Aeration assembly for self-aspirating flotation machines

Abstract

An aeration assembly (29) for a self-aspirated flotation cell (100) may have a standpipe (11). A lower inside diameter (42) of the standpipe (11) may be measured to be within ± 25% of an upper inside diameter (41) of a draft tube (106) or collar (108). The aeration assembly (29) may have an upper gap (37) that extends between a rotor (15) and standpipe (11) and a lower gap (36) that extends between the rotor (15) and draft tube (106) or collar (108), wherein the upper gap (37) may be measured to be within ± 25% of the lower gap (36). In some embodiments, the rotor (15) extends into the standpipe (11) for an upper vertical rotor depth (39) and the rotor (15) extends into the standpipe (11) for a lower vertical rotor depth (40), wherein the upper vertical rotor depth (39) is measured to be within ±25% of the lower vertical rotor depth (40).

Description

[0001] Aeration Assembly for Self-Aspirating Flotation Machines

[0002] Cross-reference to Related Applications

[0003] None.

[0004] Field of the Invention

[0005] Embodiments of the invention relate to novel aeration assemblies for flotation cells, in particular, for naturally-aspirated (i.e., "self-aspirated" or "induced-air") flotation cells. Embodiments may be especially beneficial for improving performance, energy efficiency, and / or mineral recovery when employed and used in flotation processes. Novel aeration assemblies disclosed may include a unique vortex stabilizer and annular collar structures. Some of these structures may be configured to be modular, without limitation. Aeration assembly components may include unique configurations and / or novel relative spatial arrangements. For example, unique spacings between or insertion engagement lengths spanning adjacent components are also disclosed.

[0006] Background of the Invention

[0007] Flotation cells receive slurry containing ore particles. Some of the ore particles having a target 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. Conventional and "reverse" flotation practices are common. Reverse flotation involves suppressing particles of target composition and floating unwanted gangue.

[0008] To this end, aside from columns and those flotation machines which employ spargers or inverted fluidized beds (e.g., W02011150455A1), there are generally two types of flotation cells - those that use forced air introduced under pressure through a shaft and through a rotor surface (e.g., FLSmidth® Dorr-Oliver® flotation cells), and those which naturally-aspirate (e.g., FLSmidth® Wemco® flotation cells). Embodiments of the invention are drawn to the latter types of self-aspirating flotation cells which are configured to draw ambient air downwardly into the cell through an upper standpipe via a breather port. Such machines are further configured to draw slurry upwardly through a draft tube having a lower false bottomfloor, and pump it towards a centrally-disposed rotor. The resulting flow encourages recirculation of slurry and pulp within the cell for improved bubble-particle attachment.

[0009] Self-aspirated flotation cells 100, e.g., such as the ones shown in prior art FIGS. 1 and 2, typically comprise a motor 112 which rotationally drives a shaft 114. A lower distal end portion of the shaft 114 comprises a rotor 105 affixed thereto. A drive 113 (e.g., reduction, gearbox, transmission, pulley system, or the like) may be employed between the motor 112 and shaft 114 to allow torque from the motor to spin the shaft 114 and rotor 105. Unlike forced-air units, the rotor 105 is configured in a central portion of a tank 115 above a draft tube 106 and adjacent a vertical midpoint of the tank 115. The draft tube 106 is supported by a false bottom 107 which allows slurry in the flotation cell 100 to move past the false bottom 107 and up into the draft tube 106 before it making its way to the rotor 105. The combined effect of rotor 105 and draft tube 106 provides a pumping / recirculation action for slurry within the flotation cell 100.

[0010] The upper portion of draft tube 106 may comprise a collar 108, which may comprise a fixed height collar, or an adjustable collar, to adjust a gap between rotor 105 and draft tube 106. This accommodation can make up for wear or part tolerancing variations. Radially-surrounding an upper portion of rotor 105 is a disperser 104. The disperser 104 is typically provided in the form of a perforated vertically-oriented cylindrical tube having apertures extending therethrough for allowing radially-outward flow of aerated slurry and pulp. Above, and radi-ally-surrounding an upper portion of disperser 104 is a disperser hood 101 which is thin and generally frustoconical in shape and also comprises a plurality of apertures therethrough. The disperser hood 101 serves to dampen velocities, diffuse energy, provide additional shearing, and control fine bubble size distributions.

[0011] The disperser 104 and disperser hood 101 collectively act as a unique type of stator for selfaspirated flotation cells. They serve to impart shear, control bubble size, and work in conjunction with a standpipe 102 and air inlet duct 103 to draw air surrounding the flotation cell 100 into the machine. By virtue of the pumping action induced by the rotor's 105 proximity to the draft tube 106 / collar 108, slurry moves upwards through the draft tube 106 (through false bottom 107), and air moves downwards through standpipe 102 to combine with and aerate the slurry in proximity of the rotor 105. As aerated slurry is propelled radially outwardly through disperser 104 (and / or disperser hood 101), additional bubbles can be formed through supplemental shear, and proper bubble sizing can be achieved to efficiently float particles containing a target mineral(s).As shown in FIGS. 1 and 2, a conventional self-aspirated flotation cell 100 may further comprise a weir level 111, a rotor top level 109, and a distance therebetween called a rotor submergence 110. A froth crowder 116 may be situated above the disperser hood 101 to bias rising froth radially-outwardly towards circumferential launder along an upper periphery of tank 115. Radially-extending launders may be employed to increase launder surface area across the tank 115.

[0012] Although self-aspirated flotation machines 100 of the prior art have demonstrated success within the flotation processing industry, it is desired to provide an improved aeration assembly 29 for enabling them to provide more efficient flotation processing.

[0013] Objects of the Invention

[0014] According to some embodiments, it is desired to provide a self-aspirated flotation cell 100 configured to perform flotation processes more efficiently, without limitation.

[0015] According to some embodiments, it is desired to provide a self-aspirated flotation cell 100 which is configured to pump and recirculate slurry / pulp more efficiently within the flotation cell 100.

[0016] According to some embodiments, it is desired to provide a self-aspirated flotation cell 100 which is configured aerate slurry / pulp more efficiently within the flotation cell 100.

[0017] According to some embodiments, it desired to provide an improved disperser 101 for a selfaspirated flotation cell 100 which performs better than its conventional counterparts, without limitation.

[0018] According to some embodiments, it is desired to provide an improved aeration assembly 29 for a self-aspirated flotation cell 100 which decreases power consumption, provides more uniform bubble size distributions, optimizes shearing, increases mineral recovery, and / or reduces wave-inducing vortices within a standpipe 11, 102 without limitation.

[0019] According to some embodiments, it is desired to provide an annular collar 20 supporting a number of vanes 6 to improve upon conventional disperser 101 structures.

[0020] According to some embodiments, it is desired to provide means for adjusting the position of vanes with respect to other components within an aeration assembly 29.According to some embodiments, it is desired to provide a self-aspirated flotation cell 100 having means which decreases power consumption, provides more uniform bubble size distributions, optimizes shearing, increases mineral recovery, and / or reduces wave-inducing vortices within a standpipe 11, 102 without limitation.

[0021] 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.

[0022] Brief Summary of the Invention

[0023] An aeration assembly (29) for a self-aspirated flotation cell (100) is disclosed. The aeration assembly (29) may comprise a rotor (15) attachable to, provided to, and / or attached to a distal portion of a rotatable shaft (14). For example, a cavity (15c) may be provided for accepting a shaft (14).

[0024] The aeration assembly (29) may comprise a vertically-oriented tubular standpipe (11). The standpipe (11) may have an upper proximal open end, and a lower distal open end. The standpipe (11) may surround an upper portion of the rotor (15). The aeration assembly (29) may comprise an annular frustoconical froth crowder (16). The froth crowder (16) may surround the standpipe (11). The froth crowder (16) may extend radially-outwardly and / or upwardly in relation to a lower region of the standpipe (11). The aeration assembly (29) may comprise an annular frustoconical disperser hood (1). The disperser hood (1) may be provided below the froth crowder (16). The disperser hood (1) may extend radially-outwardly and / or downwardly in relation to standpipe (11) and / or the froth crowder (16). For example, the disperser hood (1) may extend radially-outwardly and / or downwardly in relation to the lower region of the standpipe (11), without limitation. The aeration assembly (29) may comprise a draft tube (106) or collar (108). The draft tube (106) or collar (108) may be positioned below at least a lower portion of the rotor (15). The draft tube (106) or collar (108) may surround a lower portion of the rotor (15).

[0025] In some embodiments, the aeration assembly (29) may comprise a lower inside diameter (42) of the standpipe (11) which is measured to be within ± 20% of an upper inside diameter (41) of the draft tube (106) or collar (108), without limitation. For example, the lower inside diameter

[0026]

[0027] of the standpipe (11) may be measured to be within ± 15% of the upper inside diameter (41) of the draft tube (106) or collar (108). As another example, the lower inside diameter (42) of the standpipe (11) may be measured to be within ± 10% of the upper inside diameter (41) of the draft tube (106) or collar (108). As another example, the lower inside diameter (42) of the standpipe (11) may be measured to be within ± 5% of the upper inside diameter (41) of the draft tube (106) or collar (108). As another example, the lower inside diameter (42) of the standpipe (11) may be measured to be within ± 3% of the upper inside diameter (41) of the draft tube (106) or collar (108). As another example, the lower inside diameter (42) of the standpipe (11) may be measured to be substantially the same (e.g., equal to) the upper inside diameter (41) of the draft tube (106) or collar (108), without limitation.

