Technical Field A primary mined material bulking sorting system and method are disclosed.

The system and method may for example be applied to the bulk sorting of primary mined iron ore.

Background Art

Applicant's International Publication No. WO 2011/150464 discloses a method and apparatus for separating mined material. This publication discloses the general concept of bulk sorting on the basis of a measured characteristic of a segment of mined material rather than on a particle by particle basis. The present disclosure seeks to provide an enhancement to the system and method disclosed in this international publication.

The above reference to the background art does not constitute an admission that the art forms a part of the common general knowledge of a person of ordinary skill in the art. Further, the above reference is not intended to limit the application of the system and method as disclosed herein.

Summary of the Disclosure

In broad terms in a first aspect there is disclosed a primary mined bulk material sorting system comprising a material diverter as able to divert the flow of bulk material between pluralities of outlets on a basis of an analysis conducted of the grade of material as it is being transported to the material diverter. The analysis and control of the material diverter can be conducted in real time. Further, the analysis may be conducted in relation to segments of primary mined material.

The term "primary mined material" throughout the specification is intended to include material that is mined but not yet subjected to any form of diversion or sorting subsequent to being mined. However primary mined material can include mined material that has been passed through a crusher or other processing equipment provided there is no diversion or sorting of the mined material between an inlet and an outlet of the crusher/processing equipment so that in substance the entire volume or tonnage of the mined material input to and output from the crusher/equipment remains the same.

The mined material may be any form of mined material derived from either an open cut mine or an underground mine. The substantive mineral in the mined material is of no significance. Nevertheless the system and method are operable in relation to the mining of iron ore.

The disclosed method and system are also particularly although no exclusively operable in relation to primary mined material being material which has been mined and subjected only to primary crushing. The primary crushing of mined material may produce for example material having particle sizes ranging from dust through to rocks and boulders having a size of about 300mm - 350mm. Although not limited to such an application, the system and method are suited to bulk sorting of primary mined material having a particle size distribution in the range of P ₉₅ 300mm-350mm to P ₉₈ 300mm- 350mm. By way of brief explanation and example P ₉₅ 300mm means that the primary mined material has a size distribution where 95% of the particles in the material have a size smaller than 300mm. In this context, the term "particle" is understood in a broad sense to include, by way of example, any one or more of large and small rocks, large and small stones, sand like particles, fines and dust.

The size and weight of large rocks at the high end of this size range pose significant challenges in terms of the physical load and wear placed on sorting equipment. Also the very large particle size distribution poses other conflicting challenges for grade sorting. Systems that are able to sort secondary or finer crushed material do not have the physical strength and load bearing characteristic to handle at least in a practical and commercially sustainable manner primary mined material.

By performing the sorting on primary mined material it is possible to separate waste/gangue before any downstream processing. This can provide substantial cost savings because downstream processing step such as secondary crushing or other particle size reduction, particle separation, material handling, conveying and storage can be avoided for the waste/gangue component of the primary mined material. In the context of this specification the term "segment" or "segments" of mined material is to be understood to be any suitable amounts of material having regard to the relevant factors for the mined material. The relevant factors may include the type of mined material, such as iron ore, copper-containing or copper etc, and the capacities of the presentation, grade analysis, and diversion system incorporated in the sorting system and method.

The segments of mined material may be the same size or different sizes.

The size of the segments of mined material may be determined on the basis of the mass of the segments. For example, in the case of iron ore, the size of the segment may be at least 20 tonne and typically at least 100 tonne.

The size of the segments of the mined material may be determined on the basis of the amount of mined material that passes an assessment or grading location on a transport system in a given time period. For example, in the case of iron ore, the time period may be the amount of iron ore transported on a transport system for a 30 second period of time moved at rates of up to 2,500 - 3,5000 tonnes/hr. The size of the segments of the mined material may be determined on the basis of the type of mining equipment used to handle the ore. For example, in a situation where a mine operates on a drill and blast basis and material is moved by excavators and trucks, the size of the segments may be determined on the basis of the load capacity of the excavators that load mined material into the trucks and/or the load capacity of the trucks. By way of further example, in the situation where a mine operates on a surface mining basis, with the mined material being excavated from a pit floor and transferred to an in-pit conveyor, the size of the segments may be determined on the basis of supply hoppers for the conveyors. In a further arrangement where mined material is transferred directly following mining, or after stock piling, to a primary crusher, the segment may be commensurate with either the capacity of the primary crusher, or the rate of feed of the mined material to the primary crusher so as to maintain a continuous flow of mined material through the crusher.

