US1457077A - Flotation machine - Google Patents

Description

May-29, 1923. v

Y T. A. JANNEY FLoTATloN MACHINE Filed Aug. 2l, 1919 2 Sheets-Sheet l s Mwaw iwf/v5.55:

May 29, 1923. 1,457,077

f T. A. JANNEY FLOTATION MACHINE Filed Aug. 2l, 1919 2 Sheets-Sheet 2 ff\ Qt Il u AWO/P0536 Patented May 29, 1923.

UNITED STATES PATENT OFFICE.

Application led AAugust 21, 1919. Serial No. $18,958.

To all 'wlwm it may concern:

Be it known that I, THOMAS A. JANNnr, a citizen of the United States, residing at Garfield, in the county of Salt Lake -and State of Utah, have invented certain new and useful Im rovements in Flotation Machines,of whic the following is aspecifioation.

' This invention relates to improvements in iiotation machines audthe present application covers a modification of the apparatus shown and described in my prior application, Serial No.'74561, filed anuary 27th, 1916, which has now matured into Patent 16 No. 1,342,115,'granted June 1, 1920.

The purpose of the invention is to provide an improved form of apparatus for carry- .in out the iiotation process in which the pu verized ore is mixed with water to form a pulp and then agitated in contact with air after adding thereto a small quantity of an oil or other suitable frothing agent, whereby the agitation mixes the oil with the pulp and beats air into the pulp to form a multitude of oil coated bubbles which rise to the surface with the metalliferous articles of the pulp adherin to them and orming a mineral bearing roth which may be floated off. The present invention relates to dotation apparatus of that general type in which mechanical agitation is followed by pneumatic aeration in the separating box.

he principal object of the invention is to provide an improved form of agitation vessel in combination with improved means for eii'ecting the circulation of pulp. A further object of the invention is to provide improved means for introducing pulp into the agitation vessel and a new method of and location for the introduction of the pulp.

'Other objects relate to various features of construction and arrangement which will appear more clearly hereinafter.

The nature of the invention will be understood from the following specification, taken with the accompanying drawings, in which one embodiment isl illustrated.

In the drawings- Figure 1 shows a longitudinal sectional view through a series of flotation cells embodying features of the present invention;

Fi 2 shows a plan view of the construction 111ustrated in Fig. 1;

Fig. 3 shows an enlarged longitudinal sectional view through portions of two units connected in series;

Fig. 4 shows an enl plan view of the apparatus illustrated in Fig. 3; and

Fig. 5 shows a transverse sectional view taken -on the line 5 5 of Fig. 3.

The invention com rises a vvessel 10 of rectan lar cross-section having end walls 10* an Y side walls 10. This vessel forms the casing of one unit or flotation cell, and it has mounted in one end thereof an agitation cell or vessel 11, which is in the form of a frustum of a cone, being tapered toward its lower end. The lower wall of the agitation cell 11 is provided with an openin 12 which communicates with a small cham r 13 located between the base of the agitation vessel and the bottom 10 of the vessel 10. Mounted within the agitation vessel 11 is a vertical shaft 14, which carries two sets of agitating vanes 15 and 16. The vanes of the lower agitator 15 are located at right angles to the vanes of the upper a itator 16, and the shaft is driven by an e ectric motor 17 mounted on a shelf 18 which extends across the vessel 10 above the a 'tation cell 11. An opening 18 in the s elf around the shaft 14 permits thefree flow of air into the agitation cell. The ore ulp is introduced into the agitation cell t ough an inlet port or conduit 19 which extends through the end wall 10B and through the wall of the agitation cell 11 froma vessel 20, which may be a vessel containing the initial feed of the pulp, or it may be the separating box of a precedin unit of a series of connected iotation ce 1s.

