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Title:
A RAGGING BED WITH BARRIER FOR USE IN A SEPARATION APPARATUS
Document Type and Number:
WIPO Patent Application WO/2016/176713
Kind Code:
A1
Abstract:
The present invention is a ragging bed for use in a separation apparatus including a screen having a plurality of chambers that are created by a plurality of intersecting weirs. Each of the chambers includes ragging having a particular size, shape, quantity and specific gravity, that best sui ts the qualities of the material being separated, so that the entire effective area of the screen is covered by a plurality of chambers, and each chamber on the screen has a specific separation characteristic derived from the type of ragging contained within that particular chamber. The ragging bed also includes a plurality of barriers that extend upwardly from the top of at least some of the weirs, for a sufficient distance, in order to mitigate the likelihood of migration of individual pieces of ragging away from the chamber in which it belongs.

Inventors:
LEWIS-GRAY, Alexander, Hamilton (321 Learmonth Road, Ballarat, Victoria 3350, AU)
Application Number:
AU2016/000146
Publication Date:
November 10, 2016
Filing Date:
April 29, 2016
Export Citation:
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Assignee:
GEKKO SYSTEMS PTY LTD (321 Learmonth Road, Ballarat, Victoria 3350, AU)
International Classes:
B07B1/46; B03B4/02; B03B5/24; B07B1/28; B07B13/14
Foreign References:
US5616245A1997-04-01
US4310413A1982-01-12
US6286686B12001-09-11
Attorney, Agent or Firm:
ANDERSON, Stephen (Morcom Pernat, Suite 10 475 Blackburn Roa, Mount Waverley Victoria 3149, AU)
Download PDF:
Claims:
Claims

1. A ragging bed for use in a separation apparatus including a screen having a plurality of chambers that are created by a plurality of intersecting weirs, wherein each of the chambers incl udes ragging havi ng a particular size* shape, quantity an d speci fic gravity, which best suits the qualities of the material being separated, so that the entire effective area of the screen is covered by a plurality of chambers,, and each chamber on the screen has a specific separation characteristic deri ved from the type of ragging contained within that particular chamber, and wherein the ragging bed also includes a plurality of barriers that extend upwardly from the top of at least some of the weirs, for a sufficient distance, in order to mitigate the likelihood of migration of individual pieces of ragging away from the chamber in which it belongs.

2. A ragging bed as defined in Claim 1 , wherein the bed is used to separate material that is incorporated into a slurry.

3. A ragging bed as defined in either Claims 1 , wherein each barrier is a mesh having a plurality of apertures, and the size of the aperture is selected for a particular chamber so that it prevents any individual pieces of ragging from passing through any of the apertures in the selected mesh, while allowing the slurry to pass through said apertures and into a neighbouring chamber.

4. A ragging bed as defined in Claim 1 , wherein the height that the barrier extends above its respective weir is selected to exceed the travel distance of any of the individual pieces of ragging in the particular chamber.

5. A ragging bed for a mineral separation apparatus having a separation bed including:

at least two weirs, and

a screen, and

a distribution pot, and ragging, and

barrier means,

wherein the at least two weirs are included upon the screen, and the distribution pot is positioned centrally upon the screen, and the at least two weirs combine with the side wall of the distribution pot to create radially adjacent regions into which sufficient ragging is loosely placed and contained, and each region may have a different separation characteristic that is determined by the type of ragging selected to occupy that particular region, and wherein the barrier means extend upwardly from at least one of t he weirs, and is fabricated out of a suitable mesh, and wherein the aperture of the mesh is selected so that any particular piece of ragging that might be flung against the barrier is too big to pass through said aperture, and said ragging is therefore confined within its respective region, but also large enough so that the material that is to be separated by the apparatus can pass through the barrier into an adjacent region. 6. A ragging bed as claimed in Claim 5, wherein the bed is circular shaped.

7. A ragging bed as claimed in Claim 5, wherein the weirs are located at a plurality of radial distances from the distribution pot and each extends in a circular direction to create radially adjacent concentric weir rings, and the regions are defined between adjacent weir rings, and the regions effectively cover the entire area of the screen between the sidewall of the distribution pot and the outer periphery of the screen.

8. A ragging bed as claimed in Claim 7, wherein the location of the weirs are radially evenly spaced between the periphery of the distribution pot and the periphery of the screen .

9. A ragging bed, as claimed in either claim 7 or claim 8, wherein a plurality of additional weirs are Included upon the screen that extend radially to the outer periphery of the screen from the distribution pot, and intersect with the circumferentially extending weirs, to thereby create a plurality of chambers within each region.

