WO2024130312A1

WO2024130312A1 - Underground mining system and method

Info

Publication number: WO2024130312A1
Application number: PCT/AU2023/051329
Authority: WO
Inventors: Stuart David Thomas; Mark John O'TOOLE
Original assignee: Nepean Longwall Pty Ltd
Priority date: 2022-12-20
Filing date: 2023-12-19
Publication date: 2024-06-27

Abstract

A mining system (1) and method for pillar (8, 9) extraction in underground mines. The system (1) includes a central unit (2) to be propelled along a central roadway (6), and a plurality of ancillary units (3, 3') on either side thereof, and a controller to control the operation of the system (1). Each ancillary unit (3, 3') includes a main body to be propelled (35) adjacent to the central unit (2) and a canopy portion (36) to extend outwardly therefrom to define a shielded mining space thereunder.

Description

Underground Mining System and Method

Field of the invention

[0001 ] The present invention relates to an underground mining system and method, and in particular, to a system and method for pillar extraction in underground mines, whereby the safety and efficiency of resource extraction is significantly improved.

Background of the invention

[0002] Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application.

[0003] Various methods of mining in an underground environment are presently known. The choice of method typically varies dependant upon specific mining conditions.

[0004] Longwall mining is a very efficient means of underground mining, which can typically extract materials for extended periods at high rates exceeding 3000tph. Longwall mining requires regularly shaped mining plans to be established over extensive areas, typically several kilometres in length and up to 400m wide. The establishment of a new longwall system requires significant capital investment, requiring the provision of specialised bulky equipment, including powered roof supports, armoured chain conveyor systems, longwall shearers (or plow (plough) systems), crushing systems, hydraulic pumps and supply systems.

[0005] Shortwall mining is based on more compact layouts than longwall mining and the systems are less capital intensive. Shortwall blocks of product may typically be 30m to 100m wide and less than 1 kilometre long. Shortwall mining also utilises powered roof supports to support the roof and shearers or plows to cut the product and load it onto a chain conveyor. On some short wall faces continuous miners cut the product, loading it out using mobile conveyors (flexible conveyors or continuous haulage).

[0006] Longwall and shortwall mining methods both require an extensive setup of panels and roadways to facilitate the supply of the mining equipment and other mining infrastructure into the mine, and to transport the mined product from the mine. Longwall or shortwall mining necessitates these specially laid out panels which may vary in length or in some cases width but which are unfavourable for smaller pockets of resource or where the resource is affected by faults and inclusions.

[0007] In mines that utilise the longwall and shortwall methods, there are areas of the resource which cannot be mined with these systems and alternate methods are required to recover the product. These methods include bord and pillar mining, or pillar extraction. These methods are more labour intensive per tonne of product mined. Whilst conventional methods of bord and pillar mining or pillar extraction can produce high yields, results can quickly deteriorate in difficult mining conditions. Also, in these methods, personnel/operators are typically exposed to risk from unexpected roof fall or rib collapse.

[0008] Pillar extraction using mobile roof supports (breaker line supports) is an existing mining method that uses a mobile mechanical roof support device(s) in proximity to a continuous miner operation to support the roof locally and provide the continuous miner with an area from which material may be mined without the roof collapsing locally onto the continuous miner. Partial pillar extraction is an existing mining method where the remaining supporting pillars are partially mined leaving only a quarter of the pillar (or less depending on conditions) supporting the roof as the continuous mining cuts the rest of the pillar away. This method is efficient only where good roof conditions prevail and is not suitable in poor roof conditions or where mining occurs at greater depths (resulting in more pressure on the pillars). This method also experiences problems in rolling seams where pillars are loaded unevenly.

[0009] There are methods to assist in controlling the roof in difficult mining conditions. Timber props were a common method historically and still have application today. Crib blocks of timber may also be erected and provide a stable and predictable support of the roof but are labour intensive and take time to install. Hydraulic or air powered props are also used for temporary support, usually in specialised positions (protecting a corner or a piece of equipment). Additional mechanised roof support has been supplied by mobile machinery - either rubber tired or track mounted. Mobile roof supports (or breaker line supports) are used effectively either singly or in groups of two or three, to support the roof adjacent to a continuous miner as it mines a pillar. The mobile roof supports are remote controlled (as is the continuous miner) and this improves safety for the operator as they can position themselves away from unsupported roof and with good visibility of the operating equipment. These mining methods may result in variable outcomes as the control of the continuous miner when it is cutting is not always precise due to conditions, dust etc, so unexpected roof falls or rib collapses may occur from time to time.

[0010] The current methods in use for pillar extraction place emphasis on the experience and skill of operators to correctly interpret mining conditions in order to avoid roof or rib falls which may impact the continuous miner or other equipment and pose a risk to the operator. Each mine has particular requirements in relation to the extent of the mining lease, the challenges presented by the geotechnical conditions for the mine, the depth of mining activities, the sensitivity and nature of surface structures and the presence of gas in the mining area. The selected mining method will often be modified uniquely for the conditions of the site. These modifications to the mining methods mean that underground mining equipment often has unique features for each particular mine. These may be dictated by seam thickness/ mining height, primary and secondary roof support required to maintain safe mining conditions, floor conditions and ground bearing pressure of the machinery, density/ abrasiveness of the mining material, etc.

Summary of the invention

[0011 ] The present invention seeks to overcome at least some of the disadvantages of the prior art.

[0012] The present invention also seeks to provide an alternative system and method of pillar extraction, in which the safety and efficiency of resource extraction is improved.

[0013] In a broad form, the present invention relates to a mining system for the extraction of pillars on either side of a control roadway of an underground mine grid, the mining system including: a central unit, adapted to be initially positioned at an intersection of said control roadway and an installation roadway, and configured to be forwardly propelled along the control roadway in a mining direction towards an extraction roadway; and, a plurality of ancillary units, at least one ancillary unit being located on each side of said central unit, each ancillary unit including: a main body, adapted to be forwardly propelled adjacent to said central unit; and, a canopy portion, adapted to extend substantially outwardly from an upper portion of the main body to thereby define a shielded mining space thereunder; and, a controller, configured to control the operation of the central unit and each ancillary unit.

[0014] Preferably, said central unit includes the controller configured to control the operation of each ancillary unit.

[0015] Preferably, said controller is operated remotely.

