US1351096A - Apparatus for separating or concentrating ores - Google Patents

Description

D. COLE.

APPARATUS FOR SEPAHATING OR CONCENTRATING ORES.

APPLICATION FILED DEE-1,5925.

Patented Aug. 31, 1920.

2 SHETS-SHEET I.

D. CQLE APPARATUS FOR SE PARATING GR CONCENTRAHNG ORES.

APPLICATiON nuzo mama. ms.

' 1,351,096, Patented Aug. 31,1920.

2 snzrs-snan 2.

314mm fox uNIrsosrA'r s PATENT OFFICE.

.DAVID COLE, .OF EL PASQ, TEXAS, ASSIGNOB J10 MINERALS SEPARATION NORTH AMERICAN CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF MARY- APPARA'IUS FOR SEPABATING 0R CONGENTRATING ORES.

Patentedv Aug. 3t, 1920.

' Original application filed August 3 1915, Serial No. 43,444. Divided and this application filed December 4, 1915. Serial No. 64,993.

of the United States, residing at El Paso,

in the county of El Paso and State of Texas,

. have invented or discovered certainnew and useful Improvements in Apparatus for .Separatmg or Concentrating Ores of whlcb the tol lowing is a specification, re erence be had therein to the accompanying drawlhis invention relates to the separation and concentration of orcsand mineral-s by the flotation method wherein that part of the oral-liable portion which has been pulver- 126d too fine to be readily concentrated by gravity separation, water, is caused to be attached to bubble films and is carried over the top of the vessel or -'oontainer in the froth which accumulatesupon the-surface of the water and pulp when the mass is properly aerated; and'wherein that part of the valuable portion not made fine enou h to be lifted by the rising bubbles and 0 carried over by theit'rot'h as beitore mentioned, will readily falhand may then be successtully and easily separated by the usualgra-v ity system of concentration;

in the application 02E flotation methods two distinct divisions are recognized, in the older one of which violent agitation is created by-the rapid revolution of stirrer's or impellers, which has the effect of drawing air into the pill and mixing it intimately with the mass. ll his method IS expensive to operate because it uses powerjnefliciently.

In theother division, which is known as the pneumatic method, air is introduced into the pulp through filtering mediums forming the [lat horizontal, or inclined bottoms of the tanks, and theprocess is embarrassed by the settling upon t ie porous mediums of sands and mmera'l grains too coarse to be held. in suspension or moved far by the rising bubbles of air. Because it is essential that the airbe in very small bubbles in o rder to obtain efiicient and satisfactory results in these aration of the minerals, and since small bu bles have little lifting power and do not cause violent agitation, 1t has beenfound impossible in practical work ontirely to prevent the clog 'ng of the air filtering mediums oxce it won all grains are of very small size. *orcing air under relative'ly high pressure and in large volume through coarser, porous, filtering mediums will prevent the lodging of particles and blinding of the filter, but the violent agigation of' the mass undergoing treatment will then pro-vent the proper formation of froth and thus prevent the efiicient degree of separation-of'the mineralstha't is sought.

In the older machines before mentioned, depending upon mechanical agitation, it is necessary to move the material under treatmeat from one cell to another in a long series or" them'for repeated treatment, in order to get an efiicient result, and the passages between the difierent cells can only be successfully keptv open and operated when the sands in the food are exceedingly fine and easily kept in suspension. Thus both divisions of the present best practice are limited so far as sizes of sands or ore are concerned to what is known as slimes .or exceedin 'ly fine sands, and neither of these metho is adapted to the handling of relatively coarse unclassified material.

In the practice of ore concentration for the separation of minerals it is only necessary for the crushing operation to be carried far enough to liberate the valuable mineral crystals from their gan -us or matrix so that they may be separated into difierent classes. Grinding to a point finer than this, (for the purpose of bringing the maximum sized grams within the range of flotation treatment as above outlined) involves a much increased expenditure for crushing that would not otherwise be necessary.

