US1984366A - Machine for flotation of ores - Google Patents

Description

Dec. 18, 1934.

A. W. FAHRENWALD MACHINE FOR FLOTATION GP 01235 2 Sheets-Sheet l Filed May 2'7. 1927 lNvlTToR .AZWM/wuwda ATTORNEYS 1934- A. w. FAHRENWALD 1,984,356

MACHINE FOR FLOTATION 0F ORES Filed May 27, 1927 2 Sheets-Sheet 2 -lNVENTOR 2 1 ill/.Fbkremald 22/ 26 j 2 5 ATTORNEYSM iii Patented Dec. 18, 1934 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to an improved machine for the flotation of ores and has for its object the provision of an apparatus of this character that will be more efficient and easier to handle. The invention resides in the combination and arrangement of parts as herein specified.

Referring to the drawings,

Figure 1 is a side elevation of -my'machine partly in section,

Figure 2 is a plan view of the machine,

Fig. 3 is a vertical sectional view ofthe invention,

Fig. 4 is a horizontal sectional view of the same,

Figure 5 is a perspective view of the impeller,

Figure dis a view partly in vertical section and partly in'elevation of a modified impeller.

Referring now to Figures 1, 2, 3, and 4, nu-i metal 1 indicates a long rectangular tank, preferably of wood, and roughly as deep as it is wide. This tank is set within a suitable heavy framework 2, comprising timbers for the tank to rest upon,'uprights supporting the walls of the tank and extending above same, these uprights being joined together at their topmost points by cross pieces suitable for the mounting of impeller driving means. Below the first cross piece at a suitable distance therefrom is a second cross piece 2' intended as a bearing support for the impeller.

On theleft-hand side of the tank as shown in Figures 1 and 4 there is a compartment 3 which is intended for thereception of the ore to be floated. The tank itself is divided into two or more individual cells 4 and 4* by means of weirs or vertical partitions 5.

Overflow edges or lips 6 are provided on front and rear edges of the tank for the froth concentrate and a lower one 11 for the extreme tanking pulp on right hand side of the cell 4, the tank wall on this side being somewhat lowered to provide such overflow edge. The weir 5 and the lowered overflow edge are each preceded (measuring from left to right) by a baflie plate 9. On the right side of the weir 5 there is a second baille 9 at some distance from 5. This baflle, together with the'weir 5 and balfie 9, forms an overflow chamber 10 between the two compartments of the cell.

In each cell compartment, there is located at approximately the center thereof, means for agitating the liquid and ore to be contained in saidv cell and generating a froth therefrom. Such means comprise a casing 12 terminating above the froth overflow level of the tank. This casing is held in a perpendicular fixed positionin the hub 13 of the horizontal disk 14 by means of a setscrew 13 or equivalent means.

The disk 14 is held above the bottom of the tank at a fixed distance therefrom by means of lugs or spacers 15 cast integrally with the disk 14 and being preferably notched to clear the impeller. These lugs 15 have extensions or wings 16 above the disk also, the purpose of which is to provide baflies against which the contents of the cell are allowed to churn, thus assisting the frothing action.

Communicating with each casing 12 andthe pulp overflow compartment 10 of each cell is a horizontal pipe passage way 17. -Within each casing 12 there is a solid shaft 18, extending vertically down from the top framework of the cell, and supported insuitable bearings, the top bear ing 19 being preferably of the combined thrust and radial ball type taking both vertical and hori-. zontal loads. The lower bearing 19 is of the split box type.

An impeller 20 is bolted or otherwise attachedto the bottom of shaft 18, said impeller comprising a solid disk 21 having vanes 22 on its upper surface as shown in detail in Figure 5.

Rotation may be imparted to the impeller and its shaft 18 by any suitable means. I prefer to use, however, an individual electric motor drive for each impeller shaft. In this form of drive, there is an electric motor 23 vertically mounted on the top framework of the cell in such a manner that they may be connected by short belt drives to grooved pulleys 25 and fastened to the top of the shafts 19. I prefer to use multiple grooved pulleys and V bolts.

For the removal of settled ore or other matter from the machine, there is provided in the bottom of the tank in each cell an outlet and a plug 26 The general operation of the machine 'is as follows:'-

Ore pulp is fed to the feed box-3 from whence it flows by ,gravity through'the horizontal pipe passage way'l'l into the casing 12 and onto the rotating impeller 20, thence into the first cell of the machine. As the pulp continues to flow into the machine, cell No. 1 fills to the overflow level of the weir 5 and any additional pulp flows into the overflow compartment and from this compartment through a second pipe passageway 17, a second casing 12 onto the second impeller thence into the second cell of the machine.

