The present invention relates to a method of blending mined material to produce a blended product of a required customer specification.

The mined material may be a metalliferous or a non-metalliferous material. Iron-containing and copper- containing ores are examples of metalliferous materials . Coal is an example of a non-metalliferous material.

The present invention relates particularly although by no means exclusively to a mined material in the form of iron ore (and stockpiled iron ore) and is described hereinafter in this context. However, the present invention also extends to other mined and

stockpiled materials .

It is known to mine iron ore in large blocks of the ore from benches. In this conventional mining operation, typically, the blocks of ore are substantial, for example 40 m long by 20 m deep by 10 m high and contain 8000 tonnes of ore. Typically, a section of a bench is assayed by chemically analysing samples of ore taken from a series of drilled holes in the section to determine whether the ore is (a) high grade, (b) low grade or (c) waste material on a mass average basis. The cutoffs between high and low grades and between low grade and waste material are dependent on a range of factors and may vary from mine to mine and in different sections of mines. When the analysis is completed, a blockout plan of the section is prepared. The plan locates the drilled samples on a plan map of the section. Regions of (a) high grade, (b) low grade or (c) waste material are determined by sample analysis (such as chemical assay and/or

mineral/material type abundances) and are marked on the plan, with marked boundaries separating different regions. The boundaries are also selected having regard to other factors , such as geological factors . The regions define blocks to be subsequently mined. The blocks of ore are blasted using explosives and are picked up from a mine pit and transported from the mine pit. The ore is processed inside and outside the mine pit depending on the grade determination for each block . For example , waste ore is used as mine fill, low grade ore is stockpiled or used to blend with high grade ore, and high grade ore is processed further as required to form a marketable product. The further processing of high grade ore ranges from simple crushing and screening to a standard size range through to processes that beneficiate or upgrade the iron ore to produce a product of a required customer specification . The processing may be wet or dry.

A significant proportion of low grade ore is not blended and remains as stockpiled ore. As a consequence, there are large stockpiles of mined ore that have been classified as low grade ore that have potentially

significant economic value notwithstanding the low grade of the ore .

International application PCT/AU2009/001364 (International publication WO 2010/042994) in the name of the applicant describes a method of sorting mined

material , such iron ore , including low grade iron ore , comprising : (a) determining whether a volume of a material to be mined is upgradable and mining the volume of material or determining whether a volume of a material in a stockpile of mined material is upgradable; and (b) after suitable size reduction (for example by crushing and screening) dry sorting the mined or stockpiled material that is determined to be upgradable and producing an upgraded mined material .

The upgraded mined material may be a product that meets a required customer specification or may be suitable to be processed further, for example by blending with other material , to produce a product of a required

customer specification.

The International application also describes a dry sorting apparatus for sorting the mined or stockpiled material that is determined to be upgradable .

The disclosure in the specification of the

International application is incorporated herein by cross- reference .

The approach of the method of the International application of determining whether material is upgradeable is a quite different approach to conventional mining, as discussed above, which is based on making a mass average assessment of blocks of ore and categorising the ore as high grade, low grade, or waste material. In the International application (and herein) the term "upgradable" is understood to mean that the mined or stockpiled material is a material that is capable of being dry sorted to improve the actual or potential economic value of the material . The International application describes what is meant by the term "upgradable" in the following terms .

"The criteria for deciding whether, a material (including material to be mined and stockpiled material) is upgradable is not limited to the grade and may include factors relevant to a particular mine, such as the

characteristics of the material , and may include other factors such as market requirements for the material. The material characteristics may include the extent to which valuable constituents of a material can be liberated, for example by particle size reduction, the mineral

abundances, and material types.

In some situations the term "upgradable" may be understood herein to mean that there is a range of grades in the individual particles making up the material in a volume of material to be mined, such as a block of the type described above, whereby some particles are higher grades than other particles, and there would be a benefit in separating the volume of material into higher and lower grade components.

In other situations the term "upgradable" may also be understood herein to mean that there is a range of grades of materials in the particles of material in a stockpile of mined material that has been classified as low grade material, whereby some particles are higher grades than other particles, and there would be a benefit in separating the stockpiled material into higher and lower grade components. In other situations the term "upgradable" may also be understood herein to mean that the material contains particles of "impurities" within a volume of material to be mined or in a stockpile. For example, in the context of coal, the impurities may comprise any one or more of shale and silica and other ash components.