The term "grade" in the context of the present specification is understood to mean the concentration of an elemental mineral or a combination of minerals of interest in the primary mined material. Grade analysis may be performed by any appropriate analyser having the capability to grade for the element or mineral of interest. One possible grade analyser is a prompt gamma neutron activation analyser (PGNAA). A further possible grade analyser may be based on the magnetic resonance response to ore radiated with RF radiation as described in the CSIRO publication "Resourceful" Issue 2 November 2012 pp 8, 9. Another possible form of analyser is a laser induced breakdown spectrometer. However embodiments of the invention are not limited to a specific type of analyser but rather simply to an analyser that is able to detect for a target mineral, element or combination of minerals or elements of interest. When the grade is in relation to the concentration of a combination of minerals and/or elements the corresponding analyser is selected to have the capability to detect and analyse for a desired target combination of the minerals and/or elements simultaneously. For example the grade may pertain to the material containing either iron with silicon or iron with aluminium of specific concentration.

In a first aspect there is disclosed a primary mined material bulk sorting system comprising:

a material diverter system having an inlet and a plurality of outlets and operable to direct primary mined material to flow from the inlet to a

corresponding one of the outlets,;

a mined material grade analyser operable to assess the grade of one or more segments of the primary mined material; and,

a transport system arranged to transport the one or more segments to: an analysis location enabling the grade analyser to assess the grade of the one or more segments; and subsequently deliver the one or more segments to the inlet of the material diverter system;

the analyser being operatively associated with the material diverter system to facilitate operation of the material diverter system to control flow of the one or more segments from the inlet to one of the outlets on the basis of the assessed grade of the segments.

In one embodiment the bulk sorting system comprises a diverter mechanism, the diverter mechanism having two or more of the outlets and operable to direct material to one of the two or more outlets.

In one embodiment the diverter mechanism is one of a plurality of diverter mechanisms, each of the diverter mechanisms having at least two of the outlets and operable to direct material to one of the two outlets, and wherein the diverter mechanisms are arranged in series so that at least one outlet of one diverter mechanism feeds material directly to a downstream diverter mechanism.

In one embodiment each diverter mechanism is operable to switch between first and second outlet positions wherein when in the first outlet position substantially all material delivered to that diverter mechanism is directed to a first outlet of that diverter mechanism; and when in the second position substantially all material delivered to that diverter mechanism is directed to the second outlet of that diverter mechanism.

In one embodiment the material diverter system is configured to cause a change in direction of motion of a plurality of particles in a segment of mined material from the inlet to the one of the outlets.

In one embodiment the bulk sorting system comprises an energy dissipation system arranged to dissipate kinetic energy from particles in a segment after discharge from the transport system.

In one embodiment the energy dissipation system comprises one or more rock boxes or ledges disposed in each of respective mined material flow paths from the inlet to each of the outlets.

In one embodiment each outlet has respective first and second dimensions measured in two orthogonal directions which are about three time the size of a particle of an average maximum sized particle where the primary mined material has a particle size distribution in the range of P95 300mm-350mm.

In one embodiment the first and second dimension are in the range of about 900mm to 1225mm.

In one embodiment the transport system is operatively associated with the analyser and the material diverter system to transport the one or more segments for a time period of T1-T2 seconds after the analyser has assess the grade of a segment of material wherein the period T1-T2 is the time for the material diverter system to switch between respective outlet positions.

In one embodiment the diverter mechanism comprises a gate movable about a pivot axis between the first and second of the outlet positions.

In one embodiment the gate is positioned to form an impact member for a plurality of particles in a segment and wherein the transport system discharges the one or more segments with a trajectory such that when the gate is in one of the outlet positions the plurality of particles impact the gate.