[0016] Preferably, said canopy portion of each ancillary unit is configured to slide and/or pivot substantially outwardly from said main body.

[0017] Preferably, said central unit and said main body of each said ancillary unit each include a ground engaging member adapted to propel each unit over a substrate surface.

[0018] Preferably, each said roof support unit further includes a shovel member configured to forwardly push any mineral or other material atop said substrate surface away from said unit.

[0019] Preferably, said each shovel member of each unit is configured to be pivotally attached to a shovel member of an adjacent unit to thereby form a composite articulated shovel mechanism.

[0020] Preferably, said central unit is either: self propelling; or, is configured to be propelled by a separate unit.

[0021 ] In a further broad form, the present invention relates to an underground mining method for the extraction of pillars on either side of a control roadway of an underground mine grid, the method including the steps of: positioning a central unit at an intersection of said control roadway and an installation roadway; locating at least one ancillary unit on each side of said central unit within said installation roadway, each ancillary unit including a main body and a canopy portion extending substantially outwardly from a main body to thereby define a shielded mining space thereunder; mining any mineral or other pillar material provided within said shielded mining space; advancing the position of said central unit and each ancillary unit progressively towards an extraction roadway; and, repeating said mining and advancing steps until said central unit and each ancillary unit reaches the extraction roadway.

[0022] Preferably, in said advancing step, a controller is configured to progressively operate a ground engaging member of each unit to thereby propel each unit over a substrate surface.

[0023] Preferably, said controller is adapted to selectively advance the position of each unit in a snake like manner.

[0024] Preferably, said controller utilizes a lower from the roof, advance, set to the roof, methodology (LAS).

[0025] Preferably, in said advancing step, after each main body of each ancillary unit is repositioned, each canopy portion, including a forepole and/or a flipper, is thereafter operated to be pivotally and/or be slidably extended outwardly to redefine a new shielded mining space thereunder.

[0026] Preferably, in said advancing step, prior to advancement of each unit, a shovel mechanism associated with the respective ancillary unit is operated to forwardly push any mineral or other material atop said substrate surface away from said ancillary unit.

[0027] Preferably, in said mining step, mineral or other material is extracted using any one or combination of: a continuous miner vehicle; a conveyor; a shuttle car; a battery hauler; a feeder-breaker; and, a continuous haulage system.

[0028] In a further broad form, the present invention provides a controller of an underground mining system according to that described above, configured to control the operation of said central unit and each ancillary unit located on either side thereof. [0029] Preferably, said controller is operated remotely.

[0030] In a further broad form, the present invention provides an ancillary unit of an underground mining system according to that described above, the operation and repositioning thereof being configured to be controlled by a controller.

[0031 ] In a further broad form, the present invention provides a shovel member associated with an ancillary unit of an underground mining system according to that described above, configured to forwardly push any mineral or other extracted material atop a substrate surface away from said ancillary unit.

[0032] Preferably, each shovel member being pivotally attached to a shovel member of an adjacent ancillary unit, so as to thereby be moved in a snake like manner.

[0033] In a further broad form, the present invention relates to a pillar extraction system for underground mining, including: a central unit; at least one ancillary unit located on each side of said central unit, each ancillary unit including: a main body, adapted to be forwardly propelled; and, a canopy portion, adapted to extend substantially outwardly from an upper portion of the main body to thereby define a shielded mining space thereunder; and, a controller configured to control the operation of the central unit and each ancillary unit.

[0034] In a further broad form, the present invention relates to a pillar extraction method for underground mining, including the steps of: positioning a central unit within a control roadway of an underground mine; locating at least one ancillary unit on each side of said central unit within an installation roadway, each ancillary unit including a canopy portion extending substantially outwardly from a main body portion thereof to thereby define a shielded mining space thereunder; mining any mineral or other material provided within said shielded mining space; repositioning the position of said central unit and the location of each said roof support unit; and, repeating said mining and repositioning steps until the units reach an extraction roadway.

[0035] In a further broad form, the present invention relates to a method of installation of an underground mining system in an underground mine, including the steps of: positioning a central unit at an intersection of a control roadway and an installation roadway of an underground mine grid; and, locating at least one ancillary unit on each side of said central unit within said installation roadway, each ancillary unit including a canopy portion extending substantially outwardly from a main body portion thereof to thereby define a shielded mining space thereunder.

[0036] In a further broad form, the present invention relates to a method of extraction of an underground mining system from a mine, including the steps of: driving a central unit and its associated ancillary units to an extraction roadway of an underground mine; and, separating each unit and withdrawing it via said extraction roadway.

Brief description of the drawings

[0037] The present invention will become more fully understood from the following detailed description of preferred but non-limiting embodiments thereof, described in connection with the accompanying drawings, wherein:

[0038] Figure 1 illustrates a plan view of the main components of an example embodiment of an underground mining system in accordance with the present invention;

[0039] Figure 2 illustrates, in Figures 2(a) to 2(e), various sequential steps showing an example sequence in the method of underground mining in accordance with the present invention;

[0040] Figure 3 illustrates, in figures 3(a) to 3(p), various plan views of an example sequence as to how the main components of the underground mining system of the present invention interact during the mining process;

[0041 ] Figure 4 illustrates, in figures 4(a) and 4(b), a plan and a front view, respectively, of a left-hand side of an example arrangement of the main components of an example embodiment of the underground mining system in accordance with the present invention;

[0042] Figure 5 illustrates, in Figures 5(a) to 5(g), various sequential steps showing the movement of the scraper member components, which together form the overall scraper mechanism, in accordance with the present invention; and

[0043] Figure 6 illustrates architecture details of the automation and remote operation of the underground mining system.

Detailed description of preferred embodiments

[0044] Throughout the drawings, like numerals will be used to identify similar features, except where expressly otherwise indicated.

[0045] Figure 1 illustrates a typical layout of an underground mine, incorporating a plurality of roadways 4, 5, 6, and 7 with pillars 8 and 9 therebetween.

[0046] Figure 1 also shows, in schematic form, the main components of the underground mining system 1 in accordance with the present invention, which may be used for extracting some or all of pillars 8 and 9.

[0047] The system 1 includes a central unit 2, and, a plurality of ancillary units 3 and 3’ on either side thereof.

