WO2007070949A1

WO2007070949A1 - Feed box

Info

Publication number: WO2007070949A1
Application number: PCT/AU2006/001941
Authority: WO
Inventors: Peter Michael Nicolay; Wayne Steven Mckeag
Original assignee: Technological Resources Pty Limited
Priority date: 2005-12-20
Filing date: 2006-12-20
Publication date: 2007-06-28
Also published as: AU2006326938A1; AU2006326938B2

Abstract

A feed box (10) comprises an inlet (12), an outlet (14), and a fluid flow path (16) internal of the feed box (10) along which slurry entering the inlet (12) flows by action of gravity to the outlet (14). The feed box 10 includes a plurality of receptacles (18) which extend across the fluid flow path (16). Substantially all of the material flowing along the fluid flow path (16) that reaches the outlet (14) overflows at least one of the receptacles (18). The fluid flow path (16) comprises a first length 16A that extends from the inlets (12) to a first receptacle 18A, and a second length 16B that extends from the first receptacle 18A to the outlet (14). The lengths 16A and 16B extend in generally opposite directions.

Description

FEED BOX

Field of the Invention

The present invention relates to a feed box of a type that may be used in a mineral processing or separation plant.

Background of the Invention

In one type of ore concentration plant slurry is gravity fed from a heavy medium separation drum to a separation screen via a feed box. The feed box is in the general form of a chute having an inlet at an upper end and an outlet at a lower end. The outlet may be provided with a plate lying in a plane perpendicular to the direction of flow of slurry and acts to protect an underlying separation screen from the substantive impact of the falling slurry. To this end the slurry initially impacts the plate and then flows to an edge of the plate to fall onto the underlying separation screen.

Summary of the Invention

According to one aspect of the present invention there is provided a feed box comprising: an inlet; an outlet; a fluid flow path internal of the feed box along which material entering the inlet of the feed box flows by action of gravity to the outlet; and, one or a plurality of receptacles each of which extends across the fluid flow path wherein substantially all of the material flowing along the fluid flow path that reaches the outlet overflows at least one of the receptacles. In one embodiment a first of the receptacles is positioned relative to the inlet so that material entering the feed box from the inlet falls directly onto the first receptacle.

Each receptacle may comprise an open top container having a leading edge over which material flows when a corresponding receptacle is overflowed.

At least one receptacle may also comprise a panel extending in an_. upstream direction from its corresponding open top container.

In one embodiment at least one receptacle may be formed of a plurality of separate units arranged in a side by side manner across the fluid flow path. Each unit may comprise a portion of the panel and a portion of the container.

Alternately or in addition, at least one receptacle may comprise at least one webbing portion extending substantially parallel to a downstream direction of material flow to divide its corresponding container into a plurality of container portions.

When the feed box comprises a plurality of receptacles, the receptacles are juxtaposed in a manner so that material sequentially overflows successive downstream receptacles. The successive downstream receptacles may be juxtaposed so that material overflowing the edge of one receptacle flows along the panel of an adjacent downstream receptacle or falls directly into the container of an adjacent downstream receptacle.

At least one receptacle may be demountably supported in the feed box to enable replacement thereof. Further, when at least one receptacle is formed as a plurality of individual units, each individual unit may be demountably supported in the feed box. The feed box may comprise: a wall on which the receptacles are supported; and, a retention system to facilitate the demountable support of the receptacles, the retention system comprising at least one first component attached to the or each receptacle that engages the wall . The wall may further comprise, for each of the first components an aperture through which a respective first component passes. The first components may be formed on the panel of each receptacle or panel portion of each unit. The retention system comprises a second component that engages a respective first component to prevent the first component from being withdrawn from its respective aperture .

The fluid flow path in one embodiment comprises a first length from the inlet to the first receptacle and a second length from the first receptacle to the outlet wherein the first and second lengths extend in different directions.

The inlet is located on a front wall of the feed box and the receptacles are located on a rear wall of the feed box, the rear wall positioned generally opposite the front wall.

The outlet is located in a lower portion of the feed box, substantially beneath the inlet or extending beyond the inlet in the direction of flow of feed material at said outlet .

The inlet may comprise a diffuser having a feed end that receives the material to be passed through the feed box and a discharge end from which the material falls en route to the first receptacle, wherein the feed end and the discharge end have different widths. More particularly the discharge end may have a greater width than the feed end. The diffuser may further comprise a flow influencing element configured and/or positioned to provide a predetermined distribution of material across the discharge end. In one embodiment the flow influencing element is configured and/or positioned to provide a substantially uniform flow of material across the discharge end. When one of the receptacles comprises a plurality of container portions the flow influencing element provides substantially uniform flow of material into each of the container portions .

