BR112020019097A2 - CUTTING SET FOR A ROCK EXCAVATING MACHINE AND LONG WALL MINING SYSTEM. - Google Patents

Abstract

cutting set for a rock digging machine, and long wall mining system. this description refers to a cutting set (10) for mining comprising a disc cutter (18), which is movable between horizontal and vertical cutting orientations.

Description

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CUTTING ASSEMBLY FOR A ROCK EXCAVATION MACHINE AND LONG WALL MINING SYSTEM Campo da Invenção

[001] The present exhibition refers to mining and excavation machines. In particular, it refers to a cutting set for a rock-digging machine. Foundations

[002] Many types of rock formations are available in the world as large deposits, commonly known as plates. Various types of mining equipment are implemented in above-ground quarries in order to extract slabs from the ground. The plates are recovered using specialized equipment, usually dragged from their place of settlement by large and very powerful vehicles. The rock plates can weigh up to 40 t (40,000 kg). Processing, such as polishing, can take place on site or alternatively the plates can be transported off site to cut into pieces appropriately sized for domestic and industrial use.

[003] The same equipment used above ground may not always be directly usable within the confined space of an underground mine.

[004] It is an object of the invention to provide a compact and versatile cutting set to facilitate the mining and extraction of blocks of geometric or non-geometric shape of specific rock formations and one that can be used above or below the ground. Summary of the Invention

[005] According to a first aspect of the invention, a cutting set is provided for a rock excavating machine, the cutting set comprising: a base unit, one or more movable support arms extending from the base unit, a drive spindle

2/18 rotatably mounted on or on each movable support arm, a disk cutter fixed around the drive spindle in such a way that rotation of the drive spindle causes a rotation corresponding to the disk cutter, the disk cutter comprising a body cutter and one or more cutting elements peripherally arranged around the cutter body, where the or each support arm is configured to be movable for first and second cutting orientations, where in the first cutting orientation, the cutting spindle drive is horizontal and in the second cutting orientation, the drive spindle is vertical.

[006] The cutting set is particularly useful under the ground to be divided into rock formations, such as chimberlite, granite or dolerite. The intention is that the cut rocks will fragment under their own weight or by force of secondary wedge, thus enabling the mining of rock material in bulk, in solid blocks of geometric shape.

[007] Alternatively, the cutting set can be used to precondition rock surfaces by creating microcracks on the rock surface, thereby facilitating subsequent extraction with less energy consumption. In this application, pulverized rocks can be extracted in a semi-fluid paste.

[008] In one embodiment, a pair of spaced support arms is provided.

[009] Preferably, the or each support arm is movable between a first operating position and a second operating position, in each of the first and second cutting directions, according to the required cutting depth.

[0010] Optionally, the or each support arm comprises a first arm portion connected to a second arm portion by a joint, each first and second arm portion being independently movable in relation to the other.

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[0011] In some embodiments, a plurality of disc cutters are arranged on the drive spindle. In such embodiments, the plurality of disc cutters is preferably evenly spaced along the length of the drive spindle.

[0012] The plurality of disc cutters can be spaced by an interval measuring between 10 cm and 50 cm.

[0013] Optionally, the gap between adjacent disc cutters is adjustable.

[0014] In some embodiments, at least one disc cutter is mounted perpendicularly around the drive spindle. In other embodiments, at least one disc cutter is mounted non-perpendicularly around the drive spindle.

[0015] Optionally, the disc cutter additionally comprises one or more tool holders extending radially outwardly from the circular body, preferably a tool holder for each cutting element. Preferably, a plurality of tool holders can be used.

[0016] In some embodiments, tool holders are evenly spaced around the cutter body. In other embodiments, tool holders are irregularly spaced around the cutter body.

[0017] In some embodiments, the cutting element comprises a hard material selected from the group consisting of cemented carbide (e.g. tungsten carbide), cubic boron nitride, diamond, diamond-like material or combinations thereof.

[0018] The or each cutting element is optionally a compact polycrystalline diamond (PDC).

[0019] In some embodiments, each tool holder has a front face and a rear face, each cutting element being seated on the face

4/18 front of the tool holder, facing or pointing in the direction of rotation of the disc cutter.