[0028] In some embodiments, the aeration assembly (29) may comprise an upper gap (37) that extends between the rotor (15) and standpipe (11). The aeration assembly (29) may comprise lower gap (36) that extends between the rotor (15) and draft tube (106) or collar (108). The upper gap (37) may be measured to be within ± 20% of the lower gap (36), without limitation. For example, the upper gap (37) may be measured to be within ± 18% of the lower gap (36). As another example, the upper gap (37) may be measured to be within ± 15% of the lower gap (36). As another example, the upper gap (37) may be measured to be within ± 10% of the lower gap (36). As another example, the upper gap (37) may be measured to be within ± 5% of the lower gap (36). As another example, the upper gap (37) may be measured to be within ± 3% of the lower gap (36). As another example, the upper gap (37) may be measured to be substantially the same as (e.g., equal to) the lower gap (36), without limitation.

[0029] In some embodiments, the rotor (15) of the aeration assembly (29) may extend into the standpipe (11) for an upper vertical rotor depth (39). The rotor (15) may extend into the standpipe (11) for a lower vertical rotor depth (40). The upper vertical rotor depth (39) may be measured to be within ±20% of the lower vertical rotor depth (40), without limitation. For example, the upper vertical rotor depth (39) may be measured to be within ±18% of the lower vertical rotor depth (40). As another example, the upper vertical rotor depth (39) may be measured to be within ±15% of the lower vertical rotor depth (40). As another example, the upper vertical rotor depth (39) may be measured to be within ±10% of the lower vertical rotor depth (40). As another example, the upper vertical rotor depth (39) may be measured to be within ±5% of the lower vertical rotor depth (40). As another example, the upper vertical rotor depth (39) may be measured to be within ±3% of the lower vertical rotor depth (40). As another example, the upper vertical rotor depth (39) may be measured to be substantially the same as (e.g., equal to) the lower vertical rotor depth (40), without limitation.The disperser hood (1) may comprise one or more panels. The disperser hood (1) may have a plurality of apertures (5) extending therethrough (e.g., through the one or more panels). The disperser hood (1) may comprise an upper mounting ring (28) which is preferably configured for connecting to a mounting ring (30) extending from a lower body (2).

[0030] The aeration assembly (29) may comprise a vortex stabilizer (17) and / or an annular collar (20) having a plurality of vanes (6) extending therefrom.

[0031] The vortex stabilizer (17) may be provided within the standpipe (11) and may be configured for receiving a rotating shaft (14) therethrough. The vortex stabilizer (17) may comprise a tubular body structure (17b). The vortex stabilizer (17) may also comprise a tapered upper inner surface (17a) that flares out from an upper inner edge of the tubular body structure (17b). The inner surface of the tubular body structure (17b) may be configured to reduce a distance between the shaft (14) and standpipe (11) and prevent fluctuations in fluid height within the standpipe (11).

[0032] The annular collar (20) may be connectable to a lower body (2). An upper surface of the annular collar (20) may abut a lowersurface of the lower body (2). The lower body (2) may be operably connected (e.g., at an upper portion thereof) to the lower distal open end of the standpipe (11). The annular collar (20) may comprise a plurality of mounts (19). The mounts (19) may extend downwardly from the annular collar (20). The mounts (19) may be permanently attached to the annular collar (20), for example, at an underside of the annular collar (20). The mounts (19) may be arranged along radials of the annular collar as shown.

[0033] A plurality of vanes (6) may be provided to the aeration assembly (29). Each of the vanes (6) may extend from one of the mounts (19). In some embodiments, at least one through opening (10) may be provided to at least one of the vanes (6). In some embodiments, the aeration assembly (29) may comprise a plurality of through openings (10) in at least one of the vanes (6). One or more through openings (10) may be present on all of the vanes (6).

[0034] In some embodiments, the plurality of through openings (10) may comprise elongated slots. The elongated slots may be substantially parallel to each other. The elongated slots may extend through at least one of the vanes (6) as shown.

[0035] In some embodiments, the mounts (19) may be configured to be integral with the vanes (6). For example, the mounts (19) may form upper radially-inwardly extending extension portions of the vanes (19) as depicted in FIGS. 24-26. The vanes (6) may be permanently affixed to the annular collar (20), without limitation.In some embodiments, a plurality of mounting holes (26) may extend into or through the mounts (19). These mounting holes (26) may be configured for receiving or otherwise accepting one or more fasteners (not shown). Each of the vanes (6) may be radially-adjustable with respect to and / or removable from mounts (19). The vanes (6) may comprise a plurality of mounting holes (27). The mounting holes (27) of the vanes (6) may be configured to align with at least some of the mounting holes (26) of the mounts (19). The mounting holes (27) of the vanes (6) may also be configured for receiving one or more fasteners (not shown). In this regard, the one or more fasteners (not shown) may be used to secure the vanes (6) to the mounts (19) using the one or more fasteners as depicted in FIGS. 3-23.

[0036] A greater number of mounting holes (26) may be provided to each mount (19) than to each vane (6). In this regard, vanes (6) may be radially-indexable and adjusted radially-outwardly or radially-inwardly with respect to rotor (15). Thus, more or less clearance between rotor (15) and a radia I ly-i nne r sides (9a) of vanes (6) may be achieved.

[0037] According to some embodiments, radia lly-i nner sides (9a) of the vanes (6) may be flat as depicted in FIGS. 3-25. In some embodiments, radia lly-inner sides (9a) of the vanes (6) may be curved and / or concave as suggested in FIG. 26. In some embodiments, radially-outer sides (9b) of vanes (6) may be curved and / or convex as depicted in FIGS. 24 and 26. In some embodiments, radially-outer sides (9b) of vanes (6) may be flat as depicted in FIGS. 3-23 and 24.

[0038] In some embodiments, upper sides (9c) of vanes (6) may extend to or connect with a portion of a disperser hood (1) as suggested in FIG. 24. In some embodiments, upper sides (9c) of vanes (6) may be separated from the disperser hood (1) by a clearance gap or distance as suggested in FIGS. 3-23, 25, and 26.

[0039] According to some embodiments, a self-aspirated flotation cell (100) may comprise an aeration assembly (29). The self-aspirated flotation cell (100) may comprise an annular collar (20). The annular collar (20) may be connectable to a lower body (2). The annular collar (20) may be connected to a lower distal open end of a standpipe (11).

[0040] The annular collar (20) may comprise a plurality of mounts (19) extending downwardly from the annular collar (20). The mounts (19) may be permanently attached to the annular collar (20). The mounts (19) may be provided at (or adjacent) an underside of the annular collar (20). A plurality of vanes (6) may be provided to the annular collar (20). For example, each of the vanes (6) may extend from one of the mounts (19) provided to the collar (20).The annular collar (20) may comprise a substantially planar annular structure. This structure may be configured to be oriented within a transverse horizontal plane of the self-aspirated flotation cell (100); for example, at a single vertical height location within a tank (115) of the self-aspirated flotation cell (100).

[0041] The annular collar (20) may comprise a plurality of mounting holes (7) for securing the annular collar (20) to the lower body (2) with one or more fasteners (34). In some embodiments, (such as those depicted in FIGS. 24-26), the mounts (19) may form respective integral portions of vanes (6). In other words, a mount (19) may take on the form of an extension of a vane (6), without limitation. In some embodiments, (such as depicted in FIGS. 3-23), the mounts (19) may be separate and distinct from vanes (6), such that each of the vanes (6) may be removably and / or adjustably affixed to a respective mount (19). In any event, mounts (19) may be permanently attached to a lower surface of annular collar (20).

[0042] The mounts (19) may each comprise mounting holes (26), and the vanes (6) may each comprise mounting holes (27) that are configured to align with at least some of the mounting holes (26) in the mounts (19).

[0043] The mounts (19) may each comprise a plate structure as shown. The plate structure of each mount (19) may comprise a vertical height (H) in a vertical direction of the self-aspirated flotation cell (100), for example, in a direction extending parallel to a longitudinal central axis or axis of rotation of shaft (14) or rotor (15). The plate structure of each mount (19) may comprise a radial length (L) along a radial of the annular collar (20), for example, in a direction extending generally perpendicular to a longitudinal central axis or axis of rotation of shaft (14) or rotor (15). The plate structure of each mount (19) may comprise a circumferential thickness (T) defining a width. The circumferential thickness (T) may be measured along a circular path about a longitudinal central axis or axis of rotation of shaft (14) or rotor (15). The circumferential thickness (T) may be uniform, or it may vary along a radial of the annular collar (20). Vanes (6) may also comprise their own vertical height (H), radial length (L), and circumferential thickness (T), without limitation.

[0044] A self-aspirated flotation cell (100) according to some embodiments may comprise an aeration assembly (29) that has a vortex stabilizer (17) or vortex stabilizing structure. The vortex stabilizer (17) may be configured to be provided within a standpipe (11) having an upper proximal open end and a lower distal open end.

[0045] The vortex stabilizer (17) may be configured for receiving a rotating shaft (14) therethrough. The vortex stabilizer (17) may comprise a tubular body structure (17b) and a tapered upperinner surface (17a) that flares out from an upper inner edge of the tubular body structure (17 b). A lower portion of the tubular body structure (17b) may extend lower than or reach beyond the lower distal open end of the standpipe (11) (with respect to vertical), as illustrated.

[0046] A lower body (2) may extend between the vortex stabilizer (17) and the standpipe (11) as shown. The lower body (2) may take the form of an annular plate or flange which may extend radially-outwardly beyond an outer periphery of the standpipe (11). Said differently, the lower body (2) may extend radially-outwardly beyond a diameter of the standpipe (11) - or comprise a larger radius than standpipe (11).

[0047] The lower body (2) may comprise an annular plate-like structure extending between the tubular body structure (17b) and the standpipe (11). A radially inner portion of the lower body (2) may abut against or terminate at an outer surface portion of the standpipe (11), such that the lower body (2) extends radially-outwardly therefrom. The standpipe (11) may perpendicularly intersect an upper surface of the lower body at its lower distal open end, such that the standpipe (11) and lower body (2) are orthogonally arranged with respect to each other.

