES IN PREPARATION FOR MAGNETIC SEPARA 7 APPLICATION FILED JAN. .12, 1911. 1 1 ,494.

2 SHEETSSHEET 2.

mww

To all whom it may concern:

v ED STATES PA N JAMES B. nrrrnnmeramor wm'rnaor', MASSACHUSETTS, sissrsnoni'ro cmrsnnn MAGNETIC snraaa'rme'comranm'acoaroaa'rrongr amzona.

- APPARATUS roa TREATING cans IN PREPARATION FOR Maeivnrrc seem-r1011.-

Specification of Letters Yatent. Patenteq Jan, 28, 1913-;

Application filed January 12,1911. Serial No'. 602,171. y results. By means of; my process 1amable, Be it known that I, JAMES B. Errmm scemploying comparatively light and inexrrou, a citizen of the United States, residing pensive apparatus, to treat non-magnetic at \Vinthrop, in the county of Suffolk and I pyrit-iferous ores commercially and economi- State of Massachusetts, have invented a new cally so as to render the ferruginous conand useful Apparatus for Treating Qres 1n 'stituents magnetic by subjecting said ores Preparation -for Magnetic Separation, of to heat for a few minutes.

which the following is a specification. The. principal feature of my process con- Thisinvention relates to the treatment sists in conveying the ores through a furof ferruginousores:containing sulfids, and nace in'towhich is blown a flame created its object is to'provide an apparatus adapted outside the furnace-and carrying with it i to render such ores su sceptible.to magnetic into, the furnace practically only sufiicient or electrical influences, without volatilizing air to support the combustion of the fuel in or materially oxidizingthe metallic constit-' the blast, thereby preventing any consider- I uents, and to'furnish details of construction able oxidation-'01: the ore.- This is contrary .70

for convenience and economy of manufacto the former methods. Heretofore it has ture and useas hereinafter particularly set been, a common practice to roast the ore in i forth.

p V a furnace with an abundanceof air circu- The apparatus consists primarily of a lating through it, in order to oxidize fully furnace so con tructed that a IIOH-QXIClIZiHg and as rapidly as possible the sulfur of the [5 atmosphere, or an atmosphere possessing a ore, thereby converting the iron into an minimumramo nt of freeoxygen, maybe oxid. The fire was built and run inside of maintained at all times while the furnace the roaster and depended upon-a free draft is in operation I have discovered that in of air through the furnace to maintain it. order to get th best results in magnetizing There were "no means, nor any attem t to non-magnetic 0 es by heat it is desirable to provide means, to limit thesupplyo air,

' admit only sufiicient air to support the combut on the contrary to furnish the maximum bustion' of the/fuel without materially-oxiamount of oxygen to the ore, was consl dizing th metallic constituents of the ore, cred indispensable to good results. The dif-.- and I hav. applied for Letters Patent of the ference between the prior art-methods and 85 United States for a process embodying the my process is radical in this respect. My same. c invention resides in heating the ore while The apparatus described and claimed in exposed to the minimum amount of oxygen. the present application is designed espe- The prior art consists an exposing the ore cially for the practice of this process.- to the'maximum amount of oxygen while 'I am aware that prior .to the invention of roasting it. In the methods of roasting 'ore, my process, it was discovered that the ferprior to my inven ion, the heat was not ruginous constituent in non-magnetic pyr1- applied to theore with such precisionand tiferous ores containing, in addition to the uniformity that any reliance could beplaced iron, other base or precious metals, could be upon magnetizing' the 'ore that O5 magnetized by subjecting the same to heat through the .furnace, 'without excessively for.a\bsiefi timew itlrgut removing substanroasting a large percentage, and actually tial porti'ons of any at the solid constituents fusing some of its const tuents. There were of the 'ore, and that Letters Patent were two serious evils in the apparatus and methgranted for such process to Henry ods of'th'e prior art,'namel v,-first, the de- Campbell, No. 723,363 dated March 24,1903, pendence upon a natural draft of :nr which invention I am'utilizing, in my procthrough the roaster to support the fire withe ss herein described, to the greatest. pracin it; and secondly, the great length of time tical and commercialiadv'antage. required to insure the roasting of all parts Prior tothe invention of my process i of the ore, owing to the inability to control 10 was the general practice to'roast sulfid ores the degree of heat. and to pply It to the for a number of hours whilefreely exposed ore with precision'l The effect of this old to oxidation,

in order to render them magmethod of roasting ores containing the sulnetic, employing therefor costly and ponfids of iron and zinc was not only to oxidize derous apparatus, and producing wasteful i the ore excessively. but to volatilize and waste'the and 3 other metals and to i oxidize and waste'the sulfur.

