AU2005248955A1 - Sorting Assembly - Google Patents

Description

28/12 '05 WED 16:50 FAX 61 8 82119433 Leslcar Perrin Z 003 11445AU(1)

ORIGINAL

Complete Specification Applicant: Title: Opdetech Pty Ltd Sorting Assembly Address for Service: LESICAR PERRIN, 49 Wright Street, Adelaide, South Australia 5000, Australia The following statement is a full description of this invention, including the best method of performing it known to me/us: COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED~ 16:50 FAX 61 8 82119433 LscrPri 0 Lesicar PerrIn Z 004 o 2 Sorting: Assembly 00 ci The present invention relates to a sorting assembly and, in particular, to a mechanical sorting assembly adapted for use in the separation of ores containing valuable inenrals from host tfl materiail.

00 5 BACKGROUND OF THE INVENTION o The sorting assembly of the invention is directed to the sorting of mining ore that contai ns opal fr-om. mining ore that does not, according to the amount of visible light the opal radiates subsequent to being exposed to ultraviolet light. However, it is to be understood that the assembly may well be used to sort any object according to various other characteristics. For example, the sorting assembly may be used to sort fruit according to their different sizes whereby the wei gin of the fruit at a particular section of the belt is measured.

Opal sorting machines are well known and rely on the fact that opal absorbs electrmagnetic radiation in the ultra-violet part of the spectrum that is then re-radiated as visible light at a wavelength typically around 470 urn. The half-life time of this re-radiation is some 4 seconds.

This property is currently exploited whereby mined ore containing opal and other mateial, including dust and rocks, is placed on a moving belt in a dark room where the ore is exposed to ultraviolet radiation. As the belt moves out of the ultraviolet irradiating zone it reradiates in the visible spectmum where human operators then select and retrieve the opal bearing rocks. Typically, an opal-sorting table includes a number of human operators located around the belt whose task is to handpick the radiating opal. This procedure is commonly referred to as noodling.

As Ia consequence of the use of human operators it is well accepted that the efficiency of noodling, in terms of the opal that is collected is of the order of some There are a number of limitations to this method. Not only is the cost of human operators relatively high, but also people tend to make mistakes and do get tired, resulting in the efficiency COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:50 FAX 61 8 82119433 Leslcar Perrln @00 83 o of selecting the opal bearing rocks diminishing over time. Further still, in cases where there may be a range of sizes of opal or opal slivers moving down the belt, human operators will typically 00 collect the larger fragments, resulting in the smaller fragments not being collected. In addition, at times, where there may be a large number of opal stones and slivers moving down the belt, human operators may simply not be able to retrieve all the radiating stones.

Automatic sorting tables have been proposed where optical detectors are used to 00 discriminate between the opal and other material. Sorting is typically achieved with the use of In an air pulse as a detected stone falls off the belt to force the stone into a collection bin. There are o numerous problems with the use of such an assembly. One of the more common ones is the fact 10 that the use of an air pulse causes dust and other light particles to be raised into the air. Further, use of an air pulse not only separates the opal stones and slivers but other particulates since the air pulse has a certain minimum depth or length.

In addition the light detection means in these tables are not able to localise any existing stones, the optical detection means having a large field of view. Other problems of using such tables also includes the fact that the optical detectors are not extremely sensitive, this exacerbated by the conditions under which these tables may be required to operate, including high temperatures and vibrations. Furthermore, contaminating elements such as light, dust and other particles often affect the detection area.

A solution to the problems arising from contaminating elements is offered in a copending application and is also referred to in the following description.

A further difficulty with current noodling methods is the fact that mullock, the byproduct of opal mining within which is still to be found a fair percentage of opal, comes in a range of sizes. Using one table to sort out opal from different size other materials is not optimal for different sized materials requires different tuning of optical detection techniques as well as different means to physically separate the opal from the rest of the material.

It is an object of the present invention to provide for a sorting assembly that overcomes at least some of the abovementioned problems, or provides the public with a useful alternative. It is a further object of the present invention to provide for a system wherein multiple assemblies can be. used, each assembly pre-tuned to different sized objects.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:51 FAX 61 8 82119433Lsca PrinLO0 Les1car PerrIn [a 006 o 4 The sorting assembly of the present invention relies upon a flipper mechanism that is pivotably controlled between a first position defining a first trajectory, and at least one second 00 position defining at least one second trajectory. The mechanism is controlled by both the detected characteristic of the object and the speed that the object is being transported, thereby effectively sorting a plurality of objects of varying characteristics into corresponding chutes.