In one embodiment the pivot axis is near one end of the gate at a location between and adjacent the outlets.

In one embodiment the one end of the gate is spaced by a distance D from a land extending between the outlets wherein the distance D is less than 25% of the average maximum size of particles in the one or more segments.

In one embodiment the one of the gate is spaced by a distance D from a land extending between the outlets wherein the distance D is less than 10% of the average maximum size of particles in the one or more segments.

In one embodiment the pivot axis is extends substantially centrally of gate

In one embodiment the gate has first and second opposite edges and wherein when the gate is in a first of the outlet positions the first edge of the gate is disposed to lie adjacent an inner wall of the first outlet, and when the gate is in a second of the outlet positions the second edge of the gate is disposed to lie adjacent an inner wall of the second outlet.

In one embodiment the or each diverter mechanism comprises a tubular structure open at opposite ends the tubular structure being moveable between: the first of the outlet position wherein the tubular structure directs substantially of all of the particles in the one or more segments to the first outlet; and, the second outlet position wherein the tubular structure diverts substantially of all of the particles in the one or more segments to the second outlet.

In one embodiment the tubular structure narrows in internal cross sectional area in a direction of flow of particles in a segment toward one of the outlets of an associated diverter mechanism.

In one embodiment the or each diverter mechanism comprises a first gate and second gate, the first gate being movable between a fully opened position where the gate allows maximum flow of mined material through the first outlet and a fully closed position wherein the first gate substantially prevents mined material from flowing through the first outlet, the second gate being movable between a fully opened position the gate allows maximum flow of mined material through the second outlet and a fully closed position wherein the second gate substantially prevents mined material from flowing through the second outlet; and wherein when an associated diversion mechanism is in the first outlet position the first gate is in the fully opened position and the second gate is in the fully closed position, and when in the second outlet position the first gate is in the fully closed position and the second gate is in the fully opened position.

In one embodiment each diversion mechanism is arranged to move between the first and second outlet positions in a time period substantially the same as that required to fill the diverter with the mined material discharged by the transport system.

In one embodiment the analyser is arranged to assess grade of the mined material continuously as the mined material is passed through the analysis location by the transport system.

In one embodiment the material diverter system comprises an outer body, the outer body arranged to form the inlet and each of the plurality outlets.

In a second aspect there is disclosed a method of bulk sorting primary mined material comprising: transporting one or more segments of primary mined material through or past a grade analyser arranged to assess the grade of one or more segments of the primary mined material and subsequently to a material diverter system in accordance with the first aspect; controlling the material diverter system to divert segments of the mined material between respective outlets commensurate with the measured grade.

Brief Description of the Drawings

Notwithstanding any other forms which may fall within the scope of the system and method as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference with the accompanying drawings in which:

Figure 1 A is a schematic representation of one general configuration of equipment that may be utilised in an embodiment of the primary mined bulk material sorting system and method;

Figure IB is a schematic representation of segments of primary mined material being transported by a transport system through an analysis zone or location; Figure 2 is a schematic representation of an embodiment of the primary mined material bulk sorting system and method utilising a two outlet material diverter system incorporating a basket diverter;

Figure 3A is a schematic representation of the basket diverter incorporated in the system and method shown in Figure 2;

Figure 3B is a plan view of an inlet of the basket diverter shown in Figure 3A;

Figure 4 is a schematic representation of a single blade diverter that may be used in the system depicted in Figure 2 in place of the basket diverter;

Figure 5 is a schematic representation of a basket diverter that may be used in the system shown in Figure 2 in place of the basket diverter;

Figure 6A is a schematic representation of a two-way rolling blade diverter that may be used in the system shown in Figure 2 in place of the basket diverter;

Figure 6B is a section view of the two-way rolling blade diverter shown in Figure 6A;

Figure 7 is a schematic representation of an embodiment of the material an embodiment of the primary mined bulk material sorting system incorporating a material diverter system providing more than two outlets; and

Figure 8 is a flow sheet depicting steps in an embodiment of the method of bulk sorting primary mined material.

Detailed Description of Preferred Embodiments

Figure 1 A depicts in a very general form a primary mined material bulk sorting system 10 (hereinafter referred to in general as "system 10").