[0048] The lower body (2) may comprise a hollow cylindrical mounting ring (30) extending downwardly therefrom. The mounting ring (30) may be configured for securing a mounting ring (28) of a disperser hood (1) thereto. The mounting ring (30) may be a continuous annulus, such as a cylindrical tube extending from a lower surface and / or an outer perimeter of the lower body (2) as shown. However, the mounting ring (30) may be interrupted so as to form a castellated structure (not shown). In such embodiments, tabs, blocks, or protrusions which are adequate for providing a mounting surface for a mounting disperser hood (1) may be alternatively employed.

[0049] In some embodiments, the rotor (15) may comprise vanes (6) that are substantially rectangular when viewed from a broad side plan view, or when viewed perpendicular to a hydrodynamically-leading face as most clearly depicted in FIGS. 29-35. In some embodiments, as depicted most clearly in FIG. 5, 6, 9-12, 22, 28, and 27, an outer edge portion of the vanes may comprise a curved edge profile when viewed from a broad side plan view, or when viewed perpendicular to a hydrodynamically-leading face. The curved edge profile may be convex as depicted. For example, an outer shape (15a) of the rotor vanes (6) may comprise a curved barrel shape or a cylindrical shape, without limitation.

[0050] In some embodiments, as seen from FIG. 28, 31-33, rotor vanes (6) may vary in thickness in a radial direction (e.g., vanes (6) may widen as they extend further radially outwardly). For ex-ample, in some embodiments, vanes (6) may have a more centrally-located radially-inner thinner portion (44), and a more peripherally-located radially-outer wider portion (45). The radially-inner thinner portion (44) may comprise a substantially planar portion, without limitation. The radially-outer wider portion (45) may comprise an outwardly-widening portion, outwardly-flared portion, or expanding wedge portion as best depicted in FIG. 33.

[0051] The radially-inner thinner portion (44) may be provided as a generally planar radially-inward portion which is located more adjacent the shaft (14). The radially-outer wider portion (45) may be provided as an outwardly-flaring or increasingly thicker portion which is located further from the shaft (14) and more proximal to a periphery of the rotor (15).

[0052] In some embodiments, the rotor (15) may comprise an open pocket (15b) which may be provided to a central lower inner portion of the rotor (15). The open pocket (15) may be defined by an inner taper or flare (15d) on each of the vanes (6), without limitation. A cavity (15c) may be provided to the rotor for accepting a shaft (14) or portion thereof, or the rotor (15) may comprise an upper flange or mount that connects the rotor (15) to the shaft (14).

[0053] Description of the Drawings

[0054] 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 preferred, non-limiting embodiments of an improved aeration assembly 29 and components thereof for use in a selfaspirated flotation 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 understood that like reference numbers used in the drawings.

[0055] FIG. 1 shows a side partial cross-sectional view of one example of a conventional self-aspirated flotation cell 100 according to the prior art.

[0056] FIG. 2 shows a side partial cross-sectional view of another example of a conventional selfaspirated flotation cell 100 according to the prior art.

[0057] FIG. 3 shows a bottom isometric view of a drive assembly and aeration assembly 29 according to some embodiments.

[0058] FIG. 4 shows a top isometric view of a drive assembly and aeration assembly 29 according to some embodiments.FIG. 5 shows a side cutaway view of a drive assembly and aeration assembly 29 according to some embodiments.

[0059] FIG. 6 is an isometric representation of FIG. 5.

[0060] FIG. 7 is an isometric cutaway view of select components of an aeration assembly 29, in particular, vanes 6, disperser hood 1, and annular collar 20 apparatus. Other components of the aeration assembly 29 are omitted for clarity and understanding.

[0061] FIG. 8 depicts a lower isometric view of an annular collar 20 provided with radially-extending mounts 19, according to some embodiments. Other components of the aeration assembly 29 are omitted for clarity and understanding.

[0062] FIG. 9 shows an alternative side profile view of an aeration apparatus 29 according to nonlimiting embodiments of the invention.

[0063] FIG. 10 shows a side cutaway view of FIG. 9. Shaft 14 is omitted from the figure for clarity.

[0064] FIGS. 11-17 show various views of a disperser hood 1, annular collar 20, and vanes 6 extending from the annular collar 20. As shown, in some embodiments, vanes 6 may be modular separable structures that can be removed from and / or radially adjustable with respect to mounts 19 provided on the underside of annular collar 20. Thus, vanes 6 are operably connectable to the annular collar 20 via mounts 19.

[0065] FIGS. 18 and 19 show the embodiment of FIGS. 11-17 with disperser hood 1 not shown for clarity.

[0066] FIGS. 20 and 21 show the embodiment of FIGS. 11-17 with annular collar 20 and mounts 19 not shown for clarity.

[0067] FIG. 22 depicts and exploded model view of an aeration apparatus 29 according to embodiments of the invention previously illustrated.

[0068] FIG. 23 is a sectional isometric view of an aeration apparatus 29 more clearly depicting features of a vortex stabilizer 17 and its arrangement within the aeration apparatus 29.FIGS. 24-26 illustrate alternative embodiments of vanes 6 that may be permanently affixed to an annular collar 20 in monolithic fashion. As shown, mounts 19 may be provided as integral means for rigidly and permanently coupling vanes 6 to a lower side of the annular mount. Thus, vanes 6 may, in some embodiments, be configured without radial adjustability or removability from annular collar 20 as depicted in FIGS. 3-23. FIG. 24 further suggests that portions of vanes 6 (e.g., upper side 9c) may extend to a lower surface of the disperser hood 1. FIG. 26 suggests that vanes 6 may take on curved / concave inner profiles, without limitation. FIGS. 24 and 26 suggest that vanes 6 may take on curved / convex outer profiles, without limitation.

[0069] FIG. 27 depicts yet another alternative embodiment of an aeration apparatus 29 arranged within a self-aspirated flotation cell 100. This particular embodiment suggests that a portion of the standpipe 11 may be truncated or removed so as to eliminate an internal air space, gap, void, or pocket 4 between the standpipe 11 and one or more portions 17a, 17b of a vortex stabilizer 17, without limitation. This figure further depicts that baffles 16a which may comprise apertures 16b may extend between the crowder 16 and one or more portions 17a, 17b of a vortex stabilizer 17, without limitation. This figure further depicts that the rotor 15 may comprise a short shaft 14a and mounting flange 14b provided thereto for coupling to a (main) shaft 14 (e.g., via an optional coupling 14c), without limitation. In such embodiments, a cavity 15c in the rotor 15 for accepting a shaft 14 as depicted in FIGS. 5, 6, and 10 may not be employed.

[0070] FIG. 28 is a zoomed cross-sectional image of the embodiment depicted in FIG. 27.

[0071] FIGS. 29-50 show various views of an aeration assembly 29 and components thereof according to some embodiments.

[0072] FIGS. 51 and 52 suggest how certain embodiments which may optionally employ one or more horizontal annular baffles lid and / or one or more vertically-extending baffles lie to reduce vortices, waves, or pulsed flows within standpipe 11 during operation, without limitation.

[0073] In the following, the invention will be described in more detail with reference to drawings in conjunction with exemplary embodiments.Detailed Description of Embodiments

[0074] A novel aeration apparatus 29 for a self-aspirated flotation cell 100 is disclosed. The aeration apparatus 29 may comprise one or more of the following components: a standpipe 11, a disperser hood 1, a vortex stabilizer 17, a froth crowder 16, an annular collar 20, and a number of vanes 6. The vanes 6 preferably comprise one or more through openings 10 and may be permanently affixed to the annular collar 20, or removably affixed to the annular collar. If removably affixed, vanes 6 may be configured to be radially-adjustable to accommodate wear or larger diameter rotor 15, without limitation. The vanes 6 may have radially inner sides 9a that are contoured to follow or approximate a contour of a rotor 15 disposed between the vanes 6.

[0075] The disperser hood 1 may comprise an upper mounting ring 28. The mounting ring 28 may be configured to connect the disperser hood 1 to another component within the aeration apparatus 29. For example, the mounting ring 28 may be bolted to a complimentary mounting ring 30 extending from a lower body 2 extending from a standpipe 11 or froth crowder 16, without limitation. The mounting ring 28 portion of the disperser hood 1 may be provided in a single annular structure; or, it may be comprised of a plurality of arcuate segments which are joined together to form the mounting ring 28 as can be appreciated from exploded diagram FIG. 22. Moreover, disperser hood 1 may comprise a thin generally frustoconical panel structure, or, it may be comprised of a plurality arcuate plate segments which are joined together to form the body of disperser hood 1 as can be appreciated from exploded diagram FIG. 22. The disperser hood may comprise a perforated structure formed by a plurality of apertures 5 as will be described hereinafter.

[0076] The mounting ring 28 of the disperser hood 1 may comprise a number of through holes or openings 34 for receiving bolts or other connecting fasteners 32 (most clearly depicted in FIGS. 6, 7, 11, 12, and 21). Though it is preferred that disperser hood 1 is removable, the mounting ring 28 may alternatively comprise a ledge, a flange, a series of mounting tabs, or a continuous weld abutment surface configured to facilitate welding the disperser hood 1 to one or more other components within the aeration assembly 29, without limitation.

[0077] A number of small apertures 5 may extend through the conical surface of the disperser hood 1 so as to make the disperser hood 1 a perforated structure. As suggested by FIG. 24, a plurality of inwardly-projecting vanes 6 may extend downwardly and / or radially-inwardly from the lower conical surface of the disperser hood 1 as shown. While not shown, the vanes 6 may, in some embodiments, extend from the disperser hood 1 so as to be supported entirely by the disperser hood 1, or, vanes 6 may be supported by both the disperser hood 1 and themounting collar 20 (see FIG. 24). In the particular embodiments shown in FIGS. 3-23 and 25, and 26, the vanes 6 may only extend from or be supported by annular collar 20. Portions of vanes 6 (e.g. top sides 9c and / or radially-outer sides 9b thereof) may be attached to the disperser hood 1, e.g., by welding, adhesives, over-moulding with polymeric material (e.g., polyurethane or rubber mat), bolting, or a combination thereof, without limitation.