A further aspect of the present invention provides a mineral processing plant comprising: a feed box, a mineral processing apparatus, and a support system that supports the feed box in a position relative to the mineral processing apparatus so that a material entering the feed box is directed by the feed box to the mineral processing apparatus; the support system supporting the feed box in a manner so that the feed box can be lifted vertically off the support system.

The support system comprises two or more columns each provided with a land, and the feed box comprises two or more pads positioned to sit on the respective lands.

Each column comprises a cantilever arm extending along a side of the mineral processing apparatus and on which a respective land is formed.

The mineral processing plant may further comprise a plurality of support beams which provide common support to both the mineral processing apparatus and the support system. In one embodiment the mineral processing apparatus comprises a separation screen.

A further aspect of the present invention provides a method of feeding an ore slurry from a supply of slurry to a processing station, the method comprising: constraining the slurry to flow through a channel having a feed end of a first width and a downstream discharge end of a second width greater than the first width; and causing the slurry to be distributed across the discharge end.

The method may also comprise providing a flow influencing element in the channel, the element being shaped and/or configured to distribute the slurry substantially uniformly across the discharge end. The channel comprises a first length of a slurry flow path to the processing station. The method may also comprise providing a first container in a second length of the slurry flow path downstream of the discharge end at a location so that slurry flowing from the discharge end over flows the first container. A volume of slurry is retained within the first container so that slurry subsequently flowing along the second length of the slurry flow path upstream of the first container impacts the retained volume of slurry.

In one embodiment the method comprises providing at least one second container in the second length of the slurry flow path down stream of the first container at a location where slurry overflowing the first container flows into the second container. In this embodiment a volume of slurry is also retained within the second container so that slurry overflowing the first container impacts the retained volume of slurry in the second container. One embodiment of the method further entails arranging the first and second lengths of the slurry flow path so that slurry flowing along the first length of the flow path flows in a different direction to slurry flowing along the second length of the flow path. In a particular form of this embodiment the different direction may be in a generally opposite direction.

One embodiment of the method comprises subjecting the slurry , after passage along the slurry flow path, to a bulk flow in a bulk flow direction that is different, and may be generally opposite, to a direction of flow along the second length of the fluid flow path.

Brief Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a section view from the side of a feed box in accordance with an embodiment of the present invention;

Figure 2 is a perspective view of the feed box with a side panel removed, view from a first angle;

Figure 3 is a perspective view of the feed box shown in Figure 2 but from an alternate angle;

Figure 4 is a perspective view of the feed box from an opposite side to that shown in Figure 3; Figure 5 is a perspective view from the rear of the feed box;

Figure 6 is a partial view of the feed box illustrating the features of an inlet of the feed box;

Figure 7 is a view of the inlet from a discharge end of the inlet;

Figure 8 is a perspective view from a feed end of the inlet; Figure 9 is a schematic representation of part of a mineral processing plant incorporating a support system for the feed box;

Figure 10 is a representation of the support system shown in Figure 9 from an alternative viewing angle ;

Figure 11 is a schematic representation of the mineral processing plant depicted in Figures 9 and 10 but with the feed box supported by the support system; and Figure 12 is a schematic representation of the mineral processing of Figure 11 but with a separation screen also supported by the support system; and

Figure 13 is a section view of a part of the mineral processing plant shown in Figure 12.

Detailed Description of Preferred Embodiment

With reference to the accompanying drawings a feed box 10 in accordance with an embodiment of the present invention comprises an inlet 12, an outlet 14, and a fluid flow path 16 internal of the feed box 10 along which material, such as slurry, entering the inlet 12 of the feed box flows by action of gravity to the outlet 14. The depicted feed box 10 also includes a plurality of receptacles 18A, 18B and 18C (herein after referred to in general as "receptacles 18") each of which extends across the fluid flow path 16. Substantially all of the material flowing along the fluid flow path 16 that reaches the outlet 14 overflows at least one of the receptacles 18. Typically, most of the material flowing along the fluid flow path 16 that reaches the outlet 14 will overflow each of the receptacles 18A, 18B and 18C.

