US1289800A - Ore-reducing furnace and process. - Google Patents

Description

ORE REDUCING FURNACE AAAAAAAAA S.

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ORE REDUCING EURNACE AND PROCESS. AmilcATloN FILED FB. z. 915.5 RENEwEn Nov. 2.1918.

LSS. Patented Dec. 31, 1918.

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JOHN T. JONES, OF MARQUETTE MICHIGAN, ASSIGNOR TO NEW METALS-PROCESS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ORE-REDUCING FURNACE AND PROCESS.

Specication of Letters Patent.

Patented Dec. 31, 1918.

Application led Februaryv23, 1915, Serial No. 9,908. Renewed November 2, 1918. Serial No. 260,913.

To all whom t may concern.

Be it known that I, JOHN T. JONES, a citizen of the United States, residing at Marquette, in the county of Marquette and State of Michigan, have invented a new and useful Ore-Reducing Furnace and Process, of which the following is a specification.

The present .invention relates to furnaces adapted to the practice of a bathless method of recovering metals from metal oXid or carbonate ores, or the like. The improved furnace is adapted to the practice of an improvement upon the process described in the application of John M. Longyear and myself, No. 9,889, filed in the United States Patent Oice of even date herewith, the process referred to constituting an improvementV upon the process set forth in the application of Albert G. Jones, No. 827,358, filed March 26, 1914.

The present invention is illustrated in its preferred embodiment in the accompanying drawings, in which- Figure 1 represents a broken vertical sectional view of an ore-reducing furnace constru'cted in accordance with the invention, the section being taken as indicated at line l of Fig. 2; Fig. 2, a plan section taken as indicated at line 2 of Fig. l; and/Fig. 3, an enlarged broken, vertical section taken as indicated at line 3 of Fig. 2.

In the construction illustrated, A represents a furnace-shaft comprising a soakingpit A', a superposed de-oxidizing chamber A2, and a plurality of superposed pre-heating chambers A3, A4; B, B, a plurality of series of adjustable twyers extending through the side walls of the furnace and disposed at a plurality of different levels; C, C, standpipes which may contain air under small pressure, the air being supplied by a fan or compressor C; C2, laterals extending from the stand-pipes and communicating through pipes l with the adjustable t-wyers B, the pipes 1 being provided with regulatingvalves la; D, D, means for charging a mixture of distilled solid fuel (coke or charcoal) and ore-portions substantially isolated therein into the upper portion of the furnace; and E, means for charging fresh solid fuel containing hydrogen and hydro-carbons (coal or wood) directly into the de-oXidizing chamber A2. ,y

The furnace-shaft A may be of any suitable construction and of any desired shape. It is preferred to make the furnace-shaft of rectangular cross-section, the width of the shaft being relatively small and the horizontal length of the shaft being as large as desired, depending upon the capacity desired. The internal short dimension of the shaft may be vfour to eight feet. One lateral wall of the furnace-shaft is provided with a series of internal projections 2, and the other lateral Wall of the furnace is provided with a series of internal lateral projections 2a, which are staggered with relation to the projections 2; that is, the projections 2 are disposed at a'plurality of levels, and the pro-l the lower walls of the projections are underj cut. lThe result is to provide an npr-ight zig- -zag channel of substantial, but relatively narrow, width, andv of comparatively large horizontal length, giving somewhat the effect of a great rectangular chimney with a single upright zig-zag form passage adapted to contain a stack of superposed burden-sections of a comparatively few feet in thickness corresponding with the horizontal transverse dimension of the furnace-shaft, and of a comparatively-'large horizontal length, corresponding with the long horizontal dimension of the furnace-shaft. rlhe internal projections of the furnace-shaft are of such substantial character as to almost, but not quite, support the burden-sections, the purpose being to prevent undue compacting of the materials in the furnace and the crushing of the distilled fuel, which would interfere with the practice of the bathless metallizing process. rlhe adjustable twyers B are associated with the internal projections of the lateral walls of the furnace, and may extend a greater or less distance into the furnace, being adapted to aord supplemental supports for the burden-sections, as well as to introduce air into the burden-sections at a plurality of levels. The twyers are so adjusted I as to permit a slow downward gravitation ofv the burden-sections; and the internal 'pro- -jections of the furnace walls arel so limited and sloped as to permit this action to occur,

while preventing the direct transmission of solid fuel, gangue, and metals in solid form,

may be discharged into water-baths 5. The discharge means illustrated is to be regarded as a conventional form of any suitable dis' charge means.