[0078] Each vane 6 may comprise a lower side 8, a radially-inner side 9a, a radially-outer side 9b, and an upper side 9c, without limitation. A portion of each vane 6 adjacent its upper side 9c may be provided with a plurality of mounting holes 1 for removably attaching the vane 6 to a respective mount 19 extending downwardly from a bottom surface of the annular collar 20.

[0079] In some embodiments, the mounts 19 may comprise a plurality of mounting holes 26 that align with some of the mounting holes 27 on the vanes 6. In some embodiments, the number positioning, and / or respective alignment of mounting holes 26, 27 on the vanes 6 and mounts 19, respectively, may be such that the vanes 6 may be adjusted in their position, relative to the mounts 19. For example, as depicted, vanes 6 may be configured to be bolted at different radial positions or locations (along mounts 19) with respect to a center of the annular collar 20. Fasteners, such as bolts with accompanying nuts, press pins, roll pins, or rivet structures may be used to connect vanes 6 to mounts 19 via mounting holes 26, 27, without limitation. However, as suggested in latter FIGS. 24-26, vanes 6 may be welded or permanently fastened to annular collar by virtue of an integral mount 18. The provision of radially-adjustable vanes 6 may allow some degree of controlling clearances between vanes 6 and rotor 15, and allow vanes 6 to be moved radially-inwardly upon wearing of radially-inner sides 9a or outer surfaces 15a of rotor 15, without limitation.

[0080] Extending through a thickness of each of the vanes 6 may be one or more through openings 10. Through openings 10 may comprise, for example, apertures, orifices, elongated slots, slits, oblong holes, ports of predetermined geometry / shape, or the like, without limitation. These through-openings 10 may be provided with different geometries, patterns, and / or sizes, without limitation. As shown, preferred embodiments may comprise elongated through openings 10 provided in the form of slits or slots (i.e., oblong openings), such that a width of the opening is smaller (dimensionally) than a length. As illustrated, the through openings 10 may be oriented such that the openings are longer in a radial direction with respect to the annular collar 20 than they are wide in a vertical direction. Also, as shown, the through openings 10 may be arranged so as to be parallel in relation to each other, without limitation. It should be understood that while the through openings 10 are shown to extend in a purely horizontal / radial direction, they may be provided to extend obliquely at any angle with respect to horizontal, inclusive of vertical.Each vane 6 may comprise a similar pattern of through openings 10 as the other vanes 6 on the disperser hood 1 as shown; however, it is envisaged that vanes 6 may each comprise unique patterns of through openings 10, different types of through openings 10, different numbers of through openings 10, or different configurations of through openings 10 than other vanes 6 provided to the annular collar 20. In some conceived embodiments, only some of the vanes 6 may comprise through openings 10, whereas others may contain no through openings 10 at all. In such embodiments, vanes 6 may alternate between those with and without through openings 10, without limitation. From the above, it will be apparent to those skilled in the art that a plethora of vane design permutations are possible.

[0081] Turning now to the figures, an aeration apparatus 29 according to the invention is intended to be disposed within a tank 115 of a self-aspirated flotation machine 100. The aeration apparatus 29 may comprise a vertically-oriented standpipe 11 having a proximal upper open end, and a distal loweropen end. A vortex stabilizer 17 may be provided within the standpipe 11 as depicted. The vortex stabilizer 17 may comprise a tubular body structure 17b having a smaller inner diameter, and a tapered upper inner surface 17a which flares outwardly from the tubular body structure as shown, thus increasing the inner diameter of the vortex stabilizer 17 towards its upper end. The vortex stabilizer 17 may be formed from a solid hollow cylinder, or, it may be formed of sheet metal as depicted. In the event the latter configuration is used, an air gap 4 or void space may be present between the standpipe 11 and vortex stabilizer 17 as best seen from FIGS. 5, 6, 10, and 23.

[0082] To secure the vortex stabilizer 17, the standpipe 11 and vortex stabilizer 17 may be welded together at an upper intersection. While the tapered upper inner surface 17a is shown to be substantially frustoconical in shape, it should be appreciated that a truncated paraboloid surface, inner toroidal surface, bell shape, or other annular flared or curved surface may be equally employed, without limitation.

[0083] A froth crowder 16 may surround the standpipe 11. The froth crowder 16 may comprise a thin, substantially frustoconical structure. As shown, in order to facilitate fabrication, the froth crowder 16 may be provided in clamshell form, with two opposing froth crowder 16 halves that meet at respective flanges. These flanges can be bolted, riveted, bonded, clamped, or otherwise joined together to form the froth crowder 16. It is anticipated that the froth crowder 16 may be provided in more than two pieces to further facilitate manufacturing or reduce shipping size. The froth crowder 16 may extend upwardly and / or radially-outwardly from an outer surface of the standpipe 11 (e.g., as shown in FIGS. 3-26). The froth crowder 16 (e.g., as shown in FIGS. 1 and 28) may extend radially-outwardly with respect tothe standpipe 11. Accordingly, in a majority of embodiments, portions of the froth crowder 16 may be positioned radially outwardly of the standpipe 11. The froth crowder 16 may be configured to bias rising froth radially-outwardly towards a collection launder along a periphery of the tank 115.

[0084] As depicted in FIGS. 1 and 28, the froth crowder 16 may comprise one or more inner baffles 16a which may have one or a plurality of apertures 16b extending therethrough. The baffles 16a may serve to support the froth crowder 16. The baffles may, for example, as depicted, extend between one or more portions 17a, 17b of the vortex stabilizer 17, without limitation. One or more lower baffles 16c may serve to support a lower portion of the froth crowder 16. As depicted in FIG. 28, the one or more lower baffles 16 may extend between a lower end of the froth crowder 14 and the lower body 2, without limitation.

[0085] A lower body 2 may be present adjacent the distal lower open end of the standpipe 11. As shown, the lower body 2 may comprise an annular plate structure or flange that extends generally horizontally and radially-outwardly from standpipe 11. As can be gleaned from FIGS. 5 & 10, the standpipe 11 and vortex stabilizer 17 may be welded to the lower body 2 to form weld seams 31. For example, the lower body 2 may be connected to a lower end of standpipe 11 and to an outer surface portion of the tubular body structure 17b of the vortex stabilizer 17 as shown.

[0086] As can be seen from FIGS. 6, 10, 22, and 23, a mounting ring 30 may extend (e.g., downwardly) from the lower body 2 for allowing securement of a disperser hood 1 thereto. This may be accomplished by bolting an upstanding mounting ring 28 of the disperser hood 1 to the mounting ring 30 depending from the lower body 2, without limitation.

[0087] The disperser hood 1 may comprise a thin frustoconical structure formed of plate or thick gauge sheet metal, and preferably comprises a number of apertures 5 extending therethrough to make the disperser hood a perforated structure. As may be appreciated by FIG. 22, the disperser hood 1 may be formed from multiple segments which can be secured together by welding, adhesives, strip plates, or fasteners (e.g., rivets, bolts & nuts). The mounting ring 28 of the disperser hood 1 may also be comprised of multiple arcuate sections which are joined together to form a unitary disperser hood 1 assembly.

[0088] A generally planar annular collar 20 of the aeration apparatus 29 may comprise a plurality of vanes 6 extending downwardly and radially-outwardly therefrom. The collective assembly of vanes 6 and annular collar 20 may be used to effectively replace the perforated tubular dispersers 104 shown in FIGS. 1 and 2.The annular collar 20 may comprise an inner opening 3 which is sufficiently large to allow standpipe 11 to pass therethrough. Though a small clearance is shown between the outer surface of the standpipe 11 and the inner opening 3, it is envisaged that an outer surface of the standpipe 11 may abut and / or be connected to the inner opening 3 of the annular collar 20.

[0089] The annular collar 20 may comprise a number of mounting holes 7 for securing the annular collar 20 to the lower body 2. For example, a number of bolts, rivets, or other fasteners 33 (seen in FIG. 11) may be inserted through mounting holes 7 and into or through lower body to secure the annular collar 20 to the lower body 2, without limitation. Annular collar 20 may also be secured to the lower body 2 by welding or adhesion with a polymer, without limitation.

[0090] The vanes 6 attached to the annular collar 20 and extending below the annular collar 20 may each having one or more through openings 10 extending therethrough. The through openings 10 extending through a vane 6 may comprise one or more apertures, elongated slots, oblong holes, ports of predetermined geometry, or the like, without limitation. Some of the vanes 6 may be devoid of through openings 10, and in some embodiments, vanes 6 may comprise different patterns or arrangements of through openings 10.

[0091] It is further envisaged that different vanes 6 may comprise a different number of through openings 10. Different vanes 6 may comprise through openings 10 having different dimensions, shapes, or sizes without limitation. As shown, through openings 10 may be similarly configured across all vanes 6 and arranged as parallel elongated slits or slots that extend in a radial direction such that they are wider in a horizontal or radial direction than in a vertical direction. It should be understood that while through openings 10 are shown to extend horizontally, they may alternatively extend obliquely with respect to horizontal, or vertically, without limitation.

