US1702443A

US1702443A - Flotation concentrator

Info

Publication number: US1702443A
Authority: US
Publication date: 1929-02-19
Anticipated expiration: 1946-02-19

Description

v Feb; 19, I929.

. w JOHNSQN FLOTATION CONCENTRATOR 2 Sheets-Sheet l Fil ed April 30. 1927 M 4 finial 71.5011

an on W14 Patented Feb. 19, 1929.

UNITED STATES- AXEL W. JOHNSON, OF NEDERLAND, COLORADO.

I FLO'IATION CONGENTRATOR.

Application filed April 30, 1927. Serial No. 188,010.

I This invention relates to flotation concentrating machines wherein all concentration is secured by the use of a froth. The general object of this invention is to provide a con-j centrator of this character which requires no power to operate, but in which the frothing of the liquid in the frothing cell is secured by discharging the liquid into the frothing cell from a height and through a vertical feed column.

A further object is to provide a machine of this character which is adapted for all floatable ores and which will handle ores as coarse as fifteen mesh without any liability of choking.

A further object in this connection is to provide a mechanism which has no small pipes to choke, no mechanical agitators, and has practically no parts to wear out.

A further object is to provide a mechanism of this character including a frothing cell, a vertical feed column discharging into the frothing cell, a skimmer for carrying off the froth with its floated particles ofore, means for carrying off the sands and water from the frothing cell, and means operated by the current of sands and water for operating the skimmer.

My invention is illustrated in the accompanying drawings, wherein Fig. 1 is a plan view of my device constructed in accordance with my invention;

Fig. 2 is a longitudinal sectional view on the line 2-2 of Figure 1;

Fig. 3 is an end elevation of the device;

Figure 4 is a transverse section on the line d4c of Figure 2; I

Figure 5 is a diagrammatic sectional View illustrating the operation of the device;

Figure 6 is a similar view of- Figure 5 in plan.

Referring to the'se'drawings' 10 designates the frothing cell which isshown as approximately rectangular in plan and which has an upwardly and forwardly inclined front wall 11, a downwardly and forwardly inclined froth discharge board 12, and a vertical rear wall 13. Extending downward into the rear end of the frothing cell is the feed column 14 which extends upward, to any desired height, and is preferably rectangular in section and has a discharge opening at its lower end, the lower end of the pipe being out 01f at a downward and rearward inclination so that the advance of the discharge feed column is a downwardly and rearwardly inclined wall 15 which extends nearly to the bottom of the frothing cell, but is formed with a rectangular aperture 16 coinciding with the discharge .mouth of the feed column. At one endof the frothing cell, there isdisposed a sand launder 16 into which the overflow launders or troughs 17 discharge. These troughs 17 are disposed against the end wall 18 of the frothing cell, this end wall being cut away as at 19 upon its upper edge face. A sand discharge opening 20 extends through the end wall 18 and discharges into the launder 16 and the effective area of this opening is controlled by a damper 21 having the form of a lever pivoted upon the end wall 18 and shiftable to cover or uncover the opening 20. The handle of this damper operates against the inside face of the wall 18 and inward of the wall 18 is a bafli'e board 22, the upper edge of which is 1 trough 2 1 which extends entirely beneath the machine and receives sand and water from the launder 16 and from the sand wheel housing 23. The bottom of this troughis inclined downward in one direction so as to carry olf the water and sand discharged from the launder 16 and from the sand wheel housing.

Disposed within the sand wheel housing is the water wheel 25 mounted upon the shaft 26 which extends through one wall of the sand wheel housing and carries upon it the belt wheel 27. Separating the sand wheel housing 23' from the frothing cell is the end wall 28 of'the frothing cell which is cut away upon its upper edge as at 29 and which is formed with the opening 30'leading into the sand wheel housing at a point slightly below the axis of the water wheel 25. The eifective size of this opening is controlled by the damper 31 having a handle or lever extending upward to the top of the machine so that t may be readily operated. Exterior to the wall 28 there are provided the overflow chutes or troughs 32 which discharge any water pass ing over the upper edge of the wall 28 into the sand wheel housing. Inward of the wall 28, there is disposed the baffle board 33 ofthe same character as the bafl le board 22. The

wall 15 abuts at its ends against these bafile boards and. below the bafile boards abuts at its ends against the end walls of the frothing cell.