With particular reference to Figure 1, it can be seen that the fluid flow path 16 comprises a first length 16A and a second length 16B. The first length 16A extends from the inlet 12 to the first receptacle 18A, mounted on rear wall 24. The second length 16B extends from the first receptacle 18A to the outlet 14. The lengths 16A and 16B extend in generally opposite directions. Thus again with reference to Figure 1, the length 16A is directed generally to the left while the length 16B is in a general sense directed to the right. Preferably, the change in direction between lengths 16A and 16B is sufficient to cause a reduction in momentum of feed material, thereby reducing wear on processing equipment that receives the feed material from outlet 14. Typically, such wear arises due to the velocity of the feed material upon impact with the processing equipment.

Outlet 14 is located in a lower portion of the feed box 10 and is typically positioned substantially beneath inlet 12 or beyond the inlet when viewed in the direction of flow of feed material at the outlet. This positioning of the outlet 14 relative to the inlet 12 helps to ensure that the flow path of material entering the feed box 10 includes at least one receptacle 18.

As shown most clearly in Figures 2 and 3, each receptacle 18 comprises a panel 20 and a downstream open top container 22. The panel 20 forms a planar liner for a rear wall 24 of the feed box 10. The container 22 is in the form of a bucket or scoop having a leading edge 26 over which material flows when flowing from the inlet 12 to the outlet 14.

A first of the receptacles 18A is positioned relative to the inlet 12 so that material entering the feed box 10 from the inlet 12 falls directly onto the first receptacle 18A. Thus the material entering the feed box 10 will either impinge on the panel 20 and subsequently flow into the container 22 of receptacle 18A, or directly fall into the container 22 of the receptacle 18A. The receptacles 18 are further juxtaposed in a manner so that material sequentially overflows successive downstream receptacles 18 en route to the outlet 14. Thus material entering the inlet 12 will first overflow the receptacle 18A, then overflow the receptacle 18B, and finally- overflow the receptacle 18C prior to exiting from the outlet 14. Moreover, the leading edge 22 of receptacle 18 is positioned relative to an adjacent downstream receptacle 18 so that material overflowing a leading edge 26 of an upstream receptacle 18 will either fall on to the panel 20 of an adjacent downstream receptacle 18 and subsequently flow into the corresponding receptacle 22 or the material overflowing the leading edge 26 of an upstream receptacle 18 will fall directly into the container 22 of an adjacent downstream receptacle 18. For example, consider material overflowing the leading edge 26 of receptacle 18A. Depending on the momentum and flow rate of the material this material will either fall onto the panel 20 of the receptacle 18B and subsequently flow into the corresponding receptacle 22; or, will fall directly into the receptacle 22 of the underlying receptacle 18B.

As seen most clearly in Figures 2 and 3 , each receptacle 18 comprises of a plurality (in this case three) separate units 28. In particular the receptacle 18A comprises three units 28Al, 28A2 and 28A3; receptacle 18B comprises units 28Bl, 28B2 and 28B3; and, receptacle 18C comprises units 28Cl, 28C2 and 28C3. For ease of reference, each unit is referred to in general as "unit 28" .

Each unit 28 comprises a panel portion 2OP and a container portion 22P. Each of the units 28 for any particular receptacle 18 is of the same shape and configuration. Although this may not necessarily be the case. The receptacles 18 are deraountably supported in the feed box 10 and more particularly demountably supported on the rear wall 24. The method of support can vary widely, and its specific form is not critical to the performance of the embodiments of the invention. In this particular embodiment the demountable support is achieved by a retention system comprising a first component in the form of loops 30 (see in particular Figure 5) formed integrally with and extending rearwardly from the panels 20 of the receptacles 18; and second component in the form of a plurality of wedges 32 received within the loops 30. The loops 30 extend through corresponding holes formed in the rear wall 24. Three loops 30 are provided in each of the panel portions 2OP of each unit 28. Two of the loops 30 are provided near an upstream end of each panel portion 20P. These two loops are spaced apart but in horizontal alignment with each other. A third loop 30 is provided near a downstream end of each panel portion 2OP midway between the other two loops 30.

