WO1999052637A1

WO1999052637A1 - Method and apparatus for processing a conglomerate

Info

Publication number: WO1999052637A1
Application number: PCT/IB1999/000604
Authority: WO
Inventors: Andrew Joseph Vietti; George Mckinley Langefeld; Nico Van Zyl
Original assignee: De Beers Consolidated Mines Ltd
Current assignee: De Beers Consolidated Mines Ltd
Priority date: 1998-04-08
Filing date: 1999-04-08
Publication date: 1999-10-21
Anticipated expiration: 2000-10-08
Also published as: AU3047099A; CA2326316A1; CA2326316C; AU745251B2; BR9909417A; RU2232643C2

Abstract

A conglomerate processing apparatus is provided for processing a conglomerate of recoverable particles bound together by a binding medium, such as a conglomerate (20) of diamondiferous ore embedded in clay. The apparatus comprises a moving belt conveyer (12) having an upstream end for receiving the conglomerate, a downstream end, and a first upstream array of fragmenting nozzles (44A) for directing a corresponding series of fragmenting fluid jets (48) onto the conglomerate (20) to break it up. A second downstream array of eroding nozzles (46A) is provided for directing a corresponding series of fanned eroding fluid jets (50) for eroding the clay from the broken up conglomerate to expose the individual diamondiferous ore particles (54). The invention extends to a method of processing a conglomerate.

Description

METHODAND APPARATUS FORPROCESSING A CONGLOMERATE

BACKGROUND TO THE INVENTION

THIS invention relates to a method and apparatus for processing a conglomerate.

In the mining industry, one of the factors which leads to the disruption of downstream processing is the conglomeration of ore particles. Such conglomeration typically occurs when clay is present, with the clay acting as a binder which binds together a number of particles so as to form consolidated clay particles. This problem is particularly prevalent in high clay content ore bodies such as diamondiferous ore embedded in clay. SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a conglomerate processing apparatus for processing a conglomerate of particles bound together by a binding medium, the apparatus comprising a moving conveyer having an upstream end for receiving the conglomerate, a downstream end. a first array of fragmenting nozzles for directing a corresponding series of fragmenting fluid jets onto the conglomerate to break it up, and a second array of eroding nozzles for directing a corresponding series of eroding fluid jets for eroding the binding medium from the broken up conglomerate to expose the individual particles.

Preferably, the first array of fragmenting nozzles is configured to supply relatively narrow beam high intensity fluid jets, and the second array of eroding nozzles is configured to supply relatively broad beam lower intensity fluid jets.

Conveniently, nozzle directing means are provided for controlling the movement and direction of the fragmenting and eroding fluid jets.

Typically, the fragmenting and eroding nozzle arrays are incorporated in at least one spray manifold.

Advantageously, the nozzle directing means includes transverse moving means for moving the spray manifold in a direction transverse to the direction of feed of the conveyer, and tilting means for adjusting the angle of tilt of the nozzles and/or the height of the nozzles above the conveyer. In a preferred form of the invention, first array of fragmenting nozzles is upstream of the second array of eroding nozzles.

Advantageously, the eroding nozzles are arranged to spray a fanned fluid jet having beamwidth ranging from 5° to 15°, and typically approximately 10°.

Conveniently, the fragmenting nozzles are arranged to spray a fluid jet which is substantially parallel, having a beamwidth of approximately 0°.

In one form of the invention, the spray manifold comprises at least one spray arm extending in the direction of feed of the conveyor, and including an upstream row of fragmenting nozzles and a downstream row of eroding nozzles, the tilting means including an axle extending transversely relative to the direction of feed, and supported on a trunnion arrangement, and actuating means for tilting the nozzles on the axle and adjusting the distance between the nozzles and the conveyor, and the transverse moving means includes a support frame carrying the trunion arrangement on a free end thereof and pivot assembly for pivoting the support frame at a fixed end thereof about a substantially vertical axis so that the spray arm describes a transverse arc of coverage.

Alternatively, the spray manifold is supported on an overhead rotor arm assembly which rotates the spray manifold through 360° above the conveyor.