In order to simplify the operations and reduce the amount of expenditure by eliminating, to a maximum extent, the necessity of pulverizing the ore and minerals beyond the economical point previously explained, the eilic'ient practice of the flotation method of separating minerals involves, over the present state of the art, the successful and practical Working out of the following des'iderata: v

First: Providing a grated air admission filter-or diaphragm, cflic'ie-nt for aerating purposes and afl'ording ample passageways for the falling pulp and Water so that veloci-ties will be slow and no bubbles will be taken throu h the grates with the rejections.

Second: I roviding an air admission medium having the functions of the first item and whose air emitting surface is so arranged and disposed that material falling upon it will not be retained to clog the filfaring surface or impede the free How of an'.

Third: Providing an air admission medium having the functions of the first and second items and which will allow the easy passage of air outwardly into the pulp and water under treatment, but will allow the passage inwardly, under hydrostatic pres sure, of clear water only, thus preventing the blinding of the air emission filter from the deposition of solid matter on the inside of same.

Fourth: Providing a frothing machine of large capacity utilizing the filtering system mentioned in the foregoing items, into which it will be possible toput the product made by the grinding machine, at relatively coarse sizes, directly and concurrently, without the introduction of intermediate screening, sizing, hydraulic or other classification, to the end that the mineral values already fine enough for taken out first and as fast as produced by the grinding operation, thus making sure that the slimed minerals will be thoroughly combed out of the pulp being treated before it is subjected to the gravity treatment which follows for the purpose of collecting and separating the coarser rains of liberated mineral too coarse to he amendable to the irothing method of separation.

Fifth: Providing frothing Sizer of large capacity in which the stream of pulp under going flotation treatment will gravitate longitudinally through a succession of aerating compartments in such a way that the heaviest and largest sand particles which fall fastest will be lodged in the first hopper-ed subdivision of the tank, and successively smaller particles be deposited in the hoppers arranged successively farther from the point of entry for the pulp under treatment.

Sixth: Providing a frothing machine of large capacity which will, concurrently with the frothing operation, separate the portion which falls, into two or more classifications or sizes, so that one or more of the coarser sizes still containing grains of unliberated or included mineral may be returned to the grinding machine to be further pulverized.

The present invention has for its general object the provision of an im roved sizing classifier capable of fulfilling a l of the foregoing conditions, and especially the fourth, fifth, and sixth.

Other and more particular objects of the invention, together with means whereby the same may be carried into efl'ect, will best be understood from the following description removal by flotation may be 7 of one form or embodiment thereof illus trated in the aceol'npanying drawings. It will be understood, however, that the particular construction described and shown has been chosen for illustrative purposes merely, and that the invention, as defined by the claims hereunto appended, may be embodied in other forms without departing from the spirit and scope thereof.

in said drawings Figure 1 is a longitudinal vertical sectional view.

Fig. 2 is a transverse section on the line 2-2 of Fig. 1.

As shown the classifier or sizer comprises a tank 14 having, at one end, an inlet 15 with which a trough or chute l3 COJDlIllllllcates, and at the opposite end an outlet l6. 1'? denotes a sliding gate arranged within the tank 14 adjacent the inlet 15 but spaced from the latter, said gate being vertically adjustable in uides 18 by means oi a hand wheel 19, '1 1e gate 1? serves to deflect downwardly the n'iaterial entering at the inlet 15, and by adjusting said gate the effective height of said inlet may be controlled. 2O denotes a sliding gate adjacent the outlet 16 and adjustable in guides 21 by means of a hand wheel 22. By adjusting the gate 20 the effective height of the outlet, and consequently the normal level of the liquid in the tank 14, may be controlled. 23 and 2 L denote haille plates arranged adjacent the gate 20 for securing a gentle and even discharge of the liquid from said tank over said gate into the outlet 16 and for preventing the discharge of froth at this point.

