US1359497A - Apparatus for the concentration of ores - Google Patents

Description

F. G. GASCHE.

APPARATUS FOR THE CONCENTRATION OF ORES.

APPLICATION FILED IUNEZOI 1919.

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APPARATUS FOR THE CONCENTRATION OF ORES.

APPLICATION HLED JUNE 201 l9l9.

Patented Nov. 23, 1920.

2 SHEETS-SHEET 2.

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FERDINAND GUY GASCHE, CI-IIGAG/D, ILLINOIS.

APEARATUS FOR GONOENTRATION O13 GEES.

Specification oiz' Letters Patent.

Patented Nov. 235i, 1926 Original application filed March 5, 1918, Serial 1%. 220A. Divided and this application filed June 20, 1919. Serial No. 305,480.

To all who m it may concern:

Be it known that T, FERDINAND G. Gnsonn, a citizen of the United States, and a resident of Chicago, county of Cook, and State of llliuois, have invented certain new and useful Improvements in Apparatus for the Concentration of fires, of which the following is a specification.

My invention relates to apparatus for the treatment of ore to effectuate the separation of the metal particles and metal-bearing portions from the lighter gang-us which comprises the greater bulk of the ore.

This application is a division of my application entitled, improvements in and for the concentration of ores, filed ldarch 5, 1918, Serial N umber 220,427.

it is customary to ship ores direct from the mines to large concentrators, smelters, or vyanid extractors, where the values are recovered and either purchased or returned to the miner. The initial cost and the operating expenses of such plants, and the low efi'leiency thereof when operated on a small scale, practically preclude any other method of ore disposal. Furthermore, the presentcost of concentrating ore and r recovering the values therefrom, makes it unprofitable to handle and ship any other than comparatively rich ores, with the result that low-grade ore remains umnined or if "lined is treated as waste and left upon the dump at the mine; and also, rich ore deposits remain unworked because too far di tant from a smelter or xtractor, or for lack of transportation facilities.

The object of my invention is to overcome these difficulties by enabling men of little skill metallurgists, and with little labor, to handle both high and low-grade ores and speedily, efliciently and economi cally concentrate the valuable parts hereof, in the immediate vicinity of the mine or dump; and where with little added expense the concentrates may be refined, or because of the reduction in bulk may be profitably shipped even to distant points for that purpose.

My invention comprises a novel concentratins; apparatus hereinafter described and particularly pointed out in the claims:

The invention will be readily understood on reference to the accompanying drawings which form part of this specification and in which: Figure 1 is a diagrannnatic that these drawings depict only the best apparatus which I have thus far devised, containing various novel features and combinations, but are not intended to imply that my invention is restricted thereto except where so limited in the claims.

Fig. 1 illustrates a mill and power house, 2, near which is the concentrating floor, 8, covered by a long shed, The house, 2, contains a suitably driven conveyor, 5, for feeding ore to the mill or pulverizer, 6. The latter is driven by an engine or motor, 7. The pulverized product leaves the mill through a swinging spout, 8, adapted to deliver the pulverized ore first to one and then to another of the tanks, 9. These tanks are closed at the top by means of hopper valves, 10. The bottom of each tank is in the form of a hopper and leading therefrom is a down-spout, 11, which delivers into a mix ing head, 12. This head, as hereinafter explained, contains devices for discharging the pulverized ore from the tanks into respective mixing chambers, 13. Each of these mixing chambers has an elbow, let, Which communicates with the gun or nozzle, 15, the details of which, in the preferred form, will be explained hereinafter. The house, 2, also contains an air compressing or blowing engine, preferably a turboblower, 16, of a two-stage delivery type. The outlet pipe, 17, thereof is connected to the system at points within the tanks, 9, as indicated at 22 and 22 in Fig. 1, within the heads, 12, and preferably also within the nozzle, 15, as better explained hereinafter. It will be understood that the two heads, 12, and their elbows preferably join a single gun or nozzle 15; that is, the plurality of tanks or reservoirs comprise means for continuously feeding the crushed ore to the gun, 15.