The term "grade" as used herein is understood to mean an average of the amount of a selected constituent in a given volume of particles of a mined material, such as ore, expressed as a percentage, with the grade calculation being based on amounts by weight. In the context of iron ore, grade relates to the percentage by weight of iron and other constituents of the ore that are considered to be important by customers . The other constituents include, by way of example, silica, aluminium, and phosphorous." The International application describes that the term "dry sorting" is understood to mean any sorting process that does not required added moisture for the purpose of effecting separation. The term "dry sorting" is understood to have the same meaning in this specification.

The method and the apparatus described in the International application makes it possible to recover value from mined and stockpiled material such as iron ore that would otherwise be classified as low grade material or waste material as described above on a mass average basis . This is particularly the case where the particles in low grade material or waste material comprise one group of discrete particles that are above a threshold grade and another group of discrete particles that are below the threshold grade. The method and the apparatus also makes it possible to recover value from mined and stockpiled material such as coal that contains particles of shale and silica or other "impurities" by separating coal particles and these "impurity" particles. The end result is the production of products to required customer

specifications . The International application describes that dual energy x-ray analysis is one option for use in determining whether a mined material is upgradable . The International application also describes that dual energy x-ray analysis is one option for use in dry sorting particles of material that has been determined to be upgradeable material. International application PCT/AU2009/001179 (International publication WO 2010/025528) in the name of the applicant describes a method and an apparatus for dual energy x-ray analysis of a mined material . The term "dual energy x-ray analysis" is understood herein to mean analysis that is based on processing data of detected transmitted x-rays through the full thickness of each particle obtained at different photon energies . Such processing makes it possible to minimise the effects of non-compositional factors on the detected data so that the data provides clearer information on the composition, type , or form of the material . The disclosure in the specification of the International application is

incorporated herein by cross-reference.

The applicant has carried out further research and development work on the method and the apparatus for sorting mined or stockpiled material and the method and the apparatus for dual energy x-ray analysis of a mined or stockpiled material described in the above International applications. In particular, the applicant has carried out further research and development work on a dry sorter for mined or stockpiled material that uses dual energy x- ray analysis to assist in determining whether particles of a mined or stockpiled material are above or below a threshold grade and then dry sorting the particles of the material on the basis of the grade determination.

The above description is not to be taken as a description of the common general knowledge in Australia or elsewhere .

The applicant has realised that the dry sorting method and apparatus described in the above International applications can be used in a wide range of situations in a mining operation to facilitate the production of a range of products to required customer specifications . In particular, the applicant has realised that the use of the dry sorting method and apparatus is not limited to sorting mined and stockpiled material that has been determined to be upgradable and extends to any mined material and stockpiled material. In particular, the applicant has realised that there are considerable benefits in terms of production of products to required specifications that can be achieved in selectively using the dry sorting method and apparatus in a mining operation for processing some but not necessarily all of the mined material at a mine and/or at a shipping facility of the mining operation. In particular, the applicant has realised that the selective use of the dry sorting method and apparatus can provide considerable flexibility to mine operators in scheduling production to meet customer requirements and to maximise recovery of value from mines , including stockpiled material that has been classified as being low grade or waste material. In particular, the applicant has realised that the selective use of the dry sorting method and apparatus can provide considerable flexibility to a mining operation and make it possible to maintain shipped tonnages of material to customers in situations where there are unscheduled disruptions to mining operations at one or more mines .

In addition to the above, in the context of the present invention, the applicant has realised that the dry sorting method and apparatus provides an opportunity for considerable flexibility for blending mined and/or stockpiled material from different sections of one mine and/or from multiple mines to produce a range of different blended products that meet customer requirements .

Moreover, the applicant has realised that this opportunity for flexibility extends to dry sorting and blending mined and/or stockpiled material at locations ranging from the mines through to customer operations and any locations between these locations . According to the present invention there is provided a method of blending mined and/or stockpiled material from different sections of one mine and/or from more than one mine that includes dry sorting mined and/or stockpiled material and producing an upgraded material , and blending the upgraded material with other material from the mine and/or with material from one or more than one other mine and producing the product of the required customer specification.

According to the present invention there is provided a method of blending mined and/or stockpiled material from different sections of one mine and/or from more than one mine to produce a blended product of a required customer specification, the method comprising the steps of:

(a) dry sorting mined and/or stockpiled material from at least one section of at least one mine in at least one dry sorter and producing an upgraded

material , and

(b) blending the upgraded material with other material from the mine and/or with material from one or more than one other mine and producing the product of the required customer specification.