The bottom of the tank 14 is composed of a longitudinal series of hopper-shaped sizing compartments 25. Four of these compartments are shown in Fig. 1, although the precise number may be in accordance with the requirements. Cooperating with the compartment 25 at the end of the tank 14 adjacent the inlet 15 is an elevator operating in wells 56 within the sides of the tank, said elevator comprising a belt 27 carrying buckets 26 and passing over an idler pulley 28 and a supporting and actuating pulley 29. The pulley 29 is mounted on a shaft 30 suitably journaled above the tank 14 and adapted to be rotated from any suitable sourceof power by means of a belt pulley 31. Adjacent the pulley 29 the buckets 26 discharge their contents into a suitable chute 32. The remaining compartments 25, or those adjacent the outlet end of the tank, as shown, are provided with hydraulic or pneumatic lifts or ejectors 33 adapted to discharge material accumulating 111 said compartments into chutes 34 top of the tank and adapted to conduct said material to suitable concentrating tables (not shown) or elsewhere as may be desired.

arranged at the Lemons" The elevator 26, :27 and hydraulic or pneumatic lifts 33 are merely illustrative-of convenient means for discharging the material accumulating in the comipartments 25, and while such means are pre erred it is obvious that said material might be otherwise discharged, as by providing said compartments with openings in their bottoms through which the-material could be withdrawn into suitable chutes or other conveying means beneath the tank 14. Also while in the construction shown only one of the compartments 25 is arranged to discharge its contents into the chute 32, an suitable number of compartments at the i ct end of the tank may be so arranged, the essential idea being that the material from one'or more of the compartments 25 at the inlet end ofthe tank be discharged separately, as into the chute 32, from the material in the remaining compartments at the outlet end of the tank which are discharged into chutes 34.

36 denotes launders arranged to receive material overflowing the top of the tank 14. As herein shown two of said la-u-nders are provided, one at each side of the tank within the same, each of said launders discharging throu h an opening 37 in the side of the tank midway of the length thereof, the material passing out from said openings being conveyed by troughs or other means (not shown) to any desired point.

Air is admitted to the tank 14 through a series of horizontally disposed filter or air tubes 35. Said tubes, in theconstruction shown, extend transversely of the tank and collectively constitute a tubular grating which extends substantially throu hout the length of said tank so as to cover the entire horizontal cross sectional area thereof at a level above the sizing compartments 25. The-tubes 35 are so constructed as to have a finely porous air emitting surface, whereby compressed air supplied to said tubes is discharged into the tank in a finely divided state and passes upwardly through the liquid in' the tank in the forrn of numerous streams of fine bubbles. I y

The tubes 35 are closed at one "end by caps 350 and, at their opposite ends, comm-unicate with and are supported by headers 48 arranged at the opposite sides of the tank and supplied with compressed air from mains 50 through branch pi ics d9 severally provided with valves 57. he headers/l8 are preferably of less length than the tank 14, whereby the tubular grating, as a whole, is formed in sections arranged longitudinally of said tank, said sections corresponding in length substantially to the sizing compartments 25.

The pores of the tubes 35 are too small to allow solids to enter said tubes from the outside, under hydraulic pressure when the compressed air is cut oil, thereby preventing the internal clogging of said tubes. Said tubes are spaced from one another a sufficient distance to afford between them easy downward passages for the material under treatment into the sizing compartments 25, while being suiiiciently close together to provide for the thorough aeration of the contents of the tank. By the provision whereby the material in the compartments 25 is removed therefrom at a oint considerably below said tubes, all violent downward currents or vortices in the vicinity of said tubes, tending to draw the bubbles downwardly, are avoided, and all possibility of improper discharge of the finer material with the material properly deposited in the sizing compartments 25 reduced to a minimum. The air emitting surface of each tube 35 extends completely about the periphery or circumference thereof, so that all possibility of such accumulation of sediment as would clog the exterior of the tube and interfere with tl e proper discharge of air therefrom is prevented, it being obvious that, even though the entire upper surfaces of the tubes were covered by deposits, there would still belelft a total unobstructed air emission surface equal to or reater than the entire horizontal area of the tank, notwithstanding the passages between the tubes.

