US1141377A - Ore-concentrating apparatus. - Google Patents

Description

J. M. CALLOW.

ORE CONCENTRATING APPARATUS.

APPLICATION FILED on. 6, 1913.

Patented June 1, 1915.

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' APPLICATION FILED OCT. 6.1913- 1 1 4 1 ,3? Patented June'l, 1915.

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JOHN M. CALLOW, 0F SALT LAKE CITY, UTAH, ASSIGNOR, BY MESNE ASSIGNMENTS, 'IO METALS RECOVERY COMPANY, A CORPORATION OF MAINE.

ORE-CONGENTR-ATING APPARATUS.

Specification of Letters Patent.

Patented June it, 19315.

Application filed October 6, 1913. Serial No. 783,695.

To all whom it may concern:

Be it known that I, JoHN M. CALLow, a subject of the King of Great Britain, residing at Salt Lake City, in the county of Salt Lake and State of Utah, have invented certain new and useful Improvements in Ore-Concentrating Apparatus, of which the following is a specification.

My invention relates to a certain new and useful process of and apparatus for the concentration of metallic ores by separating the valuable metallic particles from the barren or rocky constituents thereof, as I will hereinafter described and claim.

In the accompanying drawings forming part of this specification and in which similar reference characters indicate like parts in the several views; Figure 1 illustrates a side elevation of an apparatus for the concentration of ores embodying my invention. Fig. 2 is a similar view of a series of tanks or agitating chambers on an enlarged scale showing certain of the chambers in section. Fig. 3 is a top plan view of Fig. 2.

This invention is distinguished from the usual amalgamation processes in which the ore formsan amalgam and it relates more particularly to what is now known as the flotation process, wherein a certain percentage of oil or of two dissimilar oils, or an oil and an acid, or an oil and an alkali, is mixed with finely ground ore pulp and the mixture then subjected to a violent agitation by means of mechanical propellers. The result is that large quantities of air are beaten into and entrained by the pulp, which action produces a froth composed of bubbles of air and oil to which the mineral particles are attached. This froth has the appearance of an aggregation or mass of fine and small soap bubbles which, when collectedand the froth discharged or broken down, by natural settlement or by the addition of cold water, or other means, displaces the mineral particles that have been caught.

The secret of successful flotation of ore particles, aside from the proper percentage of oil or other reagents, is the beating of large volumes of air into the pulp, because in the absence of air no froth will be formed, and in order to obtain the desired aeration of the pulp, mechanical. stirrers, or propellers have been adopted and are now in more or less general use in this art.

A leading object of the present invention is to simplify the aforesaid flotation process by eliminating therefrom the mechanical propellers, or agitators, for impregnating the pulp with thelarge volume of air which seems to be necessary, or. desirable, for aerating the pulp, and to this end the process portion of my invention has in View the addition to the pulp containing the proper percentage of oil, or other reagent, of compressed air which is introduced into the .pulp from beneath through some porous body, and in innumerable fine streams or jets, for the purpose of both aerating and agitating said pulp. The compressed air thus becomes the medium of (1) fully aerating or charging the pulp with'thedesired volume of air, and (2) it likewise induces and maintains that agitation of the pulp which heretofore was obtained by the mechanical propellers and stirrers before alluded to. As just stated, I introduce the compressed air into the pulp from below, and I admit this air to the pulp through a porous body to thereby subdivide the air into innumerable fine streams. The advantage of these steps will be understood and appreciated from the following: It might be imagined at first that equally good aeration could be accomplished by introducing air through a number of jets, say arranged about three inches apart, but this will not work satisfactorily as the volume of airnecessary to do the agitation, going through a restricted number of jets, would be so muchin volume from each jet as to cause a balloon of air, which, instead of making the froth, would destroy it, as the balloons of air would be too large to be maintained and would rise to the surface and burst, whereas when the jets are innumerable in numbar and infinitely small in size, the balloons are correspondin ly small, and are so small that when they use to the surface they will not burst, but will continue to accumulate and so form the froth which is the main object I have in view.