[0048] Figure 1 shows a plan view of an initial installation position of the mining system 1 , ready for commencement of a pillar extraction mining operation, wherein the central unit 2 and a plurality of ancillary units 3 and 3’ are each positioned on an installation roadway 4 of the underground mine 10. As seen, the central unit 2 is initially installed at an intersection of the installation roadway 4 and the access or control roadway 6. A plurality of ancillary units 3 and 3’ are positioned on either side of the central unit 2, thereby facing the portions of the pillars 8 and 9 which are to be extracted.

[0049] Also shown in Figure 1 are other components which may be typically utilised in the underground mining process, including a continuous miner vehicle 1 1 , which is used to cut into the pillars to be mined, and shuttle cars 12 which may be used to transport mined material away from the mined location to the conveyor boot end.

[0050] Figure 2 illustrates various plan views, similar to that as shown in Figure 1 , but showing an overall underground mine grid panel 13, so as to illustrate various other roadways and pillars and other typical features of an underground mine, and so as to gain an overall appreciation of the underground mining system and method of the present invention.

[0051 ] Figure 2(a) shows the mining system 1 installed in an initial installation position 20 on an installation roadway 4 of the underground mine grid, ready to commence a mining operation in a direction of mining, as indicated by arrow 21 .

[0052] Figure 2(b) shows the mining system 1 wherein the mining operation within the mining grid 13 has been partially conducted, the mining system having advanced from the installation roadway 4 to the position illustrated by arrow 22, whereby the goaf area 23 behind the position 22 has been mined.

[0053] Figure 2(c) shows the mining system 1 having reached a final recovery or extraction roadway 24 at the end of the mining grid 13, whereby an entire goaf section 25 of the mine grid 13 has been mined.

[0054] Figure 2(d) shows the mining system 1 , including the central unit 2 and plurality of ancillary units 3 and 3’, having been relocated from the position illustrated in figure 2(c) to a new start position 26 ready to recommence the mining operation in the direction illustrated by arrow 27.

[0055] Figure 2(e) shows the mining system 1 continuing to advance forward in the direction of arrow 27 to the mining position illustrated by arrow 28, leaving behind another mined goaf area 29.

[0056] Figure 3 illustrates various plan views, similar to that shown in Figure 1 , detailing the mining system 1 , incorporating the central unit 2 and a plurality of ancillary units 3 and 3’, performing a mining operation.

[0057] Specifically, figures 3(a) to 3(p) illustrate example steps performed in an example mining operation utilising the mining system 1 of the present invention.

[0058] Figure 3(a) shows a continuous mining machine 30, which is used to cut into the pillar 9 of coal or other mineral been mined, breaking away to its right and cutting into the pillar 9. As the material is mined by the continuous mining machine 30, a shuttle car 31 advances with it, and accepts the load of mined product. Figure 3 (a) also illustrates a second shuttle car 32 waiting in the roadway 5, so that, once shuttle car 30 is full and reverses into the boot roadway 7, the second shuttle car 32 can move into position to accept further mined material from the continuous mining machine 30. [0059] Figure 3(b) shows the continuous mining machine 30 plunging further into the cut until it is substantially aligned with the last ancillary unit 3. Figure 3(b) also illustrates the extension of canopy portions 34 of the left hand side roof supports of the ancillary units 3 (L1 to L5) to thereby supporting the roof of the underground mine from falling.

[0060] Figure 3(c) shows the continuous mining machine 30, having reversed into the roadway 6, and then preparing to break to its left side. As seen in figure 3(c), each of the left-hand side roof supports of the ancillary units 3 (L1 to L5) have then advanced forwardly in the direction of mining, shown by arrows 35, and each of these units 3 (L1 to L5) have their forepoles/canopy portions 34 fully extended to thereby prevent the roof of the mine from falling in over the newly mined section of the pillar 9.

[0061 ] Figure 3(d) then shows the continuous mining machine 30 breaking to its left, and shuttle car 32 advancing and accepting further product from the continuous mining machine 30. Figure 3(d) shows the ongoing advancement of each roof support of the ancillary units 3 (L1 to L5) towards the face 36 whilst the mining operation continues on the opposed side of the central unit 2.

[0062] Figure 3(e) shows the continuous mining machine 30 plunging across the face until it is substantially aligned with the last ancillary unit 3’ (R5) and barrier shield 33. As previously, the shuttle car 32 continues to advance and accept load of mined product from the continuous mining machine 30. Again a backup shuttle car 31 may typically wait in the cut-through roadway 5. The armoured face shovel on the left hand side ancillary unit 3 (L1 to L5) is advanced.

[0063] Figure 3(f) shows the continuous mining machine 30 reversing out of the cut into the roadway 6 as illustrated by arrow 38. Figure 3(f) also shows the extension of the forepoles of the right-hand side roof supports of the ancillary units 3’ (R1 to R5) and the advancement of the ancillary units 3’ as illustrated by arrows 39. The loaded shuttle car 32 is also depicted reversing into the boot roadway 7, so that a second shuttle car 31 can advance to then collect another load of product.

[0064] Figure 3(g) shows the continuous mining machine 30 then preparing to break away again to its right, and shuttle car 31 advancing to accept a next load of material from the continuous mining machine 30. Figure 3(g) also illustrates the right-hand side armoured face shovel 3’ (R1 to R5) advancing towards the mine face 36. The central units (C1 to C3) 2 are also shown being advanced forwardly in the mining direction down roadway 6. [0065] Figure 3(h) shows the continuous mining machine 30 then again breaking away to the right to begin another cut. Again the shuttle car 31 accepts a further load of product. The central unit 2 is advanced as shown by arrow 41 , in this case pushed by hydraulic support units 34 (C1 to C3). The right-hand side ancillary units 3’ (R1 to R5) likewise continue to advance towards the mining face 36 as illustrated by arrows 42.

[0066] Figure 3(i) shows the continuous mining machine 30 continuing to cut across the face until it is substantially aligned with the last of the ancillary units 3 (L5). The shuttle car 31 , having accepted product is shown moving towards the boot roadway 7. The armoured face shovel 3 (L1 to L5) advances further towards the mine face 36, as central unit 2 is advanced further down the central roadway 6, driven by ancillary units 3 (C1 to C3). Right-hand side ancillary units 3’ (R1 to R5) are further advanced to the mine face 36, with the forepoles thereof being retracted as the units 3’ approached the face, with the forepoles remaining extended where possible.