Conveniently, a pair of rotary spray manifolds are mounted rotatably towards opposite ends of the overhead rotor arm, the conglomerate processing apparatus including rotary drive means for rotating both the overhead rotor am and the rotary spray manifolds in concert. - 4

In one form of the invention, rotary spray manifold comprises a manifold nozzle arm having a double arrowhead configuration.

Alternatively, each rotary spray manifold comprises a manifold nozzle disc carrying a plurality of eroding and/or fragmenting nozzles.

One rotary spray manifold may carry the array of fragmenting nozzles, and the other rotary spray manifold may carry the array of eroding nozzles.

Alternatively, the arrays of eroding and fragmenting nozzles are arranged in an alternating or other predetermined configuration on each of the spray manifolds.

Conveniently, the eroding and fragmenting nozzles are tilted at a fixed angle to the vertical.

In one form of the invention, a manifold bar carrying an array of nozzles extends transversely relative to the direction of feed and is located downstream of the spray manifold.

The manifold bar may carry an array of eroding nozzles, and the spray manifold may carry an array of fragmenting nozzles.

The conveyer may be provided with perforations sized to allow the passage of the binding medium once it has been washed off the particles.

The invention extends to a method of processing a conglomerate comprising a conglomerate of particles loosely bound together by a binding medium, the method comprising the steps of feeding the conglomerate onto a moving conveyer, directing a first array of high intensity fluid jets onto the conglomerate, the fluid jets being arranged to break up the conglomerate, and directing a second array of lower intensity fluid jets onto the broken up conglomerate, the second array of fluid jets being arranged to erode the binding medium from the particles to expose them for further processing.

In one form of the invention, the method includes the steps of moving the first and second arrays of fluid jets in a direction transverse to the direction of feed of the conveyer, and adjusting the tilt angle of the fluid jets so as to provide full coverage of the conglomerate as it travels along the conveyor.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a schematic top plan view of a first embodiment of a conglomerate processing apparatus of the invention;

Figure 2 shows a schematic side view of the conglomerate processing apparatus of Figure 1;

Figure 3 shows a more detailed schematic top plan view of a typical spray manifold forming part of the conglomerate processing apparatus of Figures 1 and 2;

Figure 4 shows a side view of the spray manifold of Figure 3; Figure 5 shows a pictorial view of a second embodiment of a conglomerate processing apparatus;

Figure 6 shows a more detailed pictorial view of a spray manifold used in the conglomerate processing apparatus of Figure 5;

Figure 7 shows a partly schematic underplan view of the spray manifold of Figure 6;

Figure 8 shows a pictorial view of a third embodiment of a conglomerate processing apparatus of the invention; and

Figure 8A shows a partly schematic underplan view of a nozzle disc or head forming part of the spray manifold of Figure 8.

DESCRIPTION OF EMBODIMENTS

Referring first to Figures 1 and 2, a conglomerate processing apparatus 10 includes a moving belt conveyer 12 having an upstream end 14 and a downstream end 16, with the direction of feed being indicated by arrow 18. Conglomerations of ore particles bound together by clay 20 and having an average conglomerate size ranging from 150mm to 300mm are fed onto the upstream end of the conveyer and are conveyed downstream for further processing.

A spray manifold 22 is carried on a pair of swing arms 24 arranged in a V- configuration, with the arms 24 in turn being mounted to a pivot assembly 26 which houses a reciprocating motor 29 which pivots the arms 24 and the manifold 22 in the direction of arrows 30, transverse to the direction of feed 18. The pivot assembly is carried on a support frame 32 which is covered by a cowling 34.