The preser- Ivatfion of the sulfur 1n the oreduring the rafter separation.- .-In the practice of my process, there is a .magnetizin'g' .fprocess' increases the commercial value of both the zinc andiron'sulfids direct and uniform" application of heatv to substantial quantities the"ore',- so that: all particles of the ore are ex osed to. the-same degree of heat'for a 'brlef time and practically the same'lengthof time; andthe result of which is that all particles .of the ore are subjected to a.pre-

determined degree of heat, and for a brief and lire-determined time,

of the ore without volatilizlng' any of the metals or otherwise removing. from it any of its metallic con- .stituents,-' and without materially oxidizing 1 the same.

. .An important feature of my invention consistsin avoiding the loss of the fine par- 't-icles'of ore through thestack "or fiuelf' Dust- -composed-of zinc, iron,- sulfur orother valu- .able constituents ofthe ore escape inlarge quantities through'the flue and 'stackof the roasters heretofore co'mmonly. usedv through whichastrong draft-was maintained, and

was, necessary to support the fire within theiii': .In the practice of'my inventio'n the escape of-materials through the stack is reduced to'a'ini'nimum, 'on' accountfof the v p l he commercial practice of 'my process is ability to dispense with a draft fo-n'supportingthegfiiae;

:accomplished by the apparatus which I have tion of ore upon the invented, and which forms the subject matter of the presentapplication' as; Letters "Patent, and the essential feature of my apparatus is the means-for restricting and limiting the supply of air to the heating chamber.

The roasting furnaces employed in the.

prior-art were large and heavy and very expensive toconstruct and operate. They were invariably lined with cement or brlck, .to which the ore had a tendency to adhere .when heated,-particularly if fused to the slightest exlen't,-resulting in an accumulalining 1n irregular forms and masses, and thereby reducing the interior diameter and capacity of the furinterfered with the exp anyapproximation of thesame.

which is barely: Isufiicient to magnetize the iron constituent osure' of all portions of the-oreto the same degree of heat, or to These. masters required many hoursto prepare. them for use. It was necessary tohea't them slowly and gradually to raise their great bulk of iron and brick to the intense heat required to oxidize the ore,-the time occupied for this purpose being 24: to 30 hours.

After the roaster was heated, itwas necessary to maintain the temperature and keep. .the roaster in operation day and. night for months' at a time, because if permitted to cool, the brick arches were liable to fall, in

which case .theroaster had to be re-lined. 'l-Vhenever. any repalr was necessary,. such a as removing the orewhich had adhered to the lining, it could not be done without a delay ofseveral days to permit the cooling All these evils are obviated 5 by my invention.

of the roaster.

My furnace consistsof an unlined cyl-' inder approximatelysix feet long and three feet in diameter, made of-sheet steel or. 1ron. fiths of an inch or more in thickness. No

time; is consumed in preparing the furnace for use. It cools quickly, and shortly after the flame is withdrawn, is cool enough to handle and repair. I do. not limit-my iniention to the dimensions specified, as I find by experience that a' great variety of sizes may be successfully employed.

--My invention further consists in providing means for circulating air, water, or

other cooling med um, around the exterior -walls of the furnace, and in the preferred form of construction illustrated in-the drawing, it consists in surrounding the furnace \Vllll'tt' hood .or. acket between which and theouter wall of the furnace a narrow space is provided-through which the air is circulated by means of an exhaust fan, 'for the purpose of cooling the furnace.

I find that the durability or length of life of the furnace is prolonged by providing artificial means for circulating a cooling medium around it. It has been my practwo to use a blower .for the circulat1on of atmospheric airat the ordinary temperature, and 'this has proved: efficacious It would, of course, be an additional advantage to reduce the temperature of the air by refrigeration, as the length of life of the furnace would be increased thereby. Any means of artificially cooling the furnace is within the scope of my invention. The durability of the furnace is also. increased by my method of peimitting only sufiicient oxygen for supporting the flame to be intro: ducedinto the furnace, or at least only a minimum in excess of such amount. Not only is, the ore itself prevented from oxidation, but also the material of which the furnace is composed.