[0020] According to a second aspect of the invention, a long wall mining system is provided comprising a cutting assembly according to the first aspect of the invention, a conveyor system for transporting mined rocks out from a face cutting edge and a collecting arm to collect mined rocks from the cutting face and transfer it to the transport system. The long-wall mining system may comprise a secondary wedge tool. Brief Description of Drawings

[0021] The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a schematic plan view of an underground mine incorporating a first modality of a cutting assembly as part of a long-walled mining system and shows in particular the cutting set in a horizontal orientation; Figure 2 is a schematic end view of the long wall mining system of Figure 1; Figure 3 is a schematic plan view of an underground mine incorporating a second embodiment of a cutting set as part of a long-wall mining system and shows in particular the cutting set in a vertical orientation; Figure 4 is a schematic end view of the long wall mining system of Figure 3; Figure 5 shows a front elevation view of a first mode of a disc cutter; Figure 6 shows a front elevation view of a cutting element for use with the disk cutter of Figure 5; Figure 7 shows a side elevation view of the cutting element of the

5/18 Figure 6; Figure 8 shows a front perspective view of a second mode of the disc cutter; Figure 9 shows a side elevation view of a plurality of cutting elements for use with the disk cutter of Figure 8; Figure 10a is a side elevation view of a first individual sectioning element from Figure 9; Figure 10b is a side elevation view of a second individual cutting element from Figure 9; in the drawings, similar parts have been assigned similar reference numbers. Detailed Description

[0022] With reference initially to Figures 1 to 2, a cutting set to divide into natural formations 2 under the soil, usually indicated at 10.

[0023] The cutting set is part of a long wall mining system 1, commonly found in underground mines. The cutting set is a substitute for the well-known clipper technology, which operates on the floor of a mine 4, in the middle a series of adjustable ceiling brackets

6. As the shearer advances in the direction of mining, the ceiling brackets 6 are positioned to support the roof of mine 8 directly behind the shearer. Behind the roof supports 6, the roof of mine 6 collapses in a relatively controlled manner. Normally, a collecting arm collects mined rocks on the cutting face and transfers it to a transport system for subsequent removal from the mine.

[0024] In a first embodiment, indicated in Figures 1 and 2, the cutting set 10 comprises a base unit 12, a pair of spaced support arms 14 extending from the base unit 12, a drive spindle 16 extending between and rotatingly mounted on the

6/18 pair of movable support arms 14 and a plurality of disc cutters 18 fixed around the drive spindle 16.

[0025] In a second embodiment, indicated in Figures 3 and 4, a single support arm 14 extends from the base unit 12. The drive spindle 16 is supported centrally by the single support arm 14 and the plurality of cutters disc 18 is mounted on the drive spindle 16, distributed on each side of the single support arm 14.

[0026] In an alternative mode, not shown, only a single disc cutter 18 is used.

[0027] Preferably, the or each disc cutter 18 is mounted in its center (ie, centrally) around the drive spindle 16. However, this is not essential and the or each disc cutter 18 can alternatively be mounted displaced from its center around the drive spindle 16. Optionally, and instead, a combination of the two arrangements could be used. For example, when multiples and disc cutters 18 are used in a series, ie, in parallel next to each other along a drive spindle 16, alternating disc cutters 18 can be mounted centrally around the drive spindle 16. Each center of the remaining disc cutters 18 can be radially offset from the point where the disc cutter 18 is mounted around the drive spindle 16. Other combinations are considered.

[0028] The base unit 12 acts as a transport system for the disc cutter 18. The base unit 12 is movable to advance and retract the disc cutter 18 in and out of an operational position, in close proximity with rock formation 2 to be mapped. The speed at which the base unit 12 moves closer to the rock formation 2 is one of several variables determining the feed rate of the cutting set 10 within the rock formation 2. The base unit 12 (in harmony with the supports 6) is also mobile

7/18 laterally, from left to right and vice versa, along the long wall of rock formation 2 to be mined.

[0029] Each support arm 14 is configured to be movable for a first and a second cutting orientation. In the first cutting orientation, best seen in Figures 1 and 2, the drive spindle 16 is horizontal. As a result, cuts in the rock formation 2 made by the disc cutter 18 are correspondingly vertical. In the second cutting orientation, best seen in Figures 3 and 4, the drive spindle 16 is vertical. Consequently, cuts in the rock formation 2 made by the disc cutter 18 are correspondingly horizontal. The first and second cutting directions are possible with either the first or second modes mentioned above.

[0030] Optionally, the support arm (s) 14 can also be movable in such a way that the drive spindle 16 is operable in any cutting orientation between the above-mentioned vertical and horizontal, although this is not essential. The support arm (s) 14 can alternatively be configured in such a way that it (s) is movable between the first and second cutting orientations, but only fully operational (s) (ie the rotary cutter (s) to rotate in order to facilitate cutting or spraying of rocks) in the first and second cutting orientations.