[0092] In some embodiments (e.g., as suggested by FIGS. 24-26), the vanes 6 may be permanently fixed to the lower portion of annular collar 20, via "integral" mounts 19. In some embodiments (e.g., as suggested by FIGS. 3-23), the vanes 6 may be removeable from, and / or radi-ally-adjustable with respect to mounts 19 which are separate from vanes 6 and integrally provided to the lower side of annular collar 20. For embodiments where removability / ad-justability of vanes 6 is desired (e.g., for accommodating vane 6 and / or rotor 15 wear), mounts 19 may comprise a plurality of mounting holes 26 that align with one or more mounting holes 27 provided to the vanes 6. One or more fasteners (not shown) may be insertedinto or through respective mounting holes 26, 27 to secure the vanes 6 to their respective mounts 19, without limitation. It should be understood that one or more of the mounting holes 26, 27 may be blind holes (e.g., a threaded hole), or through holes (e.g., clearance hole) - depending on the fastening means provided. One or more of the mounting holes 26, 27 may be counterbored or have a lead-in taper to improve alignment and / or facilitate installation, without limitation.

[0093] Regardless of which vane configuration is employed (removable / adjustable or "fixed"), it is preferred that both vanes 6 and mounts 19 are substantially aligned and extend substantially radially with respect to annular ring 20 to avoid flow restrictions or impede performance. While not shown, it is anticipated that one or more of the vanes 6 may be canted or otherwise oriented with some small skew angle of deviation with respect to its respective radial extending from the center of annular ring 20. In this regard, vanes may be configured to provide a small angle of attack with respect to radially-outward flow produced by central rotor 15. Vanes 6 may also comprise a curvature or curved profile, rather than be provided as planar members, without limitation.

[0094] The vanes 6 may comprise a side plan view profile (i.e., when viewed from a broad side) which is generally rectangular in shape; or, they may comprise other shapes. For example, as depicted in FIGS. 24 and 26, one or more vanes 6 may comprise an outer curved profile, such that a radially-outer side 9b or edge of the one or more vanes 6 are curved (e.g., in convex fashion). As suggested in FIG. 26, one or more vanes 6 may comprise an inner curved profile, such that a radially-inner side 9a or edge of the one or more vanes 6 are curved (e.g., in concave fashion). If employed, the inner curved profile may be complementary to an outer curved barrel shape 15a of rotor 15 or vanes 6 thereof, without limitation.

[0095] Upper sides 9c of vanes 6 may be tapered to follow a profile of disperser hood 1 as shown. A small clearance or gap may exist between the upper sides 9c and lower surface of the disperser hood 1. Lower sides 8 of vanes 6 may be flat or horizontal as shown, but may take on other profiles and may be curved, without limitation.

[0096] The vanes of the rotor 15 may comprise an inner taper or flare 15d, or, may be configured such that a lower open pocket 15b extends upwardly into the rotor 15 proximate a lower central portion of the rotor 15. An upper portion of the rotor 15 above the pocket 15b may comprise a cavity 15c for accepting a lower distal end of a rotatable shaft 14. A securement fastener 25 may be used to secure the rotor 15 to the shaft 14, without limitation.The cavity 15c may be keyed to the shaft 14, fixed to the shaft 16 using set screws or shear pins, or may have a non-circular cross-sectional shape that is substantially the same as or complimentary to a non-circular cross-sectional shape of the lower distal end of the shaft 14. For example, a spline or toothed interface may exist between shaft 14 and cavity 15c. In this regard, torque can be adequately transmitted between the shaft 14 and rotor 15.

[0097] As depicted in FIG. 28, the cavity 15c may be replaced, in some embodiments, with a short shaft 14a extending upwardly from rotor 15. The short shaft 14a may comprise a mounting flange 14b at its upper end which functions to couple the rotor 15 to shaft 14. An intermediate coupling 14c may be provided between the two 14, 14a as shown, without limitation.

[0098] The shaft 14 may be conventionally driven, e.g., by a motor 12 and drive 13 as depicted in FIGS. 3-6. The drive 13 used may be any suitable mechanical apparatus which is configured to transfer torque from the drive motor 12 spindle to the shaft 14. For example, the drive 13 may include a transmission, a pulley system, a gearbox, or a reducer, without limitation. A support frame 23 may be employed for supporting the drive 13 and motor 12. The support frame 23 may be positioned above standpipe 11 and may rest on or be supported by a top plate 24. The support frame 23 may have a number of bearings 22 therein for rotationally supporting the shaft 14. The bearings 22 may provide some vertical support for the rotor 15 and shaft 14 assembly, without limitation. In this regard, bearings 22 may provide some axial thrust support for shaft 14, without limitation.

[0099] As shown in FIGS. 4-6, the top plate 24 may be provided with a central opening above the standpipe 11. This opening may be covered with a cover plate 21. An air inlet duct 18 may be provided to the cover plate 21 or to the top plate 24 to allow fluid (i.e., atmospheric gas, air) communication between ambient atmosphere and standpipe 11. In this regard, the flotation machine employing the aeration apparatus 29 may naturally aspirate upon rotation of rotor 15.

[0100] Turning now to FIGS. 29-50, an aeration assembly 29 according to some embodiments may comprise one or more lower side fixation features 8a provided to a lower side 8 of one or more vanes 6. Such a feature(s) may allow a support ring 35 to be mounted to one, some, or all of the vanes 6 as depicted. The support ring 35 may serve to limit relative movement between vanes 6 and reduce flexing, movement, or displacement of lower portions of vanes 6 during operation. Moreover, a support ring 35, when mounted to one or more vanes 6 may provide greater stiffness, rigidity, and / or overall strength to the stator mechanism surrounding the rotor 15.As depicted in FIG 47, the support ring 35 may comprise a number of recesses 35c which can be shaped, sized, or otherwise configured to abut and / or receive a lower portion of each vane 6, and if employed, a raised portion 35b may be formed between each recess 35c. The recesses 35c may serve to evenly space the vanes 6 and / or serve to provide a locating mechanism for mounting holes 35d so that they align with one or more lower side fixation features 8a provided to lower sides 8 of one or more vanes 6. It is anticipated that recesses 35c can (in some less-preferred embodiments) be omitted. It is further anticipated that the support ring 35 may be welded, bonded, glued, over-moulded with, or permanently fixed to or incorporated integrally with the vanes 6. In some embodiments, optional fasteners 35e may be provided to join the support ring 35 to the vanes 6. Such fasteners 35e may, for instance, comprise screws, bolts, rivets, clips, or other securing means extending through mounting holes 35d of the support ring 35 and into or engaging the lower side fixation features 8a, without limitation. While not shown, in some embodiments, the support ring 35 may be provided without recesses 35c or raised portions 35b, and the lower sides 8 of vanes may comprise recesses 35c which are able to receive the support ring 35, without limitation.

[0101] According to some embodiments, the standpipe 11 (or section 11a thereof) may comprise a plurality of froth crowder mounts lib for attaching a froth crowder 16 (or one or more sections 16g thereof), without limitation. Each froth crowder mount lib may extend outwardly from an outer (e.g., peripheral) surface of the standpipe 11, and may have a supporting web portion or gusset 11c as suggested from the top right portion of FIG. 44, without limitation. As depicted, a froth crowder mount lib may optionally comprise an opening or aperture that aligns with a respective mounting hole 16h in a lower shelf 16d of the froth crowder 16 (FIG.

[0102] 49) and which is preferably sized to receive a fastener such as a screw, bolt, retaining clip, rivet, press-fit fastener, or the like, without limitation. It should be understood that in some alternative embodiments, mounts lib may omit mounting holes and may simply serve as a ledge or platform for positioning and welding to a lower shelf 16d of a froth crowder 16 to secure the same to the standpipe 11, without limitation.

[0103] For embodiments comprising a froth crowder 16 having a lower shelf 16d, the lower shelf 16d may be optionally provided with lower openings 16e to reduce weight of the froth crowder 16, reduce material, increase aeration, reduce drag, or encourage a "self-purging" flow of solids from within the froth crowder 16 back into the main flotation chamber, thus preventing build-up of sanding bottom layers within the froth crowder 16, without limitation.

[0104] One or more support struts 16f, for example, provided in the form of a bar rigidly fixed (or pivotally pinned at its ends) to an inner surface of the froth crowder 16 (or section 16a thereof) may be used to support upper outwardly flared portions of the froth crowder 16 (orsections 16a thereof). The struts 16f may be configured to help maintain the overall shape of the froth crowder 16, provide resistance to turbulent upward hydraulic forces, discourage flexing / bending / deformation of the froth crowder 16, and / or maintain volumetric displacement against hydraulic forces acting on outside surfaces of the froth crowder 16, without limitation.

[0105] Turning now to the particulars of FIG. 44, the annular collar 20 may extend radially outwardly from a lower region, lower portion, or bottom end of standpipe 11. Thus, the annular collar 20 may take on the form of (or be configured as) a lower flange extending from standpipe 11. One or more webs 20a (for supporting the annular collar 20) may be provided and extend (e.g., orthogonally) between an outer surface of the standpipe 11 and an upper surface of the annular collar 20.

[0106] The webs 20a may serve as gussets to strengthen and / or provide rigidity to the annular collar 20 or prevent the annular collar 20 from flexing or deformation. A mounting ring 28 (similar to the one shown and described in FIGS. 1-28) may be provided to the annular collar 20, and it may run along the outside edge of the annular collar 20 as depicted. The mounting ring 28 may extend generally orthogonally with respect to the plane of the annular collar 20 so as to form a lip extending upwardly (as shown) and / or downwardly from the outer peripheral edge of the annular collar 20.

[0107] A lower body 2 may be provided to the assembly. The lower body 2 may be configured to extend downwardly from the annular collar 20 and / or extend radially-outwardly along a lower face or lower surface portion of the annular collar, forming an annular recess 2b adjacent its outer periphery as depicted. It should be understood that the lower body 2 may comprise one or more lower extensions (e.g., an annular extension) from the annular collar 20. The lower body 2 may be a separate component which is welded to or bolted to the annular collar 20, or the lower body 2 and annular collar 20 may be provided together as a single, unitary, monolithic structure.