10. A raggmg bed as claimed in Claim 9, wherein the bed is forcefully and quickly vibrated in order to vibrate the screen and agitate the ragging within each respective chamber. 11. A ragging bed as claimed in Claim 9 wherein the height that the barrier means extends above its respective weir; whether that is a circumferentially directed weir; or a radial directed weir, is selected to best suit the travel distance of any of the individual pieces of ragging in the particular chamber, so that the ragging is confined to the particular chamber it is meant to occupy.

Description:
A Ragging Bed with Barrier for use in a Separation Apparatus Field of the Invention litis invention relates to separation apparatus for use in mineral processing. Background of the Invention

Mineral ore separation is an. important function within a broader mineral processing plant The efficiency, size and weight are critical factors, particularly on sites where space is limited.

One type of separation apparatus uses a screen with a bed of ragging resting upon it. The screen is vibrated with sufficient force and frequency to cause the individual pieces of ragging to become agitated and to bounce around upon the screen. As they bounce, they collide against adjacent .ragging pieces and against the material being separated. The basic idea is that material having a higher specific gravity (SG) than the ragging, be that ore or gangue, will sink through the ragging bed and pass through the screen, and the material with lower SG than the ragging is only able to "float*' upon the agitated mass of ragging pieces.

In an associated application, the inventor has disclosed an invention directed to the creation of a separation bed having multiple regions that each have a different separation characteristic. This is achieved by creating chambers that each contain ragging that has specific characteristics, such as shape, size, quantity and specific gravity. Typically, the material to be separated is entrained in water to create a slurry. The basic principle is that the separation of the material occurs in stages, In the example where the ore has a heavier SG than the ragging, and the gangue has a lower SG, when the first stage of separation is completed, the remaining slurry has been modified because the concentration of ore in the slurry will have diminished, and the concentration of gangue will have increased. This modified slurry then passes onto the next stage in the separation process where it engages with a different ragging bed having different separation characteristics, courtesy of the use of different ragging.

One of the problems associated with this technology is the problem of ragging migration. This problem occurs when an individual piece of ragging is able to jump from -the chamber in which it is supposed to be, across into a. neighboring chamber. This may diminish the efficiency of the separation apparatus in several ways. Firstly, each chamber needs a minimum number of ragging pieces, of the correct type for that zone of the screen, to function effectively. If sufficient numbers of ragging pieces migrate away from the chamber, then the efficiency of that chamber is diminished. Secondly, if a particular chamber on the screen is the recipient of migrating ragging pieces, then the number of ragging pieces in that chamber may increase to such an extent that it takes too long for the material with a larger SG to pass through it, and again the efficiency of that chamber is diminished. Thirdly, in the case where multiple chambers exist that have different physical characteristics, such as size, shape, and specific gravity, then the inclusion of ragging pieces that do not conform to the ragging pieces meant to be in. that chamber also causes the efficiency of that chamber to diminish. Mineral processing is often a high volume low margin endeavor. Separation apparatus is a vital component in the entire process, so it is important that it can handle the required throughput within the required efficiency range to keep the site profitable . it is a goal of the present in vention to ameliorate at least some of the aforementioned problems.

Disclosure of the Invention

Accordi ngly in one aspect, the present in vention is a ragging bed for use in a separation apparatus including a screen having a plurality of chambers that are created by a plurality of intersecting weirs. Each of the chambers includes ragging having a. particular size, shape, quantity and specific gravity, that best suits the qualities of the material being separated, so that the entire effective area of the screen is covered by a plurality, of chambers, and each chamber on the screen has a -specific separation characteristic derived from the type of ragging contained within that particular chamber. The ragging bed also includes a plurality of barriers that extend upwardly from the top of at least some of the weirs, for a sufficient distance, in order to mitigate the likelihood of migration of individual, pieces of ragging away from the chamber in which it belongs.

Preferably the bed is used to separate material that is incorporated, into a slurry.

Preferably each barrier is a mesh having a plurality of apertures, and the size of the aperture is selected for a particular chamber so that it prevents any individual pieces of ragging from passing through any of the apertures in the selected mesh, while allowing the slurry to pass through said apertures and into a neighbouring chamber.

Preferably the height that the barrier extends above its respective weir is selected to exceed the travel distance of any of the indi vidual pieces of ragging in the particular- chamber.