C* SUMMARY or6 THE INVENTION 00 Therefore in one form of the invention there is proposed a sorting assembly including: 0 a sorting assembly adapted to select and separate objects identified as having pre-detennined desired characteristics from a collection of objects, wherein said assembly includes means to controllably direct a path of each object having said pre-deterinined desired characteristics between one of a first trajectory and at least one second trajectory- Preferably, said assembly further includes a detection means for detecting at least one predetermined desired characteristic in any object ini a collection of objects, and wberein said detectio-n means co-operate with said means to controllably direct a path of each object such 1$ that objects having said pme-determined desired characteristics are directed to a common trajectory to thereby separate said selected objects.

Preferably, said means to contr-ollably clireer a path of object having said pre-dctcrmined desired characteristics includes a flipper mechanism operative in response to a control means, said flipper mechanism being movable between a first position directing an object to the first trajectory and at least one second position directing an object to a second trajectory.

Preferably, said assembly further includes transport means adapted to transport said objects to said flipper mnechanismn said transport means including a sensor capable of measuring the speed of the transport means.

Preferably, the control means operate in connection with the means to controllably direct a path of each object, the detection means and the sensor means to thereby select a speed and trajectory for objects having pre-determnined desired characteristics.

In a preferred form of the invention the object is a piece of mined Ore.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:51 FAX 61 8 82119433 Leslear Perrin Z 007 o 0 Preferably, said pre-determined characteristic is the amount of light emitted from opals that C)have been subjected to ultraviolet radiation.

00 Preferably, the position of said flipper mechanism is changed using an air solenoid controlled by said control means.

Preferably, said assembly further includes a plurality of said flippers.

00 Preferably, said transport means is a conveyor belt.

In one form of the invention, the sorting assembly includes a hopper adapted to receive omullock, said mullock being transported to a dust trommel to separate mullock from dust, said dusted mullock farther being transported to a sorting trommel including a plurality of sorting means to separate the dusted mullock into different size range, each sorting means connected to a chute to feed the particular size range to said transport means, Preferably, said hopper includes a grizzly.

Preferably, said sorting trommel includes a hollow rotating cylinder having an outer skin having multiple apertures, said trommel having several different sized apertures extending longitudinally across said trommel and adapted to allow for different size particles of the mullock falling therethrough.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention. In the drawings, Figure 1 is a perspective schematic view of a table discrimination apparatus incorporating the sorting assembly of the present invention; Figure 2 is a cross-sectional view of the apparatus of Figure 1; Figure 3 is a partial perspective view of a table discrimination system detailing the light detection and shielding system of the apparatus of the present invention; COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:51 FAX 61 8 82119433 Leslcar Perrln IM008 8 6 U Figure 4 is a partial schematic view illustrating the mechanical flipper used to separate the detected opal from other material; 00 Figure 5 is a perspective schematic view of the assembly embodying the present invention; t Figure 6 is a perspective view of the assembly as in Figure 5 detailing some of the internal

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C 5 construction; and 00 Figure 7 is a schematic perspective view illustrating the relative orientation of two o adjoining opal-sorting tables used in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings.

Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.

The drawings illustrate an assembly 10 selecting objects possessing particular characteristics from a group of similar objects the majority of which do not possess special characteristics. In the case of the embodiment under consideration, the objects to be sorted are opal-bearing rocks from non opal-bearing rocks. The assembly 10 is incorporated into an opalsorting table 28 as will be described.

In brief, the objects, or rocks 12 are fed onto a variable s-speed transport means in the form of a conveyor belt 14, the speed of which is subject to control by a control means 16.