The dry sorting step and the blending step may be carried out at any suitable location or locations.

For example, the dry sorting step and the blending step may be carried out at a mine or mines , a shipping facility such as a sea port, or a customer operation. By way of particular example, in a situation where the mined and/or stockpiled material is iron ore and the customer operation is a steel works, the dry sorting step and the blending step may be carried out at the steel works. In that situation, the upgraded material may be blended with other material from the mine or one or more than one other mine, including mines of other suppliers to the steelmaker . Dry sorting and blending the iron ore at the steel works makes it possible to take into account the parameters of the other material at the steel works and to operate the dry sorting step to ensure that the blended product meets the required customer specification .

The blending step may comprise blending (a) upgraded material from the dry sorter or sorters and (b) mined and/or stockpiled material that is not dry sorted material .

The blending step may comprise blending upgraded material from a plurality of dry sorters only.

The term "upgraded" material as used herein is understood to mean that the material from the dry sorter has a higher measure of a selected parameter that is relevant to the required customer specification than the average measure of that parameter in the feed material to the sorter .

In any given situation, the required customer product specification may be based on any one or more than one suitable parameter for the product.

For example, the required customer product specification may be based on any one of more than one of grade, particle size, particle size distribution, density, and particle shape . Grade may be based on one element in the material or on other elements and/or compounds in the material .

For example , in the case of iron ore , one element may be iron, another element may be phosphorus, one compound may be alumina, and another compound may be silica.

Typically, the required customer product specification is a combination of at least two parameters . The blending step may be based on grade to achieve a required customer specification for product grade .

The blending step may be based on particle size to achieve a required customer specification for particle size .

The blending step may be based on particle size distribution to achieve a required customer specification for particle size distribution.

The blending step may be based on density to achieve a required customer specification for density . The blending step may be based on particle shape to achieve a required customer specification for particle shape .

The blending step may be based on two or more than two of the above parameters to achieve required customer specifications for these parameters .

The method may comprise monitoring the operation the dry sorter or sorters for grade and/or another

parameter that is relevant to the required customer product specification. The method may comprise controlling the operation of the dry sorter or sorters to produce upgraded material having parameters as required for use in the blending step to produce the blended product of the required customer product specification.

The method may include controlling the operation of the dry sorter or sorters using a control system that monitors all of the material being processed at the mine or mines that is used in the blending step, including material that is not being processed in the dry sorter or sorters , whereby production operators are able to take into account the parameters of any non-dry sorter feed to the blending step that are relevant to the blended product when determining operational settings for the dry sorter or sorters so that the upgraded material from the dry sorter or sorters has the required parameters to

facilitate producing the blended product of the required customer specification when blended with non-dry sorter material.

The mine or mines may be part of a mining operation that further comprises a shipping facility for shipping the product of the required customer

specification to a customer, a transportation link for transporting material from the mine to the shipping facility, and a blending facility.

The transportation link may transport to the shipping facility any one or more of mined material, stockpiled material , upgraded material produced in the dry sorter or sorters, and the product of the required

customer specification. The shipping facility may be a sea port facility, with capacity for loading one or more than one product carrier ships . The shipping facility may be a rail facility, with capacity for loading one or more than one product rail trains .

The transportation link may be a railway line and/or a roadway system.

The blending facility may be at any suitable location.

The upgraded material from the dry sorter or sorters may be any appropriate percentage by weight of the total production from the mine or mines having regard to relevant factors including capital and operating costs of equipment and the required customer specifications and the properties of the mined material at the mine or mines .

The upgraded material from the dry sorter or sorters may be less than 25% by weight of the total production from the mine or mines .

The upgraded material from the dry sorter or sorters may be less than 20% by weight of the total production from the mine or mines.

The upgraded material from the dry sorter or sorters may be less than 15% by weight of the total production from the mine or mines .

The basis of operation of a dry sorter may be changed as required from time to time .

For example, the dry sorter may be operated for a period of time having regard to a particular element in the material that is relevant for one customer

specification and may be operated for another period of time having regard to another element in the material that is relevant for another customer specification .

