FEED APPARATUS

The invention relates to a feed apparatus to receive dug mineral and feed the mineral onto a feed conveyor.

In an opencast or surface mining operation, dug mineral is typically fed into a processing plant to break down the dug mineral to ensure that it contains no lumps above a desired size, and so enables the processed mineral to be conveyed out of the mine either in a dry state on a conveyor belt or as a slurry in a pipeline.

Such processing plants typically include a feed conveyor that conveys dug mineral from a mineral deposit end to a mineral discharge end where the dug mineral is discharged into a mineral breaker.

The mineral discharge end of the feed conveyor is typically located a considerable distance above the ground so that the dug mineral is discharged from the mineral discharge end into the mineral breaker. The feed conveyor is therefore oriented at an angle relative to the ground, which, depending on the nature of the dug mineral, is chosen to avoid the risk of "hang-up" or "freezing" of the dug mineral on the feed conveyor.

Conventionally a hopper has been provided above the mineral deposit end of the feed conveyor into which dug mineral is fed such that side walls of the hopper direct the dug mineral onto the mineral deposit end of the feed conveyor.

The use of a hopper imposes certain restrictions on the rate and efficiency with which dug mineral is directed onto the mineral deposit end of a feed conveyor.

Firstly the location of a hopper above the mineral deposit end of a feed conveyor means that the dug mineral must be lifted a relatively significant distance from the ground for deposit into the hopper. Secondly the size of the hopper is directly proportional to the size of the feed conveyor and therefore often means a certain degree of accuracy is required to direct the dug mineral into the hopper.

It is therefore desirable to provide a feed apparatus that allows dug mineral to be fed onto a mineral deposit end of a feed conveyor at a greater rate and with greater efficiency.

According to an aspect of the invention there is provided a feed apparatus to receive dug mineral and feed the mineral onto a feed conveyor, the feed apparatus comprising a receptacle defining a mineral deposit zone over its entire surface to receive dug mineral and including a centrally located deflector to deflect deposited mineral onto a moveable support surface following an orbital path about the deflector to convey deposited mineral from the mineral deposit zone to a discharge where the mineral is directed onto a mineral deposit end of a feed conveyor.

The provision of a moveable support surface to convey mineral from a mineral deposit zone to a discharge where the mineral is directed onto a mineral deposit end of a feed conveyor means that the size of the feed apparatus is independent of the feed conveyor and can be offset to one side. As such the feed apparatus can be made of a size such that the rate at which dug mineral is deposited onto the mineral deposit end of a feed conveyor is dependent on the speed of movement of the support surface rather than the rate at which dug mineral is delivered to the feed apparatus.

Of course the greater the size of the feed apparatus, the greater the size of the mineral deposit zone and therefore the less accuracy is required to deposit dug mineral into the mineral deposit zone. This in turn allows dug mineral to be deposited into the mineral deposit zone efficiently.

The use of a moveable support surface means that the feed apparatus can be erected such that the support surface is relatively close to the ground. As such it is not necessary to lift the dug mineral as far above the ground to deposit it into the mineral deposit zone as would be required with a conventional hopper. This again allows dug mineral to be deposited into the mineral deposit zone efficiently.

The provision of the centrally located deflector ensures that deposited mineral is deflected onto the moveable support surface following an orbital path about the deflector.

Movement of the moveable support surface is preferably controllable to permit adjustment of the speed of the support surface and thereby permit adjustment of the rate of feed of dug mineral to the mineral deposit end of a feed conveyor.

The receptacle preferably includes a diverter located adjacent the discharge, the diverter extending across the support surface to prevent further passage of mineral about the orbital path of the support surface and divert the mineral from the support surface, via the discharge, onto the mineral deposit end of a feed conveyor.

The provision of the diverter to positively direct dug mineral from the moveable support surface onto the mineral deposit end of a feed conveyor allows the support surface to be located at the same height as the mineral discharge end of a feed conveyor. In this arrangement it is not necessary to drop dug mineral onto the mineral deposit end of the feed conveyor. As such the risk of wear and damage to the mineral deposit end of the feed conveyor from the continuing impact of dug mineral thereon is reduced.