The gun, 15, extends through the wall, 4, of the shed, a, and preferably is positioned to discharge the ore horizontally across the concentrating floor, 3. Obviously the gun may be aimed up or down from the horizontal and thus is a change sometimes made for the purpose of compensating variations in the quality of the pulverized ore.

The floor, 3, may be a simple flat surface, but preferably is provided a plurality of orereceiving sections or hoppers. Thus may be distinguished, the hoppers 18, 19 and 20. The hoppers, 18 and 19, preferably equipped. with outlet conduits or tunnels, 18, and 19, respectively. The hopper, 20, may have one or more outlets, but as a rule none is required as it is upon this section that the rich concentrate is deposited and only a periodic clearing of that portion of the floor is required. Any suitable means may be employed for clearing the conduits or tunnels, 18, 19. The hopper 19 receives the poor concentrate, and my invention comprehends the return of the poor or low grade concentrate from the hopper, 19, to the mill to be reground and again discharged through the gun, 15. The shed has a closed far end, 4, which is pref rably inclined, as shown. The roof of the shed, or, if desired, the floor thereof, contains pressure relief openings, 21, and save for the necessary doors and windows, these may be the only openings in the walls of the shed.

Referring now to Figs. 2, 3, and d, for the details of the preferred form of my novel gun or nozzle, the parts before referred to may be identified as follows, to wit: The tank, 9, the downspout, 11; the head. 12; the elbow. 1 1; the gun or nozzle, 15; and the blower pipe, 17. lne branch, 17, of the pipe, 17, communicates with the pipes, :22 and 23, containing respective valves 22 and 23. The pipe, 32, leads thrr igh the side of the tank, 9, and is bent downu aidly so that it substantially enters the downspout, 11. At the lower end of the down spout is a casting, 12, which contains in its central bore a tube, 9/1, having at its lower end a valve seat, 25. and also a con cal face, 26. A valve, 27, co-acts with the seat,

25, to regulate the flow of ore from the Qfilllt This valve is carried bv a stem 28 having a hand. wheel, 29, on the exterior of the elbow portion. 13, 1 1. T he upper part of the part 13 contains an enlarged cavity, 30, which is continued in the cavity, 31, ot the'intermedia e casting or member, 12", the lzcad. Th s intermediate part contains an a istable conical ring, 32, which is in b e toward and from the cone. 26. to provide the conical air passa e. lVithin the p rt, 12. is an annular cavity, which communicates with the pine, E23, and hence with the conic l passage, A. combining tube, p esen s its large end to the lower end of the elbow. 141-. The small end of the combining tube, 35. delivers into the pipe. 36, one section. 36. of'wh ch pre erably is flexible. To

the fo ward end of the pipe. 36, I connect a second combining tube, 37, the tip of which is formed by a nozzle, 38. Attached to the part, 37, is a head, 39, which contains a central cavity, 10, and also an annular cavity, 11. The second branch, 17", of the blower pipe, 17, communicates with the cavity, 11. A face plate, 4L2, closes the end of the head, 39, leaving, however, a narrow annular crack or opening, 43, whereby communication is established between the cavity, 11, and the cavity, 40. .4. threaded opening, d3, contains a nozzle plug, 44:, which has a specially formed conical bore, d5, which is in exact axial alinement with the tip, 38, and the tube, 37. Attention is called to the slightenlargement or flare, 1-5, at the inner end of the bore, 15. A bridge arm, 4:21, that is in tegral with the plate, 43, contains a central bore, d2, which. holds the nozzle, 38, in

axial alinement with the tube, 3?, and in firm abutment with the end thereof. 1 have thought it unnecessary to refer in detail to the several bolts and flanges whereby the several members are joined. The forms, dimensions, and relations of the parts, 31 38, 45 and l5, will be explained in the course of the description of the operation of the apparatus depicted.