The pulp is caused to flow thru as many cells in succession in this manner as practice dictates to be necessary to obtain a proper recovery of the minerals.

The pulp level, in the individual cells may be regulated by the use of narrow cleats 2'7 which are placed on the tops of the weirs 5 and which may be used to increase or decrease their height.

The air required for the aeration of the pulp and the formation of the froth concentrate is automatically drawn into the individual cells of the machine from the atmosphere by the rotative action of the impeller 20. The air enters the pulp thru the annular space 28 between the solid impeller shaft 18 and the casing 12 surrounding said solid shaft.

In addition to the flow of the pulp thru the successive cells of the machine, there is provided means to permit of closed circuit agitation of the pulp within each cell. This is accomplished by providing in the stationary horizontal disk 14, a number of holes 29, shown in Figures 2 and 4, thru which pulp flows by gravity, falling upon the rotating impeller 20.

It is to be understood that various modifications of the foregoing will readily occur to those skilled in the art, and all such modifications I claim as my own if they fall within the scope of the appended claims.

I claim:--

1. In an ore flotation device, a plate to be arranged in a flotation tank and supported in spaced relation to the bottom thereof, a conduit extending vertically from the plate for conducting air to a point between the bottom of the tank and the plate, a driven shaft extending vertically through the conduit and having its lower end located below the plate, an impeller attached to the lower end of the shaft and means for discharging ore pulp into the conduit. a plurality of radially disposed bafiie plates supported on the plate and cooperating with the impeller in agitating the pulp.

2. A pulp agitating mechanism comprising: a tank; a shaft vertically suspended in said tank; an impeller carried on the lower extremity of said shaft; a stationary sleeve spaced from and sur-- rounding said shaft and terminating above said impeller; and a stationary disk-like flange surrounding the lower extremity of said sleeve and extending outwardly therefrom so as to substantially cover said impeller and prevent pulp from settling thereon.

3. Flotation apparatus comprising in combi-' nation a plurality of flotation cells connected in series, means for continuously supplying pulp-to the first cell in the series and means for permitting the continuous discharge of pulp from the last cell in the series, a rotary impeller suspended on a vertical driving shaft in each of said cells, a stationary sleeve surrounding and substantially larger in diameter than said shaft and extending upwardly from a point adjacent said impeller, a cover carried at the lower end of said sleeve and extending over said impeller, and a conduit for carrying pulp from one cell and delivering it to the impeller in the next cell in said series.

4. Flotation apparatus of the character described comprising in combination a plurality of flotation cells connected in series, each cell having an impeller provided with agitating blades therein suspended on a vertical driving shaft, a sleeve surrounding said shaft and extending from a point adjacent said impeller to a point above the pulp and froth level in said cell, a cover above said impeller to relieve the latter of the load of pulp in the upper portion of the cell, and a con duit for carrying the pulp from one cell and delivering it to the impeller of the next cell.

5. Flotation apparatus of the character described comprising in combination a flotation cell having means for delivering acontinuous stream of pulp to said cell, an impeller provided with agitating blades therein suspended on a vertical driving shaft, a sleeve surrounding said shaft and extending from a point adjacent said impeller to a point above the pulp and froth level in said cell, a cover for said impeller which separates the pulp in the upper portion of the cell from free access to the impeller blades, and a tube leading from the point of entrance of pulp to said cell to a point adjacent said. impeller for delivering pulp to said impeller, whereby the pulp entering said tube is obliged to pass through the impeller before mingling with the pulp in said cell.

6. Flotation apparatus comprising in combination a flotation cell, a rotary shaft extending into said cell, an impeller having agitating blades carried at the lower end of said shaft, a stationary sleeve surrounding said shaft and extending from said impeller to a point above the pulp and froth level in said cell, a cover member over said impeller for carrying the load of pulp in the upper portion of said cell and conduit means for delivering air and pulp to the same side of said impeller.

7. Flotation apparatus comprising in combination a flotation cell, a rotary shaft extending into said cell, an impeller having agitating blades carried at the lower end of said shaft, a stationary sleeve surrounding said shaft and extending from said impeller to a point above the pulp and froth level in said cell, a cover member over said impeller to carry the load of pulp in the upper portion of the cell so as to provide air spaces adjacent said impeller and conduit means for delivering air and pulp together directly to said impeller blades.

8. Flotation apparatus comprising in combination a flotation cell, a rotary shaft extending into said cell, an impeller having agitating blades carried at the lower end of said shaft, a stationary sleeve surrounding said shaft and extending from said impeller to a point above the pulp and froth level in said cell, a cover member for separating the pulp in the upper portion of the cell from free access to said impeller blades so as to provide air spaces adjacent said impeller, and air and pulp conduits for delivering air and pulp to said impeller, said conduits joining each other at a point in advance of the point of delivery to said impeller.