Detection means 18, in communication with the control means 16, serves to identify those of the objects 12 having the desired characteristic, in this case the presence of opal within the rock. It is, of course, equally possible that the desired characteristic be a particular size, weight, shape or defect. The control means 16 also controls the operation of a pivoting flipper mechanism positioned at the end of the conveyor belt 14. Under the influence of the control means 16, the flipper mechanism 20 moves between first and second positions thereby allowing objects to move through either a first trajectory 22 or at least one second trajectory 24.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:52 FAX 61 8 82119433 LacrPri 0 Lesicar Perrin Z009 o 7 The control mneans 16 takes into consideration both the speed of the conveyor belt 14 and the measured characteristic obtained by the detection means 18 to effectively control the position of 00 the flipper 26. Jt is to be understood that the flipper 26 may move between more than two Ci positions so as to sort objects into a number of trajectories.

It is important to be aware that the present invention, although described herein as an assembly 10 for the sorting of opal from mnull ock 12, may well be used to sort other objects and 00 its use should therefore not be limited to this process. For example, the detection means 18 may In simply be in the form of a load cell (not shown) that measures the weight of transported fruit and o therefore the control means 16 would then soft the fruit according to their weight.

Figures 1 to 4 illustrate an opal-sorting table 28 including a frame 30, four supporting legs 32, and support beams 34 extending between each adjacent leg 32. Feet 36 on each leg 32 help distribute the weight of the table 28 on a floor.

Rollers 38 and 40 extend along the table 28 and support the conveyor belt 14. A motor (not shown) chives the rollers 38,40 and, in turn the belt 14. Typically, the motor is a hydraulic motor although it may equally well be an electric motor.

Located above and extending perpendicularly above one end of the belt 14 is a longitudinal hopper 42 that is loaded with material 12 to be sorted. A third roller 44 extends longitudinally with the hopper 42 and is in contact with the mnaterial 12. A gap 46 in between the roller '14 and the hopper 42 allows material to pass from the hopper 42 and drop onto the belt 14- By controlling the speed of the roller 44, the operator is able to control the rate of material 12 that drops onto the belt 14. As wi th the conveyor belt 14, a suitable motor drives the roller 4.

In operation the conveyor belt 14 typically moves at a speed of some 1.4 to 2.7 metres per second, the speed limited to the operation of the flippers 26 by solenoids as discussed below.

At timues the speed of the main belt 14 may by synchronised with the speed of the hopper 2$ roller 44. However, at times it my be desirable to vary the speed between the two, that depending on the type of material 12 to be sorted. For this reason the speed of the rollers is controlled independently.

COMS ID No: SBMI-02292392 Received by P1 Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:52 FAX 61 8 82119433 Leslcar Perrln oo 010 o 8 cil It is to be understood that the above process of feeding material 12 onto the belt 14 is d) merely an example of the way in which this process can be carried out and the present invention 00 is not intended to be limited to this example.

The material that passes through the gap 46 and drops onto belt 14 is exposed to t ultraviolet radiation 48 by the use of longitudinal ultraviolet lamps 50 located above the belt 14.

In 0C* A shield 52 extends over the lamps 50 to minimise the amount of radiation 48 that is scattered 00 outside of the shielded area, the lamps 50 and the shield 52 held in place by the use of arms 54 that are attached to frame 30. Any opal then absorbs the ultraviolet radiation 48 and re-radiates 0 light 56 in the visible part of the spectrum.

Located above and towards the other end of the belt are optical sensing devices extending longitudinally across the belt 14. The devices typically include optical detectors 18 that collect radiated light 56 and feed it into an optical to electrical signal converter, such as a photomultiplier tube 58. The optical sensing device 18 is in fact an optical fibre cable. Any detected signal from the photomultiplier 58 is assessed by a suitable control device 60, supplied power from source 62 that is operatively connected to the mechanical flipper 26 by control cable 64.

Each optical sensing device 18 includes its own photomultiplier tube 58 Lhat in turn controls its own mechanical flipper 26. The photo multiplier tubes 58 may be separately cooled to improve their sensitivity. Furthermore, the use of the optical fibre cable allows them to be separated from the rest of the table 28 thereby removing any unwanted vibrations.

The detection means 18 described above is directed solely toward objects that emit light- However, as previously mentioned there are various types of detection means that may be employed depending on the characteristic of the object which the user wishes to measure. A further example of a detection means is simply a camera which is able to detect a defect in an object such as a burnt potato chip.