The relative configuration of the panel 20 and container 22 of a receptacle 18 is by and large dictated by the configuration of the rear wall 24 of the feed box 10. In this particular embodiment the rear wall 24 includes a vertical portion 24V and a downstream contiguous inclined portion 241. The panel 20 and container 22 of the receptacle 18A are relatively configured to seat on an angle formed by the junction of the wall portions 24V and 241, with the panel 20 extending in the downstream direction and meeting the corresponding container 22 at the junction of the wall portions 24V and 241. A portion of the base of the container 22 is flat to sit on the wall portion 241. The container portion of the receptacle 18B also includes a planar portion that sits on the wall 241. In contrast, the container 22 of the receptacle 18C is suspended in the outlet 14. With particular reference to Figures 6 - 8, it can be seen that the inlet 12 comprises a diffuser 34 having a feed end 36 that receives the material to be passed through the feed box 10, and a discharge end 38 from which the material falls en route to the first receptacle 18A. The feed end 36 and discharge end 38 are of different width. In particular the discharge end 38 is wider than the feed end 36. This change in width between the inlet end 36 and outlet end 38 assists in distributing the material evenly across the flow path 16 so that each container portion 22P receives substantially the same volume of material.

The control of the distribution of the feed over the discharge end 38 is further assisted by the provision of a flow influencing element 40 formed on a tray portion 42 of the diffuser 34. The element 40 extends from the feed end 36 to the discharge end 38 and is in the general configuration of a semi elliptoid bulge having a longitudinal axis aligned with a direction of flow of material from the feed end 36 to the outlet end 38. The inlet 12 also includes opposite side walls 44 extending from the feed end 36 to the discharge end 38 to channel the material to flow over the discharge end 38. A downstream portion 46 of the tray 42 is inclined downwardly relative to an upstream portion 48.

As shown in Figures 1 - 3 the feed box 10 also comprises a replaceable wear liner 50 supported on a front wall 52 of the feed box 10. The wear liner 50 is disposed toward a lower end of the wall 52 and includes a tail portion 54 that defines, in part, the outlet 14. The liner 50 is demountably attached to the wall 52 by use of loops 30 and wedges 32 of identical configuration to those used for demountably coupling the receptacles 18 to the feed box 10. A cowling 56 is also attached to the wall 52 and forms an enclosed channel in which the inlet 12 is disposed. A plurality of inspection hatches 58 is provided on an upper wall 60 of the feed box 10, and a further inspection hatch 62 is provided on the wall 52.

In broad terms the feed box 10 may be considered to be a six sided box having a front wall 52, rear wall 24, upper wall 60, two opposing side walls 80 and an open bottom which forms the outlet 14, (although the bottom could be constituted by a physical wall with an opening to form the outlet, i.e. not all of the bottom of the box is necessarily left open to form the outlet 14) . Both the front wall 52 and rear wall 24 are, or include substantive portions that are, inclined to the vertical and generally parallel to each other. The front and rear walls 52, 24 also extend generally downwardly and their respective lower edges form front and rear edges of the outlet 14, or in the event of an embodiment where the feed box 10 includes a bottom wall with an opening that forms the outlet, the lower edges of the walls 52, and 24 would form front and rear edges of the bottom wall. The fluid flow path 16 is defined between the front and rear walls 52 and 24 and the outlet 14 is typically in, or in advance of, a vertical line or plane from the inlet 12 in the direction of flow of material to the outlet 14. It may also be seen from the drawings and in particular Figures 1 - 3 that the leading edges 22 of the receptacles 18 face the inlet 12.

A further aspect of the invention is depicted in Figures 9 - 13. These figures depict, in part, a mineral processing plant 70. The mineral processing plant 70 comprises a mineral processing apparatus such as a separation screen 71 (Figures 12 and 13) together with the feed box 10 and a support system 72 that supports the feed box 10 in a position relative to the separation screen 71 so that material entering the feed box 10 is directed by the feed box 10 to the separation screen 71. The support system 72 supports the feed box 10 in a manner so that the feed box 10 can be lifted vertically off the support system 72. To this end the support system 72 comprises : two columns 74 each provided with a lands 76; and, respective pads 78 attached to opposite side walls 80 of the feed box 10, where the pads 78 are positioned to sit on respective lands 76. A plurality of through holes is formed in the lands 76 and pads 78 for receiving bolts (not shown) to releasably attach or fix the feed box 10 to the columns 74. It will be appreciated that by simply undoing the bolts, an overhead crane can engage the feed box 10 and lift it vertically off the columns 74. This enables the relatively rapid exchange of feed boxes 10 for maintenance purposes .

The columns 74 comprise respective cantilevered arms 81 that run on opposite sides of the mineral processing apparatus (e.g. a separation screen) and on which a respective land 76 is formed.