The system 10 enables the performance of an embodiment of a method 100

(shown in Figure 7) of bulk sorting the primary mined material.

The system 10 comprises a material diverter system 12 (hereinafter referred to as either "material diverter 12" or "diverter 12") having an inlet 14 and a plurality (in this instance two) outlets 16A and 16B (hereinafter referred to in general as "outlets 16"). The material diverter 12 is operable to direct primary mined material 20 to flow from the inlet 14 toward one of the outlets 16. The system 10 also includes a mined material grade analyser 22 and a transport system 24. The analyser 22 is operable to assess the grade of one or more segments of the material 20. The analyser 22 is operatively associated with the diverter 12 shown by way of phantom line 26. By virtue of this association, the analyser 22 is able to facilitate control of the flow of the material 20 from the inlet 14 to one of the outlets 16 on the basis of the assessed grade of the material 20.

The material 20 is transported to and through the analyser 22, and subsequently to the inlet 14 by the transport system 24. In this embodiment, the transport system 24 comprises a single continuous vertical loop belt conveyer; and moreover may be in the form of a trough conveyor. Providing the transport system as a trough conveyor minimizes the risk of the primary mined material bouncing on the conveyor and/or falling from the conveyor when initially deposited thereon and in subsequent transport to the diverter 12.

The analysis by the analyser 22, subsequent control of the diverter 12 by the analyser 22 and the transportation of material 20 through the analyser and to the diverter 12 is conducted in real time.

The nature of the primary mined material 20 is irrelevant to embodiments of the system 10. A capability of the system 10 is that it is able to handle primary mined material which, as explained previously, is material that, from the time of mining, has not been subjected to any sorting or diversion process. In one example, the primary mined material 20 is material having a particle size of for example P ₉₈ 350mm: or P ₉₅ 300mm. The material 20 is initially fed onto the transport system 24 through a feed hopper 27 of the system 10. The feed hopper 27 can be controlled to regulate the throughput of material 20 to the transport system 24. In the event that the primary mined material 20 has particle size exceeding the aforementioned sizes, it may be passed from the feed hopper 27 through the optional primary crusher 28 as depicted in Figure 1.

In the current embodiment the analyser 22 is operated to determine an average grade of the material. Further, the analyser 14 is arranged to categorise a segment of the material 20 into one of two grades namely an "accepts" grade and "reject" grade. When the analyser 22 determines that a segment of the material 20 has an accepts grade the analyser 22 consequentially controls the diverter mechanism 18 to move to a position where the so graded material is able to pass from the inlet 14 through the outlet 16A. The material passing through the outlet 16A is then transported by a third transport system 30 to an accepts stockpile 32.

In the event that the analyser 22 accesses the grade of a segment 20 of material to be of the reject grade then the analyser 22 provides a signal to the diverter 12 to move the position of the diverter mechanism 18 so that the corresponding material 20 is diverted to the outlet 16B. Thereafter the material from the outlet 16B is transported via a transport system 34 to a reject stockpile 36.

The transport system 24 continuously transports the material 20 to and subsequently through the analyser 22 on route to the diverter 12. That is, the transport and analysis is continuous. The analysis is conducted in relation to a segment of the material 20 within an analysis zone or location 29 shown in Figure IB. Therefore, it will be appreciated that segments of the primary mined material 20 that pass through the analyser 12 are not discrete from each other. Rather, the material 20 is transported and analysed as a continuum of segments so that at any instant in time, a particle in one segment may also constitute a particle in a plurality of continuous successive segments. This is explained with further reference Figure 1B. This Figure depicts three overlapping segments of material 20 identified as A1 - A2; B1 - B2; and C1 - C2. In this example it is assumed (though it need not be the case) that the length of each of segment is commensurate with the span of the analysis zone 29.

At one particular time the segment A1 - A2 is wholly within the analysis region or zone 29 of the analyser 22. The analyser 22 will assess the average grade of this segment. At a nominal subsequent time, for example 5 seconds later, the segment B1 - B2 now wholly falls within the analysis zone 29. This segment is also now assigned an average grade. After a further subsequent time period, for example another 5 seconds, the material in the segments C1 - C2 now wholly lies within the measurement zone or region 29. At that time, the analyser 22 determines an average grade that corresponding segment.