In an alternative embodiment, the present invention is a ragging bed for a mineral separation apparatus having a separation bed including:

at least two weirs, and

a screen, and

a distribution pot, and

ragging, and

barrier means,

wherein the at least two weirs are included upon the screen, and the distribution pot is positioned centrally upon the screen, and the at least two weirs combine with the side wall of the distribution pot to create radially adjacent regions into which sufficient ragging is loosely placed and contained, and each region may have a different separation characteristic that is determined, by the type of ragging selected to occupy that particular region. The barrier means extend upwardly from at least one of the weirs, and is fabricated out of a suitable mesh. The aperture of the mesh is selected so that any particular piece of ragging that might be flung against the barrier is too big to pass through the aperture, and the ragging is therefore confined, within its respective region, but also large enough so that the material that is to be separated by the apparatus can pass through the barrier into an adjacent region.

Preferably the ragging bed is circular shaped.

Preferably the weirs are located at a plurality of radial distances from the distribution pot and each extends in a circular direction to create radially adjacent concentric weir rings, and the regions are defined between adjacent weir rings, and the regions effectively cover the entire area of the screen between the sidewall of the distribution pot and the outer periphery of the screen. Optionally the location of the weirs are radially evenly spaced between the periphery of the distribution pot and the periphery of the screen.

Preferably, the ragging bed has a plurality of additional weirs rackided upon the screen that extend radially to the outer periphery of the screen from the distribution pot, and intersect with the circumferentially extending weirs, to thereby create a plurality of chambers within each region.

In operation, the bed is forcefully and quickly vibrated in order to vibrate the screen and agitate the ragging within each respective chamber.

Preferably the height that the barrier means extends above its respective weir, whether that is a circumferentially directed weir, or a radial directed weir, is selected to best suit the travel distance of any of the individual, pieces of ragging in the particular chamber, so that the ragging is confined to the particular chamber it is meant to occupy. Brief Description of the Drawings

Figure 1 is a cut-away isometric view of a pressurised separation apparatus using a ragging bed with barriers in accordance with the present invention.

Detailed Description of the Preferred Embodiments

In Figure 1 we are shown a cut-away of a piece of pressurised separation apparatus 1 used in mineral processing. The apparatus 1 includes an outer body 3 and an inner body 5. A gap 7 is maintained between the sidewalk of the outer and inner bodies. At the top of the inner body 5 is a separation bed 9. There are a pl ural ity of spaced apart concentric circular shaped weirs 1 1.

A distribution pot 13 is located in the centre of the separation bed 9.

The regions created between an adjacent pair of weirs ! L or between the sidewail of the distribution pot 13 and its adjacent weir 1 1 creates a chamber.

The material to be separated by the apparatus 1 is typically entrained in a liquid to create a slurry. The slurry is fed into the apparatus 1 via the slurry inlet port 15 which is centrally located above the distribution pot 13. The size and shape of the distribution pot 13 is specifically designed to redirect the flow of slurry so that its gets effectively evenly distributed over the innermost ring of chambers adjacent the distribution pot 13, Optionally a plurality of radially oriented weirs (not shown) can extend out to the periphery of the bed 9 from the distribution pot 13. These radial weirs intersect with the circular weirs to create a plurality of chambers within each concentric ring.

A suitable quantity of ragging having the best physical characteristics, such as size, shape, quantity and specific gravity (SG) are placed inside each chamber.

The separation bed.9 is then vigorously vibrated in order to cause the individual pieces of ragging to become agitated. This causes the individual pieces of ragging to bounce ground and to collide with the screen and the weirs of the particular chamber it is confined in, and against one another.

Sometimes an individual piece, or pieces of ragging is impacted with sufficient force to enable it to clear th e height of the weir. In other circumstances, the individual piece, or pieces may get carried along by the flow of the slurry.

In order to prevent any of the pieces of ragging moving out of its appropriate chamber into an adjacent chamber, a plurality of barriers 17, here shown only on the circular shaped weirs 11, are included. The barrier 17 is fabricated from a suitable mesh. The size of the aperture included in the mesh is selected to be too small to allow an indi vidual piece of raggi ng to pass through, but is still large enough to allow the slurry to flow through. For additional clarity, it must be noted that not only can the circular weirs 11 have the barriers 17 included on top of them, but also if radial w eirs are utilized in the separation bed 9, then they can also.

Each chamber on the separation bed 9 can have different separation characteristics depending on the quantity and physical characteristics of the ragging used in that particular chamber. This means that some chambers may include pieces of ragging that are able to be flung higher than the ragging pieces used in other chambers. Or some chambers may include pieces of ragging that are l ight enough to be carried a way by the flow of the slurry. The height of the barrier that can be included can be chosen to ensure that the possibility of a piece of ragging either being flung out of, or carried a way from the c hamber it is meant to be in is reduced by the action of the barrier.

While the above description includes the preferred embodiments of the in vention., it is to. be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention.

It will be also understood that where the word "comprise" and variations such as "comprises" and "comprising" , are used in this specification, unless the context reqoires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features .

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge.