Cross-reference to Related Applications

None.

Field of the Invention Embodiments of the invention relate to novel disperser hoods for flotation cells, in particular, self-aspirated flotation cells. Embodiments may be especially beneficial in improving effi ciency and/or recovery of flotation machines in flotation processes.

Background of the Invention

Flotation cells receive slurry containing ore particles. Some of the ore particles having a tar get mineral therein, and others contain unwanted gangue. Reagents (e.g., collectors/float- promotors, frothers, depressors/depressants, activators, pH regulators, sulphidizers) are generally used to improve and/or optimize flotation of such ore particles, for example, to float or inhibit flotation of the ore particles containing the target mineral therein. To this end, aside from columns or those using spargers, there are generally two types of flotation cells - those that use forced air through a shaft (e.g., FLSmidth ^® Dorr-Oliver ^® flota tion cells), and those which naturally-aspirate (e.g., FLSmidth ^® Wemco ^® flotation cells) and draw ambient air into the cell as needed.

Naturally-aspirated flotation cells 100, e.g., such as the one shown in FIG. 7, comprise a motor 112 which rotationally drives a shaft comprising a rotor 105. The rotor 105 is configured in a central portion of a tank above a draft tube 106. The draft tube 106 is supported by a false bottom 107 which allows slurry in the flotation cell 100 to move through the false bottom 107 and up into the draft tube 106 before it makes its way to rotor 105. The rotor 105 and draft tube 106 provide a pumping action for slurry within the flotation cell 100.

The upper portion of draft tube 106 typically comprises an adjustable collar 108 to adjust a gap between rotor 105 and draft tube 106. Radially-surrounding an upper portion of rotor 105 is a disperser 104, which is typically provided in the form of a cylindrical tube with aper tures extendingtherethrough. Above, and radially-surroundingan upper portion of disperser 104 is a disperser hood 101 which is generally frustoconical in shape and also comprises a plurality of apertures therethrough. The disperser 104 and disperser hood 101 collectively act as a type of stator for naturally- aspirated flotation cells. They work in conjunction with a stand pipe 102 and air inlet duct

103 to draw air surrounding the flotation cell 100 into the machine. By virtue of pumping action, slurry moves upwards through draft tube 106, and air moves down through stand pipe 102 to aerate slurry. As slurry is propelled through disperser 104 and hood 101, additional bubbles can be formed and proper bubble sizing can be achieved to effect efficient flotation of particles containing a target mineral(s).

As shown in FIG. 7, a naturally-aspirated flotation cell 100 may comprise a weir level 111, a rotor top level 109, and a distance therebetween called a rotor submergence 110.

It is desired to provide an improved disperser hood 101 to enable more efficient flotation processes using naturally-aspirated flotation cells 100.

Objects of the Invention

According to some embodiments, it is desired to provide a flotation cell 100 configured to perform flotation processes more efficiently, without limitation.

According to some embodiments, it desired to provide an improved disperser hood 101 for a naturally-aspirated flotation cell 100 which performs better than its prior art counterparts, without limitation. According to some embodiments, it is desired to provide an improved disperser hood 101 for a naturally-aspirated flotation cell 100 which obviates the need for a disperser 104 alto gether, without limitation. These and other objects of the present invention will be apparent from the drawings and description herein. Although every object of the invention is believed to be attained by at least one embodiment of the invention, there is not necessarily any one single embodiment of the invention that achieves all of the objects of the invention. Brief Summary of the Invention

A disperser hood 1 for a self-aspirated flotation cell 100 includes a collar 2, and a conical member 4 extending downwardly and radially-outwardly from the collar 2. The disperser hood 1 may be characterised in that it further comprises a plurality of vanes 6 extending downwardly from the conical member 4. Each of the plurality of vane 6 may have a lower side 8, a radially-inner side 9, and an external radius, curve, or chamfer 7 extending between the lower side 8 and radially-inner side 8.

In some embodiments, the disperser hood 1 may further comprise at least one through open- ing 10 in at least one of the plurality of vanes 6, without limitation.

In some embodiments, at least one through opening 10 may be provided in at least two of the plurality of vanes 6, without limitation. In some embodiments, at least one through opening 10 may be provided in all of the plurality of vanes 6, without limitation. In some embodiments, the at least one through opening 10 may comprise a circular aperture, an elongated slot, an oblong hole, a port of predetermined geometry, or a combination thereof, without limitation.

In some embodiments, the disperser hood 1 may comprise at least one mounting feature 3 provided to the collar 2.