[0067] Figure 3(j) shows the continuous mining machine 30 reversing out of the cut into the roadway 6. Ancillary units 3 (L1 to L5) are advanced and their forepoles are fully extended. The right-hand side ancillary unit 3’ is then advanced in preparation for the next cycle.

[0068] Figure 3(k) shows the continuous mining machine 30 positioning itself on the roadway 6 to start a breakaway to its left. The ancillary unit 3 (L1 to L5) is advanced towards the face 36.

[0069] Figure 3(l) shows the continuous mining machine 30 breaking away to the left and loading the shuttle car 32 with more product, as the left hand side ancillary units 3 (L1 to L5) further advance towards the face.

[0070] Figure 3(m) shows the continuous mining machine 30 performing a left cut, whilst the left-hand side ancillary unit 3 (L1 to L5) is further advanced.

[0071 ] Figure 3(n) shows the continuous mining machine 30 continuing to perform a left cut until it aligned substantially with the ancillary unit 3’ (R5) and its associated barrier support. Shuttle car 32 continues to accept product from the continuous mining machine 30. As soon the continuous mining machine 30 is passed the roof supports of the ancillary units 3’ (R1 to R3) are advanced. In the meantime, the roof supports of the ancillary units 3 (L1 to L5) are advanced. [0072] Figure 3(o) shows the continuous mining machine 30 completing the cut, cleaning up the floor, and reversing into the centre or control roadway 6. Shuttle car 32 takes a load of product to the boot roadway 7. The ancillary unit 3 (L1 to L5) is advanced towards the face, the central unit 2 is advanced down the centre roadway 6, and, the right-hand ancillary units 3’ (R1 to R5) are advanced towards the face followed by the right-hand side ancillary units as the cycle permits.

[0073] Figure 3(p) shows the continuous mining machine 30 aligning itself in the centre roadway 6, to commence another breakaway to its right. The central units 2 are advanced down the centre or access roadway (C1 to C3). Ancillary units 3’ (R1 to R5) are advanced further towards the mine face.

[0074] Persons skilled in the art will therefore appreciate that the following aforementioned example of the various steps of the underground mining system of the present invention are for illustrative purposes to gain an understanding of the present invention and its attributes. It will be readily understood by person skilled in the art that the aforementioned examples are nonlimiting and may vary in specific sequence, et cetera, whilst achieving the same overall function.

[0075] Figure 4 shows, in Figures 4(a) and 4(b), plan and front views, respectively, of a left-hand side of an example arrangement of the main components of the underground mining system 1 in accordance with the present invention. As shown, the mining system 1 includes a central unit 2, and, a plurality of ancillary units 3. As previously described, the central unit 2 is, in use, positioned at the intersection of the installation roadway and a control roadway, and a plurality of roof support units 3 are positioned on either side thereof. It will be appreciated that whilst Figures 4(a) and 4(b) only show ancillary units 3 on the left hand side of the central unit 2, in use, ancillary units 3’ would also be provided on the right hand side of the central unit 2.

[0076] Each of the ancillary units 3 and 3’, as illustrated in figure 4, may be embodied utilising commercially available roof support machines, as are well known to persons skilled in the art. In essence, the ancillary units 3 and 3’ incorporate a main body 44, and a canopy portion 45. The canopy portion 45 is adapted to extend substantially outwardly from the upper portion of the main body 44 to thereby define a shielded mining space thereunder. The canopy portion 45 may optionally incorporate a forepole 47 and/or a flipper 48 to effectively further extend the canopy portion 45. The roof support produces a force applied to the roof of the mine to maintain strata stability. The principle functions of the roof support are: 1 ) To control strata deformation, fracture and movement around the mining face, 2) To maintain a safe and productive working environment, 3) To limit the amount of roof to floor convergence, 4) To prevent broken rock from entering the work area, and 5) To secure and advance all plant on the working face including the roof supports. Various mechanisms for propelling the ancillary units 3 and 3’ may be embodied, such as wheels, tracks, and the like, so that the main body 44 is adapted to be forwardly propelled across a substrate surface 46. As these machines of substantially this type are well known to be used in longwall and shortfall mining operations, the details and operation of these machines will be well understood to persons skilled in the art, and therefore, will not be further described herein.

[0077] The present invention provides a unique configuration of these ancillary units 3 and 3’, positioning them on each side of the central unit 2, and, controlling the operation of these ancillary units 3 and 3’ therefrom, as will be described hereinafter. Any number of ancillary units 3 and 3’ may be provided on either side of central unit 2, depending upon the length/width of the pillars 8 and 9 (Fig 1 ) which are desired to be mined/extracted.

[0078] In an example embodiment, the central unit 2 (Fig 1 ) incorporates controller and other components to control the operation of each of the ancillary units 3 and 3’, such that they operate to perform the sequential movement of each of the ancillary units 3 and 3’ as was hereinbefore described with reference to Figure 3. Various components of the central unit 2 may include a processor to control the operation of each of the ancillary units 3 and 3’, a motor, a pump, a hydraulic tank, an electrical distribution enclosure, hydraulic valves, etc.

[0079] In Figure 4 is also illustrated the provision of a shovel mechanism 50, which operates to push any material which falls onto the substrate surface/floor of the underground mine forward and out of the pathway of the ancillary units 3 and 3’. The shovel mechanism 50, as seen in figures 4(a) and 4(b) is made up of a plurality of shovel members 51 which are interlinked together to thereby form the composite shovel mechanism 50. Details of the shovel members 51 , the composite shovel mechanism 50, and the operation of these components will be hereinafter described with reference to Figure 5.

[0080] In figure 4 is also illustrated the provision of one or more roof support operatively attached to the central unit 2 to thereby move the central unit 2 over the substrate surface or mine floor as was described in Figure 3. In an example embodiment, this may be achieved by incorporating a ground engaging member designed to enable the central unit 2 to easily move across a substrate surface. For example, wheels or tracks may be provided below the central unit 2. In an alternative example embodiment, the central unit 2 may be provided with a motor and wheels/tracks thereon such that it can self-propel without the need to be pushed by separate units 3 and/or 3’.