[0031] Each support arm 14 is movable between a first operating position and a second operating position, and optionally each between the first and second cutting orientations, according to the required cutting depth. This is indicated by the double-headed arrow A in Figure 2. For example, in the first operating position, the drive spindle 16 is lowered so as to be in close proximity to the mine floor 4 and in the second operating position, the drive spindle. drive 16 is elevated so as to be in close proximity to the mine roof 8.

[0032] Optionally, each support arm 14 can have a

8/18 first arm portion connected to a second arm portion by a pivot joint (or alternatively, a universal joint), each first and second arm portion being independently movable in relation to each other. This arrangement increases the degrees of freedom with which the cutting set 10 can operate and advantageously improves its maneuverability.

[0033] The drive spindle 16 is driven by a motor to rotate at a particular speed. The motor power is normally between 20 and 50 kW per disc cutter 18, depending on the type of disc cutter 18 selected and the required cutting force.

[0034] As best seen in Figure 5, in one embodiment, the disc cutter 18 comprises a circular body 20 and a plurality of cutting elements 22 arranged peripherally around the circular body

20. The rotation of the drive spindle 16 causes a corresponding rotation of the disc cutter 18. However, the disc cutter 18 does not need to be circular and can only be generally circular, for example, depending on its size, an octagonal cutter could approach a generally circular disc cutter. Consequently, the disc cutter 18 can be hexagonal, octagonal, decagonal etc., or actually have any number of circumferentially extended sides.

[0035] The or each disc cutter 18 may additionally comprise one or more sensors. These sensors can be embedded or integrated in the cutter body 20. The sensor can be any of the following: a temperature sensor, a pressure sensor, an X-ray sensor, a gamma ray sensor, an accelerometer, a sensor configured for monitor the chemistry of cutting conditions or a sensor to identify rock formation or materials for extraction. In such a modality, the sensors can be coupled to a data collection system and potentially also coupled with an online or remote data analysis package from the mining / extraction operation.

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[0036] In a preferred embodiment, a plurality of disc cutters 18 are arranged on the drive spindle 16. Typically, six or more disc cutters 18 can be provided. The disk cutters 18 are preferably evenly spaced along the length of the drive spindle 16, between the pair of spaced support arms 14a, 14b or either side of the support arm 14, depending on the embodiment.

[0037] The spacing of the disc cutters 18 is selected according to the required depth of cut and the mechanical properties, eg final tensile strength (UTS), of the rock formation 2 being cut in order to optimize the specific cutting energy, which will dictate the required power consumption. The goal is to obtain conditions under which the cut material will fragment under its own weight. For example, for a cutting depth of 0.4 m in chimberlite, the ideal spacing between adjacent disc cutters is around 0.3 m. However, this can be increased or decreased depending on the force required for fragmentation. Preferably, the spacing is adjustable in situ and can be an automated process or a manual process. Spacing can be remotely adjustable, for example from an above ground operations office. A die-shaped tool can be used to apply such a fragmentation force, to assist in the fragmentation of rocks.

[0038] Disc cutters 18 are spaced apart by an interval measuring between preferably 0.01 m and 2 m, more preferably between 0.01 m and 0.5 m. Even more preferably, the disc cutters are spaced 18 by 10 cm to 40 cm apart.

[0039] The circular body 20 of the disc cutter 18 is normally made from steel and has a diameter of approximately 100 mm and a thickness (measured axially, also considered to be a lateral extension for subsequent descriptions) of approximately 11 mm. Realistically, such a diameter allows a cutting depth of up to 400 mm. O

10/18 circular body 20 has a shaft diameter 23 of between 60 mm and 100 mm and is dimensioned and shaped to receive the drive spindle 16.

[0040] The diameter (or effective diameter in the case of non-circular disc cutters) and the thickness of the disc cutter 18 are selected appropriately according to the intended application of the cutting set. For example, cable laying applications require a disc cutter 18 with a smaller diameter. Robotic arm angle rectifiers would require an even smaller diameter. However tunneling applications would require a disc cutter 18 with a significantly larger diameter and would be adapted accordingly.

[0041] In this embodiment, the disc cutter 18 also comprises a plurality of tool holders 24 for receiving a corresponding amount of cutting elements 22. In an alternative embodiment, the disc cutter comprises one or more tool holders.