It would be noted however that at the time the segment A1 - A2 is being analysed as to average grade, this segment also contains particles which fall within the segments B1 - B2; and C1 - C2. Thus, in effect the analyser 22 provides a sliding window average grade for the mined material 20 passing through the analyser 22 although at any one instant in time the material 20 within the analysis zone or region 29 constitutes a single segment.

In the event of a detected change in grade by the analyzer 22 the diverter 12 requires a period of time T1 - T2 seconds to operate to direct the material from one of the outlets 16A or 16B to the other. This is equivalent to the required for the diverter 12 to switch between the outlet positions when there is a detected change in material grade. This time may be in the region of for example 30 to 60 seconds. In order to minimise contamination of the stockpiles 32 and 36, the transport system 24 is also arranged so as to take the same period of time Tl - T2 seconds to transport a segment of material after analysis by the analyser 22 to the inlet 14. Thus, for example if the analyser detects a change in the average grade of a segment from the accepts grade to the reject grade, then by the time the graded segment reaches the diverter 12 the diverter 12 has switched to the outlet position required to divert the material to the appropriate reject stockpile 36.

The diverter 12 may comprise a single diverter mechanism 18 operable to direct material to one of two or more outlets 16. Alternately the diverter 12 may comprise a plurality of diverter mechanisms 18 each having at least two outlets where the diverter mechanisms are stacked or arranged in series so that at least one outlet of one diverter mechanism feeds material directly to a downstream diverter mechanisms. In this way the diverter system 12 and analyser 22 can act together to separate a feed stream of primary mined material into two or more output streams without the need of any intervening analyser, bin or transport system. This will be explained in greater detail below.

Figure 2 illustrates a specific embodiment of the system 10 in which the material diverter 12 has two outlets 16A and 16B. The diverter 12 incorporates or is associated with or otherwise connected to a feed hopper 40. Irrespective of the provision of the hopper 40, it will be noted that the diverter 12 is configured to effect a change in direction of motion of substantially all the particles in a segment 20 of mined material from the inlet 14 to one of the outlets 16A or 16B. This is achieved by configuring the diverter 12 so that there is minimal or no possibility of a particle following a direct path from the inlet 14 (and more particularly from the end of the conveyer 24) to one of the outlets 16. The possibility of this occurring is not completely excluded however the geometry of the system 10 is such that the probability of this occurring is very low and the proportion of particles within a segment that could travel without the change in direction of motion from the inlet 14 to the outlet 16 will be very low. The significance of this is that changing the direction of particles in the segment 20 will most likely be accompanied by a dissipation of kinetic energy from the particles. This dissipation kinetic energy is of benefit in view of the size of the particles in the segments of material 20 (being primary mined material). Many of the particles will be very large (e.g. 300mm-350mm) and accordingly dissipation of kinetic energy will be beneficial in terms of minimising impact damage and wear to components of the system 10.

Dissipation of kinetic energy from particles in a segment may be enhanced by the provision of energy dissipation systems such as rock boxes or rock ledges within an outer body 43 of the diverter system 12 and/or within the hopper 40. The energy dissipation systems are most helpfully disposed at locations in a flow path between the end of the transport system 24 and the outlets 16. The material can collect, or otherwise impact with other particles already collected, in the rock boxes or ledges.

In Figure 2 the material diverter system 12 is constituted by a single diverter mechanism 18 in the form of a basket diverter. The basket diverter is illustrated in greater detail in Figures 3A and 3B. The outer body 43 of the diverter system 12 also constitutes the outer body of the single diverter mechanism 18. The outer body 43 is configured to form the inlet 14 and the two outlets 16A and 16B. Thus the outlets of the diverter mechanism 18 constitute the outlets of the outer body 43 and outlets of the diverter system 12. The outer body 43 fully contains all of the material 20 and associated dust and fines form entry to the inlet 14 until passage through the outlets 16A, 16B.