Mounted in bearings upon the end walls of the frothing cell is a shaft 34 carrying upon it the skimmer 35 which may be formed of thin metal or any other suitable material. to provide reversely curved wings. The skimmershaft is driven by the pulley or band wheel 36, driven by a band from the pulley 27, which in turn is driven by the water wheel.

In the operation of this mechanism, the pulp with the frothing agent is discharged into the column 14 and descends vertically into the frothing cell with such violence as to cause the proper frothing of the agent. The froth or bubbles so produced support the particles of ore in the manner well known and the deflecting wall 15 acts to cause a whirling and rolling agitation of the pulp such as is produced by a mechanical revolving agitator and this froth is immediately removed by the skimmer 35 and discharged over the discharge board 12. The sand and other foreign matter which falls to the bottom of the cell is discharged through the

openings

20 and 30 into the sand launder 16 and into the sand Wheel housing 23. By closing one of these openings and entirely opening the other, the sand and water may be discharged in either direction desired, thus for instance all of the sand and water may be discharged into the sand wheel housing to operate the water wheel or if. this would cause too rapid an operation of the water wheel, and therefore of the skimmer, a portion of the sand and water may be discharged into the launder 16. The re cesses 19 and 29 act to hold the pulp and water at a constant level within the frothing cell, this level being below the top of the frothing cell. The bafiie boards 22 and 33' act to prevent the froth from escaping through these

overflow recesses

19 and 29. The pulp is fed through the vertical feed column and the fall of pulpthrough this column forces a sufficient amount of air into the frothing cell and into the pulp and frothing agent so as to cause such agitation as to produce a mineral bearing froth without the necessity of using any mechanically operating agitators. The sand in the pulp sinks to the bottom of the cell and around pocket or bowl is formed in this sand by the downward discharge of the pulp through the feed column. This bowl spreads or deflects upwardly rising currents of the pulp so as to secure a uniform and proper agitation of the pulp.

It will be seen that this machine requires no power, has no parts to wear out, no small pipes to choke up, and no mechanical agitators. It makes a particularly clean product, cleaner than the products of power driven machines and requires no attention. The proportion of concentrate secured by this machine is relatively high. The economy of the construction enables a number of these machines to be installed through which the pulp can be run until the values are all saved, and this installation and operation of the machine will be less than the cost of any machine requiring mechanical power to operate it. By eliminating the mechanical agitators, etc., I secure not only economy in cost, but economy of operation in that I eliminate the use of a motor, engine or other mechanical device, andfurther there is no necessity of continued or constant supervision of the machinery. I have found in actual practice that the-provision of the sand bowl at the bottom. of the frothing cell and through the elfect'of the downwardly discharging column of materials acts to thoroughly agitate and mix the pulp and oils in the frothing cell and this agitation will be more thoroughly performed than by any form of mechanical agitation known to me. There are no small pipes for the injection of airas the feed pipe takes in sufficient air for proper aeration, the force of the falling pulp and water drawing down and heating the air into the pulp and water in the frothing cell. The level of the water in the frothing cell is maintained at all times no matter how great the influx 0f the pulp and water may be. This does away with a constant supervision.