In a further aspect of the support system 72 a plurality of beams 82 is provided that form a common support for both the mineral processing apparatus and the columns 74. Each column 74 is located on a beam 82 adjacent the mineral processing apparatus. The column extends upwardly from the base portion and its corresponding cantilevered arm 81 extends generally parallel with the beam 82 in the direction of the mineral processing apparatus. The cantilevered arms 81 typically extend adjacent the mineral processing apparatus whereby outlet 14 of the feed box can be positioned so as to discharge feed material to the mineral processing apparatus. This use of cantilevered arms allows the feed box to be supported on the same structural beams as the mineral processing equipment, simplifying plant structural requirements. The columns 74 may be formed as generally hollow or box like structures. Figure 13 depicts the relative juxtaposition of the feed box 10 and the separation screen 71. The separation screen 71 comprises a screen portion 84 and an adjacent wear plate 86. Respective upper surfaces of the screen 84 and wear plate 86 lie on a common horizontal plane. The separation screen 71 reciprocates so as to cause a net bulk flow of slurry in a direction D from the wear plate 86 to the screen portion 84. The reciprocating motion is of a stroke to ensure that the wear plate 86 is always located below the outlet 16. The slurry is discharged from the feed box 10 to flow in a direction that is different, and more particularly a substantially opposite, to the direction D, The slurry initially falls onto the wear plate 86 and then, by action of the separation screen 71 is caused to flow in the direction D over the screen 84.

Now that embodiments of the invention have been described in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, the feed box 10 may be provided with any number of receptacles 18 that extend across the fluid flow path 16. While the present embodiment depicts three receptacles, the feed box 10 may be made with one, two or more than three receptacles. In addition it is not critical that each receptacle comprises a panel 20. The panel in effect acts as a wear liner for the rear wall 24. Thus the form of the receptacles 18 may be changed so as to comprise solely a container or open top box like portion that is attached to the rear wall 24, with separate wear liners protecting the wall 24 from wear. In addition while the use of loops 30 and wedges 32 is depicted for demountably attaching the receptacles 18 and the liner 54 to the feed box 10, other mechanical couplers may be used.

Claims

Claims :

1. A feed box comprising: an inlet ; an outlet; a fluid flow path internal of the feed box along which material entering the inlet of the feed box flows by- action of gravity to the outlet; and, one or a plurality of receptacles each of which extends across the fluid flow path wherein substantially all of the material flowing along the fluid flow path that reaches the outlet overflows at least one of the receptacles .

2. The feed box according to claim 1 wherein a first of the receptacles is positioned relative to the inlet so that material entering the feed box from the inlet falls directly onto the first receptacle.

3. The feed box according to claim 1 or 2 wherein each receptacle comprises an open top container having a leading edge over which material flows when a corresponding receptacle is overflowed.

4. The feed box according to claim 3 wherein at least one receptacle comprises a panel extending in an upstream direction from its corresponding open top container.

5. The feed box according to any one of claims 1-3 wherein at least one receptacle comprises a plurality of separate units arranged in a side by side manner across the fluid flow path.

6. The feed box according to claim 5 wherein each unit comprises a portion of the panel and a portion of the container.

7. The feed box according to claim 4 wherein the at least one receptacle comprises at least one webbing portion extending substantially parallel to a downstream direction of material flow to divide its corresponding container into a plurality of container portions .

8. The feed box according to any one of claims 1 - 7 wherein the feed box comprises a plurality of receptacles juxtaposed in a manner so that material sequentially overflows successive downstream receptacles.

9. The feed box according to claim 8 wherein the successive downstream receptacles are juxtaposed so that material overflowing the edge of one receptacle flows along the panel of an adjacent downstream receptacle or falls directly into the container of an adjacent downstream receptacle.

10. The feed box according to any one of claims 1 - 9 wherein at least one of the receptacles is demountably supported in the feed box to enable replacement thereof .

11. The feed box according to claim 10, wherein when at least one receptacle is formed as a plurality of individual units, each individual unit may be demountably supported in the feed box.

12. The feed box according to claim 10 or 11 comprising a wall on which the receptacles are supported; and, a retention system to facilitate the demountable support of the receptacles, the retention system comprising at least one first component attached to the or each receptacle that engages the wall .

13. The feed box according to claim 12 wherein the wall comprises for each of the first components an aperture through which a respective first component passes.

14 The feed box according to claim 13 wherein the first component is formed on the panel of each receptacle or panel portion of each unit.

15. The feed box according to any one of claims 12 - 14 wherein the retention system comprises a second component that engages a respective first component to prevent the first component from being withdrawn from its respective aperture.

16. The feed box according to any one of claims 1 - 15 wherein the fluid flow path comprises a first length from the inlet to the first receptacle and a second length from the first receptacle to the outlet wherein the first and second lengths extend in different directions .

17. The feed box according to claim 16 wherein the different directions are generally opposite to each other.

18. The feed box according to claim 16 or 17 wherein the inlet is located on a front wall of the feed box and the receptacles are located on a rear wall of the feed box, the rear wall positioned generally opposite the front wall.

19. The feed box according to claim 18 wherein the outlet is located in a lower portion of the feed box, substantially beneath the inlet or extending beyond the inlet in the direction of flow of feed material at said outlet.

20. The feed box according to any one of claims 1 - 19 wherein the inlet comprises a diffuser having a feed end that receives the material to be passed through the feed box and a discharge end from which the material falls en route to the first receptacle, wherein the feed end and the discharge end have different widths.

21. The feed box according to claim 20 wherein the discharge end has a greater width than the feed end.

22. The feed box according to claim 20 or 21 wherein the diffuser comprises a flow influencing element configured and/or positioned to provide a pre-determined distribution of material across the discharge end.

23. The feed box according to claim 22 wherein the flow influencing element is configured and/or positioned to provide a substantially uniform flow of material across the discharge end.

24. The feed box according to claim 22 or 23 wherein when one of the receptacles comprises a plurality of container portions the flow influencing element provides substantially uniform flow of material into each of the container portions .

25. A mineral processing plant comprising: a feed box, a mineral processing apparatus, and a support system that supports the feed box in a position relative to the mineral processing apparatus so that a material entering the feed box is directed by the feed box to the mineral processing apparatus; the support system supporting the feed box in a manner so that the feed box can be lifted vertically off the support system.

26. The mineral processing plant according to claim 25 wherein the feed box is in accordance with any one of claims 1 - 24.

27. The mineral processing plant according to claim 25 or 26 wherein the support system comprises two or more columns each provided with a land, and the feed box comprises two or more pads positioned to sit on the respective lands.

28. The mineral processing plant according to claim 27 wherein each column comprises a cantilevered arm extending along a side of the mineral processing apparatus and on which a respective land is formed.

29. The mineral processing plant according to any one of claims 25 - 28 further comprising a plurality of support beams which provide common support to both the mineral processing apparatus and the support system.

30. The mineral processing plant according to claim 29 wherein the columns are supported on the support beams adjacent the mineral processing apparatus, the cantilevered arms extending generally parallel with the support beams adjacent the mineral processing apparatus.

31. The mineral processing plant according to any one of claims 25 - 30 wherein the mineral processing apparatus comprises a separation screen.

32. A method of feeding an ore slurry from a supply of slurry to a processing station, the method comprising: constraining the slurry to flow through a channel having a feed end of a first width and a downstream discharge end of a second width greater than the first width; and causing the slurry to be distributed across the discharge end .

33. The method according to claim 32 comprising providing a flow influencing element in the channel, the element being shaped and/or configured to distribute the slurry substantially uniformly across the discharge end.

34. The method according to claim 32 or 33 comprising forming the channel as a first length of a slurry flow path to the processing station.

35. The method according to claim 34 comprising providing a first container in a second length of the slurry flow path downstream of the discharge end at a location so that slurry flowing from the discharge end over flows the first container.

36. The method according to claim 35 comprising retaining a volume of slurry within the first container so that slurry subsequently flowing along the second length of the slurry flow path upstream of the first container impacts the retained volume of slurry.

37. The method according to claim 35 or 36 comprising providing at least one second container in the second length of the slurry flow path down stream of the first container at a location where slurry overflowing the first container flows into the second container.

38. The method according to claim 37 comprising retaining another volume of slurry within the second container so that slurry overflowing the first container impacts the retained volume of slurry in the second container.

39. The method according to any one of claims 35 -38 comprising arranging the first and second lengths of the slurry flow path so that slurry flowing along the first length of the flow path flows in a different direction to slurry flowing .along the second length of the flow path.

40. The method according to any one of claims 35 - 38 comprising arranging the first and second lengths of the slurry flow path so that slurry flowing along the first length of the flow path flows in a direction generally opposite to slurry flowing along the second length of the flow path

41. The method according to any one of claims 36 - 40 comprising subjecting the slurry, after passage along the slurry flow path, to a bulk flow in a bulk flow direction that is different, to a direction of flow along the second length of the fluid flow path.

42. The method according to any one of claims 36 - 40 comprising subjecting the slurry, after passage along the slurry flow path, to a bulk flow in a bulk flow direction that is generally opposite, to a direction of flow along the second length of the fluid flow path.