The operation is as follows: By means of a suitable mill, 6, the ore as comes from the mine or dump is pulverized, granulated or powdered with substantial uniformity. The degree to which pulverization should be carried is determined by the character of the ore, but in many cases it is suflicient if the pulverized ore is fine enough to pass through a twenty-mesh screen; and in pactically all cases a pulverization corresponding to forty-mesh screen will prove suiiicient. Finer pulverization ordinarily is too slow a. d too expensive and also malres a slower precipitation of the ore. Obviously, part of the ore will be reduced to a still liner state, leaving the larger particles of the maximum sizes indicated.

Compressed air from the blower 17, flows through the nozzle or gun, 15. The pulverized ore which is furnished by the mill is fed into this stream of a'; and taking on approximately the velocity of the stream. of air is thus ejected or discharged from the gun, 15. In practice a substantially uniform velocity is imparted to every particle of the ore, and all of the particles leave the mouth of the gun or nozzle, 15. at a substantially uniform and very high velocity. The velocity thus imparted would afford each particle of the ore a maximum trajectory of many times the length of the shed, 4i, were it notfor the force of gravity and the baflling or interfering effect of the air or atmosphere in the shed. Due to such impedance, the lighter particles of gangue are caused quickly to lose velocity and to settl upon the concentrating floor points not far remote from the mouth of the gun,

15. Particles of metal, on the other hand, being heavier, for a longer time resist the impeding action 01 the air and carry nearly or quite to the end of the shed before setting upon the floor. Uther particles of gangue which are burdened with small particles or quantities of metal fall upon the floor at an intermediate point. The high velocity which I impart to the particles by means of the air jet or blast, is not so much for the purpose of throwing tlm particles to great distances beyond the mouth of the gun as for the purpose of accentuating the reaction of the air in the shed against the particles, whereby l secure a clear and distinct separation of the particles according to respective masses and shapes, and enable even a very slightly burdened particle of gangue to penetrate the shed to a point beyond that to which the largest particle of unburdened gangue can proceed. With this as a measure of required service of the gun, it is a simple matter to ascertain the degree to which the ore needs to be pulverized and the pressure of air which needs to be main tained in the nozzle or gun.

in dealing with ores which contain several metals in a native or pure state, or substantially such. so far as concerns the respective specific gravities of the several metals or metal compounds, it is possible by the described means to secure an approximately clear separation of the several metals upon the floor of the space or hopper, 20'.

This it have indicated by showing, in dotted lines, several separate troughs or hoppers, :20, in the floor portion, 20. Beginning at the tar-end of the shed, these troughs may be taken to represent a series of metals. of different specific gravities, such as platinum, gold, lead, silver, etc. However, as a rule, it is suihcient to collect all of the rich or heavy concentrates in the hopper or floor section, 2t, leaving to the metallurgist the usual task of refining andseparating the same by chemical means, with or without the aid or". heat. It will be understood that the great bulk of t 1e pulverized. ore, to wit, the gangue proper, is deposited in the large hopper, 18. The discharge of the hopper, 18, may through the waste conduit or tunnel, whence the gangue is removed to a spoil bank, The low grade or poor concentrate deposited in the intermediate hopper, 19, iron whence it may be taken, tor direct reduction by tie metallurgist; but preferably 1 discharge the poor concentrate into the return duct, 19, and thence carry it back to the mill, 6, or to a separate mill if desired, to be reground and again projected through the concentrating gun or nozzle, 15, whereby a further separation of the metals from the gangue is secured, with a view to lessening the work of the metallurgist.

Dbviously a considerable volume of air is discharged into the shed, 4, and while it is desirable to maintain a slight pressure therein, whereby to increase the in'r eding action of the air upon the projected particles from the gun, there is of course a practical limit which must be observed, both to avoid disruption of the walls of the shoe, and it too great back pressure at the mouth of the gun; hence the provision of the valved vent or vents, 21, whereby a substantially constant low pressure condition may be maintained in the shed.

To avoid loss of extremely line particles of metal, the vents preferably are arranged approximatel above the gangue hoppers,

eyond which point the heavy particles are sure to be projected. This manner of venting the shed is attended by the advantage of the banking or" the air in the closed end 01" the shed, for the more certain precipitation of the metal particles and heavily loaded pieces of gangue after they pass over the floor sections or hoppers, 18 and 19.