In the drawings I have shown for illustrative purposes one type of apparatus which may be successfully used in carrying out myprocess, but it will be understood that other and specifically different types of apparatus can also be used and hence I consider it within the scope of my invenvessel containing the pulp, whereby imme- 'water and which pulp ma diately upon the introduction of the air, a violent agitationor ebullition takes place and a froth begins to generate and to finally rise and form'on the surface of the pulp,

, from which it is discharged, as I will hereinafter describe.

Referring now to the accompanying drawings, A, is a feed-tank of any suitable character supported upon a framework which will elevate the tank a sufficient height to insure a satisfactory gravity feed of the pulp to the balance of the apparatus, it being understood that this tank is adapted to receive ore-pulp together with its carrying tank through a pipe line, A as indicated in Fig. 1. Disposed adjacent and above the feed tank isa vessel, C, adapted to contain one of the reagents, which I will call oil.

D is a vessel adapted to contain another reagent, which I will call an acid, said vessels, C, and D having suitable cocks or valves, by which the percentage of reagent, say oil and acid, admitted with the ore-pulp and water may be regulated, as desired. The oil, the acid and the pulp mix in the feed tank, A, and are conveyed therefrom by a pipe, E, to the first of a series of tanks or receptacles in which the pulp is agitated and aerated. I have shown four of these tanks or receptacles, F, F F and F for illustrative purposes, but it will be understood that the number of tanks used may be increased or diminished from what I have shown, without in any manner departing from the spirit of my invention.

The tanks or receptacles are preferably constructed alike and each consists of an outer casing of suitable form, dimensions and construction, and an interior easing K, of smaller size and spaced from the walls of the outer vessel to-form a circumscribing space, M, the purpose of which will hereinafter appear, said inner casing'having, preferably, a flaring or funnel-shaped upper end.

.In the upper part of the tank or receptacle, F, is suitably secured an invertedcone, S, the top or smaller end of which is disposedbelow the top of the tank, said cone having its lower part connecting with the inner wall of the tank so as to form a be fed to the regulation of the valve, 0, in relation to gutter, S, in the upper portion of the tank betweenthe cone and the inner wall of said tank. This gutter or launder, S, terminates in a spout, G, Fig. 3, at one side, and the spouts of the several tanks or receptacles, F, F, and F which as before stated are similar in construction and arrangement, connect with a side launder or trough, H, which conveys the contents of the several gutters or launders, S, into an appropriate feedbox, I, from which box the contents are delivered by a pipe or down-take, J, into the final tank or receptacle, F", which I will hereinafter designate as a cleaner, while the first three of the tanks, F, F and F I designate as roughers. As before stated, the tanks have substantially the same design and construction, and the frothy concentrates made on the first three of the tanks are conducted by the side launder or trough, H, into the feed box, I, and then are conducted into the cleaner, F through the pipe, J. 1

In the lower portion, of the inner casing, K, of each tank or receptacle and elevated a suitable distance above the bottom thereof, is a porousmedium, L, which is supported upon suitable brackets, or other rests, L. By elevating this porous medium above the bottom of the tank or receptacle, I am permitted to form between the bottom of said medium and the bottom of the tank, a chamber, P, which is cutofi' from communication .with the upper portion of the tank, and with the pulp contents thereof, except through the pores of the medium, L, and

-which medium is centrally pierced to admit itself through the upturned end of the pipe,

and directly into the main chamber of the vessel above said porous floor, or medium, L, referred to. In practice, the pulp is allowed to run into the tank or receptacle, until the latter is partly filled, the level of the water being variable according to the conditions of the ore and the work to be accomplished.