[0108] The annular recess 2b formed by virtue of the annular collar 20 and lower body 20 may be sized, shaped, or otherwise configured to receive mounting portions 19 of vanes (FIG. 46).

[0109] The mounting portions 19 of the vanes 6 may be provided in various configurations other than what is shown. However, as depicted, the mounting portions 19 may be configured to extend laterally from the vanes 6 as shown and thus, be configured as "wings" or flanged portions that extend or protrude from upper side surfaces of each vane 6 as depicted andbest observed from FIG. 46. The mounting portions 19 may extend substantially perpendicularly to the main side faces of their respective vane 6. Each mounting portion 19 may be configured with mounting holes 27 that align with corresponding mounting holes 20b provided to the annular collar 20 (e.g., adjacent or above annular recess 2b as depicted).

[0110] As most clearly seen from FIG. 33, fasteners 20c may be used to connect each mounting portion 19 of each vane 6 to the annular collar 20 such that the mounting portions 19 are arranged within the annular recess 2b surrounding the lower body 2. The disperser hood 1 may be inclined such that it rests on a complementarily-inclined upper side 9c of each vane 6. However, as shown in FIGS. 24-25, upper sides 9c of each vane 6 may extend at different angles than the disperser hood 1, without limitation.

[0111] As suggested from FIG. 28 & 33-35, preferred embodiments of an aeration assembly 29 include a rotor 15 that protrudes upwardly into a standpipe 11 by an upper vertical rotor depth 39, and protrudes downwardly into a collar 108 or draft tube 106 by a lower vertical rotor depth 40. Preferably, the rotor 15 only protrudes slightly into the lower region of the standpipe 11 and / or upper region of the collar 108 or draft tube 106.

[0112] The upper vertical rotor depth 39 may be measured from a lower end, edge, or lower inner corner of standpipe 11 to an upper end, edge, corner, or top surface of the rotor 15 or a portion of a rotor 15, such as an upper end, edge, corner, or top surface of a vane of the rotor 15. The lower vertical rotor depth 40 may similarly be measured from an upper end, edge, or upper inner corner of standpipe 11 to a lower end, edge, corner, or bottom surface of the rotor 15 or portion of a vane thereof. Adjacent the upper vertical rotor depth 39, may be provided an upper (clearance) gap 37 existing between an outer surface rotational path of rotor 15 and an inner surface of standpipe 11. The rotational path of the rotor 15 may be defined by an outer shape 15a of rotor 15 or its vanes. Adjacent the lower vertical rotor depth 40, may be provided a lower (clearance) gap 36 between an outer surface path of rotor 15 and an inner surface of the draft tube 106 (or inner surface of the collar 108 - if a collar 108 is provided to the upper part of draft tube 106).

[0113] The upper 37 and lower 36 gaps may differ, but in preferred embodiments are preferably substantially the same or at least within ± 25% of each other. For example, the upper and lower 36 gaps may be sized to be within ± 20% of each other (e.g., within ± 18% of each other), without limitation. As another example, the upper and lower 36 gaps may be sized to be within ± 15% of each other (e.g., within ± 10% or within ± 5% or within ± 3% of each other), without limitation. The upper 37 and lower 36 gaps may also be sized to be equal to each other within tolerance, without limitation.Moreover, the upper vertical rotor depth 39 and lower vertical rotor depth 40 may differ, but in preferred embodiments are preferably substantially the same or at least within ± 25% of each other. For example, the upper vertical rotor depth 39 and lower vertical rotor depth 40 may be sized to be within ± 20% of each other (e.g., within ± 18% of each other), without limitation. As another example, the upper vertical rotor depth 39 and lower vertical rotor depth 40 may be sized to be within ± 15% of each other (e.g., within ± 10% or within ± 5% or within ± 3% of each other), without limitation. The upper vertical rotor depth 39 and lower vertical rotor depth 40 may also be sized to be equal to each other within tolerance, without limitation.

[0114] In some embodiments, the upper vertical rotor depth 39 and upper gap 37 may differ, but in preferred embodiments are preferably substantially the same or at least within ± 25% of each other. For example, the upper vertical rotor depth 39 and upper gap 37 may be sized to be within ± 20% of each other (e.g., within ± 18% of each other), without limitation. As another example, the upper vertical rotor depth 39 and upper gap 37 may be sized to be within ± 15% of each other (e.g., within ± 10% or within ± 5% or within ± 3%of each other), without limitation. The upper vertical rotor depth 39 and upper gap 37 may also be sized to be equal to each other within tolerance, without limitation.

[0115] In some embodiments, the lower vertical rotor depth 40 and lower gap 36 may differ, but in preferred embodiments are preferably substantially the same or at least within ± 25% of each other. For example, the lower vertical rotor depth 40 and lower gap 36 may be sized to be within ± 20% of each other (e.g., within ± 18% of each other), without limitation. As another example, the lower vertical rotor depth 40 and lower gap 36 may be sized to be within ± 15% of each other (e.g., within ± 10% or within ± 5% or within ± 3% of each other), without limitation. The lower vertical rotor depth 40 and lower gap 36 may also be sized to be equal to each other within tolerance, without limitation.

[0116] In some embodiments, each of the upper vertical rotor depth 39, lower vertical rotor depth 40, upper gap 37, and lower gap 36 may differ. However, in preferred embodiments they may each be substantially the same or at least within ± 25% of each other. For example, each of the upper vertical rotor depth 39, lower vertical rotor depth 40, upper gap 37, and lower gap 36 may be sized to be within ± 20% of each other (e.g., within ± 18% of each other), without limitation. As another example, each of the upper vertical rotor depth 39, lower vertical rotor depth 40, upper gap 37, and lower gap 36 may be sized to be within ± 15% of each other (e.g., within ± 10% or within ± 5% or within ± 3% of each other), without limitation. It is anticipated that in some embodiments, the upper vertical rotor depth 39, lower verticalrotor depth 40, upper gap 37, and lower gap 36 may also be sized to be equal to each other within tolerance, without limitation.

[0117] By keeping the relative rotor depths 39, 40 and gaps 36, 37 similar or symmetrical, better pumping performance, wear performance, aeration performance, and / or energy consumption profiles may be achieved, without limitation.

[0118] The rotor 15 may comprise an outside diameter 38 which, at least at portions of the rotor 15 adjacent the standpipe 11 and collar 108 (and / or draft tube 106), is smaller than both an inside diameter 42 of the standpipe 11 and an inside diameter 41 of the collar 108 (and / or draft tube 106). In this respect, the rotor 15 is preferably configured to rotate freely within the standpipe 11 and collar 108 (and / or draft tube 106) while spaced from inside surfaces of the standpipe 11 and collar 108 (and / or draft tube 106) to prevent binding, contact, or seizing during operation. Near gaps 36, 37 and vertical rotor depths 39, 40, the maximum outside diameter 38 of the rotor protruding into the standpipe 11 and collar 108 (and / or draft tube 106) is preferably configured to be the same at each of these locations. While it is preferred that the gaps 36, 37 remain small, relative to the diameter of the rotor 15, the gaps should be sufficiently large so as to prevent contact between the rotor 15 and surrounding elements 11, 106, 108. In some embodiments, the gaps 36, 37 may be approximately l%-30% of the rotor's 15 radius, and more preferably less than 25% of the rotor's 15 radius. For example, a gap 36, 37 may be sized to be less than 20% of the rotor's 15 radius (or less than 10% of the rotor outside diameter 58). As depicted, the gaps 36, 37 are approximately 17% of the rotor's 15 radius or approximately 8.5% of the rotor outside diameter 18.

[0119] In some embodiments, the inside diameter 42 of the standpipe 11 and the inside diameter 41 of the collar 108 (and / or draft tube 106) are preferably substantially equal to one another (i.e., within ± 5 to 10 percent of one another, and more preferably less than 5% of a difference as measured), such that the upper 37 and lower 36 gaps remain substantially equal to each other.

[0120] It should be understood that while preferred embodiments of an aeration assembly 29 comprise a draft tube 106 with a separate collar 108 (which may be adjustable) attached thereto at its upper end, it is anticipated that those skilled in the art could readily provide a draft tube 106 having an integral collar 108; or, said persons skilled in the art could easily configure or size the draft tube 106 such that a collar 108 is superfluous, redundant, or deemed unnecessary. In such instances, embodiments of an aeration assembly 29 may only comprise a draft tube 106 with no collar 108. Accordingly, where shown and described herein (and in theappended claims), the term collar 108 may, as a matter of preference, be interchanged synonymously with the term draft tube 106, and the relative gap 36, vertical rotor depth 40, and inside diameter 41 of a collar 108 with respect to the rotor 15 may also equally apply to a draft tube 106 configured without a collar 108. While not shown, the collar 108 may be configured to be telescoping or otherwise vertically-adjustable to provide fine adjustment of height in relation to the draft tube 106 and / or rotor 15, without limitation. Moreover, the collar 108 may be configured with means for radial expansion or contraction to fine tune lower gap 36, without limitation.

[0121] Certain components of the disclosed aeration assembly 29 may be modularized, without limitation. For example, as suggested by FIG. 47, the support ring 35 may be configured as a single unitary monolithic ring structure, or provided in separate parts, components, or segments 35a, without limitation. Similarly, as suggested in FIG. 44, a standpipe 11 according to any of the embodiments depicted may be formed from one or more standpipe sections Ila, without limitation. Moreover, as suggested in FIG. 45, a disperser hood 1 according to any of the embodiments depicted may be formed from one or more sections la, without limitation.

