US2064398A - Mineral separator - Google Patents

Description

Dec. 15, 1936. w. L. ZEIGLER MINERAL SEPARATOR Filed March so, 1935 3 Sheets-Sheet 1 Inventor m w 2 .m m

Attorney Dec. 15, 1936. w, ZEIGLER 2,064,398

MINERAL SEPARATOR Filed March 50, 1-955 3 Sheets-She et 2 lilllllli u m-unmm I Dec. 15, 1936. w ZE|GLER 2,064,398

v MINERAL SEPARATOR Filed March 30, 1935 3 Sheets-Sheet 3 Patented Dec. 15, 1936 UNITED STATES, PATENT QFFICE MINERAL SEPARATOR William L. Zeigler, Wallace, Idaho I Application March 30, 1935, Serial No. 13,897

4 Claims;

My present invention relates to improvements in mineral separators of the flotation type, in which a continuous circulation of the liquid pulp is maintained in the cell or tank, during the process of separation of theminerals from the pulp.

By the construction and operation of the separator of my invention the liquid pulp is continuously fed to the cell or tank, and also discharged therefrom, and during the circulation of the pulp through the tank, the material passes through the steps of settling, agitation, aeration,

separation, and froth discharge for the recovery of the minerals.

In carrying out my invention I utilize a. tank or cell having a specially constructed bottom portion for the introduction of the pulp, and a stationary separating bowl'located above the bottom of the tank, and a rotary agitator or impeller is suspended within the bowl for creating a turbulence of the pulp, and at the same time aerating the pulp. Means are provided for maintaining 'mineral, as will hereinafter be more fully pointed out and claimed. In the accompanying drawings I have illustrated one complete'example of the physical embodiment of my invention, but it will be understood that various changes and alterations are contemplated and may be made therein, to suit diiferent conditions. I

Figure l is a vertical central sectional view of the mineral separator embodying my invention.

Figure 2 is a detail transverse sectional view at line 22 of Figure 1. I

Figure 3 is a top plan view of theapparatus of my invention, with parts broken away to, disclose the interior construction and relation of.

parts.

Figure 4 isa detail perspective view of one of the baiiie plates for subduing the turbulency of the agitated and aerated liquid material.

Figure 5- is a top plan view of the rotary agi-' tator.

Figure 6 is a detail perspective .view'at the outeredge of the rotary agitator illustrating one of the agitating blades and a conveyer-slot or slit. I

. culation of the liquid pulp.

' shaft.

Figure 9 is a detail view showing the relation of the tank bowl, agitator, deflecting or guide blades, and the frusto-conical screen, and the cir- Figure 10 is a detail transverse sectional view 10 at line Ill-l0 of Figure 8 illustrating particularly airpassages through the supporting hub mounted on the power shaft.

Figure 11 is a detail sectional view at the extreme upper end of the power shaft showing the 15 operating means for the skimmer which revolves at the upper edge of the tank. 7

In carrying out my invention I employ a tank I of suitable size and preferably cylindrical in shape, that is supported in elevated position by legs 2, 2, and whichis provided at its upper edge with anannular launder or trough 3 having an outlet or discharge spout 3' for the separated minerals.

The bottom of the tank is provided with an interiorystepped casting 4, which is secured in the tank, and provided in its upper face with an annular chamber 5 that is concave in crosssection, and provided with an intake pipe 6 and port 6, the pipe being connected in suitable manner to the source of supply for the liquid pulp. ,The annular chamber forms an annular trough through which the liquid pulp is fed into the tank and distributed around the interior of the tank,- the whole forming a comparatively shallow feed trough for distribution of the pulp.

Toprovide a wear face or surfacefor revolv-. ing parts of the separator, a hard metal ring I is mounted at the upper edge of the inner wall of the feed trough, and of course the wear ring is 4 concentric with the trough.

The upper face of the bottom-casting I is also fashioned with an-inner annular aerating trough 8, concentric with the annular feed trough, and this comparatively shallow aerating trough 8 :merges with a central, perforated, tapered portion 8 01' the bottom-casting, which may have the form of a-sleeve, as indicated by dotted lines in Figure 1. I

Directly above the annular feed trough 5 is located astationary bowl 9, which is provided with an open center bounded by the inner ring.

it), which is concentric withpbut spaced outwardly from the wear ring I of the bottomcasting.

Below and exterior of the inner ring I 0 the bowl is recessed, and then its wall flares upwardly and outwardly, terminating in an annular, grooved, edge ll, concentric with but spaced within thewall of the tank I On the bottom face of the bowl are provided radiating ribs l0 that rest in the feed trough, and these ribs or supporting lugs elevate the bowl above the trough sufliciently to permit distribution of the liquid pulp throughout the trough. The bowl is thus spaced from the trough and from the tank wall to provide communication between the interior of the bowl and the feed trough, and between the feed trough and the upper portion of the tank, thus assuring movement of currents of the liquid pulp around the bottom portion of the tank and upward through the upper portion thereof.