[0081 ] Figure 5 illustrates, in a schematic form, the details and operation of the shovel mechanism 50 utilised in the underground mining system 1 of the present invention. The shovel mechanism 50 incorporates a plurality of shovel members 51 , each shovel member 51 configured to interlink with adjacent shovel members 51 , via a pivotal linkage. The opposed end 52 of the shovel mechanism 50, remote from the central unit 2, is configured as a leg or barrier which is adapted to surround the side of the last ancillary unit 3/3’, that is, the ancillary unit 3/3’ which is located furthest from the central unit 2. Figures 5(a) to 5(g) illustrate typical example sequential movement steps (or snake movement) of the shovel mechanism 50 as it is pushed forward by the ancillary units 3/3’.

[0082] In use, the underground mining system 1 (Fig 3) of the present invention may be initially installed within an installation roadway of an underground mine by positioning the central unit 2 at the intersection of the installation roadway 4 and the main access or control roadway 6. Any desired number of ancillary units 3 and 3’ are then located on either side the central unit 2 within the installation roadway 4. Once the canopy portion of the ancillary units 3 and 3’ are extended substantially outwardly from the main body portion thereof, a shielded mining space is therefore effectively defined thereunder. Material may then be mined from within the shielded mining space. Once mined, the central unit 2 and the ancillary units 3 and 3’ are then repositioned as hereinbefore described with reference to figure 3. Sequential mining and repositioning of the components is therefore repeated.

[0083] As a mining operation progresses, the roof of the mine is permitted to fall behind the roof supports thereby defining the goaf area of the mine, which is alternatively also known as the gob. Once the system components reach the end of the panel to be mined, they are consequently positioned within the final roadway, and therefore may be readily separated and withdrawn by the extraction roadway.

[0084] It will therefore be appreciated that the present invention provides an underground mining system 1 which permits the extraction of pillars from an underground mine in a safe and controlled manner, and which provides an increased productivity of the mine.

[0085] The system of the present invention therefore includes an arrangement which, in one embodiment, includes a central unit or services hub which is located in a supported roadway, and includes all the services necessary for the overall system machinery including electrical control system, hydraulic pump, hydraulic tank, storage systems and optionally ventilation fan.

[0086] To protect the central unit services hub and providing the means of propelling it down the roadway, ancillary units may be used. The ancillary units may be connected to the central unit services hub through a relay bar and clevis arrangement to allow for articulation of the system in varying floor gradients. The central unit services hub may be used as the operator area for the machine and include central controls for the ancillary units, communications, lighting, cameras, ventilation, water sprays, other ancillary equipment and emergency stops.

[0087] Extending away from the central unit services hub on each side of the roadway are ancillary units arranged side by side, which are able to move independently (using the lower, advance, set cycle). The ancillary units are connected by an armoured face shovel mechanism which effectively forms a flexible beam on the face side (advance side) of the ancillary units.

[0088] The ancillary units are able to advance forward by each roof support being lowered itself from the roof, hydraulically pulling itself forward toward the armoured face shovel mechanism (which is prevented from moving by the adjacent supports being stationary and holding it in position), and then resetting the support to the roof. This is known in the industry as the "lower, advance, set cycle” or LAS. The system specification requires that only one roof support is lowered from the roof at a time, which maintains the geomechanical forces required for support of the strata.

[0089] The last powered ancillary unit distant from the services hub may be fitted with a protective shield on the outside edge. There are two of these protective shields with one on each end of the row of ancillary (PRS) units. The protective shield mechanism prevents roof and rib material from falling into the last ancillary unit and from damage and the ingress of fines and debris. It may be hydraulically operated to raise and lower from the roof and to position itself. [0090] By following a “lower, advance, set” cycle, the entire machine may snake (propel) itself forward under its own power. In the case of the central unit services hub, the centrally located units advance into the central or control roadway. In the case of the ancillary units to the right and left of the central unit services hub, they advance into the cavity left once the seam of product has been mined by the continuous miner.

[0091 ] The armoured face shovel mechanism is comprised of sections or members which are interconnected with flexible joints which allow for adjacent beams to flex in the horizontal and vertical planes.

[0092] The machine may be installed in seam conditions where the floor dips or rises locally across the face line, or where the machine is mining uphill or downhill.

[0093] The armoured face shovel mechanism may include a blade on the front edge which sits on the floor and pushes product forward as the machine advances. This product may be then picked up by the shovel mechanism of the continuous miner as it traverses across the face line.

[0094] The powered ancillary units may include features in the canopy of the unit which assist in closing the distance to the face line and reduce the amount of unsupported roof that is exposed in front of them. This additional support may be in the form of hydraulically extending forepole or a flipper plate or a combination of both.

[0095] The method of use of the invention is to erect the machine in an installation roadway (which has been prepared and typically around 8m wide and with strata control roof support installed such as chemically anchored roof bolts, W-straps and mesh) with ancillary units having powered roof support mechanisms adjacent to one another on both sides of the central unit services hub. The central unit services hub is located in the central or control roadway facing the direction of mining. Services such as compressed air hoses, electrical power cables and water hoses are connected to the machine via a flexible connection such as a roof mounted monorail system which is located in the central or control roadway leading up to the central unit services hub. This allows the machine to be propelled forward for some distance without having to manually handle the service connections. The mining plan will determine how many ancillary units may be installed onto the system and the number may vary depending on the plan. There are a plurality of powered ancillary units protecting the central unit services hub and the machine may require a plurality of PRS units on each side of the central unit services hub. [0096] The installation roadway for the machine (RES) needs to be sufficiently wide to arrange the machine components so that they are facing the direction of mining and the machine is ready to support the roof and propel itself forward. The tips of the powered roof supports are located as close as practical to the mining face (around 300mm) and the armoured face shovel mechanism is in the fully advanced position, close to the mining face.

[0097] Depending on the mining conditions and the features of the continuous miner and product haulage machinery, the ancillary units may be installed in a roadway which is at an angle of greater than 90 degrees to the centre or control roadway. In this arrangement the ancillary units are installed with each support staggered a certain distance back from the adjacent support. The centre line of the supports may still remain parallel with the centre or control roadway. This arrangement may be desirable to enable the continuous miner to more easily make the breakaway cut from the centre or control roadway. An angled roadway may also be an advantage if a continuous haulage system is selected as the longer elements of these machines may not be able to negotiate the 90-degree turn.

[0098] The mining system/arrangement of the present invention locates the central unit services hub in a central or control roadway location with the ancillary units aligned to the right hand side and left hand side, permitting mining of the product to be undertaken on both sides of the control or central roadway. Another embodiment of the central unit services hub may place the electrical enclosure, pumps and tank removed from the roof supports with hoses and cables supplying the services to the system by means of a monorail or similar.