Typically, there are some twenty flippers 26 extending below and across the front of the belt I4. The flippers are adjacent to each other so that there is a minute gap there in-between, typically of the order of 1-2 millimetres. The flippers are designed to very quickly pivot around pivot point 66. Their position is chosen so that when the flipper 26 has not been activated COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:52 FAX 61 8 82119433 LscrPri 1 Les1car Perrin Roil 0 9 o material transported on belt 14 is cause to fall in trajectory 22 whilst when the flipper 26 has been activated it rotates inwardly and upwardly to deflect material into trajectory path 24.

00 Cl'Those skilled in the art will now appreciate that when one of the detection means 18 detects a particular characteristic of an object 12, such as radiated light 56 from opal, the signal is fed into the control means 60. The control means is semni-intelligent and can calculate, based upon the speed of the belt, which may be measured by an appropriate sensor or timing pulse 68, 00 precisely when it needs to activate the flipper 26 to cause that object 70 that the detection means 18 has detected to possess that characteistic, to be ejected into trajectory 24 where it may then o be collected in a bin 72. Defletion plates 74 and 76 may also be used to collect the flipped or C 10 ejected matarial 70 into the bin 72.

Each flipper is activated by the use of an air solenoid 78 fed air by the use of hoses and 82 that control the air solenoid 78 to extend and retract as desirable. An air supply is provided though regulator 84 as is well known in the art.

Those skilled in the art will appreciate that with a row of flippers extending across the belt 14, different flippers will be caused to operate to ensure that any detected material is collected into bin 72. Other material 86 that is non-radiating then drops onto a further conveyor belt 88 supported at one end by roller 90 to be transported away from the table 28, typically to an area that is some distance away.

To avoid any contaminating light from being detected by the photomultipliers through fibres 18, a shield 92 covers the detection area and the optical detection means 18 extends into shield 92 through aperture or slit 94. A cover 96 houses the ends of the optical detecton means 18S.. A transparent glass or plastic screen 98 protects the optical detection means 18 from any dust or unwanted material and is typically adapted to be easily removable for cleaning. One typical way to be able to do this is to have the screen 98 longitudinally slidabie within a housing 100, the end of the screen 98 reachable through a slot on the side of the shield 92 where it is covered by plate 102. The screen 98 may also include filters adapted to filter out the ultraviolet light that is used to excite the opal in the first instance.

It is obviously quite integral to the operation of the whole of the table 28 that the light that is sensed reaching each optical detector 18 be localised to allow for the fine control of each COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:53 FAX 61 8 82119433 Leslcar Perrin a 0i2 0 Cl flipper 26. For that reason inside the shield 92 that extends towards the centre of the belt 14 are 0 curtains 104 and 106 that further ensure that no other light reaches the optical detector 18.

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Although the curtains 104 and 106 are designed to extend downwardly, they are very light and S can easily:. be swayed to ensue that they do not cause material.12. to be :he: back o the t::t 14.

oo l Finally, although not shown in the embodiment above there may very well be a further table designed to separate particles that are up to 75 mm in size. Such a table may include S flippers that are some 140 mm in length and are some 550 mm in width there being only some two flippers across the table.

Other features that may be changed include the configuration of the flippers as well as the optical detection means. The primary advantage of the present invention is that it improves upon the efficiency of opal separation by using tables that are configured for different size particles by the use of the dust and sorting trommel. The use of multiple tables improves the total amount of mullock that can be passed through the assembly per any given hour. Common use of cooling means that the tables can all operate under optimal conditions. Mounting of the assembly on a trailer means that it can be easily transportable to different sites and especially ones where the mullock has already been rudimentary sorted and where the use of current hand-techniques is no longer economically feasible.

The sorting assembly of the present invention provides for the effective sorting of objects that possess different characteristics to each other by firstly detecting the characteristic and then controllably sorting the objects according to their detected characteristic. Although the description above teaches an entire opal sorting assembly, it is to be understood that this is by way of example only and the sorting assembly of the present invention including the transport means, control means and flipper mechanism may be used in alternate equipment. The present invention also provides a means of initially sorting objects into various size groups prior to being fed to individual sorting assemblies which are pre-tuned in accordance with those size groups.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:53 FAX 61 8 82119433 Leslcar Perrin 013 o 11 0 The belt illustrated in Figure 1 is a V-shaped belt that in some circumstances may have the advantage of ensuring that any material is linearly aligned as it travels down the belt However, the optical devices as used in the present invention are capable of detecting the opal 00 Cl across a flat belt without requiring the use of a grooved belt.