The pulp flowing throu h the port 19 is discharged into the centra? part of the agitation cell 11, the inlet conduit extending to a point adjacent the shaft 14, so that the pulp discharged by the inlet ort enters the vertical surface depression w ich is formed in the pulp withinthe agitation cell by the rotation o the rotary agitators 15 and 16. The froth formed by the a itators and a portion of the pul are impe ed upwardly and discharged wit a swirling motion over the upper edge of the a 'tation cell 11 into the space beneath the s elf 18 and above the air mat 21, which is inclined downwardly from the region of the agitation cell to the opposite end of the vessel 10. The frame of the air mat extends substantially around the agitation cell 11 and forms an inclined floor upon which the ulp falls; the air mat 21 1s mounted on the rame from the agitation cellY downwardly and the pulp asses therefrom as it moves toward the disc arge end of the cell. The pulp which is discharged over the overflow lip formed b the annular wall shelf 18 between the side walls 10", terminating above the air mat 22 but below the level of the upper edge of the agitation cell 11. The pulp and froth discharged through the outlet 22 enter the s ace 24 above the air mat and between the si e walls 10", which space constitutes the separating box or spitzkasten of the unit. The air mat 21, formed of canvas, porous concrete, or other suitable material, is mounted on a supporting frame 25, having a plurality of air chambers 26 therein below the agitation cell. Compressed air is su plied independently to each of the cham rs 26 through a series of pipes 27, which extend through the lower wall 10 of the vessel 10 and thence in a lateral direction, as shown in Figs. 1 and 2. Each of the pipes 27 may be provided with a separate va ve, so that the air pressure in the different parts of the separating box may be regulated, as desired.

Ad'acent the lower end of the air mat 21 a ba e wall 29 extends transversel of the vessel 10 and terminates slightly a ove thev lower edge of the mat, leavin an opening 30, through which the pulp ows into the outlet channel 31 between the baffle 29 and the overflow weirs 32. The weirs 32v are formed of a lurality of vertically slidable plates 32 w ich are mounted in grooves formed in the side walls l0b and in the vertical partitions 33. Three sets of overflow weirs 32 are thus formed, the central weir communicating with a central outlet chamber 35. That portion of the pulp which overflows the central weir 32 enters the chamber 35, and thence passes through an inlet conduit 19, which leads therefrom into the agi-` tation cell 11 of the next unit of `the series. That portion of the pulp which overflows the side weirs 32 enters the return flow chambers 34, and thence passes throu h the return flow conduits 36 to the previously described chamber 13, which is located beneath and in communication with the agitation cell 11 of the same unit. The froth which collects in the separating box overflows the upper ed es of t e side walls 10b into the longitudina y-extending inclined launders 37.

The agitation cell and the separating box connected directly thereto constitute one unit or flotation cell, and although any unit may be used alone to .carry on the flotation process, it is usually desirable to employ a num- Each succeedin unit is located slightly be low the level o the precedin unit, and the outlet conduit which leads rom the lower part of the outlet chamber 35 of one unit forms the inlet conduit leading to the central portion of the agitation vessel of the next unit of the series. Each unit is located slightly below the level of the preceding unit, but with the forni of apparatus herein described the difference in level is slight, whereby` it is possible to use a lo series of connected units with comparative y little head room. The return ilow conduits -36 communicate with the return flow chambers 34 above the lower walls thereof, and are inclined downwardly and rearwardly to the chambers 13 located below the agitation vessels. At the end of the series of units the pulp, from which substantially all of the metalliferous content has been separated, is discharged through the conduit 19* into an overflow or waste channel 38.

In the operation of the invention the pulp, to which a small quantity of frothin agent has been added, is introduced into t e agitation vessel of the first unit of the series through the inlet port 19, and as the pulp in this vessel is agitated a vortex is created in the pulp which forms a vortcal surface depression extending downwardly from its upper level around the shaft 14. The inflowing` pulp enters this vortcal surface depression, and is thus not opposed by any back pressure within the chamber, inasmuch as it enters a space which is open to the outer air. The violent agitation of the pulp within the cell 10 produces a mineralbearing froth and discharges the froth and a portion of the pulp over the upper end of the agitation cell and onto the inclined perforated medium 21. The pulp flows through the outlet port 22 onto the portion of this perforated medium which lies above the air chambers 26, and while in this separating box or spitzkasten 23 it assumes a comparatively quiescent state while being subJected to the action of an uprising current of air bubbles which is discharged through the mat 21. The effect of the agitation and aeration in the agitation vessel is thus supplemented by the pneumatic aeration in the separating box, and the mineral bearing froth which collects on the surface as a result of this combined agitation and aeration overflows the upper edges of the side walls 10b. The pul which settles and flows downwardly past tllie lower edge of the air mat rises in the chamber 31 and is disheight of the overflow lips 32 may be adjusted` as desired in order to regulate the height of the pulp in the spitzkasten and the amount of the pulp which enters the returnflow chamber 34 for re-circulation. That portion of the pulp which enters the chambers 34 flows back through the inclined return flow conduits 36 and through the chamber 13 to the cell y11. A portion of the pulp is thus caused to circulate locally through the agitation vessel and the separating box of each unit. That portion of the pulp which enters the outlet chamber 35 flows through the conduit 19 of the agltation vessel of the next unit of the series. Thus the pulp is treated not only to repeated agitation and aeration in each unit but to agitation and aeration by the successive units of the series.