By way of further example , a threshold grade for a given element may be increased or decreased over time depending on the grade of that element in other mined or stockpiled material from the same mine and/or from other mines that is used in the blending step . The upgraded material from the dry sorter or sorters may be processed further to facilitate production of the blended product to the required customer

specification. For example, the upgraded material may be subjected to size reduction, for example in a crusher, to a required particle size range. By way of further example, the upgraded material may be subjected to further sorting operations . The further sorting operations may be wet or dry sorting operations . The material supplied to the dry sorter or sorters may be mined or stockpiled material that has been assessed as being upgradable material , as described herein . In the event that the dry sorter or sorters are operated to sort upgradable material , the mining operation may include analysis of material to be mined or of material in existing stockpiles of mined material to determine whether the material is upgradable material .

The analysis may comprise taking a plurality of samples , such as drilled samples , from a volume of material to be mined, such as a block of ore of the type described above , prior to mining the material and

analysing the samples, for example by determining the grade of each of the samples, and making an assessment of whether the ore in the volume of ore is upgradable . The analysis may also comprise taking a plurality of samples from a stockpiled material and analysing the samples , for example by determining the grade of each of the samples, and making an assessment of whether the material in the stockpiled material is upgradable .

The number of samples required in any given situation will depend on factors relating to a particular mine or a section of the mine to be mined.

Any suitable technique may be used to analyse the samples in the analysis step. The dry sorter or sorters may use any suitable analytical technique to determine the basis for sorting particles of material being processed in the sorter .

There may be a correlation between the analysis technique used in the analysis step and the dry sorter or sorters .

One suitable analytical technique for the analysis step and the dry sorter or sorters is dual energy x-ray analysis. Other analytical techniques include, by way of example, x-ray fluorescence, radiometric,

electromagnetic, optical, and photometric techniques. The applicability of any one or more of these (and other) techniques will depend on factors relating to a particular mine ore or a section of the mine to be mined.

The dry sorter may be adapted to dry sort on the basis of analysis of a parameter, such as grade, of individual particles of the material .

The material may be mined by any suitable mining method and equipment . For example , the material may be mined by drilling and blasting blocks of ore from a pit and transporting the mined ore from the pit by trucks and/or conveyors. By way of further example, the material may be mined by surface miners moving over a pit floor and transported from the pit by trucks and/or conveyors .

The present invention also provides a method of producing a product of a required customer specification in the above-described mining operation, which method includes mining material from at least one mine,

transporting material from the mine or the mines to a shipping facility, and shipping a product of the required customer specification, to a customer, and which method also includes processing at least some of the material at the mine or mines or at the shipping facility in at least one dry sorter and producing an upgraded mined material , and producing at least some of the product of the required customer specification by blending upgraded material and other material from the mine of the mines .

The present invention is described further with reference to the accompanying drawings , of which :

Figure 1 is an example of a blockout plan for a section of a mine bench in a conventional mining

operation , with the Figure being Figure 1 of the

specification of International application

PCT/AU2009/001364; Figure 2 is one embodiment of a mining operation in accordance with the present invention; and

Figure 3 is a flowsheet illustrating one, although not the only, embodiment of the method and an apparatus for sorting ore in accordance with the present invention , with the Figure being Figure 2 of the specification of International application

PCT/AU2009/001364.

The description of the invention is in the context of a mined material in the form of iron ore. It is noted that the invention is not confined to iron ore and extends to other mined materials containing valuable components . The invention relates generally to mined metalliferous and non-metalliferous materials . In

addition to iron ore, copper is an example of a

metalliferous material . Coal is an example of a non- metalliferous material .

Figure 1 is a blockout plan for a section 51 of a bench in an open pit iron ore mine operating as a

conventional mine . The plan shows the locations of a series of drilled holes 53 (indicated by crosses) that have been drilled to obtain samples. The samples are analysed to determine the grade of ore in the samples .

The plan also shows assayed and is marked with a series of boundaries 55 that divide the section into a series of blocks 57 on the basis of whether the ore in the blocks is determined by the sample analysis to be (a) high grade, (b) low grade or (c) waste material based on ore grade. There are six blocks 57 shown in the Figure. High grade blocks 57 are referred to as "HG" , low grade blocks are referred to as "LG" , and waste blocks are referred to as "W" in the Figure . The cut-offs between high and low grades and between low grade and waste material are dependent on a range of factors and may vary from mine to mine and in different sections of mines . Each block 57 of ore is blasted using explosives and is picked up from a mine pit and transported from the mine pit. The ore is processed inside and outside the mine pit depending on the grade determination for each block. For example, waste ore is used as mine fill , low grade ore is stockpiled or used to blend with high grade ore, and high grade ore is processed further as required to form a marketable product. The processing may be wet or dry.