Description of the Drawings

To complement the description which is being made, and for the purpose of aiding to better understand the features of the invention, a set of drawings illustrating a preferred, non-limit ing embodiment of an improved disperser hood 1 for use in a conventional self-aspirated flo tation cell 100 is attached to the present specification as an integral part thereof, in which the following has been depicted with an illustrative and non-limiting character. It should be un derstood that like reference numbers used in the drawings.

FIG. 1 shows a side view of one example of a disperser hood 1 according to non-limiting em bodiments of the invention. FIG. 2 shows a side cross-sectional view of the disperser hood 1 shown in FIG. 1.

FIG. 3 shows a bottom isometric view of the disperser hood 1 shown in FIGS. 1 and 2. FIG. 4 shows a top isometric view of the disperser hood 1 shown in FIGS. 1-3.

FIG. 5 shows a side cross-sectional view of a disperser hood 1 according to alternative embodiments. FIG. 6 shows a side cross-sectional view of a disperser hood 1 according to alternative embodiments.

FIG. 7 shows a conventional self-aspirated flotation cell 100 according to the prior art, and incorporating a conventional disperser hood 101. The conventional disperser hood 101 shown in FIG. 7 is preferably replaced with one as described herein and shown in FIGS. 1-6, and the disperser 104 may be optionally omitted.

In the following, the invention will be described in more detail with reference to drawings in conjunction with exemplary embodiments. Detailed Description

A disperser hood 1 for a self-aspirated flotation cell 100 according to some preferred embod iments of the invention is shown in FIGS. 1-4. The disperser hood 1 may comprise an upper annular or tubular collar 2 from which a conical member 4 extends. One or more mounting features 3 for mounting the disperser hood 1 to a disperser 104 or stand pipe 102 may be provided to the disperser hood 1 (e.g., around collar 2 as shown). The mounting feature 3 may, for example, comprise a number of bosses and/or through holes for receiving a bolt. The mounting feature 3 may alternatively comprise a ledge, flange, or weld abutment sur- face, without limitation.

A number of small apertures 5 may extend through the conical member 4 so as to make the conical member 4 a perforated structure. A plurality of inwardly-projecting vanes 6 may ex tend downward and/or radially-inwardly from the conical member 4 as shown. The vanes 6 may, in some embodiments, not extend more radially inwardly than collar 2, so as to provide enough clearance for a rotor 105 to turn within the disperser hood 1.

Each vane 6 may comprise a lower side 8 and a radially-inner side 9 connected therebetween by an external radius, curve, or chamfer 7, without limitation. In some embodiments, as shown in FIG. 5, the lower side 8 may be flat (i.e., extend horizontally in relation to the flota- tion cell 100; or, in a plane parallel to the collar 2), without limitation. In some embodiments, as suggested in FIGS. 2 and 6, lower side 8 may be alternatively angled upwardly from the lower portion of the conical member 4, without limitation.

On each of the vanes 6, there may be one or more through openings 10. Through openings 10 may comprise, for example, apertures, elongated slots, oblong holes, ports of predeter mined geometry, or the like without limitation. Each vane 6 may comprise a similar pattern of through openings 10 as the others on the disperser hood 1 as shown; however, it is envis aged that vanes 6 may each comprise unique patterns of through openings 10, different types of through openings 10, different numbers of through openings 10, different configurations of through openings 10. In some conceived embodiments, only some of the vanes may com prise through openings 10, whereas others may contain no through openings 10 at all. In such latter embodiments, vanes 6 may alternate between those with and without through openings 10, without limitation. In some embodiments, such as the one shown in FIGS. 5 and 6, a disperser hood 1 for a self- aspirated flotation cell 100 may only comprise vanes 6 which have a chevron or triangular profile, without limitation.

It should be known that the specific features, functions, process steps, and possible benefits shown and described herein in detail are purely exemplary in nature and should not limit the spirit and/or scope of the invention. Moreover, although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of these teachings, can generate additional embodiments and modifications without departing from the spirit of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.

Listing of Reference Numerals

1 Disperser hood

2 Collar

3 Mounting feature

4 Conical member

5 Apertures

6 Inwardly-projecting vanes

7 External radius, curve, or chamfer

8 Lower side

9 Radially-inner side

10 Through openings

(e.g., apertures, elongated slots, oblong holes, ports of predetermined geometry)

100 Self-aspirated flotation cell

101 Disperser hood

102 Stand pipe

103 Air inlet duct

104 Disperser

105 Rotor

106 Draft tube

107 False bottom

108 Adjustable collar

109 Rotor top level

110 Rotor submergence

111 Weir level

112 Motor

113 Drive (e.g., transmission)

114 Shaft