Lest it be thought that this process entails the expenditure of much force in the compression of air, I will explain that an air-gage pressure of considerably less than forty pounds in the gun, 15, accomplishes the projection of the metal p isles to distances upward of one hundred :te t while the gangue particles seldom found beyond forty feet, and which therefore is fully adequate for the accomplishment of the separating or concentrating effect here described.

It will be understood that there is a top closure or "alve, 10, for each tank, and also a bottom closure or valve, 27, for each tank. lVhen filling a tank from the mill, the valve, 10, of course open, lo the valve, 2?, is closed. When the tank, I, is substa tially filled with. pulverized ore, the valve, 10, is closed. Thereupon compressed air from the pipe, 17, is admitted to the tank through the pipe, 22, and preferably also to the top of the tanl: through a branch pipe, 22. The maximum pressure of the system, say sixty-five pounds absolute pressure, is thus placed upon the material in the tank, 9 Then after closing the dis charge valve, 27, of the other tank, I open the like valve 27 of the tank which has been tilled and put under pressure; at the same time opening the valve, 23, belonging to the mixing head, 12-. Thereupon the pulverized ore under compulsion of pressure in the tank, 9, and aided by gravity and the exit oi air from the pipe, 22, flows through the opening between the seat, 25, and the valve, 27. Upon emerging therefrom, the or of pulverized ore receives the added impulsion of the full pressure of air flowing through the converging channel or jet, 26. By this means the burdening of an air current with ore is accomplished. The current of mixed air and ore passes swiftly downward through the elbow, 14:, and enters the crunbining tube or coniel passage, 35. Due to the shape of this passage, the pressure energy of the stream is in part converted into veloc'ty energy and the particles of ore talre on a higher velocity. Entering the communicating pipe, 36, at this velocity, the stream next encounters the second combining tube, 37, wherein the velocity of the particles is again augmented. ln consequence, the stream emerges from the tip, at a pressure considerably lower than the initial or starting pressure, but at a high velocity. To be exact, the pressure at the tip, 38, under the conditions of initial velocity developed. approximates fifty-eight per cent. of the initial pressure following the law of maximum o'lllun and has a velocity corresponding to that pressure;

ll it were possible to attain a suiilcient velocity it might be feasible to project the particles direct from the nozzle tip, 88; dispensing with the head shown thereon, but a stream projected from. such a nozzle tip,

due to immediate QXPEUlfI-llGll into the atmos phero, sets up detrimental conflicting movements among the ,)articlos, robbing some thereoi of the true trajectories which should be given. them it the best concentrating effects are to be secured. The head, 39, which I have invented, and the pressure of air which I use therein, not only suppress this objectional action, but also operate greatly to increase the linear velocity of the particles suspended in the stream of air. The first essential of this head comprises the secondary nozzle tip and mouth, l5, in the form of a conical passage, the inner end of which. is of the same diameter as the tip opening of the nozzle, 88, and the large end of which is outward. The function 01 this conical passage, whether or not forming a direct, or as shown indirect, continuation of the reversely tapered tip, 238, is to restrict the lateral expansion of the stream of air and thereby necessitate the linear ex pansiou thereof; whereby further velocity is imparted to the particles after leaving the tip, 38. If it were not for the outwardly flared passage, 45, the air would be permitted to expand abruptly on leaving the tip, 88, and the consequence of such uncontrolled expansion would be the deflection of some of the particles from their direct linear paths. By thus limiting thelateral expansion to that simple degree which directly responds to the d* p of pressure oc casioned by the unrestricted linear expansion, 1 able to convert the pressure energy of the stream into velocity energy and motion, whichis the force desired for the propulsion of the particles. Thus I secure the highest speeds derivable from the in steam itial or starting pressure at the pumping engine. or blower. V