The spray manifold 22 is illustrated in more detail in Figures 3 and 4, and comprises an H-shaped frame 36 which is journalled to a pair of trunnions 38 via a central shaft 40, with the trunnions 38 in turn being mounted to the arms 24. A high pressure hose coupling 42 carrying water at a pressure of 30 to 60 MPa communicates with two upstream rows of fragmenting nozzles 44A and 44B and with two downstream rows of eroding nozzles 46A and 46B. The nozzles 44A and 46A are raised to a height of 200mm to 400mm above the level of the conveyer 12. It is clear from Figure 4 that the upstream rows of fragmenting nozzles are arranged to spray high pressure narrow beam parallel water jets 48 having a beamwidth as close to 0° as possible, whereas the eroding nozzles 46A are arranged to spray fanned water jets 50 having a relatively broad beamwidth of 5° to 15°, and preferably of 10°. The fragmenting nozzles 44A have a diameter ranging from 2mm to 3.5mm. and the erosion nozzles 46A have a diameter ranging from 1.5mm to 3mm. As the conglomerated lumps 20 travel underneath the intense water jets 48, they are fragmented or broken up into smaller clusters or particles surrounded by some clay. The conveyer belt 12 is provided with a matrix of perforations 52 which typically have a diameter of 1mm to 3mm, which allows the resultant clay and water slurry to wash through the perforations, whilst being sufficiently small to prevent the passage of ore recoverable particles.

The broken up conglomerate then travels underneath the broader bandwidth and more gentle fanned eroding jets 50, which have the effect of eroding or 8 -

washing away most of the remaining clay from the ore particles 54.

In addition to the transverse arcing movement of the spray manifold 22 in the direction of arrows 30, the spray manifold is also able to tilt about an axis defined by the axle 40 in the direction of arrows 55. The tilt angle is controlled by means of an hydraulic reciprocating ram 56 which is mounted to the overhead frame 32. By tilting the spray manifold, the distance between the different spray jets and the conglomerate can be controlled, which effectively controls the intensity of the jets. By way of example, in the case of a conglomerate which is more firmly bound together, the spray manifold may be tilted so that its upstream end is closer to the conveyer belt 12, as a result of which the more intense fragmenting jets 48 come into closer contact with the conglomerate. The angle at which the jets strike the conglomerate is also varied by the tilting of the manifold, thereby increasing the effective area of coverage and angles of attack of the jets. Similarly, the downstream end of the manifold can be tilted downwards in a situation where significant quantities of clay still remain on the broken up conglomerate, thereby increasing the intensity of the eroding nozzles as well as their effective direction.

Referring now to Figure 6, a second embodiment of a conglomerate processing apparatus 60 is shown which includes a moving belt conveyer 62 having an upstream feed end 64 and a downstream end 66. The moving belt conveyer is divided into troughs 68 by transverse partition walls 70 and side walls 72 to contain the consolidated clay particles, ore particles and slurry, with the clay slurry draining through perforations in the belt conveyer similar to the perforations 52 in Figure 1 and out through an exit aperture 74 at the base of the conveyer. The belt conveyer is conventional, in that it has an upstream drive roller driven by a motor 76 via a reduction box 78, and an adjustable downstream idler roller 80. An overhead spray manifold assembly 82, which is illustrated in more detail in Figures 6 and 7, includes a central rotor arm assembly 84 which is mounted rotatably about a central drive shaft 86 extending vertically from an overhead gantry 88. The drive shaft is driven by a motor 90 via a drive chain or belt, which is indicated in broken outline at 92. The drive shaft 86 is in turn arranged to rotate the rotor arm assembly 82 about a vertical axis 94.

As is clear from Figures 6 and 7, manifold nozzle arms 96 and 98 are mounted rotatably to opposite ends of the rotor arm 84 on hollow vertical side shafts 100. The side shafts 100 are arranged to rotate in concert with the central hollow drive shaft 86 via a pulley assembly 102 including drive chains or belts 104 and 106, whereby rotation of the drive shaft 86 in the direction of arrow 108 will cause the side shafts 100 to rotate in the same direction indicated by arrows 110 to rotate the manifold nozzle arms 96 and 98. Each of the manifold nozzle arms 96 and 98 have a double arrowhead configuration, with an array of nozzles 112A, 112B, 112C, 112D, 112E, 112F, 112G and 112H extending downwardly from the arm 96. A similar array of nozzles 114A, 114B, 114C, 114D, 114E, 114F, 114G and 114H extends downwardly from the underside of the manifold nozzle arm 98, and have the same configuration as nozzles 112A to 112H. Pressurized water is fed to the nozzles via the hollow shafts 86 and 100, which incorporate rotary seals (not shown).

