US1688998A - By eose lima - Google Patents

Description

Patented Get. 23, I928.

UNl'i. TIES rarer rice.

FREDERICK SWINNEY, DECEASED, LATE OF TUCSON, ARIZONA, BY ROSE LIMA SWINNEY, ADMINISTRATRIX, OF TUCSON, ARIZONA.

FROTH-FLOTATIGN CONCENTRATION OF ORES.

Application filed May 24, 1927.

This invention relates to process and apparatus for carrying out the froth-flotation process, and is herein illustrated as embodied in a flotation cell in which the flotation pulp is delivered in opposing streams from the sides of the cell, and air is delivered by perforated pipes so that it mingles with the inflowing pulp and aerates and agitates the pulp and produces a strong upcast tending to carry mineralladen bubbles upward. In this form of cell the pulp and the froth may flow in the same direction, i, e., flow lengthwise of the cell, the froth overflowing over a lip at the pulp-discharge end of the cell; and its flow may be aided by a blast or a current of air moving with the floating froth toward the foot or discharge end of the cell.

Other features and advantages will hereinafter appear.

In the accompanying drawings-Figure 1 is a central longitudinal vertical section of one complete flotation cell and a portion of the neat succeeding flotation cell embodying one form of the present invention.

Figure 2 is a plan view of the same with the cover at the discharge end of the cell which is completely shown swung back into open position; and Figure 3 is a vertical cross-section taken on the line 33 of Figure 1.

A pulp suitable for the froth-flotation process coming down a launder 1 enters a distributing box or feed chamber 2 at the head of the flotation chamber 3 of the frothflotation cell. The end 4 of the flotation chamber 3 between it and the box 2 is closed and the entering pulp divides itself so that it flows toward each side of the chamber 3 into a covered conduit or launder 5, of which there is one on each side of the cell. Each conduit or launder-5 extends a considerable part of the length of the cell and delivers pulp into the chamber 8 by an elongated opening 6 near the bottom of the launder and near the bottom of the side wall 7 of the cell- Each side feed launder is closed at the top by a cover 8 so that it is a conduit which forms an enclosed connection between the feed-box 2 and the bottom of the chamber 3.

In the form of the cell herein shown, the opening 6 is not quite at the sloping floor 9 of the cell, but is spaced therefrom by the thickness of a fairly thick plank 10 which Serial No. 193,806.

lies flat upon the floor of the cell and may be of considerable width so as to extend a substantial distance horizontally. Above the opening 6 is a similar plank 11 which may be supported in any suitable manner so that a passage or channel 12 is formed between the planks 10 and 11. In the form of the cell herein shown the passage 12 is, at the opening 6, constricted to about half its depth by a throat-piece 13 placed above the opening 6. The throat-piece 13 as h rein shown lies against the underside of the plank 11 and forms a restricted and flaring threat from the opening 6 into the passage 12.

For aerating the pulp as it passes through the passage 12 this passage contains means for delivering air into the pulp. Accordin to the present disclosure the air is supplied under pressure to a pipe 14 which runs lengthwise of the cell and is located about centrally of the passage 12. This pipe is provided with openings 15 which may in certain instances be three sixty-fourths of an inch. in diameter and arranged in two lines one half an inch apart on the surface of the pipe facing toward the chamber 3, and in staggered arrangement. An inch and a quarter pipe will usually be sufficient for a seven foot cell, this pipe delivering air under a pressure of four and a half to five pounds to the square inch at its feed end. The pipe may be closed on the end by an ordinary cap 16.

Since there is a similar pipe 14: on each side of the cell in an identical passage 12, the pulp entering from the opposite sides is well agitated by the confluence of the entering opposing streams and turned upward, causing an upcast and upward flow of the bubbles. To facilitate the action of the cell and to prevent undue settling on the plank 11 there are provided planks 17 filling in each corner of the chamber 3 formed by its side 7 and the top-plank 11, and thus the effective chamber assumes a \!shape having a bottom center extension into which pulp flows from the opposite sides while the bubbles forming the froth rise to the top.