The means D shown for introducing distilled solid fuel (coke or charcoal) and ore into the upper portion of the furnace comprises hoppers having chutes 6 extending through the lateral walls ofthe furnace, the hoppers being equipped with closures 7 The devices D are toy be regarded as conventional examples of any suitable means for introducing solid fuel and ore into the upper portion of the furnace.

The means E comprises a hopper or ho pers, and it is to beunderstood that such form is selected merely for the purpose of illustration.

Assuming the furnace to bein operation, the stack of materials fills the furnace from the bottom to the chutes 6, thus forming a afforded by the ru imentary staggered botv toms 2, 2, which, while sufficient to prevent the transmission of crushing 'stress from the top to the bottom of the furnace, will nevertheless permit the slow settling of the stack of lmaterials as materials are withdrawn from the bottom of the furnace. The stack -of materials is replenished by the proper charges lof distilled solid fuel and ore-portions substantially isolated therein, introduced througlh the charging-devices D at the top of the rnace; and the supply of distilled solid fuel is replenished 'by fresh solid fuel introduced through the charging-device E directly into the deoxidizing chamber A2, it being understood that the fresh" Solid fuel. supplies within the de-oxidizing chamber hydrogen gas Aand carbo-hydrates which are highly efficacious in the metallizr -ing operation, while the distilled Solid fuel which is thus produced serves as a constant sfplu'ce forreplenishment of dist-illed solid Air is supplied through the lowermost twyers to the chamber A2.in limited quantity, but suiicient to produce in the chamber A2 a high-tem erature de-oxidizing medium and a metalxing zone. The temperature in the lower portion of the chamber A2 should exceed 2000 F. for iron, and usually a temperature'of 3000 F. is ample for re ducing iron-ores, ferro man,=,vanesev ores, and the like. .Much depends upon the character of the ore, however. n dealing with lean ores containing some natural iux, too high a temperature is desirably avoided. T he air i supplied at the other levels of the furnace is so regulated as to afford a progressive reduction in the temperature as the top of the furnaceA is approached, somewhat as indi` catedby the temperature-scale Shown .on Fig. 1. It will be understood that a zone of intense heat is produced in thevicinityof the inner ends ofthe lower twyers and that the carbon dioxid produced in that zone changesto carbon monoxid as the gases ascend inthe chamber A2. Owing tothe hightemperature maintained in the chamber A2,

a rapid interchange 'of oxygen occurs, and' the metal ores are rapidly robbed of their oxygen, and asthe metalhzingoperation proceeds, the metals are fused, or partially fused, and agglomerated or run together,- `thus producing metal bodies of tangible size, ranging from small meshes to large chunks. Inasmuch as-theore-clusters are substantially isolated in the solid fuel, the

production of a bathis avoided, and the metal freezes as itdescends to the chamber A. Isolated pools of metal may be produced, and likewise isolated pools of gangue, especially where the ore contains a natural iux, may be produced, which will congeal as the'ore descends. No lime or other flux need be introduced with the charge, however, 'as general fusing ofthe chargeistobe avolded.

It will be understood that somewhat in-` tense zones of heatV will be produced at the inner ends of the several series of twyers, the heat in these zones becomlng of less and less ico intensity as the upper end of the furnace isA that the solid fuel is attacked less and less as the upper end. of. the furnace 1s approached, and {inally the combustible gasesA produced b elow are burned with the .air introduced through the upper twyers, 1n contact with the entering fuel and ore, and thus serving to preheat thesematerials,without' atapproached. "Thus, it will beY understood tackng the solid fuel, the products of combe burned to a state of-complete combustion,

under .ideal conditions. As anillustration,

ortions, will be carried wholly through the in dealing with a high-grade iron ore, the materials may be used in the proportion of 400 pounds of coke, 100 pounds of bituminous coal, and 25() pounds of ore, the fuel having approximately twice the weight of the ore and being approximately five times as large in volume as the ore. If wood and charcoal be used in place of coke and coal, the disparity in volume is much greater. For illustration, with 2240 pounds of ore one may use 96 cubic feet of charcoal and 32 cubic feet of wood. The proportions may be variedto gain the best and most economical results. In any case, it is preferred to use the fuel mainly in large block or lump form, although this is not indispensable. The coke (or charcoal) is used over and over again, being gradually reduced in size but being` constantly replenished by freshly formed coke (or charcoal) when the process is carried on in the preferred manner.