In one version of the invention, all of the nozzles 112A to 112H are fragmenting nozzles, and the nozzles 114A to 114H are eroding nozzles. Alternatively, eroding and fragmenting nozzles may alternate on each manifold nozzle arm. For instance, the nozzles 112A, 112C, 112E and 112G 10 -

may be fragmenting nozzles, and the nozzles 112B, 112D. 112F and 112H may be eroding nozzles, with the same arrangement being applicable with respect to the nozzles 114A to 114H. In a yet further alternative, the cluster of nozzles 112A to 112D may be eroding nozzles, and the cluster of nozzles 1 12E to 112H on the opposite arrowhead may be eroding nozzles. The nozzles are angled inwardly towards the side shafts 100 at an angle of 5 to 15°, and preferably at an angle of 10° to the vertical. It is not necessary to adjust the angle of the nozzles during the fragmenting and eroding process, as the rotary motion of the nozzles ensures that, even though the angle of attack remains the same, the consolidated clay particles are attacked from all sides by the rotating fragmenting and eroding jets as they travel along the conveyer belt. It is clear from Figure 7 that the spray manifold of Figure 6 provides comprehensive coverage of the conveyor belt, with the individual manifold nozzle anus 96 and 98 having respective circular loci 96A and 98A when stationary, and an effective circular locus 115 when rotated on the rotor arm 84.

A downstream gantry frame 116 may be fitted with a tilted manifold bar 118 carrying an array of eroding nozzles 120 which are angled upstream at 10° to the vertical to erode the remains of clay adhering to the ore particles after the consolidated clay particles have been broken up and most of the clay has been removed by virtue of the rotary spray manifold assembly 82. In the case of a downstream array of eroding nozzles 120, all of the upstream nozzles 112A to 112H and 114A to 114H may be fragmenting nozzles.

Referring now to Figures 8 and 8A, an alternative embodiment of a conglomerate processing apparatus 120 is shown. For the sake of clarity, the main drive motor and pulley assembly have been removed. A rotary spray 11

manifold assembly 122 has a similar configuration to the spray manifold 82 of Figure 6, save that the manifold arms 96 and 98 are replaced by manifold discs 124 and 126. As is clear from Figure 8A, an array of evenly spaced nozzles 128A, 128B, 128C, 128D, 128E, 128F, 128G and 128H are positioned on the underside of the outer periphery of each of the discs 124 and 126. The nozzles are angled inwardly or outwardly at 10°, and, as was the case with the nozzles illustrated in Figures 6 and 7, fragmenting and eroding nozzles may alternate, or may be arranged in clusters such as nozzle clusters 128A to 128D and 128E to 128H. High pressure couplings 130 are arranged to be fitted with high pressure hoses for directing water into each of the manifold discs 124 and 126.

Claims

12 CLAIMS

1. A conglomerate processing apparatus for processing a conglomerate of particles bound together by a binding medium, the apparatus comprising a moving conveyer having an upstream end for receiving the conglomerate, a downstream end, a first array of fragmenting nozzles for directing a corresponding series of fragmenting fluid jets onto the conglomerate to break it up, and a second array of eroding nozzles for directing a corresponding series of eroding fluid jets for eroding the binding medium from the broken up conglomerate to expose the individual particles.

2. A conglomerate processing apparatus according to claim 1 in which the first array of fragmenting nozzles is configured to supply relatively narrow beam high intensity fluid jets, and the second array of eroding nozzles is configured to supply relatively broad beam lower intensity fluid jets.

3. A conglomerate processing apparatus according to either one of the preceding claims in which nozzle directing means are provided for controlling the movement and direction of the fragmenting and eroding fluid jets.

4. A conglomerate processing apparatus according to either one of claims 2 or 3 in which the fragmenting and eroding nozzle arrays are incorporated in at least one spray manifold.