As before stated, a space, M, is formed between the inner and outer casings of each tank, and this space forms a gutter or channel which connects with a discharge pipe,

N, having a valve, 0, which controls the height of the waterin the vessel by restrictmg the discharge. In other words, by the the amount of feed, any level of pulp inthe vessel, F, can be maintained. The pipe, N, from tank or-receptacle, F, leadsinto the-f second tank, F and through the porous medium, L, therein and the discharge from a shield or deflector, R. The pipe,

' receptacles, including the cleaner, F and to this end, I admit the compressed air through a pipe, Q, from which a valvecontrolled branch, Q, leads through thebottom of the tank and into the space, P, between the sameand the under part of the porous medium, L. To prevent the air from impinging directly upon the porous medium immediately above the inlet end of the pipe,

, I place over the discharge end of tae pipe y be otherwise disposed, but in any event its function is to admit into the chamber between the bottom of the porous medium and the bottom of the tank proper, a volume of compressed air.

The porous medium may be of any suitable construction and material; porous brick, or a layer of fine sand between two restraining layers of screen cloth, or layers of fibrous material laid one above the other, such for instance as cocoa matting, or certain kinds of porous wood, such as bamboo, may be used, or in fact any porous material through which air can be forced in more or less irregular jets of infinite number and fineness. The character of the porous material employed is, therefore, unimportant, ex-

- cept that it shall have the property of permitting the air introduced into the chamber, P, to be discharged through the pores of the material throughout the entire surface thereof, and into the body of pulp in thechamber above, with the result that immediately upon the introduction of the air, a violent agitation or ebullition takes place, and froth is observed to rise and form on the surface of the pulp contents, which greatly increases in volume and density as the action proceeds. As the froth accumulatesabove the surface of the pulp within the vessel, F, it overflows the rim of the in side top cone, S, and continues to do so as long as the tank or vessel is supplied with the necessary ingredients of pulp, oil, acid and compressed air, and the overflowing froth is received into the gutter or annular launder, S. and finally is delivered into the feed-box, I, through the side launder *or trough, H. During this agitation of the pulp and the formation of the froth, the tailings settle into the annular space, M, formed between ffiflfili aid theinner cas in K. thereof, and the discharge of these tailings takes place through the discharge pipe, N, and through whichpipe, the particles which are too heavy to float in the first tank and which have settled into the annular space, M, thereof, are delivered into the succeeding tank, F this action occuring in all of the tanks, and the Waste material being delivered from the final or roughing tank, F through the discharge pipe, W, before mentioned. In other Words, the discharge from the first tank, F, makes feed for the succeeding tank, F and the discharge from the latter in turn makes feed for the next tank, F Each of these tanks in turn makes a frothy concentrate in the manner before described, and the froth of the several tanks is in turn led to the feedbox, I, from which latter it is discharged into the cleaner tank, F where a similar action occurs, and the rough or crude concentrates made on the first series are cleaned, or further refined by a similar action in the tank, F the concentrates being discharged therefrom through a side launder, U, and the tailings being delivered from the bottom of the tank, F, by means of a siphon-pipe, or otherwise.

It is customary to conduct the discharge from the cleaner tank, F back to the original feed so that it may be again and again acted'upon, and to this end, I have shown in Fig. 1, the use of a pump, 10, for conducting the discharge from the cleaner tank back to the feed tank, A, through the medium of a suitable pipe, 11. It will also be observed that in each of the tanks between the flaring top of the inner casing, K, and the top of the cone, S, I have shown three or more diaphragms, X, X and X These diaphragms extend clear across the pulp chamber and are arranged in parallel order and are perforated; the perforations may be of the same size, or they may vary in fineness from the diaphragm, X, to the diaphragm, K the lowermost of-the diaphragms having the coarsest perforations and the uppermost diaphragm the finest. These perforated diaphragms form baflies and serve the-purpose of preventing eddies or isolated or seggregated currents within the machine. At the same time they serve the purpose of sustaining the froth and though not indispensable to the forming of the froth, yet at the same time, they have the effect of increasing the efficiency of the apparatus.