[0099] The central unit services hub may have the function of locating the required services for the machine in one area to efficiently control them and variously connect them. Incoming electrical power is connected to an electrical control marshalling enclosure which allows the control and distribution of power through various outlets. The electrical marshalling enclosure allows electrical power to be turned on and off, allows individual machine components to be turned on and off, and, may be isolated or quickly shut down in an emergency.

[0100] A control panel or panels allow for the control of machine components. This may include the logic control of the ancillary units, lighting systems, proximity systems, a camera system and other ancillary functions. Cameras may be mounted remotely along the machine so that the operator may remain at the central unit services hub and be able to drive both the continuous miner and the ancillary units, monitoring the movement of the continuous miner visually, using the cameras or a proximity detection system.

[0101 ] Another embodiment of the control panel may be a remote operating center which could be in another part of the mine, on the surface of the mine or remote from the mine.

[0102] A pump system may be located at the central unit services hub (or may be located remotely on the monorail or some other place) and may be powered by an electric motor. The pump may provide hydraulic pressure and flow which powers the ancillary units. Hydraulic fluid (or water hydraulics) may be distributed to the ancillary units through a network of hydraulic hoses which run in a ring system through the machine.

[0103] A hydraulic tank may store the hydraulic fluid necessary to provide a tidal flow of fluid as the various hydraulic circuits are operating and the machine is moving. The tank may also include various filters and strainers to keep the fluid clean and to clean any new fluid that is introduced into the closed system.

[0104] The ancillary units have the function of providing roof support to the local mining area and generating a bridging force against the roof strata to maintain roof stability while mining is occurring in front of the machine. Each ancillary unit has its own valves and controls to sequence the operation of the hydraulic legs which support the roof, the advancing cylinder which propels the system forward and the various cylinders which provide alignment and extension of components.

[0105] The armoured face shovel mechanism is a heavy cross section construction which is strong enough to form a moveable beam along the face line with flexible connecting linkages between its sections. It includes connecting points on the rear which provide a flexible and strong connection for the relay bar of the ancillary units to be attached. The armoured face shovel mechanism sits on the floor and a blade arrangement on its front face has the purpose of pushing forward any product that is left on the mine floor by the continuous miner. The interconnecting pieces of the armoured face shovel mechanism have a joint design which permits flexible movement, is able to be dismantled easily and yet is strong enough to withstand the forces applied when the face advances and it becomes a reactive beam that allows each unit to pull itself forward.

[0106] The protective shield members on the remote end roof supports have the function of protecting the last powered roof support unit on each end of the machine from collapsing roof material or collapsing rib material and from the ingress of fine material, rocks, and debris into the body of the powered roof support unit which keeps it clean and able to operate correctly.

[0107] There may be an operator’s platform on the services hub that provides the operator with an elevated area to view the operation of the continuous miner which is only required in thick mining seams where the roof height permits and is not required in unmanned systems.

[0108] The storage area on the platform may be used for the efficient handling of monorail beams. Where a monorail has been mounted in the centre or control roadway the beams must be progressively removed as the machine advances or else, they will be struck by the units. Generally, a light weight easily disassembled beam is selected which may be removed from the roof at the central unit services hub and then stored on the central unit services hub platform for later removal.

[0109] When installed, the ancillary units are preferably provided in a line to the right and left of the centrally located services hub unit. The tips of the powered roof supports are best brought forward and touching the face of product in front of them (or as close as practical to the face). The powered roof supports should be extended to the roof. The armoured face shovel should be fully advanced against the face. The protective shields on each end of the machine should be fully extended against the roof.

[0110] Mining preferably commences by the continuous miner advancing towards the machine in the centre roadway and then breaking away to the right or left. The continuous miner (CM) cuts and loads the product working forward across the face of the PRS unit and 90 degrees (or a greater angle) to the direction of mining.

[0111 ] The CM advances across the face of the ancillary units loading product either into shuttle cars, haulage trucks or continuous haulage (mobile conveyor) which follows the CM across the face. As the CM reaches the end of the last ancillary units and mines past the protective shield which is located on the end of the line of ancillary units the operator may continue to overdrive the heading (drive past the last roof support depending on the mine plan and local roof conditions). It may be possible to overdrive the heading several meters in favourable roof conditions and depending on the length of services to the continuous miner and coal haulage systems. The intention always is that operators are working under supported roof and so if shuttle cars are utilised the limit of the continuous miner depth of cut will be as far as the continuous miner is still able to load product into the shuttle car with the driver of the shuttle car still located under the supported roof of the central roadway. In another embodiment a remotely controlled shuttle car or surge car may follow the CM across the face under unsupported roof.

[0112] As the CM is advancing across the face the armoured face shovel mechanism remains in position so that it does not obstruct the continuous miner but the ancillary units are operated and advanced fully forward as soon as it is possible to do so behind the continuous miner cutter head. These are then set to the roof and the forepole roof support may also be extended. This reduces the amount of exposed roof as quickly as possible.

[0113] As soon as the continuous miner has finished the cut it is trammed back out of the heading into the center or control roadway and the cycle of advancing the ancillary units continues. The aim of this cycle is to rapidly advance the armoured face shovel mechanism and the ancillary units until the tips of the roof supports are against the face again and the area which has just been cut by the continuous miner has the roof supported by the ancillary units. The first ancillary units to be advanced are remote from the central unit services hub which is occurring as the CM is driving backwards out of the cut. The forepole and flipper plates are extended (providing maximum coverage of the heading that has just been cut). Then the ancillary unit is run through the lower, advance, set cycle (LAS). As adjacent ancillary unit is advanced a snaking pattern is formed by the ancillary units and the armoured face shovel mechanism.

[0114] While the newly mined side of the machine is advancing toward the face and supporting the roof, the central unit services hub is left in position. The continuous miner now advances onto the opposite side of the heading cutting in the opposite direction. The process of the continuous miner cutting across the face of the powered roof support units is repeated on this opposite side.