In a conventional iron ore mining operation, the low grade ore blocks are not usually blended with other ore and are stockpiled and not sold and hence represent significant lost economic value. However, some or all of these blocks and existing stockpiles of previously mined ore that has been classified as low grade material, may be suitable for upgrading in accordance with the present invention and are processed, including dry sorted, by way of example with reference to the flowsheet of Figure 3.

As is described above , International application PCT/AU2009/001364 describes an alternative approach to mining material which, in the context of iron ore, is based on assessing whether an ore to be mined or a stockpiled ore is "upgradable", with an assessment of whether an ore is upgradable being based on a number of factors. The factors include whether the ore particles can be sorted into particle streams that are above or below a threshold grade . Upgradable ore includes ore that has discrete particles that are above the threshold grade and discrete particles that are below the threshold grade. The assessment may include assessing the extent to which size reduction of ore can separate ore into such discrete particles . Ore that has finely disseminated iron through all the particles is generally not upgradeable. The present invention is based on a realisation of the applicant that dry sorters , particularly dry sorters that process ore to be mined or stockpiled ore that is upgradable and would otherwise be classified as low grade ore on the basis of conventional mining

methodology, can provide a mining operation with

considerable flexibility to blend mined and/or stockpiled ore to produce a range of blended products having required customer specifications and to maintain maximum shipped ore tonnages in situations where there are interruptions to scheduled operation at one or more mines . In

particular, the present invention is based on a

realisation of the applicant that this opportunity for flexibility extends to dry sorting and blending mined and/or stockpiled material at locations ranging from the mines through to customer operations and any locations between these locations .

With reference to Figure 2 , the embodiment of the mining operation in accordance with the invention

illustrated in the Figure comprises three iron ore mines identified by the numerals "1", "2" and "3". Each of the mines produces crushed iron ore of a required particle size range for customer product requirements that is transported by trains to a shipping facility in the form of a sea port. The ore is unloaded from the trains into stockpiles . The stockpiled material is subsequently loaded onto ships and transported to customers in

Australia and overseas. Each of the mines is operated to load trains with iron ore of a selected grade, which may be different for different mines . The basis of the selection is that the ore on the trains can be blended to produce blended ore of the required customer

specification. As is illustrated in the Figure, at the particular point in time of the mining operation captured by the Figure, mine 1 produces trains of ore of grade "A", mine 2 produces trains of ore of grade "B" , and mine 3 produces trains of ore of grade "C" . The unloading sequence of the trains is controlled to blend the ore so that the stockpiles comprise ore of the required customer specification in terms of ore grade . The operation of the mines is monitored and controlled to produce ore of selected grades that can be blended at the port to produce a product of the required customer specification. Each of the mines includes one or more than one dry sorter, such as a dry sorter operating on the basis of dual energy x- ray analysis , such as described in International

application PCT/AU2009/001179 , for sorting mined or stockpiled ore that has been assessed as "upgradable" as described above . Each of the mines also mines and processes mined and stockpiled ore in accordance with conventional mining practice of categorising blocks of ores as high grade , low grade , and waste material based on mass average assessment of the blocks . In the case of mine 1 the dry sorter (s) at the mine processes 10% of the mined material in the sorter. In the case of mine 2 the dry sorter (s) at the mine processes 15% of the stockpiled ore in the sorter. In the case of mine 3 the dry sorter (s) at the mine processes 10% of the total mined production from mined and stockpiled ore in the sorter. The mining operation also includes a control system that monitors the production from the mines in terms of the parameters for a given required customer product specification. These parameters may include grade, particle size, particle size distribution, density, and particle shape. In the present embodiment, grade is the key parameter. The grade may be the iron content. The grade may be the content of other elements and compounds in iron ore . One such element is phosphorous. One such compound is silica.