The diverter may be pivotally mounted relative to the support surface to permit movement of the diverter relative to the support surface.

This arrangement allows adjustment of the position of the diverter relative to the support surface so that interaction between the dug mineral and the diverter leads to efficient diversion of the dug mineral, via the discharge, to the mineral deposit end of the feed conveyor.

Once an optimal position of the diverter relative to the moveable support surface is obtained, the diverter may .be fixed in position relative to the support surface. However, in other embodiment, the diverter may remain moveable relative to the

support surface, when required, to sweep mineral from the support surface, via the discharge, onto the mineral deposit end of a feed conveyor.

Such movement of the diverter is useful in circumstances where the dug mineral has a relatively high moisture content, rendering the dug mineral more likely to stick to the support surface.

The receptacle may be mounted on a frame which, in use, rests on the ground such that the support surface is supported at an angle relative to the ground.

Locating the receptacle such that the support surface is supported at an angle relative to the ground permits the use of bulldozers to deposit dug mineral into the mineral deposit zone.

In such embodiments a lowermost edge of the receptacle preferably rests, in use, on the ground. This arrangement prevents dug mineral on the ground directly in front of the receptacle being pushed under the receptacle by a bulldozer, for example, and allows dug mineral to be swept onto the support surface from the ground.

The frame is preferably moveable to allow re-location of the feed apparatus to a new processing location within a mine, for example. In this regard the frame is preferably constructed to allow the use of a crawler-mounted lifting device or the like to lift the frame off the ground and move it to a new location.

The frame may be adjustable to permit adjustment of the angle of inclination of the support surface relative to the ground through a range of angles. This allows the angle of inclination to be adjusted until an optimum angle of inclination is achieved. Depending on the nature of the dug mineral, and the method by which the dug mineral is deposited into the mineral deposit zone, the optimum angle of inclination of the support surface may be the same, shallower or steeper than the angle of inclination of the feed conveyor to be supplied with dug mineral.

In embodiments where the receptacle is mounted on a frame such that the support surface is supported at an angle to the ground, an outer wall may be provided along an uppermost edge of the receptacle, about an outer edge of the orbital path of the moveable support surface. The outer wall thereby prevents dug mineral falling over the back of the receptacle from where it would otherwise be difficult to retrieve for deposit into the mineral deposit zone.

In other embodiments, the receptacle may be mounted on a frame such that the support surface lies flat relative to the ground. This arrangement results in a larger mineral deposit zone, which may be particularly useful in arrangements where a dragline is used to deposit dug mineral into the mineral deposit zone.

In such embodiments, the outer wall may be extended so as to extend further about the outer edge of the orbital path.

Regardless of whether the receptacle is mounted on a frame such that the support surface is supported at an angle to the ground or lies flat relative to the ground, the deflector is preferably formed to define an inner wall about an inner edge of the orbital path of the moveable support surface, the height of the inner wall determining a maximum depth of a mineral bed that can be conveyed on the moveable support surface.

The deflector preferably houses a drive assembly to drive the support surface and thereby protects the drive assembly from the impact of dug mineral being deposited into the mineral deposit zone, and preferably includes a domed lid to deflect deposited mineral towards the moveable support surface.

The support surface preferably includes a plurality of ribs on its upper surface to resist sliding movement of the deposited mineral across the support surface in the direction of movement of the support surface, particularly in circumstances where the support surface is supported at an angle relative to the ground.

In a preferred embodiment, the support surface is defined by a wheel formed from metal plate. In such an embodiment, the wheel preferably includes a plurality of radially extending grouser bars welded onto its surface.

A particularly preferred embodiment of the invention will now be described, by way of a non-limiting example, with reference to the accompanying drawings in which:

Figure 1 shows a perspective view from a first side of a feed apparatus according to an embodiment of the invention arranged to feed a feed conveyor;

Figure 2 shows a side view of the feed apparatus and feed conveyor of Figure 1;

Figure 3 shows a perspective view from a second side of the feed apparatus and feed conveyor of Figure 1 where a portion of a cap portion of a deflector of the feed apparatus is removed; and

Figure 4 shows an enlarged view of a support surface and deflector of the feed apparatus of Figure 1 where the cap portion of the deflector and a portion of the support surface are removed.