F or the best functioning of the outwardly enlarged conical passage or mouth, 45, and for the presciwation thereof against the abrading action of the particles of ore, I provide means for two other purposes, to wit, means to prevent the lateral expansion or enlargement of the jet as it emer es from the tip, 38, and, second, means to derend the walls of the conical passa e, so, from the impact of the particles oi: ore which pass igh it. These purposes I accomplish 'ough the employment of the air chamber, a0, byjthe employment of a space or gap, l9, between the two parts, 2-38, and l i, and by admitting air under pressure to the chamber, lO, through the crack, leading from the space, l-l. The valve, which is included in the pipe branch, ii"

is preferably a pressure reducing valve, whereby the mum. pressure in the supply pipe, 17, is reduced in the chamber, i0, and made to equal the static pressure in the stream which from the nozzle, 38. Jponopening or freeing the valv 17, therefor, air is admitted to the chamber, l-0, at the stated pressure. This compressed air from the chamber, 4:0, finds escape in conjunction with and as an envelop for the jet which emerges from the tip, 38. To facilitate the forming of air-envelop around said jet, and. within the passage, l preferably reverse] bevel the intake end of said passa e 'os shown l. Obviously the emergj cannot expand within the gap, l0, tor LllQ reason that it iscncompassed by an atmosphere or the same pressure. Obvioi ly also. as the air from the chamber, 40, finds exit through the passage, the en velop which itiorrns upon the initial jet is preserved directly upon and against the walls of the conical passage, 45. this manner, the initial jet is prevented from expanding suddenly; also, is limited substantially to linear expansion within the passage and the walls of said passage are lubricated by the added envelop of air and thus are protected against abrasion by the particles within the jet.

It will now be understood that air coniposing the jet is allowed to expand substantially down to atmosphere by the time it emerges from the passage, L 3, and though it preserves its velocity, it is robbed or its capacity to disperse or laterally disturb the particles which it contains in suspension. It will also now be understood that by means of the compound nozzle here depicted, I secure a very valuable augmentation of the velocity of the particles of ore and what is ofgreat practical value, secure this effect This last is especially important when it is considered that the best efiects are secured only when the taper of the nozzle, 45, is determined by an exact mathematical calculation of that lateral expansion of the emerging jet which must be permitted to avoid the building up a back pressure or the impedance of linear expansion on the one hand; or an excessive lateral expansion and concurrent lateral displacement of particles on the other hand; wherefore, it is desirable that the exact predetermined shape shall as long as possible be preserved against an abrading or out action which would change its shape.

By way of example, drawn to accord with a mountain altitude and an atmospheric pressure 01" ten and one-hali pounds, it may be stated that an initial pressure of sixty? five pounds absolute in the blower pipe, 1-7, and hence at the openings or" the pipes, 22 and 2-3, affords a pressure closely approximating thirty-eight pounds absolute at the tip, 38; and in such cases the reducing valve, 17, is adjusted to maintain the same pressure, to wit, thirty'eight pounds absolute in the internal chamber, l0, oi the nozzle head. Under these conditions the conduit between the elbow l4, and the tip, 38, may be reduced to a length of approximately eighteen inches, and yet admit of the attainment of maximum velocity by the particles therein. in practice, I prefer that this dimension shall be increased one or more times as a factor for safety as well as for mechanical convenience. With the equipment shown and at the pressures indicated, the air is expanded substantially to that of the atmosphere on emergence from the nozzle, L5, and to the particles held. in suspension therein, there is imparted a substantially uniform velocity of about seven hundred feet per second.

My invention is not limited to the employment of air as the vehicle for carrying and expelling the pulverized material. for it will be evident that other compressed gases may be substituted; and likewise superheated steam may be used with substantially the same results as the gun or nozzle is concerned, but with the disadvantage of a wet concentrating shed due to the condensation of the steam therein. I desire also that it shall be understood that my invention is ap plicable to materials other than ore.