[0042] Preferably although not essentially, each tool holder 24 provides a seat for a cutting element 22. Preferably, each tool holder 24 is made from steel, but may alternatively comprise any metals or carbides or materials based on ceramic with a hardness above 70 HV (Vickers hardness). Each tool holder 24 can either be permanently connected to the cutter body 20 (eg using brazing or welding), as in the embodiment shown in Figures 5, 6 and 7 or it is detachably mounted on the cutter body 20 using a retention mechanism, as in the embodiment shown in Figures 8, 9 and 10a and 10b. A mixture of brazing, welding and / or mechanical connections could be used. Alternatively, the tool holder (s) 24 can be formed in solidarity with the body 20 of the disc cutter 18, for example, by forging, powder metallurgy, etc.

[0043] The retention mechanism may comprise a locking pin arrangement 25 which is used to secure the tool holder 24 to the

11/18 cutter body 20. Grip, shrink fit etc. can alternatively be used.

[0044] In one embodiment, each cutting element 22 is rigidly or fixedly supported by one of the tool holders 24. Each tool holder 24 is preferably evenly spaced around a circumferential surface of the cutter body 20. Each cutting element 22 can be held in place on or over the tool holder 24 using brazing. Alternatively, the or each tool holder 24 can be configured to rotatively receive a cutting element 22. In such an embodiment, the cutting element 22 and tool holder 24 can be configured in such a way that the cutting element 22 can rotate freely inside the tool holder 24, eg with a clearance fit or alternatively be caps d rotate inside the tool holder 24 only when the cutting element 22 comes into contact with the rock formation being mined / excavated, eg with a fitting transition.

[0045] Each of the cutting elements 22 comprises a hard, wear-resistant material with a hardness value of 130 HV and above. The cutting element 22 preferably comprises a super hard material selected from the group consisting of cubic boron nitride, diamond, diamond-like material or combinations thereof, but may instead be a hard material such as tungsten carbide. The cutting element 22 may comprise a cemented carbide substrate to which the super hard material is joined.

[0046] In one embodiment, the cutting elements 22 are compact polycrystalline diamonds (PCDs), most commonly found in the oil and gas drilling field. Such PCDs are often cylindrical and usually comprise a diamond layer sinter bonded to a steel or carbide substrate.

[0047] The PCD has a diameter of between 6 mm and 30 mm,

12/18 preferably between 8 mm and 25 mm. For example, the PCD can have a diameter of 13 mm or 16 mm or 19 mm. Preferably, the PCD has a diameter of 16 mm. A combination of diameters can be used on a disc cutter.

[0048] Each PCD can be chamfered, double chamfered, multiple chamfered.

[0049] Each PCD may comprise a polished cutter surface or be at least partially polished.

[0050] Alternatively, instead of being a traditional PCD, the cutting element 22 can be a 3-D cutter. A cutting edge 22 of the cutting element 22 can be conical, pyramidal, ballistic, chisel-shaped or hemispherical. The tip of incidence can be truncated with a flat apex or not truncated. The tip of incidence can be axisymmetric or asymmetric. Any shape of cutting element 22 could be used, in combination with any aspect of this invention. Examples of such shaped cutters can be found in WO2014 / 049162 and WO2013 / 092346.

[0051] In a first modality of a tool holder 24, in Figures 5, 6 and 7, each tool holder 24 is generally tapered when viewed axially (see Figure 6). Each tool holder 24 has a front face 26 and a rear face 28, each cutting element 22 being received at a seat 30 on the front face 26 of the tool holder 24. Each seat 30 is angled in such a way that the cutting element 22 faces tangentially (or usually points towards) the intended direction of rotation. This is particularly useful for PCDs that have a flat primary cutting surface 32. Thanks to the seat, a cutting edge 33 of the cutting element 22 can be oriented at a range of angles with respect to the cutter body 20, which contrasts with the conventional approach of having cutting elements 22 pointing exclusively radially or axially outward at

13/18 direction of advance of the face of rocks. This allows great flexibility to obtain a desired cutting angle without having to change the configuration of the cutting element's tip.

[0052] Furthermore, having a seat to receive a separate cutting element 22 means that advantageously, any excess PDC stock can be used and find utility in a new application, thereby reducing a company's working capital.

[0053] Optionally, the angle of inclination of the cutting element is between 25 degrees and 30 degrees. Optionally, the tilt angle is around 25 degrees. Optionally, the angle of inclination can be positive or negative.

[0054] The front face 26 of the tool holder 24 is generally shorter than the rear face 28, thereby providing significant structural support for the cutting element 22 during use. The tool holder 24, particularly the rear of the tool holder 24 in the direction of rotation, absorbs a significant proportion of the impact forces during use and reduces the risk of the cutting element 22 otherwise jumping out of the cutter body 20 and be lost.