[0122] Moreover, as can most clearly be gleaned from FIGS. 28, 41, and 48, a shaft 14 according to any of the embodiments depicted may be formed from one or more sections 14a, 14c or "segments" to facilitate removal / installation, increase modularity, and / or provide "changeout" functionality without completely removing the entire shaft 14 from its drive 13, without limitation. This may be accomplished by attaching shaft components to each other using connection means such as mounting flanges 14b.

[0123] Moreover, as suggested in FIG. 49, a froth crowder 16 according to any of the embodiments depicted may be formed from one or more sections 16g, without limitation. Moreover, as suggested in FIG. 50, a collar 108 and / or a draft tube 106 according to any of the embodiments depicted may be formed from one or more sections - and may be formed from two clamshell halves joined together, without limitation.

[0124] It should be understood that the number of sections of each component of an aeration assembly 29 may vary, and sections of each component may be joined using any conventional manner known - including, but not limited to mating flanged seating edges which can be bolted, clamped, or riveted together. Components of an aeration assembly 29 may alternatively be provided as one single, unitary, monolithic piece, if preferred.

[0125] Turning now to FIGS. 51 and 52, it is conceived that any embodiment of an aeration assembly 29 may optionally employ one or more horizontal annular baffles lid and / or one or morevertically-extending baffles lie to reduce vortices, waves, or pulsed flows within standpipe 11 during operation, without limitation. If a plurality of baffles are employed, alike baffles may be evenly spaced from one another within the standpipe 11, although in the instance of horizontal annular baffles lid, vertical spacings may be different (e.g., graded spacings that reduce or increase in a vertical direction), without limitation. In some instances only horizontal annular baffles lid may be employed. In some instances, only vertical baffles lie may be employed. In some instances (as depicted) both species of baffles lid, lie may be employed. Moreover (as depicted) there may be more of one specie lie of baffle than other species lid, without limitation. The baffles lid, lie may supplement the vor-tice / wave / pulsed flow-reducing configuration of relative spacings 37, 36, 39, 40 disclosed, and / or relative positioning of rotor 15 within standpipe 11 and draft tube 106 or collar 108, without limitation.

[0126] In the particular non-limiting embodiment depicted in FIGS 51 and 52, a single horizontal annular baffle 11c may be employed within the standpipe 11 at a lower portion thereof. The horizontal annular baffle 11c may be positioned above the lower distal end opening of the standpipe 11 as shown, and may be positioned above top surfaces of the rotor 15 so as to form a sufficient clearance gap 11g therebetween. The horizontal annular baffle 11c may have a shelf width or radial width Ilf which is substantially equal to, less than, or greater than upper gap 37. In the embodiment depicted, the shelf width or radial width Ilf of the horizontal annular baffle 11c is slightly greater than the upper gap 37 so as to overhang at least a portion of the rotor. Narrower shelf / radial widths Ilf may be used, especially if multiple horizontal annular baffles 11c are provided in different regions of the standpipe 11.

[0127] As shown, vertically-extending baffles lie may be planar, although curved, undulating, or arcuate versions are contemplated. The vertically-extending baffles lie may run continuously along a vertical length of the standpipe 11 (e.g., uninterrupted), or a portion of the vertical length of the standpipe 11 (e.g., in an interrupted fashion), without limitation. The vertically-extending baffles lie may extend vertically, in line with the rotor 15 and standpipe 11 as shown, or they may run at an angle with respect to vertical (e.g., obliquely with respect to an axis of shaft 14 rotation), without limitation. The baffles may comprise flanged mounting portions llh as shown, and may be bonded, adhered, welded, fastened, riveted, brazed, or attached to one or more inner portions of standpipe using any conventional fastening means, without limitation.

[0128] In cases where both vertically-extending lie and horizontal annular lid baffles are employed to a standpipe 11, the vertically-extending baffles lie may extend inwardly for the entire shelf width or radial width Ilf of the horizontal annular baffle(s) lid or, they mayextend inwardly to a lesser extent, as depicted. Alternatively, while not shown, the vertically-extending baffles lie may extend inwardly beyond the horizontal annular baffle(s) lid so as to overhang an inner edge of one or more horizontal annular baffle(s) lid, without limitation.

[0129] 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. It is anticipated that the proffered aeration apparatus 29 may be used to replace an aeration apparatus of the prior art shown in FIGS. 1 or 2. Moreover, one or more components of the proffered aeration apparatus 29 may be configured to be interchangeably swapped with one or more components of the conventional self-aspirating flotation cell 100 shown in FIGS. 1 or 2. For example, an annular collar 20 with vanes 6 extending therefrom may replace only the disperser 104 depicted in FIGS, land 2. As another example, only the vortex stabilizer 17 may be introduced into the standpipe 102 depicted in FIGS. 1 and 2. Accordingly, it is anticipated that one or more select components of the described aeration apparatus 20 may be introduced “a-la-carte” into a conventional self-aspirated flotation machine 100 to improve its performance and efficiency.

[0130] 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.

[0131] 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

[0132] 1 Disperser hood

[0133] la Side flange(s) (of individual segments of disperser hood 1)

[0134] lb Fastener (for connecting individual segments of disperser hood 1)

[0135] 2 Lower body

[0136] 2b Annular recess

[0137] 3 Mounting feature

[0138] 4 Internal air space, gap, void, or pocket

[0139] 5 Apertures

[0140] 6 Vanes (e.g., downwardly-projecting fixed or adjustable / removable)

[0141] 7 Mounting holes (of annular collar 20)

[0142] 8 Lower side (of vane 6)

[0143] 8a Lower side fixation feature (of vane 6) - e.g., threaded hole(s), extension peg(s), recessed portion(s)

[0144] 9a Radia I ly-inne r side (of vane 6)

[0145] 9b Radially-outer side (of vane 6)

[0146] 9c Upper side (of vane 6)

[0147] 10 Through openings

[0148] (e.g., apertures, elongated slots, oblong holes, ports of predetermined geometry) 11 Standpipe

[0149] Ila Section (standpipe 11)

[0150] 11b Froth crowder mount

[0151] 11c Web or gusset (of froth crowder mount lib)

[0152] lid Horizontal or horizontally-extending annular baffle (standpipe 11)

[0153] lie Vertical or vertically-extending baffle (standpipe 11)

[0154] Ilf Mount or base (vertically-extending baffle lie)

[0155] 11g Mounting hole (of froth crowder mount lib)

[0156] 12 Motor

[0157] 13 Drive (e.g., transmission, pulley system, gearbox, reducer)

[0158] 14 Shaft

[0159] 14a Short shaft (of rotor 15)

[0160] 14b Mounting flange (of short shaft 14a)

[0161] 14c Coupling (between short shaft 14a and shaft 14)

[0162] 15 Rotor

[0163] 15a Outer shape (vanes 6) - e.g., outer curved barrel shape or cylindrical shape 15b Open pocket

[0164] 15c Cavity (for accepting shaft 14)15d Inner taper or flare (vanes 6)

[0165] 16 Froth Crowder

[0166] 16a Baffle(s) (of froth crowder 16)

[0167] 16b Aperture(s) (of baffle 16a)

[0168] 16c Lower baffle(s) (of froth crowder 16)

[0169] 16d Lower shelf (of froth crowder 16)

[0170] 16e Lower opening (of lower shelf 16d)

[0171] 16f Support strut (for froth crowder 16)

[0172] 16g Segment (froth crowder 16)

[0173] 16h Mounting hole (lower shelf 16d)

[0174] 17 Vortex stabilizer / Wave suppressor

[0175] 17a Tapered upper inner surface (e.g., chamfer, fillet, radius)

[0176] 17b Tubular body structure

[0177] 18 Air inlet duct

[0178] 19 Mounts

[0179] 20 Annular collar

[0180] 20a Web (for annular collar 20)

[0181] 20b Mounting holes (through annular collar 20)

[0182] 21 Cover plate

[0183] 22 Bearing

[0184] 23 Support frame

[0185] 24 Top plate

[0186] 25 Securement fastener (to secure rotor 15 to shaft 14)

[0187] 26 Mounting holes (of mounts 19)

[0188] 27 Mounting holes (of vanes 6)

[0189] 28 Mounting ring

[0190] 29 Aeration assembly

[0191] 30 Mounting ring

[0192] 31 Weld seam(s)

[0193] 32 Fastener(s) (for securing mounting ring 28 of disperser hood 1 to mounting ring 30) 33 Fastener(s) (for securing annular collar 20 to lower body 2)

[0194] 34 Openings (for fastener(s) 32)

[0195] 35 Support ring (for vanes 6)

[0196] 35a Segment (support ring 35)

[0197] 35b Raised portion (support ring 35)

[0198] 35c Recess (support ring 35)

[0199] 35d Mounting holes (support ring 35)

[0200] 35e Optional fastener (for joining support ring 35 to vanes 6)36 Lower gap (between rotor 15 and collar 106 or draft tube 108)

[0201] 37 Upper gap (between rotor 15 and standpipe 11)

[0202] 38 Rotor outside diameter (e.g., maximum rotor 15 diameter adjacent upper 37 and lower 36 gaps, within span of vertical rotor depths 39 & 40)

[0203] 39 Upper vertical rotor depth (e.g., adjacent upper 37 gap, protruding into standpipe 11) 40 Lower vertical rotor depth (e.g., adjacent lower 36 gap, protruding into collar 108 or draft tube 106)

[0204] 41 (Upper) Inside diameter (of collar 108 and / or draft tube 106)

[0205] 42 (Lower) Inside diameter (of standpipe 11)

[0206] 43 Fastener (for securing mounting portions 19 to annular collar 20)

[0207] 44 Radially-inner thinner portion (e.g., substantially planar portion)

[0208] 45 Radially-outer wider portion (e.g., outwardly-widening portion, outwardly-flared portion, expanding wedge portion)