I claim:

1. An ore concentrating apparatus embodying therein an ore receptacle having a discharge passage therein; a conduit leading from the discharge passage; means for admitting air to the conduit to facilitate the flow of ore therethrough; and means at the terminus of the conduit for increasing the velocity of the ore; said means comprising a chamber in which the conduit terminates, a nozzle leading from the chamber, being spaced from the terminus or" said conduit, and having an outwardly flaring passage in axial alinement with the terminus of the conduit, and means supplying and maintaining an air pressure condition in said chamber substantially equal to the static pressure of the air that discharges thereinto from said conduit.

2. An ore concentrating apparatus embodying therein an ore receptacle having a discharge passage therein; a conduit leading from the discharge passage; and having a converging nozzle passage at its end; means for admitting air to the conduit to facilitate the flow ore therethrough; and means at the terminus of the condui for increasing the velocity of the ore; said means comprising a chamber in which the con verging conduit passage terminates, a nozzle leading from the chamber, being spaced from the terminus of said cont nit, and having an outwardly flaring passage in axial alinement with said converging nozzle passage, and means for supplying and maintaining an air pressure condition in said chamber substantially equal to the static pressure of the air that discharges there, into from said conduit.

3. An ore concentrating apparatus embodying therein an ore receptacle having a discharge passage therein, a conduit lead-- ing from the discharge passage, means for admitting air to the conduit to facilitate the flow of ore therethrough, and means at the terminus of the conduit for, increasing the velocity oi the ore, said means comprising two longitudinally separated tips containing oppositely tapered nozzle passages in axial alinement and presenting their small openings one to the other, and a chamber surrounding the inner tip, and means for supplying and maintaining an air pressure condition in said chamber sub stantially equal to the static pressure oi the air that discharges thereinto from said conduit.

4. An ore concentrating apparatus embodying therein an ore receptacle having a discharge passage therein, a conduit leading from the discharge'passage, means for admitting air to the conduit to facilitate the fiow of ore therethrough, and means at the terminus of the conduit for increasing the velocity of the ore, said means comprising two longitudinally separated tips containing oppositely tapered nozzle passages in axial alinement and presenting their small openings one to the other, the large opening of one tip leading to the atmosphere and at the inner end being reversely beveled, and a chamber surrounding the inner tip, and means for supplying and maintaining an air pressure condition in said chamber substantially equal to the static pressure of the air that discharges thereinto from said conduit.

5. The herein described velocity increas ing device comprising, in combination, two (outer ano inner) longitudinally separated tips containing oppositely tapered nozzle passages in axial ieinent and presenting their small openings one to the other, means for supplying a particle-laden aerii'crzn stream to one of said nozzles at a given veloeity and static pressure, a chamber sur rounding the gap between tips, n cans for supplying an aeriform fluid to said chamber at substantially the same static pressure as that of the particledaden aeriform stream issuing into ap, whereby lateral dispersion or the is prevented and an enveloping and a lubricating stream is formed for eharee through said outer tip with the particle-laden stream.

6. The herein described velocity increas ing head, comprising in combination a;

in. said chamber, a nozzle spaced from said conduit,-having a in axial alimement with the terminus thereof leading said chamber and daring outwardly, and means for supplying and maintaining an air pressure condition in said chamber substantially equal to the e To pressure of the lr that is to discharge into said chamber irom said conduit.

8. The herein described velocity increasing head chamber, a conduit terminating in said mber, nozzle spaced from said conduit having a in alinement with the terminus thereof leading from said out mrdly, and means chamber and .iari :tor supplying; ans maintaining an air pressure condition aid chamber substan tially equal to the atie pressure of the air that is to discharge into said chamber from said conduit.

9. An ore concent Q apparatus em hedying therein an 01 receptacle having a disc 'ge orifice, conduit leading from the discharge orificaa valve positioned in the discharge orifice adapted to regulate the how of ore therethreugh, and means for admi ting air to the conduit on the dis charge side of said valve, said means including a valve seat and. a member adjust able to and from the seat for regulating the flow of air.

in testimony whereof I have hereunto set my hand, this 28th day of May, 1919.

FERDINAND our GASCHE.

comprising, in combination a

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