From the foregoing it will-be understood that no mechanical propellers are used for producing the necessary agitation and heating into the froth of arge volumes of air and which propellers usually require all the way from 7 to 15 H. P., to operate. Thus the power and the wear and tear incident pulp, in my invention, is the small amount to'the machinery usually emp y to I of compressed air used in the agitation, which would not be more than 1/10 of that required by mechanical propellers. The simplicity of-my apparatus is self-evident.

Its efliciency also is much higher in the recovery of the values, as instead of depending upon the hit or miss method of forcing air into pulp-by means of mechanical agitators, the airis introduced in the more simple and logical manner herein described, namely, in the form of innumerable fine streams or jets which. are distributed over the entire surface of the vessel containing the pulp, it having been found by experiment that by admitting alarge volume of air in the form of innumerable fine streams I fully impregnate the pulp with the air and cause the formation of froth-in the form of fine bubbles of air enveloped in the reagent and which bubbles are so small that when they rise to the surface-1 they will not. burst, but will continue-to accummuiate so that they may overflow and be delivered through the launders before mentioned.

Having thus described my invention what I'claim as new and desire to secure by Letters Patent'isz 1. In apparatus of the character described, the combination of a tank or receptacle' adapted to receive ore pulp and a substancehaving the property of frothing "in the presence of a gaseous medium and agitatien, a casing within the lower portion of the'tank and separated therefrom to form a surrounding space or chamber, a -body of ,porous material within said inner casing and siippdrted above the bottom thereof so as to form a chamber between said porous body and the bottom of the tank, a feed-pipe terminating in the lower portion of the tank above the porous body and adapted to deliver the pulp into the casing above said body, a pipe leading into the chamber below said porous body and adapted to admit a gaseous medium under pressure thereinto,

said porous body subdividing the gaseous medium and distributing the same irregularly substantially throughout the entire surface of the pulp, and a. discharge means connecting with the space or chamber be:

tween the inner casing and the tank and adapted to deliver therefrom the heavier material which has settled into said space.

'2, In apparatus'of the character described, the combination of a tank or receptacle adapted to receive ore pulp and a substance having the property of frothing in the presence of a gaseous medium and agitation, a

' casing within the'lower portion of the tank and separated therefronnto form a-surrounding space for chamber; a "body .ofporous materialwithin said" inner casing and supported above the bottom thereof so as to form a chamber-between said porous body and the bottem of the tank, a feed-pipe terminating in the lower portion of the tank above the porous'body and adapted to deliver the pulp into the casing above said body, a pipe leading into the chamber below adapted to receive ore pulp and a substance having the property of frothing in the presence of a gaseous medium and agitation, a casing within the lower portion of the tank and separated therefrom to form a surrounding space or chamber, a body of porous material within said inner casing and supported above the bottom thereof soas to form a chamber between said porous body and the bottom of the tank, a feed pipe terminating in the lower portion of the tank above the porous body and adapted to deliver pulp into the casing above said body, a pipe leading into the chamber below said porous body and adapted to admit a gaseous medium under pressure thereinto, said porous body subdividing the gaseous medium and distributing the same irregularly substantially throughout the entire surface of the pulp, a discharge means connecting with the space or chamber between the inner casing and the tank and adapted to deliver therefrom the heavier material which has settled into said space, and a cone-shaped member in the upper part of the casing below the top thereof and through which the accumulating frothy contents of the tank pass and over, which they are discharged.

4. In apparatus of the character described, the combination, of a tank or receptacle adapted to, receive ore pulp and a substance having the property of frothing in the presence of a gaseous medium and agitation, a casing within the lower portion of the tank and separated therefrom to form a surrounding space or chamber therebetween, a body of porous material within said inner casingand supported above the bottom adapted to deliver pulp into the casing above said porous body,'a pipe leading into thev chamber below said porous body and adapted to admit a gaseous medium under pressure' thereinto,said porous, body subd1v1dmg said gaseous medium and distribproduced in the tank is allowed to overflow, and means for conducting the froth from said gutter.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN M. CALLOW.

Witnesses:

F. W. NIXON, O. M. OWEN.

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