9. Flotation apparatus comprising in combination a plurality of flotation cells connected in shaft and extending upwardly from a point adja-' cent said impeller, said sleeve having an air inlet to allow air to be drawn down the sleeve by the impeller, a cover carried at the lower end of said sleeve and extending over said impeller, and a pulp conduit leading into the cell and connected with said sleeve above said impeller to allow the pulp to fall by gravity upon the impeller.

10. Flotation apparatus comprising in combination a plurality of flotation cells connected in series, means for supplying pulp to the first cell in the series and means for permitting the discharge of pulp from the last cell in the series, a rotary impeller suspended on a vertical driving shaft in each of said cells, a stationary sleeve surrounding and substantially larger in diameter than said shaft and extending upwardly from a point adjacent said impeller, said sleeve having an air inlet to allow air to be drawn down the sleeve by the impeller, a cover carried at the lower end of said sleeve and extending over said impeller, said cover being adapted to separate the impeller from the full load of pulp in the cell above but having restricted openings therethrough to allow a limited access of the pulp in the cell to the impeller to permit recirculation thereof, and a pulp inlet for allowing the entry of pulp from the preceding cell.

11. Flotation apparatus comprising in combination a plurality of independent flotation cells connected in series, means for continuously supplying pulp to the first cell in the series, means for permitting a continuous discharge of pulp from the last cell in the series, each cell comprising abox-like container of substantial depth providing in its upper part a separating and froth collecting chamber having means for permitting the discharge of froth therefrom, the lower portion of said cell below said separating chamber constituting an agitating chamber, a rotary agitating impeller in said ,chamber adjacent the bottom of said cell for producing currents of pulp, means lying above the agitating impeller and below the superposed separating chamber for substantially confining violent pulp agitation to said agitating chamber and resisting its transmission to said separating chamber, means for driving said impeller to cause the same to agitate the pulp and discharge the sametherefrom into said agitating chamber, an overflow weir for maintaining the pulp level in the cell, and a conduit connecting said agitating chamber with said weir overflow and opening into the agitating chamber at a point substantially in the path of a portion of the pulp currents created by the impeller and extending in the direction of said currents whereby a portion of said pulp is driven by the impeller into said conduit.

l2. Flotation apparatus of the character described comprising a plurality of flotation cells,

each cell comprising a box-like container of substantial depth which provides both a pulp agitating zone and a froth-separating'zone, each cell being provided with a pulp inlet and a tailings outlet, the tailings outlet and the pulp inlet of two adjacent cells being connected by a passage provided with a weir overflow for controlling the level of the pulp in the preceding cell, a rotary agitating impeller in the agitating zone in the lower part of each cell to receive the pulp from the pulp inlet and impel currents of pulp outwardly, a bafile above the impeller for directing the pulp upwardly from the agitating zone and to resist transmission of swirling currents I of pulp to said froth-separating zone, said tailings outlet leading from the agitating zone at a point closely adjacent said impeller and lying in the path of a portion of said pulp currents whereby pulp may leave said cell without causing disturbance in the froth-separating zone.

13. Flotation apparatus of the character described comprising a plurality of flotation cells, each cell comprising a, box-like container of substantial depth which provides both a pulp agitating zone and a froth-separating zone, each cell being provided with a pulp inlet passage and a tailings outlet passage, the tailings outlet passage and the pulp inlet passage of two adjacent cells being connected by a passage provided with a weir overflow for controlling the level of the pulp in the preceding cell, an agitating impeller in theagitating zone in the lower part of each cell to receive the pulp from the pulp inlet and impel currents of pulp outwardly, a baille for directing the pulp currents upwardly from the agitating zone, the tailings outlet passage having an opening in the agitating zone adjacent the impeller and substantially in the path of pulp currents expelled by said impeller, said outlet passage leading substantially directly to -21 the overflow weir.

' l4. Flotation apparatus comprising in combination a flotation cell adapted to be connected in series with other similar cells, a rotary im peller suspended on a vertical driving shaft near the bottom of said cell, a stationary sleeve surrounding and substantially larger in diameter than said shaft and extending upwardly from a point adjacent said impeller, said sleeve having an air inlet to allow air to be drawn down the sleeve by the impeller, a cover carried at the lower end of said sleeve and extending over said impeller, and a pulp conduit leading into the cell and connected with said sleeve above said impeller to allow the pulp to fall by gravity upon the impeller.

ARTHUR WILLIAM FAHRENWALD.

Images