Although I have shown and described one embodiment of the invention for purposes of illustration, it will be understoodj that it may be constructed in various other forms without departing from the scope of the appended claims.

I claim:

1. The combination in a flotation machine, of an agitation vessel open at its upper end, means for agitating` ore pulp in said vessel and discharging the same over the u per end thereof, an inclined perforated me ium adapted to receive the pulp and froth dis'- charged over the upper end of said vessel, means for inclosing said perforated medium to form a separating box, means for introducing air through said perforated medium, a plurality of chambers at the lower end of said separating box, overflow lips lead1ng to said chambers, means for conveymg pulp from one of said chambers to a succeeding agitation vessel, and a return conduit for conveying pulp from another of saidchambers back to said first named agitation vessel.

2. The combination in a flotation machine, of an agitation vessel for containing -ore pulp, means for introducing the ore pulp into said vessel, a separating box communicating with said vessel, means for agitating the ore pulp in said vessel and discharging the same and the 'l' roth formed by said agitation into said separating box, an over-flow lip for discharging the froth from said separating box, a plurality of separate weirs over which the pulp from said separating box is discharged. and means for returning the pulp discharged over some of said weirs back to said agitation vessel.

3. The combination in a flotation machine, of an agitation vessel for containing ore pulp, means for introducing the ore pulp into said vessel, a separating box communieating with said vessel, means for agitating the ore pulp in said vessel and discharging the same andthe froth formed by said agitation into said separating box. an over-flow lip for discharging the froth from said separating box, a plurality of separate weirs over which the pulp from said separating box is discharged, means for regulating the height of said weirs, means for returningl the pulp discharged over one of said weirs back to said agitation vessel, and means for conve ing the pulp discharged over another of said weirs away from the machine.

4. The combination in a flotation machine, of an agitation vessel for containing ore pulp, means for introducing ore pulp into said vessel, a separating box communicating with said vessel through an upper port, means for agitating the ore pulp in said vessel and discharging the same and the froth formed by said agitation through said upper port into said separating box, an overflow lip for discharging the froth from said separating box, a discharge channel communieating with the lower part of said separating box, a plurality of weirs over which the pulp flows from said discharge channel, and

means for conveying the pulp discharged over one of said weirs to the lower part of said agitation vessel.

5. The combination in a flotation machine, of an Aagitation vessel for containing ore pulp, means for introducing ore pulp into said vessel, a separating box communicating with said vessel through an upper port, means for agitating the ore pulp in said vessel and discharging the same and the froth formed by said agitation through said upper port into said separating box. an overflow lip for discharging the froth from said sep, arating box, a discharge channel communicating with the lower part of said separating box, a plurality of weirs over which the pulp flows from said discharge channel, and means for conveying the pulp discharged over one of said weirs to the lower part of said agitation vessel, said weirs being adjustable in height to regulate the level of the pulp in said separating box.

6. In combination, a series of flotation cells each comprising an agitation vessel and a separating box, means for agitating ore pulp in the agitation vessel of each flotation cell and impelling the same therefrom through an upper port into the separating box of said cell, and means for conveying pulp by gravity from the lower part of the separating box of one cell into the central part of the agitation vessel of the next cell of the series, said last-named means opening into the vortical surface depression created by the agitation of said pulp and being located beneath the fluid level of both said cells.

7. In combination, a` flotation cell comprising an agitation vessel for vcontaining ore pulp, a separating box communicating with 'said vessel, mean's for agitating the pulp in said vessel and creating a vortex .therein and impelling said pulp into said separating box, a second-cell adjacent said first named cell 5 and likewise comprising an agitation vessel and agitating means, and apulp delivery f pipelocated below the uid level of both said cells and leading from 'said rst named cell into the agitation vessel in said second cell. said pipe terminatin in the vortical de-l 10 pression in said secon cell.

In testimony lwhereof, I have subscribed my name. y

vTHOMAS A. JANNEY.

Images