For controlling the overflow from the chamber 3 there is provided a transverse lip 18 above the lower end of the sloping bottom 9, which lip controls the overflow of froth and over which the froth flows and drops into a suitable transverse frothlaunder 19. The wall of the launder next the cell under the lip 18 forms the transverse rear end of the chamber 3 and rises from .the bottom 21 of the launder, such bottom being spaced above the bottom 9 of the cell. In the space between the bottom 9 of the cell and the bottom 21 of the launder 19 the depleted pulp flows into a feedbox 22 of a second cell 23 (not fully shown) corresponding to the feed-box 2 at the front end of the first cell, which is fully shown and described. This second cell 23 may be identical with the first cell except as to its feed-boa. The means for controlling the depth or height of the pulp in each cell is conveniently located in the feed-box of the next succeeding cell and therefore the feedb0 of'the second cell contains this depth or height controlling means for the first cell, consisting of a weir 24 provided with an auxiliary baiile 24 to adjust the effective height of the weir. To enable heavy solids in the pulp to pass under the weir 24 the weir may be provided, at the floor 9 of the cell, with a narrow transverse opening 22 and a removable closure 23 may he provided at the bottom of the rear wall of the 'feed-box22 for access to it for cleaning.

For convenience in construction, the air supplied for the pipes 14 may come from an overhead pipe 25 down a vertical valved feeder 26 to a horizontal cross-pipe 27 so that the feed-pipe 26 is equally spaced from the two air delivery pipes 14, and for this purpose may go down adjacent the weir 24. Thus the pressure of air in the pipes 14 is greatest at their lower ends where the hydrostatic head of pulp is greatest, with the result that uniform perforations 15 in the pipes may provide for substantially uniform distribution of the air, though it may not be essential to have perforations of any given size or sizes. The pipes 14 are suitably supported by blocks herein illustrated at 28 at any desired intervals.

In order to facilitate the flowing of the froth lengthwise of thechamber 3 above the out) contained therein there ma 1 be rovided a blast or current of air coming through a valved feedpipe 29 into an airspreading box 30 which carries a vertical battle 31 above a flat floor 32 extending across the top of the chamber 3 and separated from the vertical wall 4 by an opening 33, below which is a deflector 33 to direct the stream of air horizontally over the froth in the chamber 3. To confine the air to the surface of the froth and cause it to flow out near the overflow lip 18 there are provided hinged covers 34 pivotally connected'at one side of the top edge of the cell by hinges 35 and adapted to lie across theeell, thus forming a closed top just above the froth, with the result that the air entering the top of the chamber 3 from the airspreading box 30, flows in contact with the froth at the top of the chamber 3 toward the overflow lip, inducing an even flow of the froth toward and over the lip. The top of the froth is roughly indicated at 39.

For controlling the flow of pulp in the flotation chamber 3 there may be provided the internal baffles 36 shown as projecting upward from the planks 11 at the end thereof near the discharge end of the chamber 3 and extending inward from the side walls of the chamber. These baffles serve to defleet into the upcast current values that might otherwise escape at the side of the chamber.

In order to properly control the flow of the pulp from the side conduitsor launders 5 into the cell, the covers 8 of the launder 5 are herein shown as sloping down from about the height of the froth level at the wall 4 at the feed end of the cell to meet the planks 11 near the lower end of the cell about where the battles 36- are located, if such are used. the How of incoming pulp throughout the lengths of the openings 6.

If for any reason or at any time a side overflow of the froth is desired,this may be accomplished by suitably buildingup the lip 18 as to compel the froth to flow over the sides of the cell into the side launders 38 which are shown as provided on top of the side conduits 5. lVhen this is done the hinged covers '34 are either removed or are swung back into the position shown as to one of them in Figure 2, the hinges 35 being offset so that the covers will, when open, be a substantial distance clear of the sides of the cell and will not interfere with the side overflow of the froth.