5. A conglomerate processing apparatus according to claim 4 in which 13

the nozzle directing means includes transverse moving means for moving the spray manifold in a direction transverse to the direction of feed of the conveyer, and tilting means for adjusting the angle of tilt of the nozzles and/or the height of the nozzles above the conveyer.

6. A conglomerate processing apparatus according to any one of the preceding claims in which the first array of fragmenting nozzles is upstream of the second array of eroding nozzles.

7. A conglomerate processing apparatus according to any one of the preceding claims in which the eroding nozzles are arranged to spray a fanned fluid jet having beamwidth ranging from 5° to 15°.

8. A conglomerate processing apparatus according to claim 7 in which the eroding nozzles are arranged to spray a fanned jet having a beam width of approximately 10°.

9. A conglomerate processing apparatus according to any one of the preceding claims in which the fragmenting nozzles are arranged to spray a fluid jet which is substantially parallel, having a beamwidth of approximately 0°.

10. A conglomerate processing apparatus according to claim 5 in which the spray manifold comprises at least one spray arm extending in the direction of feed of the conveyor, and including an upstream row of fragmenting nozzles and a downstream row of eroding nozzles, the tilting means including an axle extending transversely relative to the direction of feed, and supported on a trunnion arrangement, and 14

actuating means for tilting the nozzles on the axle and adjusting the distance between the nozzles and the conveyor.

11. A conglomerate processing apparatus according to claim 10 in which the transverse moving means includes a support frame carrying the trunion arrangement on a free end thereof and pivot assembly for pivoting the support frame at a fixed end thereof about a substantially vertical axis so that the spray arm describes a transverse arc of coverage.

12. A conglomerate processing apparatus according to claim 4 in which the spray manifold is supported on an overhead rotor arm assembly which rotates the spray manifold through 360° above the conveyor.

13. A conglomerate processing apparatus according to claim 12 in which a pair of rotary spray manifolds are mounted rotatably towards opposite ends of the overhead rotor arm, the conglomerate processing apparatus including rotary drive means for rotating both the overhead rotor arm and the rotary spray manifolds in concert.

14. A conglomerate processing apparatus according to claim 13 in which each rotary spray manifold comprises a manifold nozzle arm having a double arrowhead configuration.

15. A conglomerate processing apparatus according to claim 13 in which each rotary spray manifold comprises a manifold nozzle disc carrying a plurality of eroding and/or fragmenting nozzles. - 15

16. A conglomerate processing apparatus according to either one of the preceding claims 14 or 15 in which one rotary spray manifold carries the array of fragmenting nozzles, and the other rotary spray manifold carries the array of eroding nozzles.

17. A conglomerate processing apparatus according to claim 16 in which the arrays of eroding and fragmenting nozzles are arranged in an alternating or other predetermined configuration on each of the spray manifolds.

18. A conglomerate processing apparatus according to any one of the preceding claims 12 to 17 in which the eroding and fragmenting nozzles are tilted at a fixed angle to the vertical.

19. A conglomerate processing apparatus according to any one of the preceding claims 12 to 18 in which a manifold bar carrying an array of nozzles extends transversely relative to the direction of feed and is located downstream of the spray manifold.

20. A conglomerate processing apparatus according to claim 19 in which the manifold bar carries an array of eroding nozzles, and the spray manifold carries an array of fragmenting nozzles.

21. A conglomerate processing apparatus according to any one of the preceding claims in which the conveyer is provided with perforations sized to allow the passage of the binding medium once it has been washed off the particles. 16 -

22. A method of processing a conglomerate comprising a conglomerate of particles loosely bound together by a binding medium, the method comprising the steps of feeding the conglomerate onto a moving conveyer, directing a first array of high intensity fluid jets onto the conglomerate, the fluid jets being arranged to break up the conglomerate, and directing a second array of lower intensity fluid jets onto the broken up conglomerate, the second array of fluid jets being arranged to erode the binding medium from the particles to expose them for further processing.

23. A method according to claim 22 which includes the steps of moving the first and second arrays of fluid jets in a direction transverse to the direction of feed of the conveyer, and adjusting the tilt angle of the fluid jets so as to provide full coverage of the conglomerate as it travels along the conveyor.