The outlets 16A and 16B are adjacent to each other and angularly offset or inclined by approximately 30° one to each side of a vertical plane 44. The diverter mechanism 18 has a planar gate 48 that is movable by way of pivoting about a pivot axis 49. The gate 48 may be considered as one form of material director. The pivot axis 49 coincides with a horizontal centre line of the gate 48. The gate 48 is attached to a lever 50 at about the pivot axis 49. An opposite end of the lever 50 is attached to a hydraulic actuator 52. The actuator 52 is operated or controlled by signals from the analyser 22 communicated via line 26.

The gate 48 has opposite joined horizontal edges 54 and 56. Further, the gate 48 is dimensioned so that when in one of two possible outlet positions, one of the edges 54, 56 lies immediately below one side of the inlet 14 while the other one of the edges 54, 56 bears against a side of the outlet 16 corresponding to the required outlet position.

For example, consider the outlet position shown in Figure 3 A in which material that enters the diverter 12 (and corresponding diverter mechanism 18) via the inlet 14 is directed to the outlet 16A. The edge 56 is adjacent and in substantial vertical alignment with a side 58 of the inlet 14. Further, the edge 54 is adjacent and indeed bears against a side 60 of the outlet 16 A. The contact position between the edge 54 and the side 60 is below an apex 62 of the body 42. This provides support to the gate 48. In this configuration material 20 entering the inlet 14 is diverted via the gate 48 to flow to the outlet 16A.

In the event that the analyser 22 assesses a change in grade of the material 20, the analyser 22 operates the diverter mechanism 18 to switch form outlet 16A to outlet 16B as the outlet to which the material 20 is directed. In this instance this is achieved by the analyser 22 causing the actuator 52 to operate to rotate the gate 48 about the axis 49 so that at expiration of the time period T1 - T2 the edge 54 of gate 48 would now lie adjacent to and in vertical alignment with an opposite side 64 of inlet 14 while the edge 56 would lie adjacent and against an inside surface 66 of the outlet 16B.

The diverter 12 is formed with square openings at its inlet 14 and each of the outlets 16. Figure 3B depicts the inlet 14 in plan view. The opening of the inlet 14 has orthogonal directions of Amm x Amm. The dimension Amm is approximately three times the size of a particle of an average maximum size particle in the segments material 20. Thus when the material has a particle size distribution in the range of P ₉₈ 300mm; the dimension Amm is about 900nm; when the size distribution P ₉₈ 350mm, Amm is about 1050mm. The openings of the outlets 16 have the same shape and dimensions as that of the inlet 14.

The gate 48 will form an impact member for a plurality of particles in the segment of material 20 as the material 20 moves from the transport system 24 through the diverter 12 to one of the outlets 16. In particular when the gate 48 is in one of its outlet positions, a plurality of particles in a segment of material 20 will be discharged from the transport system 24 with a trajectory such that the plurality of the particles will impact on the gate 48. These particles may subsequently slide down, or bounce from, the gate 48 on route to the corresponding outlets 16.

Figure 4 illustrates a diverter mechanism 18A in the form of a single blade or flop gate diverter. The diverter mechanism 18A has a body 43 which is configured with a single opening 14 and two outlets 16A and 16B. The general configuration of the inlet 14 and outlets 16A and 16B for the diverter mechanism 18A is in substance the same as that of the diverter mechanism 18 shown in Figure 3 A. One substantive difference between the diverter mechanisms 18 and 18A is the location of the axis 49 for the gate 48 in the diverter mechanism 18A. In the diverter mechanism 18A the axis 49 is along or adjacent to the downstream edge 54 of the gate 48. The gate 48 is configured so that its upstream edge 56 abuts a lower end of either wall 58 or 64 of the inlet 14 when the gate is in one in of its outlet positions. Actuator 52 is coupled to the gate 48 at a location approximately centrally between the edges 54 and 56 and operates to pivot the gate 48 about the pivot axis 49 to divert a flow of material 20 from the inlet 14 to one of the outlets 16A or 16B.

A further difference between the diverter mechanism 18 and 18A is that rather than the outlets 16 forming an apex 62, in the diverter mechanism 18A a planar land 68 is formed between the outlet 16A and 16B directly beneath the pivot axis 49. The land 68 provides superior wear performance in comparison to an apex against direct impact from the primary mined material. Also it is easier to secure wear liners to the land 68 that to the opposite sides that form of an apex.