At suitable points longitudinally of the tank 14 are provided vertically arranged shutters 52 extending across said tank and preferably spaced to correspond with the spacing of the sizing-compartments 25. Said shutters are provided with slats 53 inclined downwardly in the direction of the flow through the tank and with adjustable flaps 5% connected to operating rods 55. The shutters 52 prevent currents from being set up longitudinally of the tank, racing one way at the bottom and the other at the top, the flaps 54 acting as valves to prevent the material from flowing in an improper direction, and, together with the inclined slats 53, directing the path of the current, caucing it-to plunge more or less in passing through the shutters, whereby the operation of the sizing compartments hereinafter crplaiucd may be varied or controlled. r-rlso said shutters 52 tend to direct the upward passage of the bubbles from the air tubes, causing them to remain within that longitudinal portion of the tank in which they originated, so that the froth formed by said bubbles, as hereafter explained, will be richer above the first compartment {than above the succeeding ones and may be separated from the other grades if desired.

The complete operation of the apparatus is as follows. The comminuted material from the mill, together with a suitable amount of water, and with or without ccr taiu other materials or frothing agents, such as oils, acids and the like, the whole forming what is known as pulp," is discharged into the tank 14 through the inlet 15, the liquid filling said tank and overflowing intd the outlet 16. The comminuted material above referred to, when the mill is operated in its most efiicient and economical manner, as heretofore explained, includes, indiscriminately, finely pulverized ore including mineral particles or metallic sultlds, coarse lumps or oversize containing more or less unliberated mineral, and a considi-u'able quantity of material of various intermediate sizes comprising grains of liberated mineral and gangue. The compressed air admitted through the tubular grating 35 passes upwardly through the tank in the form of numerous streams of fine bubbles, carrying with them the finest material, particularly the pulverized metallic sulfide, colloidal matter, and gels, and forming a froth column above the level of the liquid in the tank, the froth, together with the material carried thereby, overflowing at the top of the tank into the launders 36 and being suitably discharged through the openings 37. The bubbles also cause upward currents in the mass which resist the tendency of the rock particles to fall in response to gravity. As the pulp flows through the tank from the inlet to the outlet the coarsest particles and oversize will sink to the bot tom of the tank first, and the successively smaller particles at successively later periods, so that said coarsest material and oversize will be retained in the sizing COD1- partment nearest the inlet, and the successively smaller sizes in the other compartments, according to their size, practically nothing but muddy water passing out at the outlet 16. This grading or sizing of ma terial may be controlled to a large extent by the adjustment of the ate 17 and of the shutter flaps 54, making the current plunge more or less at various points, and also by adjustment of the air pressure supplied to the several sections of the tubular grating by means of the valves 57. The coarsest material retained in the first sizing compartmcnt 25 is removed therefrom by the ele vator 2G, 27 and discharged through the chute 32. The finest suliid material discharged through the openings 37, as also the grains of intermediate sizes discharged by the hydraulic lifts 33 and chutes 34 are severally and separately delivered at suitable points for such further treatment as may be ap licable.

It will t us been seen that the apparatus above described is capable of receiving the ordinary run of the mill when run in its most economical manner, and without previous screening, that during the passage of the pulp through the apparatus the mineral values already fine enough for removal by flotation are immediately and constantly lifted out and discharged at suitable points, that the pulp is subsequently subjected to gravity separation or classification, that the several sizes thus graded are separately discharged from the apparatus, and that the oversize with its un'liberated mineral values is further segregated from the other sizes and may be returned to the mill for regrinding.

The air tube grating herein shown and described, and other parts of the apparatus which are limited in their utility to the irothing operation, are not claimed herein, being covered by the claims of a prior application filed by me August 3, 1915, Serial No. 43,444, of which this case is a division.

Having thus described my invention, I claim:

1. A hydraulic sizer comprising a tank having an inlet at one end, an outlet at the opposite end, and a plurality of sizing compartments at the bottom, said tank being constructed and arranged to permit a free flow of material therethrough in a substantially horizontal direction from said inlet to said outlet and above said compartments, and a series of vertically disposed spaced sets of shutters within said tank, said shutters having slats downwardly inclined in the direction of flow.

2. A hydraulic sizer comprising a tank having an inlet at one end, an outlet at the opposite end, and a plurality of sizing compartments at the bottom, said tank being constructed and arranged to permit a free flow of material therethrough in a substantially horizontal direction from said inlet to said outlet and above said compartments and a series or vertically disposed sets 01 shutters within said tank spaced to correspond with said compartments.

In testimony whereof I aflix my signature.

DAVID COLE.

Images