In the process as carried on the cell above particularly described the ull-p flows in restricted zones as it enters the elongated main body of the pulp and is aerated as it flows in these restricted zones by streams of air of the orderof one-thirty-second of an inch or more in diameter entering the pulp as it flows together in these restricted zones after having been divided by flowing over the aerating pipes, and the aerated pulp then enters in opposing streams the main body of the pulp near its bottom, and the main body of the pulp substantially narrower at its lower part where the impinging streams of aerated pulp enter it than at its upper part upon which the mineral-bearing froth is formed. As above noted the tailings are removed at that end of the body of pulp at which the overflow and separation of the n'iineral bearing froth is effected.

Various modifications may be made in the construction shown and above particularly described within the principle and scope of this invention, and the proeediu'e may also This results in distributing be varied without departing from this invention.

I claim:

1. A froth-flotation cell having passages for feeding pulp in opposing streams from the sides of the cell so that the streams are directed against each other to effect agitation of the pulp and the pulp is substantially dependent upon the impinging streams for its agitation and a failings outlet at one end of the cell so that the general course of pulp through the cell is longitudinally across the direction of the entering streams, and means at the side passage for aerating the pulp as it enters the cell through the side passages.

52. A froth-flotation cell having passages for feeding pulp in opposing streams from the sides of the cell. and a tailings outlet at one end of the cell so that the general course of pulp through the cell is longitudinally across the direction of the entering streams, and perforated pipes in the side passages for aerating the pulp as it enters the cell through the side passages.

3. A froth-flotation cell having passages for feeding pulp in opposing streams from the sides of the cell and a failings outlet at one end of the cell so that the general course of pulp through the cell is longitudinally across the-direction of the cnterin streams, and a perforated pipe in each side passage for aerating the pulp as it enters the cell through said side passage.

41-. A combined agitating and aerating and froth-separating and overflow cell having passages for feeding pulp in opposing streams from the sides of the cell, each of said passages having a constricted throat, and means in each passage for aerating the pulp after it leaves the throat as it enters the cell through said passage, a failings outlet at one end of the cell so that the general course of pulp through the cell is longitudinally across the direction of the entering streams, and means for overflowing froth from the surface of the pulp in the cell.

5. A froth-flotation cell having a closed feed end, side longitudinal launders opening through feed passages into the cell along the sides of the cell and at the bottom thereof through which pulp delivered adjacent the feed end of the cell is fed into the cell, and aerating means in the feed passages whereby the pulp is mingled with air as it flows through such passages.

6. A froth-flotation cell having a closed feed end, side longitudinal launders opening into the cell along the sides of the cell and at the bottom thereof through which pulp delivered adjacent the feed end of the cell is fed into the cell, and a longitudinal perforated pipe at each launder lying in the track of the entering pulp and serving to deliver air into the entering pulp to aerate it.

7. In a froth-flotation cell, a feed box at the head of the cell, a launder on each side of the cell having an elongated delivery opening and passage for delivering pulp to the bottom of the cell, each such launder having a closed top to cause the pulp to be delivered into the cell throughout the length of the delivery opening of the launder, and aerating means at each launder in each such passage for aerating the enterin pulp.

8. In a fro ic-flotation cell, a feed box at the head of the cell, a launder on each side of the cell having an elongated delivery opening and passage for delivering pulp to the bottom of the cell, each such launder having a closed top to cause the pulp to be delivered into the cell throughout the length of the delivery opening of the launder, and a longitudinal perforated pipe each laun der lying within the delivery passage thereof so to be lying in the track of the entering pulp and serving to deliver air to the entering pulp to aerate it.

9. A frotlrflotation cell having a side longitudinal launder with an elongated constricted opening through which pulp is fed into the cell so that the pulp enters over a wide area, and aerating means at the opening for aerating the entering pulp over the whole area at which it enters the cell.