The bowl is provided with an upper perforated screen l2 of frusto-conical shape having its lower annular edge supported on the grooved upper edge of the bowl. This 'frusto-conical screen is indicated as fashioned of sheet metal with perforations l3 therein, but it will be understood that the conical perforated top portion of the bowl,.with its open center, may be fashioned of any suitable material that will permit circulation of the liquid pulp, upwardly, from the interior of the bowl toward the top of the tank. I

In the central sleeve 8 of the bottom casting 4 is fixed a standpipe H, which forms a housing for the rotary power shaft 15, and the latter is journaled in upright position at the center of the tank or cell in bearings l6 and I! at the, lower and upper ends of the shaft respectively, bearing bushings It! being used, adjacent the bearings, between the shaft and its housing. The power shaft is driven or revolved by a suitable motor as l9, which is suspended beneath the cell or tank I by means of the frame 20, and which transmits power to the shaft through suitable transmission mechanism.

Above the upper bearing ll of the power shaft, a circular hub 2| having a tapered bore, is mounted on the shaft I5 to revolve therewith, and this hub, at its outer periphery is fashioned with air notches 22, through which air may pass downwardly to the interior of the tubular agitator shaft 23 that is fixed at its upper end to the hub. This tubular shaft is concentrio with and spaced about the stand pipe M to form an annular air chamber that is, open to the atmosphere above the top of the tank or cell, through the vent notches 22 of the hub 2|.

The hub 2| and the tubular shaft 23 rigidtherewith are securely clamped on the tapered end of the power shaft by means of a lock nut 24 which is threaded on the reduced end of the power shaft, and the under face of the nut is provided with an annular groove 25 directly above the air notches 22 to admit air through said notches to the interior of the tubular shaft.

As thus arranged, the hub on the power shaft provides an overhead support for the suspension of the impeller or agitator head 26, which has an attaching flange 21 fitted in the lower end of the tubular shaft and rigidly fixed to is suspended slightly above the central portion 8 to provide an annular flaring chamber at the lower end of the tubular shaft through which the air currents flowing down through the tubular shaft are distributed, radially, from beneath the impeller head and into the liquid pulp of the cell or tank. On the under face of the head 26 are provided a plurality of radial agitating blades or ribs best shown in Figure 1, and

in dotted lines Figure 5 that revolve with the head to agitate or stir up the pulp as it is being aerated in the aerating chamber beneath the impeller head.

At its peripheral edge the impeller head is fashioned with a substantially horizontal portion to which .a flat ring 29 is bolted. as at 30, and the outer edge of this flat ring which projects into the bottom portion of the bowl, is fashioned with a series of radial slits or slots 3|, to form spaced vanes 32, and the leading edges 33 of these vanes are bent downwardly to form guides for passage of pulp, upwardly through the slits or slots, as the agitator or impeller revolves anti-clockwise as indicated by the arrows in Fig. 3.

These agitator vanes, as indicated follow a circular path just above the annular space or mouth of the feed trough formed between the ring ll] of the bowl and the wear ring 7 of the bottom casting 4, and the vanes impartto the liquid pulp a spiral or swirling movement to assist in the agitation aeration, and consequent separation of the minerals from the pulp.

This swirling movement or turbulency of the liquid pulp is quieted as the pulp rises from the bowl, and the currents of circulation are brought to a more directly vertical movement in their ascension by means of a series of baffle plates 34 located just within the upper portion of the bowl, above the slotted edge of the impeller or agitator head.

As indicated in Figure 4 each of the baffle plates is provided with hubs as 34' and the plates are supported between the inner and outer concentric rings 35 and 36 on bolts 31. The batile plates may be located in vertical planes as indicated in. Figure 9, or they maybe turned slightly at an angle, for deflecting or guiding the ascending currents of liquid pulp.

The baflie plates, which are arranged in radial formation, and their concentric supporting rings 35 and 36, are supported by brackets 38 attached at the under side of the screen-top 12 of the bowl 9.

Thus it will be apparent that as the finely ground ore or mineral, mixed with water and flotation reagents to form the liquid pulp, flows into the feed trough 5 and is distributed throughout the area of this annular trough from which the pulp flows upwardly, in the shape of a ring, toward the interior of the bowl, and this upward movement of the pulp is assisted by the inclined vanes 33 that cut into the pulp and force the pulp through the slots 3| to the upper surface of the agitator ring. At the same time theserevolving vanes tend to create a vacuum which induces the flow of air from'the central tubular shaft 23, down through the aerating space beneath the agitator head, and the air is discharged in bubbles into the bowl. The multiple arrangement of the agitator vanes around the outer periphery of the impeller-or agitator head results in a uniform distribution of the incom ng air throughout. the area of the tank or cell. A comparatively large volume of air is thus drawn down through the air tube or tubular shaft, but this large volume is distributed in small quantities throughout the entire area of the bowl, and the aeration of the pulp is thus established, uniformly, at all parts of the bowl. The impeller or agitator travels with a comparatively slow revolution, and the aeration, separation, and ascension of the pulp is accomplished smoothly and with a minimum turbulence to accomplish separation of the values from other materials. 1

After the flow of pulp from the impeller, the swirling currents, as they ascend, strike the baffie or rectifying plates 3%, and the course of the currents is thereby deflected into a more nearly vertical plane. These rectified currents pass upwardly through the cone-shaped screen H, which slackens the flow of the material and equalizes the volume of the pulp passing upwardly into the open upper chamber or portion of the cell or tank.