Another compound is alumina. The parameters also include the required tonnage of the product for the customer. The control system assesses the output in terms of grade from the dry sorters that is required to produce upgraded ore from the sorters that, when blended with other ore produced from the mines, produces the blended product of the required customer specification. The control system adjusts the operation of the dry sorters as required to produce the upgraded material of the required grade (or other selected parameter or parameters) . For example, the control system may adjust a threshold grade for ore, with ore above the threshold grade being upgraded material and ore below the threshold grade being waste material. It can be appreciated that the dry sorters operate to tune the mine production to smooth out perturbations in the grade of the other material supplied to the blending facility to make it possible to produce on-specification product. By way of particular example, in a situation where the bulk of the ore from mine 1 is below a required customer specification for the ore grade, the dry

sorter (s) at mine 1 and/or the other mines may be operated to provide upgraded ore that is above the required customer grade to blend with the ore that is below the required customer grade and produce on-specification product. This is a particularly useful outcome where the upgraded ore comes from stockpiles that are categorised as low grade . Such use of low grade ore optimises recovery of value from the mining operation .

The flowsheet shown in Figure 3 is one embodiment of a dry sorting operation that includes the use of a dry sorter as described above .

The flowsheet shown in Figure 3 is described in the context of ore that has been transported from a mine pit to a primary crusher 3 and is crushed in the crusher. It is noted that the invention also extends to situations in which the ore is crushed and sorted in the mine pit.

With reference to Figure 3 , the crushed ore from the primary crusher 3 is supplied to a scalping screen 5, for example in the form of a vibrating screen, that separates the ore on the basis of particle size into an oversize fraction of +75 mm and an undersize fraction of - 75 mm.

The oversize fraction from the scalping screen 5 is transferred to a secondary crusher 7 and, after size reduction in the crusher , is transferred back to the stream from the primary crusher 3. The undersize fraction from the scalping screen 5 3 is transferred to a downstream scalping screen 9 , for example in the form of a vibrating screen, that separates the ore on the basis of particle size into an oversize fraction of 8-75 mm and an undersize fraction of -8mm.

The undersize fraction from the scalping screen 9 is a fines stream that is transferred for further wet or dry processing.

The oversize fraction from the scalping screen 9 is transferred to a product screen 11, for example in the form of a vibrating screen. The product screen 11

separates the ore on the basis of particle size into an oversize fraction of 32-75 mm and an undersize fraction of -32 mm.

The oversize fraction from the product screen 11 is transferred to the secondary crusher 7 and, after size reduction in the crusher , is transferred back to the stream from the primary crusher 3.

The undersize fraction from the product screen 11 is transferred to downstream product screen 13 that separates the ore on the basis of particle size into an oversize fraction of 8-32 mm and an undersize fraction of -8 mm.

The undersize fraction from the product screen 13 is a fines stream that is transferred for further

processing with the undersize fraction from the scalping screen 9.

The oversize fraction from the product screen 13 is a product stream, at least in terms of particle size distribution . The oversize fraction from the product screen 13 is transferred to an ore sorter 15 and the particles are sorted on the basis of ore grade , i.e. average

composition, of the particles into two streams. The sorter 15 may be a sorter that uses dual x-ray analysis or any other suitable analytical technique to determine ore grade of particles processed in the sorter. One stream, referred to as "lump" in the Figure, from the ore sorter 15 comprises ore that has an iron concentration above a threshold ore grade, for example 63 wt. % Fe. This stream is a required product stream, in terms of particle size distribution and composition, and forms a marketable product or a product that can be blended with other ore streams to produce a marketable product. The other stream, referred to as "rejects" in the Figure, from the ore sorter 15 comprises ore that has an iron concentration below a threshold ore grade, for example 63 wt.% Fe. This stream is transferred to a stockpile to be used, for example, as land fill.

A key feature of the above-described flowsheet is of Figure 3 that the grade sorting step is carried out only on the ore that is in the required product particle size distribution, i.e. the 8-32 mm size fraction. This fraction is an oversize fraction from the product screen and there is no ore sorting of fines .

The above-described embodiment is an example of a number of possible embodiments for sorting ore in a dry sorter . There is a large number of other possible

embodiments , each of which has particular features that may be appropriate depending on the requirements of a particular mining operation .

Many modifications may be made to the embodiment of the present invention described above in relation to Figures 2 and 3 without departing from the spirit and scope of the invention.

By way of example , whilst the embodiment of the sorter shown in Figure 3 describes particular size fractions , the present invention is not so limited and extends to separating ore into any suitable size fractions for a particular mine and mining operation and downstream market requirements. Specifically, it is noted that the present invention is not confined to the specific product size fractions described in relation to the embodiment.

In addition, whilst the embodiment of the sorter shown in Figure 3 describes a particular product grade , the present invention is not so limited and extends to any suitable grades for a given market.