By controlling the. degree of heat, making a direct application ofthe flame to th ore and artificlally reducing the tempera consists of the hollow cylin presentfa smooth surface-lion thefpassa'gef Of-fiheHOI'e' through the-same? T v 'My*- inve nti on Jfurthercon'srstsl'in constructing-the apparatus of cylindrical sec-u 5 'tions and .circhlar heads assembledxby meansof separable connections whereby'the parts may be removed and'replacecl'at' will; and,- so that the 'strncture may be readily taken apart; for shipment for. other p.1rrpose's,-.anc 1 maybe readily jre=assexh b'led.'- f .rThegparticnlai', construction'of my app'aratns consists of two or" 'more flhollow, cylindrical'iisec-tions, the ,ends'ofwhichfare ar-- rang cl to" be icou 'pled wvi'th circulapheads: One ofthese-sec'tions' is "designed as, furs naoe, and; the-other sectionorsectio' s are" designedlforlfeeding the ore'to. the furnace anddr'ying and heating-thesame in i s' pas; sage. Th 's-head s'of the fnrnac'e'ar con? nected by olts or 1,'0ds,'a nd-,s aid cylindrical sections-she provided with bear'ngmingm which engage with rollers for the purpose ofpermitting the rotation of .the fiurnace. Itis obvious that an unlined furnace is: less, protected front. the deteriorating -actio .of'heat than one having a brickwr-en en lining and th'atii't -i's .clesi ral )le to ha e the parts freaclil'y "removable, 'so asto be able to; replace them conveniently and econo'lni cally, and especially those parts which are mosflperishahle; For this reason, I have" constructed my furnace in sections with. separable 'connections, for the purpose of a convenient and ready replacement of' 5 8 -,tage of compactness.- I v Inthejaceompan ing dra'wing similar nu-' meral's of." designation represent similar parts throngh bnt the several views f Figure-1 is aside elevation. partly i'n'section of my furnace. ancl'-- the hood-covering ,the same; t-ogether Willi. the burners and, p

"blowers andft-li'efmechanism for rotatingihe furnace. Fig. 2 is an end; elevation partly in section of the furnace and hood shown Fi lfshowi'ng the discharge" openings and 1 interior of the cylindrical fu'rnacer- .Fig. '-',3 is a section on line. 3+3 of 1, lookin in the direction of the arrow showing the rotatingmechanism. {Fig.4'is 'a'sectiqn of the furnace .on-line of Fig. -1 looking in the direction 'of the a1'rotv,,'ancl "showing etl one or the bearing rings-and-rollsitherefor."

, Fig.- -5 is a\longitu,dinal section of a moth fication of the general construction of my 'fu-rnace'..'..-Fig.' ..6 is a -diagrammatic. planview' illus trat-lng the bnrnefrs and the courseof the flames and he t" in the furnace.

- Referring'to; the rawin thefurhace' ae'r 8, preferably "formedof hear' 'v plate steel or iron, or of east-iron, and the circular heads 9 and 1.

{connected together by meansfof xzhe rods 11',

'i the-endsgof-eaeh of;which are breaded ,to

,in eachifo'f heads- 9 andflO far the rec e15? 'tionbf fthe rods I11; and-each.-l1 ead-has an,

annular recess,' l 5 on thelinner surface .to

"receive and {Hold one end. of the cylinder" H8; forming. the furnace. To'theT outer side "o fthe-heakj' {his secu'r I the annular flange F16 Whichsh'rrorinds th eentralopening m throngh whichithe llame from. the hydr'o 'ca rhon hurner lQ-is projected into th'effurj knace 7'. 1 For my iarpolsefl prefer' flo use the 7 typeof'hurners o'wnin-the United "States "-1'3atent-t0 'Barke'r, No."8i 5,290", issixeglfJuly' :pable-ofprodncing a jet oflfla-me when pro.-

jected byahlastof 'airint'o the furnace, willf.