[0209] 100 Self-aspirated flotation cell

[0210] 101 Disperser hood

[0211] 102 Standpipe

[0212] 103 Air inlet duct

[0213] 104 Disperser

[0214] 105 Rotor

[0215] 106 Draft tube

[0216] 107 False bottom

[0217] 108 Collar (for draft tube 106)

[0218] 109 Rotor top level

[0219] 110 Rotor submergence

[0220] 111 Weir level

[0221] 112 Motor

[0222] 113 Drive (e.g., transmission)

[0223] 114 Shaft

[0224] 115 Tank

[0225] 116 Froth crowder

[0226] H Vertical height (of mount 19)

[0227] L Radial length (of mount 19)

[0228] T Circumferential thickness (of mount 19)

Claims

Claims1. An aeration assembly (29) for a self-aspirated flotation cell (100), the aeration assembly (29) comprising:a rotor (15) provided to a distal portion of a rotatable shaft (14);a vertically-oriented tubular standpipe (11) having an upper proximal open end, and a lower distal open end and surrounding an upper portion of the rotor (15);an annular frustoconical froth crowder (16) surrounding the standpipe (11) and extending radially-outwardly and upwardly in relation to a lower region of the standpipe (11);an annular frustoconical disperser hood (1) provided below the froth crowder (16) and extending radially-outwardly and downwardly in relation to the lower region of the standpipe (11); anda draft tube (106) or collar (108) positioned below and surrounding at least a lower portion of the rotor (15);wherein the aeration assembly (29) is CHARACTERISED IN THAT: one or more of the following statements is true:a.) a lower inside diameter (42) of the standpipe (11) is measured to be within ± 20% of an upper inside diameter (41) of the draft tube (106) or collar (108);b.) an upper gap (37) extends between the rotor (15) and standpipe (11) and a lower gap (36) extends between the rotor (15) and draft tube (106) or collar (108), and the upper gap (37) is measured to be within ± 20% of the lower gap (36);c.) the rotor (15) extends into the standpipe (11) for an upper vertical rotor depth (39) and the rotor (15) extends into the standpipe (11) for a lower vertical rotor depth (40), and the upper vertical rotor depth (39) is measured to be within ±20% of the lower vertical rotor depth (40).

2. The aeration assembly (29) according to claim 1, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be within ± 18% of the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be within ± 18% of the lower gap (36); c.) the upper vertical rotor depth (39) is measured to be within ±18% of the lower vertical rotor depth (40).

3. The aeration assembly (29) according to any one of the preceding claims, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be within ± 15% of the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be within ± 15% of the lower gap (36); c.) the upper vertical rotor depth (39) is measured to be within ±15% of the lower vertical rotor depth (40).

4. The aeration assembly (29) according to any one of the preceding claims, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be within ± 10% of the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be within ± 10% of the lower gap (36); c.) the upper vertical rotor depth (39) is measured to be within ±10% of the lower vertical rotor depth (40).

5. The aeration assembly (29) according to any one of the preceding claims, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be within ± 5% of the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be within ± 5% of the lower gap (36); C.) the upper vertical rotor depth (39) is measured to be within ±5% of the lower vertical rotor depth (40).

6. The aeration assembly (29) according to any one of the preceding claims, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be within ± 3% of the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be within ± 3% of the lower gap (36); c.) the upper vertical rotor depth (39) is measured to be within ±3% of the lower vertical rotor depth (40).

7. The aeration assembly (29) according to any one of the preceding claims, wherein one or more of the following statements is true:a.) the lower inside diameter (42) of the standpipe (11) is measured to be substantially the same as the upper inside diameter (41) of the draft tube (106) or collar (108);b.) the upper gap (37) is measured to be substantially the same as the lower gap (36);c.) the upper vertical rotor depth (39) is measured to be substantially the same as the lower vertical rotor depth (40).

8. The aeration assembly (29) according to any one of the preceding claims, further comprising at least one through opening (10) in at least one of the vanes (6).

9. The aeration assembly (29) according to any one of the preceding claims, further comprising a plurality of through openings (10) in at least one of the vanes (6).

10. The aeration assembly (29) according to claim 8, wherein the at least one through opening (10) extends entirely through a thickness of said at least one of the vanes (6).

11. The aeration assembly (29) according to any one of claims 8-10, wherein the at least one through opening (10) is an elongated opening, slit, or slot.

12. The aeration assembly (29) according to claim 9, wherein the plurality of through openings (10) are substantially parallel to each other.

13. The aeration assembly (29) according to any one of the preceding claims, wherein mounts (19) are provided to upper portions of vanes (6) and are configured to be permanently or temporarily affixed to a portion of an annular collar (20) extending outwardly from a lower portion of the standpipe (11).

14. The aeration assembly (29) according to claim 13, wherein the mounts (19) are provided as wings extending beyond a thickness of each of the vanes (6).

15. The aeration assembly (29) according to claim 13 or 14, wherein the mounts (19) are received in an annular recess (2b) defined below an annular collar (20) extending outwardly from a lower portion of the standpipe (11).

16. The aeration assembly (29) according to claim 15, wherein the annular recess (2b) is defined below the annular collar (20) and radially-outwardly of a lower body (2) below the annular collar (2).

17. The aeration assembly (29) according to claim 16, wherein the annular recess (2b) is defined between the lower body (2) and a mounting ring (28) provided at a periphery of the annular collar (20).

18. The aeration assembly (29) according to claim 13, wherein the mounts (19) extend downwardly from the annular collar (20) and the vanes (6) are secured to the mounts (19).

19. The aeration assembly (29) according to claim 18, wherein the mounts (19) comprise mounting holes (26) which align with mounting holes (27) provided to upper portions of vanes (6).

20. The aeration assembly (29) according to any one of preceding claims 13-19, further comprising one or more webs (20a) extending between the annular collar (20) and standpipe (11).

21. The aeration assembly (29) according to any one of the preceding claims, further comprising one or more froth crowder mounts (lib) for supporting a lower portion of the froth crowder (16).

22. The aeration assembly (29) according to claim 21, wherein the froth crowder (16) comprises a lower shelf (16d) which is configured to rest on an upper surface of each of the one or more froth crowder mounts (lib).

23. The aeration assembly (29) according to claim 22, wherein the lower shelf (16d) comprises one or more mounting holes (16h) which are configured to align with one or more mounting holes (11g) on the one or more froth crowder mounts (lib), each of the respective mounting holes (11g, 16h) being configured to receive a fastener therethrough.

24. The aeration assembly (29) according to any one of preceding claims, wherein each of the vanes (6) are radially-adjustable with respect to and / or removable from mounts (19).

25. The aeration assembly (29) according to claim 24, wherein each of the vanes (6) comprise one or more mounting holes (27) which are configured to align with one or more ofmounting holes (26) provided to mounts (19) or one or more mounting holes (20b) provided to an annular collar (20) extending radially outwardly from a lower portion of standpipe (11).

26. The aeration assembly (29) according to any one of the preceding claims, wherein one or more mounting holes (27) are provided to the vanes (16) on cantilevered wing sections of a mount (19), such that the one or more mounting holes (27) are offset from outer main faces of the vanes (6) or such that they straddle a thickness of each vane.

27. The aeration assembly (29) according to any one of the preceding claims, wherein ra-dially-inner sides (9a) of vanes (6) are curved and / or concave.

28. The aeration assembly (29) according to any one of the preceding claims, wherein ra-dially-outer sides (9b) of vanes (6) are curved and / or convex.

29. The aeration assembly (29) according to any one of the preceding claims, wherein at least one of the radially-outer sides (9b) of vanes (6) are straight.

30. The aeration assembly (29) according to claim 29, wherein at least one of the radially-outer sides (9b) of vanes (6) extend substantially vertically.

31. The aeration assembly (29) according to any one of the preceding claims, wherein the froth crowder (16) is substantially annular and frustoconical.

32. The aeration assembly (29) according to any one of the preceding claims, wherein a vortex stabilizer (17) is provided within the standpipe (11) and is configured for receiving the shaft (14) therethrough.

33. The aeration assembly (29) according to claim 32, wherein the vortex stabilizer (17) is situated radia lly-within the froth crowder (16) such that the froth crowder (16) surrounds at least a portion (17a, 17b) of the vortex stabilizer (17).

34. The aeration assembly (29) according to claim 32 or 33, wherein the vortex stabilizer (17) is situated radially-within the disperser hood (1).

35. The aeration assembly (29) according to any one of claims 32-34, wherein the vortex stabilizer (17) comprises a tubular body structure (17b).

36. The aeration assembly (29) according to any one of claims 32-35, wherein the vortex stabilizer (17) comprises a tapered upper inner surface (17a) that flares out from an upper edge of the tubular body structure (17b).

37. The aeration assembly (29) according to claim 32, wherein the vortex stabilizer (17) comprises at least one horizontally-extending annular baffle (lid).

38. The aeration assembly (29) according to claim 32 or 37, wherein the vortex stabilizer (17) comprises at least one vertically-extending baffle (lie).

39. The aeration assembly (29) according to any one of the preceding claims, wherein the lower body (2) is operably connected to the lower distal open end of the standpipe (11).

40. The aeration assembly (29) according to any one of the preceding claims, wherein the rotor (15) comprises a rad ia I ly-i nner thinner portion (44) that is substantially planar or substantially uniform in thickness.

41. The aeration assembly (29) according to any one of the preceding claims, wherein the rotor (15) comprises a radially-outer wider portion (45) having an outwardly-wideningthickness, expanding wedge portion, or an outwardly-flaring cross-sectional profile when viewed perpendicular to an upper or lower end of the rotor (15).

42. A self-aspirated flotation cell (100) comprising an aeration assembly (29), CHARACTERISED IN THAT the self-aspirated flotation cell (100) comprises an aeration assembly (29) as described in any one of the preceding claims.

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