[0055] Preferably, the seat fully supports the rear (i.e., the surface which is generally opposite the cutting surface 32) of the cutting element 22.

[0056] In side view (see Figure 7), each tool holder 24 has a variable lateral cross section, indicated by arrow B. Each tool holder 24 tapers laterally inward from the head 34 of the tool holder 24 near from the cutting element 22 to a foot 36, close to the circular body 20.

[0057] A lateral extension (best seen in Figure 7) of each cutting element 22 is greater than a lateral extension of the tool holder

24. This projection protects the tool holder 24 from significant wear

14/18 during use. Preferably, a thickness (i.e., lateral extension) of the tool holder 24 is around 14 mm. In this embodiment, the cutting element 22 projects beyond the tool holder 24 of approximately 1mm on each side. This ensures that it is the cutting element 22 and not the tool holder 24 or the cutter body 20, which is subject to primary wear during use. The protrusion prevents the tool holder 24 from rubbing against the rock formation 2. In the event of rubbing, a hard coating or a multilayer approach can be used.

[0058] In a second embodiment of a tool holder 24, as shown in Figures 8 and 9, successive tool holders 24 are laterally displaced with respect to the cutter body 20. As indicated in Figures 10a and 10b, each tool holder 24 includes a slight twist to one side. In other words, a distal portion 24a of the tool holder 24 is laterally displaced with respect to the circular body 20 and a proximal portion 24b of the tool holder 24. Both the distal and proximal portions 24a, 24b are laterally elongated. The distal and proximal portions 24a, 24b of the tool holder 24 are at an intersection, usually indicated in

38. The direction of the lateral displacement is in either a first direction, axially away from one side of the cutter body 20 or in a second opposite direction, away from the other side of the cutter body 20. In Figure 10a, tool holder 24 is twisted to the right and in Figure 10b, toolholder 24 is twisted to the left. Intersection 38 can be a sudden change of direction, such as a dog's leg or a prolonged change of direction, such as a curve. The intersection 38 can comprise a median portion joining the distal portion 24a with the proximal portion 24b.

[0059] As an alternative, it is considered that the proximal portion 24b could be laterally displaced with respect to the cutter body 20 while the distal portion 24a is in alignment with the circular body 20. However, since the cutting element 22 is usually located on the

15/18 distal portion 24a of tool holder 24, the first arrangement mentioned is preferable.

[0060] Along the circumferential surface 40 of the cutter body 20, the direction of lateral displacement alternates for successive tool holders 24. The benefit of this arrangement is that it increases the effective cutting area offered by the cutting elements 22 during rotation circular body 20, regardless of the size of the cutting element 22. This also facilitates a quick and easy change of an individual tool holder 24 during maintenance and repair, without having to remove the entire cutter body 20. Furthermore, the arrangement helps to reduce erosion of the cutter body 20 (sometimes known as ‘body wash) caused by the flow of cut rocks beyond the cutter set 10.

[0061] The cutting set 10 may additionally comprise a hard contact material (not shown). The hard contact material may comprise a low melting carbide (LMC) material, distinguished by its iron base. Exemplary materials are described in US 8,968,834, US 8,846,207 and US 8,753,755, although other wear-resistant materials could be used instead. The purpose of the hard contact material is to limit body wash of the circular body 20. The hard contact material can be located rotatably behind the tool holder 24, close to the rear face 28. If the tool holders 24 are spaced, then the hard contact material can be provided on or on the cutter body 20, between successive tool holders 24. Additionally or alternatively, the hard contact material can be provided on the rear face 28. Additionally or alternatively, the hard contact material can be provided on the front face 26. The hard contact material can be provided on the front face 26, the rear face 28 and on the additionally circumferential 40. The location of the hard contact material on the cutter body 20 and / or tool holder 24 is site specific and is

16/18 selected according to the nature of the rock formation being mined at that site.

[0062] In use, the disc cutter 18 is put in contact with the rock formation 2 and rotation of the drive spindle 16 and, therefore, of its disc cutter (s) 18, causes division of the rock formation 2 The cutting set 10 splits into the rock formation 2, for example, to create clean orthogonal cuts of around 16 mm, depending on the size of the cutting elements 22 selected. The cut rocks break up either under their own weight or with secondary wedge force, e.g. using a wedge-shaped tool.