The tailings settle from this unobstructed portion of the cell, and are discharged through one or more discharge openings 39 in the side wall of the tank.

The ascending currents of pulp from the bowl, because of the conical shape of the screen l2, change their course after emerging through the screen and tend to move toward the circular wall of the tank or cell, and then these currents flow downwardly along the side wall of the tank into the annular feed trough, thus creating a continuous circulation of the pulp within the tank, which-includes movements in upward and downward direction, as well as a circular motion around the exterior of the bowl, and around the interior of the bowl in the counter clockwise direction. of the arrow in Figure 3. The distance of travel of the pulp in its circular path can be determined bythe angularity of the position of the deflecting or rectify-blades or plates 34. Thus, with a comparatively small amount of flowing pulp, the plates may be adjusted to deflect the currents as they flow in vertical planes, and these currents will complete a number of circuits in the vertical planes while making one circuit around the tank or cell starting at the feed point 6 and flowing around the tank to the discharge port 39.

The air bubbles rising from the impeller pass upwardly through the conical screen and then rise, naturally, toward the surface of the pulp in the cell or tank, passing through the outwardly .and downwardly flowing currents of pulp, and in their, cross passage through these currents, the bubbles gillect the mineral or buoyant material of the pulp andconvey it to the surface of the liquid, within the tank or cell.

The froth thus formed by the bubbles on the surface of the liquid pulp is transferred to the launder 3 by the use of a revolving skimmer which includes a pair of curved blades 40 which curve backwardly from the circular path of movement of the skimmer, which movement 'is clockwise, as distinguished from the anti-clockwise movement of the impeller and of the flow.

of the pulp.

The skimming blades, which stand in vertical with a sheave or pulley 45 which is connected I by a belt to a source of power for revolving or driving. the skimmer and the screw cap 46 is provided for access to the interior of the rotary head for lubricating purposes. Through the instrumentality of the gearing 45 the rotary skimmer is operated in reverse direction to that of the power shaft, and the backwardly curved skimmers or blades 40, as they turn, push the froth from the surface of the pulp level, forwardly and outwardly, into the launder 3. As the skimmer blades push the froth forwardly and outwardly an outward movement of froth from the central portion of the tank is induced behind the blades-"and toward the launder, thus producing an outward movement of the froth into the path of the continuously revolving skimmer. 7

Thus it will be apparent that the circulation of pulp through the cell is such that a given portion of the pulp must pass through the cycle of settling, agitation, aeration, separation, and froth discharge, repeatedly, before the pulp can be discharged through the outlet '39.

Numerous advantages accrue from the simplicity of construction and operation of the separator. The driving motor, it will be noted, is located beneath the tank or cell where it is protected from the mineral spray that is produced by the bursting froth bubbles outside the launder. The drive shaft or power shaft l5 and its accessories are supported from below i. e. at the bottom of the tank or cell, thereby eliminating the necessity for use of cumbersome and expensive overhead frames or superstructures, and

alfording a direct drive for the agitator or impeller and for the skimmer. The overhead suspension of the rotary impeller, and its widely spaced bearings insure an even wear of parts without wabbling or.vibration of the impeller, and the manner of supporting the impeller permits the use of comparatively light material as sheet metal or steel that may be coated with wear resisting alloys to enhance the durability of the impeller.

The parts of the unit may readily be assembled, and with equal facility they may be dismantled for repairs, replacements and other necessary attention, and the whole unit maywith convenience be inspected and cleansed when necessary for proper maintenance and. emciency.

A single cell or tank may be utilized as illus-' trated in the drawings, and it will also be apparent that a number of these units may readily be connected up in series, for the complete separation of the mineral from the pulp.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:--

1. The combination in a mineral separator having outer and inner concentric chambers in its bottom portion, an annular open-center bowl rents, and a perforated cover for said .bowl

enclosing said deflecting means.

2. The combination in a mineral separator comprising a tank having an outer annular feed chamber in its bottom portion, of an annular open-center bowl supported above said chamber,

a frusto-conical screen mounted over the bowl, a central aerating-impeller within said bowl and.

, having its periphery extending partially over said bowl and chamber, and means for revolving the impeller.

3. The combination in a mineral separator comprising a tank having an annular feed chamber in its bottom :portion, of an annular bowl 10 supported above and communicating with said chamber, a frusto-conical screencovering the bowl, adjustable deflecting blades mounted beneath said screen and within said bowl, a central rotary aerating head and operating means there--

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