- sufiice fo1'-n1y-.purpose. To regnlate the size interior "wall. of the furnace; and- 1 secured thereto in iii- 1y desired manner.' '1 The said shelve s'i. preferably extend longitudinally go from t-herecei'ving end of the fn'rna'ce nearly: .m the-discharge end ,thereof, leaving a nar-f row" space 23 free for .the'receptien of the or -adjacent to the discharge ports. The;

ex inder Qis likewise provided gvith similar radial-shelves, and is formecl in two sections" 24? and'Q lL and. is preferably about .18 inches in. .tliarneten-i :It is connected with the furnace 7, at a central opening in the -heacl"10 Said sections, 24*" and 24f, are-10 "bolted"-t0'get l1e1 "through the flanges 14 at their respectiveends,- the othefenclof sectionQP being 'secured 'in "like manner to the 'head'lOlby thefholtsfQG; and the other end of section, 24 being secu'recl to the cast; 'ing 25. 'j The hopper-30 islprovidekl font-he urpose' of feeding theore- .into the cylin} der 24;? throu 'h the spout 31; and is; braced 1 .by means of the rods- 249.- For thesescape of the gaseous products ofcombustion I pro [11c wide-the flne 3'2 communicating:with the npa perjend of the 'cylinc lerfll-as shown, and supported by' the strnts-2 8. I

I'support the furnace 7 -l mea1 1s of'the rem'ovable bear ngrings 33'engaging.'.w ith ("friction rollers ll, which are suitably niountin-the Well. known wa'y lipon the inclinedbas'e 35. The Worm gea'r 27 is 'cletachablv fsequreclj to struts 49 which ihturn'areboltecl a to the cylinder Qi 'ancl is .operated, b, v -the '01111'36, which is mounted uimn said base- 35, iii-bearings 37 The worm-3T4 mountedon one end of'tl 'e sha'ft 38. on he other enclotqshich mounted th eclriving pulley 39.. Friction. rollers 40 mounted. on said base' and similar tqao-llis 34-servet0engage with the bearing ring 5 m1 thereby provid-ef a means for supporting and rotating the cylinder 24. "The: axis .ofrotationof the ap'-- parat-us is; slightly "inclined'sp. that the .ore 1 -3 "wi y' 1-by, -g -'ity toward h toward the right hand .side of'. the furnai d scharge end ofth e furnace. It isfjobvious that.the; flame of one will; v In Bhgs 1 and-21s shown the a1r cooling pprojeetedfl-against, the wall of the fu'rna device which n this case consists .of'a hood dvance' of the other, as shown b the; or-sh eld41, c sely-c r P l 2 6 rovih; andth' t the flames of both-S 11 b'e'c' 'and- -1s supported- 1n any suitable manner; fiec't'ed by th wall-hndheadot the furna w one end of sa-1df-sh1'eld being "cut away torettlr'ningupon :themeselve's a'nl eddyil form the opening 47 in order that the dis- 'abou {so-as to,forman"intense body olf he H l chapge d f th furnace may be made ac ."in tlii region throughhich theore .is fa cessible for the hydro-carbon burner 19." ing froni-the shelves, "The-furnace isi-rot: The hood 41 is connected'prithl'an exhaust ingfinthh directionofthe' arr-0W,- 'so th fan (.npt shown) bythe pipe42,said exhaust the. ore. is falling'ofrom' .th e, righti hall fan bemg" preferably located near the top psh 'lves' directlty nto the flames. I

of the structure in which my furnace is used" it is obvious t at the several parts of n 5 The hood 41 issomewhat larger tha n t-lte apparatus may. readily replac'q ed'. wh

' furnace 7, in order to form anair space be-- -,wor' A. or burned out] This isz-deeirabletween them through which! circulation of to al parts-but'partic la'rly'so with a cold air may becreated by an exhaust fan, spect'lto the-sh 'liof thelfdrnace'l which blower, Onothersuitable means. I have exposed to the 'se'yerest' uta e; ,With '11 'found in practice that the lifeof the-furnace construction for quickly 1 unc'oupling -t may be greatly prolonged'wherethis cooling. parts and 'arrangement for-'codiihg t device. is used, and that it is possible to use, furnacepquickly the frequent replacerne the't rnac-e indefinitely with'out'the ore ad; of-a shell of the furnace is a'matte'r'of'i hering to the wall} of the 'furnace 7, considerable'expen'se orinconvenience. T lgi5 It is obvious-that 'th 1 cylinder 24 could'beflf eature. of making theappar'atusin shc composed of rn.or e=', than two sections and lengths 'readily separatedland coupled i could be made off-different diameters if. de gether'afiords a great advantage inaoct sire In. the modification of the'furnao'e sibility to the interior of the cylinders f sho n in Fig. the heads 9, 10",arepr0: repairs. I am now enabled te'umaket vided Fill-l1 c'rcu iferentia lliang'es 936.0 to; several parts'of'the apparatus of aetan Which-the shell Sis bolted. This 's an eco-' ard size, to replace any part at short notir nomical construction, butjhas the hisadvanand; loyv taking-the apparatus .apart', I a