The edge 54 of gate 48 is spaced by a distance D from the land 68. The distance D is in the order of or less 25% of the average maximum size of particles in a segment of the material 20. However, in alternate embodiments, the distance D may be less than 10% of the average maximum size of particles in a segment of material 20.

Figure 5 depicts an embodiment of diverter mechanism 18Bin the form of a bucket diverter. The diverter mechanism 18B is formed with a body 43 having an inlet 14 and two downstream outlets 16A and 16B. The outlets 16A and 16B, and the inlet 14 are in the same general configuration as the body 43 for the diverters mechanisms 18 and 18 A. The main difference between the bucket diverter form of the diverter mechanism 18B and the diverter mechanisms 18 and 18 A is the configuration of the material director. In the diverter mechanism 18 A, the material director comprises a tubular structure 70 having open opposite ends 72 and 74. The end 72 is an upstream end and the end 74 is a downstream end with reference to the direction of flow of material 20 from the inlet 14 to one of the outlets 16. In this embodiment, the tubular structure 70 is tapered to reduce in inner and outer diameter in the downstream direction that is in the direction from the end 72 to the end 74. The tubular structure is perfectly mounted near its upstream end 72 about a pivot axis 49. The diameter of the upstream end 72 is arranged so that when the material director/tubular structure 70is in one of its outlet positions, essentially all of the material 20 entering the inlet 14 will pass through the opening at the end 72. It will be understood that when the tubular structure 70 is transitioning between one of its two outlet material 20 will impact on the apex 62 between the outlet 16A and 16B. In order to provide protection sacrificial wear plates may be provided on inside of the apex 62 to protect from impact damage and abrasive wear.

The downstream end 74 is dimensioned and configured to fit within the outlets 16, although the end 74 spaced upstream of the outlets 16. Further, the tapering of the tubular structure 70 is arranged so that when the structure 70 is in one of its outlet positions, the lower side of the structure 70 lies substantially parallel to an inside surface of the corresponding outlet 16. For example, with reference to Figure 5, where the diverter mechanism 18B is shown in an outlet position directing the material 20 to the outlet 16B, lower side 76 of the tubular structure 70 lies substantially parallel to an inside surface of the side 60 of the outlet 16B.

Figure 6A and 6B depict a two-way rolling blade diverter embodiment of a diverter mechanism 18C incorporated in a corresponding diverter system 12C. The diverter mechanism 18C has a body 43C having an inlet 14 and two downstream outlets 16A and 16B. The material director in the diverter mechanism 18C comprises two accurate blades or gates 48A and 48B. The gate 48A has an open position as shown in Figure 6A where the gate 48 A allows maximum flow of material 20 from the inlet 14 through the outlet 16A. The gate 48 A also has a fully closed position shown in Figure 6B where the gate 48 A extends across the outlet 16A and substantially prevents material 20 from flowing from the inlet 14 through the outlet 16A. Similarly, the gate 48B is movable between a fully open position shown in Figure 6A and a fully closed position shown in Figure 6A. The gates 48A and 48B are synchronised with each other so that when one gate is in the fully open position the other is in the fully closed position.

Each of the gates 48A and 48B is provided with a respective actuator 52A and

52B operable to move its respective gate between the fully open and fully closed positions. The actuators 52A and 52B are controlled by signals provided by the analyser 22. Due to the configuration of the gates 48A and 48B the housing 43C is provided with cowlings 80A and 80B configured to accommodate the respective gates 48 when in their opened positions.

Notwithstanding the great mechanical complexity of the two-way rolling blade diverter 12C, in comparison to the previously described diverters, it believed to have benefit of reduced wear.

Figure 7 depicts a diverter system 12D that may be utilised with an alternate form of system 10. The diverter 12D differs from the diverters described above in that it has a single inlet 14 and three outlets 16 A, 16B and 16C. The diverter 12D comprises upstream and downstream diverter mechanisms 18Bu and 18Bd respectively which are stacked or arranged in series with each other. The specific form of diverter mechanisms 18 utilised in the diverter system 12D is not essential.