10. A froth-flotation cell having a side longitudinal launder with an elongated constric"ed opening through which pulp is fed into the cell so that the pulp enters over a wide area, and a perforated pipe at the opening lying beyond the constriction for aerating the pulp as it enters the cell.

ll. In a froth-flotation cell, means for delivering pulp to the cell so as to cause a flow of pulp longitudinally of the cell and for discharging the depleted pulp at one end thereof, a cover for the cell so that froth can form between the cover and the level of the pulp of the cell, a. froth-overflow lip at the pulp-discharging end of the cell, and means for delivering air beneath the cover adjacent the froth near the head of the cell to cause a current of air to move with the froth lengthwise of the cell throughout the length of the cover.

12. A frothrflotation cell having a closed feed end, side longitudinal launders through which pulp delivered adjacent the feed end is fed into the bottom of the cell, passages from the launders to deliver tae pulp well towards the center of the cell, and longitudinal perforated pipe lying in each passage serving to deliver air to the entering pulp to aerate it.

13. A froth-flotation cell having a sloping bottom and a side longitudinal launder having a constricted opening into the cell along the sloping bottom thereof through which pulp is fed into the cell, a perforated pipe lying beyond the constriction for delivering air to the entering pulp to aerate it, and

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means for delivering air to the pipe at the end of greatest hydrostatic pressure in the cell.

15 In a froth-flotation cell having a sloping bottom, the combination with means for? feeding pulp at the side, of a pipe for aerating the pulp delivering air at points along the side, and a feed pipe for conveying air to said pipe and connected thereto. at the deep end of the cell so that the maximum air pressure comes at the point of greatest hydrostatic pressure.

15. A froth-flotation cell in the shape of .an elongated box having a constriction at its lower part formed by the sides of the box, means for deli; sing air into streams of pulp so as to mingle the air with the pulp, and means for delivering such streams of mingled-air and pulp to the cell near the bottom of the be); and at opposite sides thereof and into the constricted part thereof so that the incoming streams of mingled air and pulp are directed against each other, whereby the impinging streams of mingled air and pulp etlect agtation of the pulp near the bottom of the box so as to form a froth.

'16. A froth-flotation cell. in the shape of an elongated box, means for delivering pulp to the cell near the bottom at opposite sides of a central constriction formed by the sides of the box, sloping sides above the constriction, a perforated pipe lying longitudinally of the cell in the path of the entering pulp, and means for supplying air to the pipe.

17. The process of froth-flotation concentration which consists in feeding opposing streams of pulp mingled with previously admixed air into the opposite sides of a body of pulp near its bottom with the result that the impinging streams are directed against each other to efl'ect agitation thereof so that the pulp is substantially dependent upon the impinging streams of aerated pulp for its agitation and the streams of pulp turn upward and bubbles arise over the impinging streams to form a mineral-bearing froth, and removing the tailings at one end of the body of pulp so that the pulp flows longitudinally across said feed streams of aerated pulp.

18. The process of froth-flotation concentration which consists in feeding the pulp mingled with previously admixed air in opposing streams into the lower part of the opposite sides of a body of pulp which is substantially narrower at its lower than its upper part so that the impinging streams are directed against each other :to etl'ectagt tation thereof so that the pulp is substantially dependent upon the impinging streams of aerated pulp for its agitation and the streams of pulp are turned upward and lnibbles rise over the impinging streams @to form mineral-bearing froth, removing the tailings at the end of the body of pulp so that the pulp flows longitudinally across said.

feed streams of aerated pulp, and separating the froth at the same end thereof.

19. The process of froth flotation concentration which consists in feeding the pulp previously mingled with air in opposing streams into the lower part of the opposite sides of a body of pulp which is substantially narrower atits lower than its upper part so that the impinging streams are directed against each other to effect agitation thereof so that the pulp is substantially dependent upon the impinging streams of aerated pulp for its agitation and the strean'is of pulp are turned upward and bul bles rise over the impinging streams to form a mineral-bearing froth, removing the tailiiigs at the end of the body of pulp, so that the pulp flows longitudinally across said feed streams of aerated pulp, and separating the froth at the same end thereof.

In testimony whereof, I have affixed my signature to this specification. 1

' ROSE LIMA SWVINNEY, Adminiswat'rim 0f the Estate of Fredericln Swimiey, Deceased.