I t 'th ,t th narts cannot, be readily teable'tq conveniently..handleand ship t1 placed. same from place to place. I

-- The operation of my: apparatus is as 101- For thesd'ccessful raoti'c'e ofi my inye 'loWs':-'I first adjust thehydro --carbon tion, the 'a-ir-blast-an o'ilyapor shoufld burner 19 to produce the degree of heat recarefully-and homogeneouslymixedltogethl quired, I' also, adjust the size of theiports in the manner of which: the hydrocarbl '17 to discharge the ore in such amounts as burner of the type'shown-in the drawing :0 may-be necessary. The ore is then tt'd into capable;- By its: use the oil is conyerh the hopper 30,,' from which it descends into a spray, and forms a mechanical mi through the spout.3l into the cylinder ture with-the air flThe air liich is ut: preferably in'hsuch quant-i as to permlt --'ized for burning the oil is. or the. Inc

the shelves 22 to produce'their maximum part derived from the air pipe directly co M amount of agitation. The cylindernis then nected.w1th the burner, and in smaller pa slowlyrot'a'ted, causi g the-ore to fall trom- 'frorn the free air in the vicinity of t. -one of the shelves to nothe'rand by gravity nozzle of said burner,. the free "air jbeii slowlyto travel along the ylinder 2st and drawn into the "furnace'by the blast tro to fall into the furnace 'Z'thr'ough the opensaid pipe' with lthe spray of bu-rnil 0 rag i'n'its reteiving end. I pi efer toe nploy' oil-. By carefully adjusting the stop coc t'vvo' burners, and 'to project'the flames of the plpes' supplying alr'and' oil to sa against the .Wall'ofthe furnace. The flames burner, the blast of flame after N185 and. heat are deflected from the wall,-then-- from saidnozzle W1ll carry with lt'on y strike the head of "the f1 rnace,.from whi h: sutficien ofthe outside air in connecti they are again deflected lb'ack into the turf I ith the" air oft-he blast to maintain cor nacfi forming an'i'n'tense, heat." The ore 11s 'bustion -of,-th o11.- V "tumbled about from-shelf to shelf intofarld ITh'e const'r ction of -t he furnace and tl through the flames and heat as-it'advances method v of operation are designed esp alongthe 'furnace, which-maintainsthe. ore ciallyto iprovide eans a plying CQ -atared heat forwa few-minutes when it is mercially.,'and economically t e'winventn fidi scharged throl'igh the'ports 17. The fiange' described'in the here nbefore mentioned "16 -i's proi'ide d to protecttheburher from ters' P I 1 .tO. Chmpbell. In thlS respe' "Qthefalling' ojre. 1 4 n p r a a eth ,e trl l ""TFR9ferringtO F g, -:6, I- -have 'sh w '1' the furnace har a v dlameter" vantage,. and.uniformly upon all its paris subjected to the The sma lcylinder 2i s. .p vid d i ting the product'sof combustion to escape A5 aration for magnetic separation consisting said furnace and independentof the natural therein to the action of fire combined wlth whereby oxidation of the contents of the latter is materially restricted. j

4. p In an apparatus for-treating ore-fin preparation for magnetic separation, the combination of an unlined metallic furnace, a source of heat created outside of said furthroughwhich the ore is delivered into the furnace. The heat' is thereby effectually confined within the furnace and controlled. It'is'directed upon the ore to the best ad-.