In Figure 5, I show a vertical sectional view of the cell which illustrates the manner in which the sand bowl is formed and the manner in which the froth is directed by the deflecting board or wall towards the skimmer. As shown in Figure 6, diagrammatically the main bowl A is formed immediately beneath the discharge pipe and beneath the upwardly extending wall 15. This bowl A projects outward to a point in frontof a vertical plane touching the edge of the wall 15. Forward of this main bowl A two subsidiary bowls B are formed separated from each other by a dividing wall C. These bowls B are scoured out by the passage of sand and water and other like material toward the sand discharge apertures whereby the water and sand Attention is particularly called to the function of the deflecting board 15, as disclosed in Figure 5. As the pulp flows down the relatively long tubular member 14 and en.- trains air with it, the pulp is discharged into the sand bowl and this sand bowl acts to defleet the flow to an upward current which strikes the under face of the deflecting board 15, this board extending transversely entirely across the cell and extending on each side of the column 14 to the rear of the cell. The deflecting board 15 acts to cause a slight downward current of the pulp and part of this downward current of pulp enters again into the sand bowl and the other part, seeking the discharge outlet, comes in contact with the upward current of the pulp and is again drawn upwardly, thus giving a circular movement of agitation'to the pulp. Thus the deflecting board 15 acts to obtain a whirling agitation of the pulp such as ordinarily secured by a mechanical revolving agitator. The deflecting board 15 does not act as a crowding board to crowd the froth forward and over the discharge lip. The deflecting board 15 is too far back from the discharge lip to give any such action and this is shown by the fact that in actual practice'the froth appears a few inches from the upper margin of the deflecting board and remains in this position in a state of rest until the skimmer draws the froth forward and over the dis charge lip.

It is to be particularly noted that the feed pipe 14 has an approximately uniform cross sectional area for its entire length, or at any rate, for a length sufficient to secure a high velocity for the pulp moving downward through this feed pipe so that the pulp is delivered into the cell with a high velocity and without any possible impediment. The pulp carries with it entrained air and the velocity of the pulp as it discharges into the frothing cell agitates the pulp below the level of liquid in the frothing cell so as to form a froth capable of lifting up with it the particles of mineral matter. One of the features of this invention is the provision of a feed pipe which is relatively high and which is of uniform cross sectional areathrough its length so that there can'be no impediment to the downward discharge of the pulp.

With regard to the formation of the sand bowl A, the agitation by this bowl is more effective than if there were nothing there to change and spread the current of the descending pulp. To thoroughly agitate the material in the pulp, it is necessary that some sort of abaflle be present to violently spread the uprising current and this must be done be fore the descending pulp loses any of its velocity. The said bowl acts to do all this much better than if an artificial bowl or baffle were used, for the reason that the sand bowl is naturally formed and builds up according to the velocity and amount of feed. Thus the sand bowl is naturally formed and is, in a sense, automatically taken care of at all times.

I claim 1. A froth flotation concentrator including a frothing cell, a vertically disposed feed column having a substantially uniform cross sectional area from top to bottom extending vertically down into the cell and discharging below the level of the liquid contents of the cell, the feed column being open only at its upper end for the inlet of pulp and entrained air, and an upwardly and forwardly inclined deflecting wall intersecting the lower extremity of the feed column and extending to the ends of the frothing cell and on each side of the column to the rear of the frothing cell.

2. A flotation concentrator including a frothing cell, a vertically disposed feed column having its lower end terminating within the cell and below the level of liquid therein and adjacent the rear wall of the cell, the lower end of the feed column being forwardly and upwardly inclined, and a deflecting board through which the lower end of the feed column passes, the deflecting board ex tending upwardly and forwardly to the top of the cell at the same inclination as the lower end of the feed column and extending transversely to the ends of the cell.

3. A flotation concentrator including a frothing cell, a tall, straight, vertically disposed feed column unbroken throughout its length and having its lower end terminating within the cell and below the level of liquid therein, the lower end of the feed column be ing forwardly and upwardly inclined, and an upwardly and forwardly inclined deflecting board intersecting the lower end of the feed column extending laterally to the ends of the cell, and means disposed in spaced relation to and adjacent the forward wall of the cell whereby the froth may be drawn over the upper edge of the forward wall.

4. A froth flotation concentrator including a frothing cell, means for discharging pulp and entrained air into the frothing cell, a rotatable skimmer mounted at the front of the cell, a water wheel casing disposed at one end of the cell and communicating therewith near the bottom, a. water wheel therein operated by the discharge from the cell, a manually operable valve for controlling theflow of sand and water into said casing, and means for driving the skimmer from said water wheel.

In testimony whereof I hereunto affix my signature.

AXEL W. JOHNSON.