[0115] When mining on the opposite side is completed (mirroring the technique of extension of forepoles and ancillary units over the CM as soon as the cutter head has passed), the continuous miner will again be located in the central roadway a number of metres back from the central unit services hub. The last part of the machine to be advanced is the central unit services hub which is advanced down the roadway by a plurality of central units pushing it forward using hydraulic cylinders while they are locked in position against the roof. If a monorail is being utilised the end monorail beams at the central unit services hub should be removed prior to advancing the central unit services hub and the beams stored in the storage rack or removed from the area. Once the central unit services hub has been advanced the central units are lowered from the roof and then advance themselves pulling forward against the central unit services hub.

[0116] The machine is now in the starting position again having completed one mining cycle and the mining cycle may be repeated.

[0117] In an example embodiment, the entire machine system typically mines into a roadway (recovery or extraction roadway) where it may then be dismantled, although this is not necessary, and it could be possible for the machine to complete its mining and then be removed from the “cavity” where it stops. In this case the machine could be recovered in a manner similar to that used at longwall mines where mesh is installed to the roof in the run down to the stop position using roof bolts and chemical anchors. Then using specialised machinery such as an underground dozer with a jib the armoured face shovel mechanism would be removed, interconnecting hoses and cables would be disconnected, and the powered roof supports would be lowered one at a time and pulled out of line. Another method of extracting the roof supports in preparation for moving them to a new location is by use of an E-Frame (or F frame) where two additional roof supports are installed at 90 degrees to the face line at the end of the face line. They are used to support the roof as each ancillary unit is removed, and they advance in each cycle toward the services hub roadway until all the ancillary units have been removed.

[0118] The invention may be used to mine material on an advancing panel where 3 or more headings are typically developed, and the conveyor is located in one of the central or control roadways (Fig 2). In this case the system of the present invention is installed facing the direction of mining as the panel advances. Once the panel has reached its planned length a recovery or extraction roadway must be built to allow the relocation of the units from one side of the panel to the other. The units will be assembled onto the other side of the panel in the opposite direction to the advance and from this position they are ready to retreat. Product is then mined on the retreat of the panel and the conveyor belt is shortened as each pillar is mined on retreat.

[0119] The system of the present invention utilises a unique layout with a central unit in a central location in a control or central roadway and ancillary units arranged to the left hand side and the right hand side in a row. This is a completely different arrangement/configuration from that used in longwall mining or shortwall mining. [0120] The system of the present invention allows the ancillary units to achieve strata control in the localised mining area on a scale suitable to perform pillar extraction in a safe controlled method in a variety of roof and strata conditions.

[0121 ] The system of the present invention may use a central unit services hub which contains the services for the machine (hydraulic oil storage tank, hydraulic pumps, electrical distribution and control board, control panels, operator area, monorail storage pods).

[0122] The system of the present invention may use protective screens at each end of the line of ancillary units to protect them from the ingress of goaf material, fines, rocks and debris and these move with the system via linkages.

[0123] The layout of the panel will depend on mine plans and mining conditions which will be influenced by a variety of factors such as resource location, geological conditions, presence of gas, layout of the mine, type of product haulage utilised, layout of services, location of conveyors. It is possible to use the mining method to mine existing panels (pillar extraction, removal of main roadway pillars) although an installation roadway would have to be established to set up the ancillary units initially. In panels laid out for this mining method roadway intersections may be at 90 degrees or some other angle (herringbone pattern).

[0124] The number of ancillary units employed on each side of the central unit services hub may vary depending on requirements. It is not necessary to have an equal number of ancillary units on each side of the services hub and the system could run a “long” side and a “short” side if required.

[0125] The arrangement of the central unit services hub may vary depending on the requirements of the system and how many ancillary units intend to be used (the number of ancillary units used may vary from location to location). There may be multiple pumps required where additional ancillary units are being used or where redundancy is desirable. The tank size and shape can vary depending on individual mine requirements. The features included in the control system will vary depending on the requirements and budget of the mine. The central unit services hub may be fashioned from a single skid plate, multiple skid plates or track mounted frames, wheeled frames or similar.

[0126] The sequence of advancing the armoured face shovel mechanism and ancillary units may vary depending on local conditions and level of automation included in the control system. [0127] Some of the units (for instance those in the centre or control roadway) may be replaced with track mounted mobile roof support units, depending on the mine requirements.

[0128] The length and shape of the armoured face shovel elements/members may vary depending on seam heights and floor conditions. The connecting elements between the armoured face shovel component may vary depending on floor conditions and may include bolts, ropes, chains, pins, forgings of different sizes and arrangements.

[0129] In an example embodiment, automation may be included to the system to allow for remote operation of both the system components and the continuous miner. The advantage of remote operation is to allow the operator to be distant from the mining area and not exposed to dust or the risks inherent in underground mining such as roof or rib collapse, movement of machinery and other risks. A higher level of automation may require remote control equipment, additional cameras, proximity equipment to allow remote assessment of the machinery interaction, remote monitoring screens and the like. With an automation package installed, the system could be operated remotely from an underground control station (either mounted on the monorail in a pod format or located in a cut-through in a control room format) or from the mine surface (in a surface control room format). The cyclical process of operating the system and advancing the system makes remote operation possible. This provides mines with the option of having no personnel at the mining face while the continuous miner is cutting and pillar extraction is taking place.

[0130] Integration of control systems between the operation of the continuous miner, haulage system and the system may be desirable to prevent collision between elements, to enable to advance of the ancillary units and armoured face shovel mechanism to be efficient and fast without risk of machine collisions. Automation importantly enables the use of an unmanned haulage system in the face area. If the haulage system could follow the continuous miner down the face greater distance then the width of the face could be increased (with the addition of ancillary units) without exposing the haulage operators to working under unsupported roof.

[0131 ] Ancillary units that contain features enabling them to be more easily relocated may be desirable whereby the specialised equipment required to move these heavy elements would be minimised and the normal “load haul dump” or roof mounted monorail machines in use at most underground mines would then be able to relocate the heavy powered roof support units. [0132] In some mining areas the roof behind the machine may not cave and this standing roof area then becomes a windblast hazard if the standing area is too large. The powered roof supports provide some protection to the operator in these conditions but it is not complete protection. An improvement may take into account a safe area for protection from windblast or the inclusion of a means of collapsing the roof behind the machine (hydraulically fracturing or similar).

[0133] It may be desirable in some grid or panel layouts to include ventilation integrated with the component parts of the invention. This may include a ventilation fan and ventilation ducting to either extract air or blow air. The ventilation fan could be installed onto the central unit services hub or could be mounted remotely on the monorail. The ducting could run along the line of ancillary units by integrating the ducting with the armoured face shovel mechanism or suspending the ducting from the ancillary unit canopies.