Those skilled in the art will now appreciate that the use of the present invention Sovercomes the problems of separating out opal from rest of the material even where the relative 0 0 sizes and amounts of the opal vary greatly across the belt. The optical devices 18 may further C' include a focal lens (not shown) that can be adjusted to vary the diameter of the area from which O optical light is collected.

The table 28 as proposed in the present invention has increased the efficiency of noodling to levels well above 90% and even close to 98%. This has great economic advantages in that it enables mullock heaps from current opal mining to be thoroughly processed. It also enables mullock that has already been noodled by human operators to be re-noodled to collect and opal that has been missed. With the speed of the belt operating at metres per second, a typical table that has a belt some 1 metre in width can process up to 1 tonne of mullock per minute.

Removing the use of human operators increases the total operating time of such a table without concern of operator fatigue and efficiency.

The provision of a light shelf, curtains, and UV filter means that the photomultiplier tube can detect even a small amount of light Further isolation and cooling of the photomultiplier tubes increase their sensitivity.

The above description detailed the operation and structure of an individual opal-sorting table incorporating the sorting assembly of the present invention. As mentioned above, the optical detectors field of view and size of the flippers need to be able to accommodate different sizes of mullock that passes through the table. In the case where there are a variety of sizes of mullock the efficiency of opal detection may not be as high as it could be if the mullock was more uniform in size. Once again, the following embodiment need not only apply to mullock but any material or object that may vary in size.

Illustrated in Figures 5 to 6 is an assembly embodying the present invention and including a plurality of opal-sorting tables all of which incorporate the sorting assembly of the COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:53 FAX 61 8 82119433 Leslcar Perrin 1014 S12 o present invention. The tables are set in series, wherein each table is pre-set to be able to detect Sopal from mullock of a certain uniform size. The assembly further includes means to separate 0 the mullock into separate sizes as well as to separate the mullock from dust. Finally, the assembly is mounted on a drivable platform and can thus be transported to a desired location where it can be used to sort opal from general mullock.

SReferring to Figures 5 to 6 in detail there is shown a truck trailer 124 mounted at the front 00 on a dolly 126 including wheeled axles 128 with a plurality of wheels 130. The trailer 124 Sfurther includes a wheeled axle 132 at the rear end for supporting the trailer 124. Mounted at the o front of the trailer is a grizzly hopper 134 into which can be loaded mullock 136 using typically a C K- 10 front-end loader 138. The hopper 134 includes a grid 140 commonly known as a grizzly gird that only allows passageway therethrough of particles less than a certain size, typically millimetres and less. The mullock 136 is then transported by a conveyor belt 142 located at the bottom of the V-shaped hopper, the conveyor belt supported by the use of rollers 144. Typically an electric motor is used to drive the conveyor belt although other motors, such as hydraulic motors, could very well be used.

Conveyer belt 142 feeds the mullock 136 from the hopper 134 into a dust trommel 146, the dust trommel including a cylindrical mesh 148 of a fine size through which passes fine and small particles to be discarded from the rest of the mullock 136. Typically the size of the mesh in the dust trommel is of the order of some 7 to 7.5 millimetres. The dust trommel 146 includes a plurality of ribs 150 for structural integrity and is adapted to rotate on a central shaft 152 rotatably driven by an appropriate motor at a speed of up to several revolutions per second.

Any particles and dust that fall out of the dust trommel 146 are collected on a dust conveyor belt 154, shield 156 assisting to direct the fine particles onto the conveyor belt. The conveyor belt 154 then passes through the rest of the trailer 124 until it emerges at the rear end thereof, where it is dropped onto a cross-over conveyor 158 to the tailing conveyor 160 to be disposed of as a sorted mullock heap 162.