Figure 1 shows a feed apparatus 10 according to an embodiment of the invention arranged to feed a feed conveyor 12.

The feed apparatus 10 includes receptacle 14 defining a mineral deposit zone 16 over its entire surface to receive dug mineral. The feed apparatus also includes a centrally located deflector 18 to deflect deposited mineral onto a moveable support surface 20, which follows an orbital path about the deflector 18 identified by arrow A in Figures 1 and 3.

As will be described below the moveable support surface 20, in use, conveys deposited mineral from the mineral deposit zone to a discharge 22 where the mineral is directed onto a mineral deposit end 24 of the feed conveyor 12.

In the embodiment shown in Figure 1, the receptacle 14 includes a diverter 26. As can be seen more clearly from Figure 3, the diverter 26 extends across the support surface 20 to prevent further passage of mineral about the orbital path A of the support surface 20 and divert mineral from the support surface 20, via the discharge 22, onto the mineral deposit end 24 of the feed conveyor 12.

The diverter 26 is preferably pivotally mounted relative to the support surface 20 to permit movement of the diverter 26 relative to the support surface 20. This allows adjustment of the position of the diverter 26 relative to the support surface 20 to ensure dug mineral is diverted, via the discharge 22, to the mineral deposit end 24 of the feed conveyor 12 in as efficient a manner as possible.

Once an optimal position of the diverter 26 relative to the support surface 20 is obtained, the diverter is preferably secured in position.

In other embodiments the diverter 26 may remain moveable relative to the support surface 20 to allow movement of the diverter 26 to sweep mineral from the support surface 20 when required.

As shown in Figures 1-3, the receptacle 14 is mounted on a frame 28 resting on the ground 30 (Figure 3) such that the support surface 20 is supported at an angle relative to the ground 30 and a lowermost edge 32 of the receptacle rests on the ground 30.

The frame 28 permits movement of the receptacle 14 should re-location of the feed apparatus 10 be required. Such movement is preferably effected by means of a crawler-mounted lifting device or the like that lifts the frame 28 off the ground and then carries the feed apparatus 10 to a new desirable location.

The frame 28 is preferably adjustable to permit adjustment of the angle of inclination of the support surface 20 relative to the ground 30, and thereby permit adjustment of the angle of inclination of the support surface 20 relative to the angle of inclination of the feed conveyor 12.

In the embodiment shown in Figures 1-3, the angle of inclination of the support surface 20 relative to the ground 30 is the same as the angle of inclination of the feed conveyor 12.

In other embodiments, the angle of inclination of the support surface 20 may, depending on the nature of the dug mineral, be shallower or steeper than the angle of inclination of the feed conveyor 12.

In yet further embodiments, the receptacle 14 may be mounted on the frame 28 such that the support surface 20 lies flat relative to the ground 30.

An outer wall 34 is provided along an uppermost edge 35 of the receptacle 14, along an outer edge of the orbital path A of the moveable support surface 20, and the deflector 18 is formed to define an inner wall 36 about an inner edge of the orbital path A of the moveable support surface 20.

In the embodiment shown in Figures 1-4, the moveable support surface 20 is defined by a wheel formed from sections 38 of metal plate (Figure 4), which are mounted on outer wheel mounts 40 (Figure 4) provided on the frame 28. A plurality of radially extending grouser bars 39 are welded on the surface of the wheel defining the support surface 20.

A drive assembly 42 (Figures 3 and 4) housed in the deflector housing 44 of the deflector 18 includes a series of hydraulic wheels drives (not shown) and a geared slew bearing (not shown) to drive the wheel forming the support surface 20, and permits the speed of rotation of the wheel to be varied so as to vary the rate at which mineral is delivered to the mineral deposit end 24 of the feed conveyor 12.

A domed lid 46 is provided to close the deflector housing 44 and prevent the ingress of dug mineral into the deflector housing 44.

In use, dug mineral is deposited into the mineral deposit zone 16 of the receptacle 14, the deflector 18 deflecting deposited mineral onto the moveable support surface 20.