. 1 ticles asthey 'aretumbled. freely about in the furnace. The progress of the ore nace, and means for pro ecting heat there? through the furnace is determined by its ,n'- minto s'aidfurnace and for controlling incl nation and speed 'of' rotation. The ore the supply of air to said furnace.

heat in the furnace for 5. A furnace for treating ore preparatory to the "magnetic separation thereof consist- 7 5 ing'of a rotatable furnace, combined with a a few minutes only, varying with the kind' burnerlocated.outside of said furnace, and "means for blowing the flame of said burner of ore. The-ore is sufficiently magnetized intosaid furnace and for admitting'a preinterior annularfiange near its opening. intot-he flue, for thepurpose of confining the heatandpreventing the escape of ore as much as possible consistently-with permit and avoiding .the smotheringof the flame, What I 'claimand desire to secure by Letters'Patent is: t i a 1. An'apparatus for treating ores in prep- .aration for magnetic separation, consisting of a rotatable cylinder having an air inlet opening, combined with a source of heat created outside of saidcylinder, and means for, projecting a blast of heat into said cylinder 40 and for admitting a predetermined amount- 'of air into the cylinder, whereby oxidation of, the contents of the latter is materially-re- .stricted. i

profitable separation, and the time of expreparation for magnetic separation, the-- into said furnace from said source of heat.

nace'a'nd independent of the natural draftpreparation for, magnetic separation, the

. the'latter.

.2. An apparatus for treating ores inprepthereby to enable the niost profitable-magnetic separation of the same to be made. 15 Practically all the ironparticles are sufliciently magnetized to result 'inthe most determined amountof air tothe furnace, 8 0 whereby oxidation of the contents of the 'po'sure to heat is too shortto' materially latter ismaterially restricted. waste theconstituents of the ore byoiridiz 6.. In an apparatus for. treating ore in 20 ing or volatilizing thesa-me; The rapid magnetization of the ore in the furnace is combination of an unlined metallic furnace, 86 faciliatated by-the previous heating of the a source of heat. created outside of said furore during its approach to'th'e furnace nace and. independent of the natural d'raft through the cylinder 24. v -I therethrou-gln'and means for projecting heat 7. In an'apparatus for treating ore 1n90,

preparation for magnetic separation, the. combination of an unlined metallic furnace, a source of heatcreatedoutside of-said furtherethrough, means for projecting heat into sa-idzfurnace from said source (if-heat, and means for cooling the walls .of-s'aid furnace.

SJIn an apparatus for treating ore in, combination of an unlined metallicfurriace,100 means for projecting a flame into said fur-' I nace produced by a burner located outside of the same and-for admitting a predetermined amount. 'of air to'the furnace, and means for causing a circulation of air over the exterior surface of the furnace to cool '9. In an apparatus for treating ore. in preparation for magnetic separation, the combination of 'a furnace, means-for feeding of afurnace, means for feeding ore through said furnace and subjecting it therein to the the ore through the same, means for proaotion of fire combined withmeans for cre jecting a blast of heat into said furnace, and ating and maintaining said fire outside. of subjecting the ore tothe action of the same,

' and a hood coveringsaid furnace and separated from the same b a slight space, with 11! means for artifica-lly circulating air through said space. I 10; In an apparatus for treating'ore in preparation for magnetic separation, a fur nace consisting of acylindrical shell, com- 12 bined with circular heads'detachably con nected together by longitudinal rods extend ing through the heads. H

11-.*In an apparatus for treating ore in d preparation for magnetic separation, a fur- 1A nace consisting of a cylindrical-shell, com bined with circular heads detachably con- =nectedtogether by longitudinal rods extend draft therethrough, said means also including means for admitting a predetermined amountof air into the furnace, whereby oxidation'of the contents of the latter is mate-v 551ria1ly restricted.

' 3. An apparatus for treating ores in prep aration for magnetic separation consisting of afurnace, and means for feeding ore through" said furnace and subjecting it means for creatlng and maintaining sai fire outside of said furnace, said means also including means for admitting a pre'deter mined amount of air into the furnace,

ing through the heads,c0mbined with means for projecting anon-oxidizing flame into" said furnace, and means for causing ac'irculation of air over the exterior surface'Of the furnace to cool the latter.

'12. Inan apparatus for treating ore in preparation for magnetic separationfla fur-- nace consisting of a cylindrical shell'and ,circular heads detachably connected together by longitudinal rodsextending through said 1 heads, combined Withmeans for projecting nesseSft-his a blast heat iniid said furnace and fdr mitting a pre'd'ec'ermine d amount of airtonae e1 In testlmony whereof I have'hereunto set] presence of two subscribing witmy hand in 28th dayof December, 1910. AMES B. ETHE-RINGTON. \Vi'tnesses:

HAROLD. C. HASKELL, ELMER L. BRIGGS. I

Images