The dust trommel 146 angles downwardly and other particles that are larger than the mesh size on the dust trommel 146 fall under gravity into bin 164, bucket elevator 166 than raising the dusted mullock to a sorting trommel 168.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:54 FAX 61 8 82119433 Leslcar Perrin 1015 o 13 0 C IThe sorting trommel is of a cylindrical configuration and includes different sized meshes C) extending around the outer circumference of the sorting trommel 168, the sizes of the meshes increasing down the trommel. The first mesh 170 typically is a grid with spacings some CN millimetres in size enabling particles from around 7 to 10 mm to fall through. Second mesh 172 is typically some 16 mm grid spacings allowing particles up to 16 mm to fall through. Third tf mesh 174 has grid spacings some 25 mm apart allowing particles of up to that size to fall through 01 whilst fourth mesh 176 has grid spacings up to 50 mm allowing particles up to that size to fall through. The different meshes are mounted on a central shaft 178 and are separated by wheels 180 that are attached to the shaft to provide the structural support for attaching the mesh to the shaft.

It is to be understood that it is not the intention to limit the present invention to the particular sizes of mesh as detailed above. The mesh sizes are a general guide only.

Furthennore, it is not intended to limit the invention to four mesh sizes. In fact, the assembly may include more or less different mesh sizes to aid in the separation of the mullock into particular size ranges.

Located below, and coupled with each mesh size, is an opal-sorting table incorporating the sorting assembly of the present invention. Thus, mesh 170 feeds particles of sizes up to mm to table 182, mesh 172 to table 184, mesh 174 to table 186 and mesh 176 to table 188. The tables are all located in a dark room 190 ensuring that no outside light can enter the room, a door providing access (not shown). Each table has a hopper to feed material through chute 192 to ensure that material passing through the mesh is fed into the table hopper 42 only as discussed earlier Mullock that is more than 50 mm in size can either fall into a separate bin subsequent hand sorting. Alternatively, a table adapted for sorting out such large stones (not shown) is used.

Any other material that has not passed though any of the grids then passes out of the sorting trommel to chute 194 where it then falls onto the cross-belt 158 and is removed from the trailer assembly.

Those skilled in the art will now appreciate that the present invention provides for an assembly that can sort opal from other material regardless of the size of the other material by COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:54 FAX 61 8 82119433 Leslcar Perrin o016 o 14 sorting out the material into separate size ranges before it reaches the sorting assembly. Since d the relative range of particles sizes for each table is known beforehand, the configuration of the table can be optimised for that particular size range. Some of the factors that can then be C optimised include the field of view of the optical detectors. Larger particles will require a larger field of view than smaller ones. The width and length of the mechanical flippers may also be varied to suit different particle sizes.

00 The mullock that has had opal removed from it then falls onto a central conveyor belt 196 (equal to the conveyor belt 88 in Figure 1-4) that then conveys the mullock to the crossover belt O 158 for disposal as discussed above.

Illustrated in Figure 7 is a schematic diagram illustrating two opal-sorting tables 28 both of which contain the sorting assembly of the present invention, positioned next to each other, each table configured for a different range of particle sizes. The tables 28 form a part of a larger arrangement of four tables designed to separate opal bearing rocks of differing size ranges.

Located above and extending longitudinally along the trailer is a main duct 196 in which are mounted photomultiplier tubes 58. The main duct 198 allows for the passage of air therethrough providing cooling for the photomultiplier tubes from an air-conditioning means (not shown).

Ducts 200 connect cavities 202 located below the duct 198 within which are located the control systems 60 associated with each photomultiplier tube 58 and flipper 26. Both the main duct 198 and the cavities 202 include transparent doors 204 enabling visual inspection and access to the tubes 58 and control systems As the size range encountered by each table varies, so the size and number of the flippers 26 on each table may vary. For example, a first table separates particles whose size is up to mm uses flippers that are some 110 mm in length and 48 mm wide, with a total of twenty flippers extending across the table. A second table separates particles up to 16 mm in size typically uses flippers that are the same size as the first table. A third table separates particles up to 25 mm in size typically uses flippers that are 120 mm in length and 54 mm in width, there being some 18 flippers across the table. A fourth table separates particles up to 50 mm in size uses flippers that are 140 mm in length and some 65 mm in width, there being 16 flippers across one table.