The separation of the metals, gangue and distilled solid fuel, after removal from the bottom of the furnace, may be effected in any desired manner.

In practice, the method of feeding materials to the furnace may be varied, according to conditions. 1f green or wet wood be used for fuel, it may be fed in at a higher level, so that the water will be driven oif before the wood reaches a lower and hotter zone. ln such case, the wood will be thoroughly dried and somewhat charred during the pre-heating, the volatile hydro-carbone being mainly liberated at a ,flower l:level where they can be utilized most effectively. In some cases, it may be desirable to feed all or a large portion of the fuel in at a lower level than that at which the ore is fed."

Much will depend upon the character of the ore and the solid fuel used. ln any event, it will be necessary to maintain suficient interstitial passages for the air and gases through'the burden; and it will be necessary to maintain a large preponderance of solid fuel in the lower, hotter zone.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitation should be understood therefrom, but the appended claims should be construed as broadly as permissible in view of the prior art.

lihat l regard as new and desire to secure by Let-ters Patent is- 1. An ore-reducing furnace having walls forming a tortuous upright passage adapted to contain a stack of solid fuel and ore-portions isolated therein and afford supports at intervals for the burden-sections, and twyers disposed at a plurality of levels and adapted to supply air in such limited quantities to the burden-sections as to produce a deoxidizing atmosphere. 2. An ore-reduclng furnace comprising soaking-pit equipped at its lower portion with means for removing' unconsumed solid fuel, gangue and metal in solid form, a

superposed de-oxidizing chamber, means for charging fresh solid fuel into the deoxi'dizing chamber, superposedpre-heating chambers having walls provided with staggered internal projections, twyers disposed at a plurality of levels and serving to furnish limited air-supplies to the pre-heating chambers, andmeans for charging distilled solid fuel and ore-portions mixed therein into the upper portion Aof the furnace.

4. An ore-reducing furnace comprising a soaking-pit provided with discharge means, a superposed de-oX-idizing chamber with a contracted passage between said chambers, means for supplying air to the de-oxidizing chamber, a series of pre-heating chambers above the de-oxidizing chamber, the walls thereof having internal projections arranged lin staggered relation, a plurality of series of twyers arranged at a plurality of levels for supplying air to the pre-heatinr chambers, and means for charging solid uel and ore into the upper portion of the furnace.

5. In an ore-reducing furnace, the combination of a shaft provided with a series of internal staggered burden-section supports, adjustable twyers disposed at Aa plurality of levels and associated with said internal supports,`means for supplying air in limited quantities to said twyers,and means fory charging solid fuel and ore mixed therei into the upper end of the furnace.

6. 1n an ore-reducing furnace, the combination of a shaft provided with side walls spaced a few feet apart and provided with end walls, internal projections carried by the side walls and arranged in staggered relation, a series of horizontally arranged. adjustable twyers associated with the internal projections'at diiferent levels, means for supplying air in regulable quantities to said twyers, and means for charging solid fuel andere into ,the upper. portion of kthe furnace. I l

7. The fbathless process of metallizing ores, which consists in supporting burdensections composed of solid fuel and oreportions substantially isolated therein, in

aiczd substantially independent support to the burden-sections and eiect turning mixing 'of the materials as the stack settles slowly, introducing and burning in the 5 lower portion of the stack air in such quantity as to produce a high temperature metalfixing zone and a high temperature de-oxidizing medium aibove said zone, and intro?.

ducing and burning air in limited quan- 10 tities at a plurality of higher levels in and,

such manner as to attack `the solid fuellessvand less as the upper portion of the stack is approached, finally burning thecombustible gases to a state of practically complete com at the upper portion of the stack.

JOHN T. JONES. In the presence of- ALBERT G. JONES, E. W. JONES.

ustion Without attacking the solid-fuel 15

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