The diverter system 12D has an outer body 43D that is provided with a single inlet 14 and the three outlets 16 A, 16B and 16C. As with the previous embodiments the material 20 is fully contained within the outer body 43D form the time of initial entry through the inlet 14 of the until it passes through one of the outlets the 16 A, 16B and 16C. However in this embodiment the outer body 43D also house two diverter mechanism 18Bu and 18Bd.

The outlet 16A, 16B and 16C are outlets specific to particular grades of material 20. The upstream diverter mechanism 18Bu has an outlet 16D which directs material into the downstream diverter mechanism 18Bd. The diverter system 12D is operated by the analyser 22. In particular the analyser 22 is coupled to respective actuators of each of the diverter mechanisms 18Bu and 18Bd to cause the respective diverter mechanisms to switch between respective outlet positions depending on the assessed grade of the material 20. In this embodiment the system 10 is able to sort primary mined bulk material into three grades. To this end the analyser 22 can be arranged to categorise segments of the material 20 into three grades for example high grade, low grade, and reject grade. Depending on the assessed grade the analyser 22 communicates signals to the diverter system 12 and in particular each of the diverter mechanisms 18Bu and 18Bd to switch between appropriate outlet positions so that material of a particular assessed grade is directed to a corresponding one of the outlets 16A, 16B or 16C. For example bulk material sorting system 10 incorporating the diverter system 12D can be arranged so that material assessed as high grade is directed to the outlet 16A, material assessed as being low grade is directed to the outlet 16B and material assessed at the reject grade is directed to the outlet 16C.

In order for high grade material to be directed to the outlet 16A, the upstream diverter mechanism 18Bu is operated so that its corresponding material director, in this instance the tubular structure 70, directs material from the inlet 14 to the outlet 16A. In the event that materials assessed as being at the low grade then the diverter mechanisms 18Bu and 18Bd are switched so that their respective tubular structures 70 direct material initially from the inlet 14 to the outlet 16d and subsequently to the outlet 16B. This is the configuration depicted in Figure 7. Finally, in the event that the material is assessed as being at a reject grade then the diverter mechanisms 18Bu and 18Bd are operated so their respective tubular structures 70 direct material from the inlet 14 through the outlet 16D and subsequently through the outlet 16C.

It will be appreciated that in the above described diverter system 12D once the material has been assessed by the analyser 22 it is then sorted into three outlet streams by the two diverter mechanisms 18Bu and 18Bd without the need for any intervening or intermediate analyser, bin or transport system. The integrity of the assessment of grade of the material 20 is not compromised or otherwise changed once passing through the initial inlet 14.

Figure 8 depicts a flow sheet for one embodiment of the method 100 for the bulk sorting of primary mined material 20 utilising embodiments of the system 10. In a board sense, the method 100 comprises at step 102 transporting primary mined material 20 to and through the analyser 22. At step 104 the analyser conducts a grade analysis on segments of the material 20. At step 106 the analyser 22 controls the diverter mechanism 18 of the diverter 12 to move to an outlet position commensurate with the assessed grade of the analysed material. Subsequently at step 108 the analysed material is continued to be transported by the transport system 22 and delivered to the inlet of the diverter 12. Material 20 subsequently pass to the outlet 16A or outlet 16B and subsequently transported to accepts stockpiles at step 110A or a rejects stockpile at step 110B in accordance with the assessed grade.

Now that embodiments of the system 10 have been described in detail it will be appreciated to those of ordinary skill in the art that the system and method may be embodied in many other forms. For example with particular reference to the diverter 12D illustrated in Figure 7 the upstream and downstream diverter mechanisms 18Bu and 18Bd are illustrated as being of the same type or form. However this is not critical and different types of diverter mechanisms can be used in a stacked or series form of diverter system 12D. For example it may be advantageous in some circumstances to have a downstream diverter mechanism which is able to switch between outlet positions at a quicker rate than an upstream diverter mechanism. Also again with reference to the diverter system 12D, it should be appreciated that further diverter mechanisms can be stacked or added in series with the outlets 16 A, 16B or 16C.