COMS ID No: SBMI-02292392 Received by IP Australia: Time 18:31 Date 2005-12-28 28/12 '05 WED 16:55 FAX 61 8 82119433 LscrPri 0 Lesicar PerrIn [a 0ol o o Finally, although not shown in the embodiment above there may very well be a further table designed to separate particles that are up to 7/5 mmnini size. Such a table may include oc ~flippers that are some 140 mm.i in length and are some 550 nun iu width there being only some CI two flippers across the table.

V) 5 Other features that may be changed include the configuration of the flippers as well as the C* optical detection means- The primary advantage of the present invention is that it improves upon 00 tbe efficiency of opal separation by using tables that are configured for different size particles by In the use of die dust and sorting trommel. The use of multiple tables improves the total amount of o mullock that can be passed through the assembly per any given hour- Comnmon use of cooling A10 means that the tables can all operate under optimal conditions. Mounting of the assembly on a trailer mecans that it can be easily transportable to different sites and especially ones where the mullock has already been rudimentary sorted and where the use of current hand-techniques is no longer economicaily feasible.

The sorting assembly of the present invention provides for the effective sorting of objects that possess different characteristics to each other by firstly detecting the characteristic and then control lably sorting the objects according to their detected characteristic. Although the description above teaches an entire opal sorting assembly, it is to be understood that this is by way of example only and the sorting assembly of the present invention including the transport means, control means and flipper mechanism my be used in alternate equipment, The present invention also provides a me-ans of initially sorting objects into various size groups prior to being fed to individual sorting assemblies which are pre-tuned in accordance with those site groups.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and descibed in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is -not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

SBMI-02292419 Received by IP Australia: Time 18:35 Date 2005-12-28

Claims (9)

1. 3. A sorting assembly according to claim 1 or claim 2, wherein said means to controllably direct a path of object having said pre-determined desired characteristics includes a flipper mechanism operative in response to a control means, said flipper mechanism being movable between a first position directing an object to the first trajectory and at least one second position directing an object to a second trajectory.
2. 4. A sorting assembly according to claim 3, wherein said assembly further includes transport means adapted to transport said objects to said flipper mechanism said transport means including a sensor capable of measuring the speed of the transport means. A sorting assembly according claim 3, wherein the control means operate in connection with the means to controllably direct a path of each object, the detection means and the sensor means to thereby select a speed and trajectory for objects having pre-determined desired characteristics.
3. 6. A sorting assembly as in any one of the above claims wherein said object is a piece of mined ore. COMS ID No: SBMI-02292419 Received by IP Australia: Time 18:35 Date 2005-12-28 28/12 '05 WED 16:56 FAX 61 8 82119433 Leslcar Perrin @003 0 17
4. 7. A sorting assembly as in any one of the above claims wherein said pre-determined C) characteristic is the amount of light emitted from opals that have been subjected to 0 ulltraviolet radiation. .8 A sorting assembly according to any one of claims 3-7, wherein the position of said i 5 flipper mechanism is changed using an air solenoid controlled by said control means.
5. 9. A sorting assembly as in any one of claims 3-8, wherein said assembly further includes a plurality of said flippers. In O 10. A sorting assembly as in any one of the above claims wherein said transport means is a Sconveyor belt.
6. 11. A sorting assembly as in any one of the above claims wherein said assembly further includes a hopper adapted to receive mullock said mullock then transported to a dust trommel to separate mullock from dust, said dusted mullock further transported to a sorting trommel including a plurality of sorting means to separate the dusted mullock into different size range, each sorting means connected to a chute to feed the particular size range to said transport means.
7. 12. A sorting assembly as in claim 11 wherein said hopper includes a grizzly.
8. 13. A sorting assembly as in claim 12 wherein said sorting trommel includes a hollow rotating cylinder having an outer skin having multiple apertures, said trormel having several different sized apertures extending longitudinally across said trommel and adapted to allow for different size particles of the mullock falling therethrough.
9. 14. A sorting assembly, substantially as hereinbefore described and as illustrated in the accompanying drawings. Dated this 10 July 2003 Opdctech Pty Ltd By their Patent Attorneys LESICAR PERRIN COMS ID No: SBMI-02292419 Received by IP Australia: Time 18:35 Date 2005-12-28