[0134] It will be appreciated that the above disclosures only provide example embodiments of the invention. Numerous variations and modifications to these example embodiments will become apparent to persons skilled in the art. All such variations and modifications should be considered to be within the scope of the present invention as hereinbefore described and as hereinafter claimed. For example, alternate styles of powered roof support may be utilised depending on mine site requirements. Roof supports with 2 leg or 4 leg designs may, for example, be utilised. Roof supports with canopy designs which include a two piece canopy which is able to hydraulically fold down assisting relocation of the equipment around the mine may also alternatively be utilised. Other embodiments which provide for a lighter roof support and one that is more easily transported around the mine should also be considered to be within the scope of the present invention.

[0135] Where ever it is used, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of”. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.

Claims

1 . A mining system for the extraction of pillars on either side of a control roadway of an underground mine grid, the mining system including: a central unit, adapted to be initially positioned at an intersection of said control roadway and an installation roadway, and configured to be forwardly propelled along the control roadway in a mining direction towards an extraction roadway; and, a plurality of ancillary units, at least one ancillary unit being located on each side of said central unit, each ancillary unit including: a main body, adapted to be forwardly propelled adjacent to said central unit; and, a canopy portion, adapted to extend substantially outwardly from an upper portion of the main body to thereby define a shielded mining space thereunder; and, a controller, configured to control the operation of the central unit and each ancillary unit.

2. A mining system according to claim 1 , wherein said central unit includes the controller configured to control the operation of each ancillary unit.

3. A mining system according to claim 2, wherein said controller is operated remotely.

4. A mining system according to any one of claims 1 to 3, wherein said canopy portion of each ancillary unit is configured to slide and/or pivot substantially outwardly from said main body.

5. A mining system according to any one of claims 1 to 4, wherein said central unit and said main body of each said ancillary unit each include a ground engaging member adapted to propel each unit over a substrate surface.

6. A mining system according to any one of claims 1 to 5, wherein each said roof support unit further includes a shovel member configured to forwardly push any mineral or other material atop said substrate surface away from said unit.

7. A mining system according to claim 6, wherein said each shovel member of each unit is configured to be pivotally attached to a shovel member of an adjacent unit to thereby form a composite articulated shovel mechanism.

8. A mining system according to any one of claims 1 to 7, wherein said central unit is either: self propelling; or, is configured to be propelled by a separate unit.

9. An underground mining method for the extraction of pillars on either side of a control roadway of an underground mine grid, the method including the steps of: positioning a central unit at an intersection of said control roadway and an installation roadway; locating at least one ancillary unit on each side of said central unit within said installation roadway, each ancillary unit including a main body and a canopy portion extending substantially outwardly from a main body to thereby define a shielded mining space thereunder; mining any mineral or other pillar material provided within said shielded mining space; advancing the position of said central unit and each ancillary unit progressively towards an extraction roadway; and, repeating said mining and advancing steps until said central unit and each ancillary unit reaches the extraction roadway.

10. An underground mining method according to claim 9, wherein, in said advancing step, a controller is configured to progressively operate a ground engaging member of each unit to thereby propel each unit over a substrate surface.

11. An underground mining method according to claim 10, wherein said controller is adapted to selectively advance the position of each unit in a snake like manner.

12. An underground mining method according to claim 11 , wherein said controller utilizes a lower from the roof, advance, set to the roof, methodology (LAS).

13. An underground mining method according to any one of claims 9 to 12, wherein, in said advancing step, after each main body of each ancillary unit is repositioned, each canopy portion, including a forepole and/or a flipper, is thereafter operated to be pivotally and/or be slidably extended outwardly to redefine a new shielded mining space thereunder.

14. An underground mining method according to any one of claims 9 to 13, wherein, in said advancing step, prior to advancement of each unit, a shovel mechanism associated with the respective ancillary unit is operated to forwardly push any mineral or other material atop said substrate surface away from said ancillary unit.

15. An underground mining method according to any one of claims 9 to 14, wherein, in said mining step, mineral or other material is extracted using any one or combination of: a continuous miner vehicle; a conveyor; a shuttle car; a battery hauler; a feeder-breaker; and, a continuous haulage system.

16. A controller of an underground mining system according to any one of claims 1 to 8, configured to control the operation of said central unit and each ancillary unit located on either side thereof.

17. A controller according to claim 16, wherein said controller is operated remotely.

18. An ancillary unit of an underground mining system according to any one of claims 1 to 8, the operation and repositioning thereof being configured to be controlled by a controller.

19. A shovel member associated with an ancillary unit of an underground mining system according to any one of claims 1 to 8, configured to forwardly push any mineral or other extracted material atop a substrate surface away from said ancillary unit.

20. A shovel mechanism including a plurality of shovel members according to claim 19, each shovel member being pivotally attached to a shovel member of an adjacent ancillary unit, so as to thereby be moved in a snake like manner.

21 . A pillar extraction system for underground mining, including: a central unit; at least one ancillary unit located on each side of said central unit, each ancillary unit including: a main body, adapted to be forwardly propelled; and, a canopy portion, adapted to extend substantially outwardly from an upper portion of the main body to thereby define a shielded mining space thereunder; and, a controller configured to control the operation of the central unit and each ancillary unit.

22. A pillar extraction method for underground mining, including the steps of: positioning a central unit within a control roadway of an underground mine; locating at least one ancillary unit on each side of said central unit within an installation roadway, each ancillary unit including a canopy portion extending substantially outwardly from a main body portion thereof to thereby define a shielded mining space thereunder; mining any mineral or other material provided within said shielded mining space; repositioning the position of said central unit and the location of each said roof support unit; and, repeating said mining and repositioning steps until the units reach an extraction roadway.

23. A method of installation of an underground mining system in an underground mine, including the steps of: positioning a central unit at an intersection of a control roadway and an installation roadway of an underground mine grid; and, locating at least one ancillary unit on each side of said central unit within said installation roadway, each ancillary unit including a canopy portion extending substantially outwardly from a main body portion thereof to thereby define a shielded mining space thereunder.

24. A method of extraction of an underground mining system from a mine, including the steps of: driving a central unit and its associated ancillary units to an extraction roadway of an underground mine; and, separating each unit and withdrawing it via said extraction roadway.