The arrangement of the receptacle 14 on the frame 28 relative to the ground 30 permits the use of either bulldozers or a dragline to deposit dug mineral into the mineral deposit zone 16.

Contact between the lowermost edge 32 of the receptacle 14 and the ground 30 prevents dug mineral on the ground 30 directly in front of the receptacle 14 being pushed under the receptacle 14 by a bulldozer, for example, and allows dug mineral to be swept onto the support surface 20 from the ground 30.

The provision of the outer wall 34 along an uppermost edge 35 of the receptacle 14 prevents mineral falling over the back of the receptacle 14 from where it would otherwise be difficult to retrieve for deposit into the mineral deposit zone 16.

The arrangement of the receptacle 14 on the frame 28 relative to the ground 30 allows the dug mineral to be deposited into the mineral deposit zone 16 efficiently in that the distance by which the mineral must be lifted from the ground is minimized.

In addition, the provision of the centrally located deflector 18 having a domed lid 46 ensures that mineral deposited towards the centre of the mineral deposit zone 16 is deflected onto the moveable support surface 20. The provision of the centrally located deflector 18 also serves to protect the drive assembly 42 from the impact of the deposited mineral.

The height of the inner wall 36 defined by the deflector 18 determines a maximum depth of a mineral bed that can be conveyed on the moveable support surface 20. In the event that the depth of the mineral bed exceeds the height of the inner wall 36, the excess mineral will fall under the influence of gravity towards the lowermost edge of the receptacle 14. It may from there by collected for re-deposit

into the mineral deposit zone 16 of swept back onto the support surface by means of a bulldozer.

In embodiments where a greater depth of mineral bed is desirable, the height of the inner and outer walls 36,34 may be increased.

The dug mineral, once deposited into the mineral deposit zone 16, is conveyed about the orbital path A of the moveable support surface 20 towards the feed conveyor 12. During this movement, the radially extending grouser bars 39 provided on the moveable support surface 20 prevent sliding movement of the mineral relative to the support surface 20 in the direction of movement of the support surface 20.

Once the dug mineral reaches the discharge 26 of the feed apparatus, contact between the mineral and the diverter 26 causes the mineral to be directed, via the discharge 22, on the mineral deposit end 24 of the feed conveyor 12.

In the arrangement shown in Figures 1-4, the discharge 22 of the support surface 20 is arranged at the same height as the mineral deposit end 24 of the feed conveyor 12, and at the same angle of inclination relative to the ground 30. This means that the dug mineral can be pushed directly onto the feed conveyor, thereby avoiding the risk of wear and/or damage that could otherwise occur through the impact of dug mineral dropped onto the mineral deposit end 24 of the feed conveyor 12.

In embodiments where the diverter 26 remains moveable relative to the support surface 20 following set up of the feed apparatus 10 to obtain an optimal position of the diverter 26 relative to the support surface 20, in circumstances where the dug mineral becomes clogged or otherwise stuck to the moveable support surface 20, movement of the support surface 20 may be halted and the diverter 26 may be swept across the support surface 20 to push mineral onto the mineral deposit end 24 of the feed conveyor 12.

As outlined above, depending on the nature of the dug mineral, the angle of inclination of the support surface 20 relative to the ground 30 may in other embodiments be varied so as to be steeper or shallower than the angle of inclination of the feed conveyor 12. This allows an interface between the moveable support surface 20 and the mineral deposit end 24 of the feed conveyor 12, at the discharge 22 of the feed apparatus 10, to be achieved that ensures dug mineral is fed to the feed conveyor as efficiently as possible.

In embodiments where the dug mineral is intended to be fed by dragline only, the receptacle 14 may be supported on the frame 28 such that the support surface 20 lies flat relative to the ground 30. This arrangement maximizes the size of the mineral deposit zone 16 into which the dug mineral is to be deposited.

hi such embodiments, the upper wall 34 may be extended so as to extend further about the outer edge of the orbital path A of the support surface 20 and thereby prevent dug mineral falling over the edge of the receptacle 14 onto the ground 30.