[0063] Although several applications of the cutting set have been mentioned above, tunneling is a particularly attractive application. Conventionally, in order to create a new underground tunnel, a tunnel drilling machine (TBM) is used. TBMs create a cylindrical shaped tunnel in a known way. If the purpose of the tunnel is vehicular or pedestrian traffic and only a circular lateral cross section is possible, a new horizontal floor must be included within the lower portion of the tunnel. Effectively, the tunnel diameter is oversized. Excessive rock material must be extracted in order to create the actual usable space required within the upper portion of the tunnel and this increases tunnel opening costs, not only because a larger TBM demands more consumable cutting tips than a smaller TBM , but also that the tunnel opening operation takes significantly longer. In addition, additional material is required to build the new floor. Thanks to the cutting set described here, a tunnel with a smaller lateral cross section can be created, thus producing the required shape of the upper tunnel. The cutting set then follows the smaller TBM to form the lower half of the tunnel, creating a floor perpendicular to the walls and removing significantly less material than with a

17/18 TBM higher.

[0064] Although this invention has been particularly shown and described with reference to modalities, it will be understood by those skilled in the art that various changes in shape and detail can be made without departing from the scope of the invention as defined by the appended claims.

[0065] For example, in the second embodiment of the cutting set, although only a single support arm 14 has been described, instead two or more spaced support arms 14 can be provided.

[0066] For example, the two modalities described here both include a plurality of disc cutters 18 mounted on the drive spindle 16. This need not be the case and instead a single disc cutter 18 could be used.

[0067] For example, instead of using a combination of cutting elements 22 and paired tool holders 24, the cutting elements can be integrated directly into the body of the cutter 18 at a peripheral edge thereof, thereby eliminating the need for an intermediate tool holder 24.

[0068] For example, the or each cutting element may comprise monocrystalline diamond instead of polycrystalline diamond material.

[0069] For example, cutting element 22 may comprise metal impregnated with diamond or abrasive grain or be ceramic based

[0070] Although cutting set 10 has been described as being for use underground, it can also be used above ground, for example in an open quarry.

[0071] Furthermore, a smaller scale version could be used to dig micro trenches on highways and pavements, for example, for launching small diameter fiber optic cables. In this case, cutting set 10 would be cutting asphalt and concrete, not rocks. In

18/18 in such an embodiment, the diameter of the cutter body 20 would be in the order of 300 mm, the lateral thickness of the cutter body up to 20 mm and the cutting elements correspondingly sized. The intention is to obtain a cutting depth of around 50 mm to 100 mm.

[0072] Certain standard terms and concepts as used here are briefly explained below.

[0073] As used here, polycrystalline diamond material (PCD) comprises a plurality of diamond grains, a substantial number of which are directly interconnected with each other and where the diamond content is at least about 80 percent in volume of the material. Intersections between the diamond grains can be substantially empty or they can be at least partially filled with bulk fill material or they can be substantially empty. The bulk cargo material may comprise sinter promotion material.

[0074] PCBN material comprises grains of cubic boron nitride (cBN) dispersed within a matrix comprising metal, semimetal and or ceramic material. For example, PCBN material can comprise at least about 30 volume percent of cBN grains dispersed in a binder matrix material comprising a Ti-containing compound, such as titanium carbonitride and / or an Al-containing compound, such as nitride aluminum and / or metal-containing compounds such as Co and or W. Some versions (or "types") of PCBN material can comprise at least about 80 percent by volume or even at least about 85 percent by volume of grains cBN.

Claims (18)

1. Cutting set for a rock excavation machine, characterized by the fact that it comprises: - a base unit, - one or more movable support arms extending from the base unit, - a rotating drive spindle mounted on or on each movable support arm, - a disc cutter fixed around the drive spindle in such a manner that the drive spindle rotates causes a corresponding rotation of the disc cutter, - the disc cutter comprising a cutter body and one or more cutting elements peripherally arranged around the cutter body, - where the or each support arm is configured to be movable for first and second cutting orientations, where in the first cutting orientation the drive spindle is horizontal and where in the second cutting orientation the drive spindle is vertical. 2. Cutting assembly according to claim 1, characterized by the fact that a pair of spaced support arms is provided. Cutting set according to claim 1 or 2, characterized in that the or each support arm is movable between a first operating position and a second operating position, in each of the first and second cutting directions, according to the required cutting depth. Cutting assembly according to claim 2 or 3, characterized in that each support arm comprises a first arm portion connected to a second arm portion by a joint, each first and second arm portion being independently movable one in relation to the other. Cutting set according to any one of the preceding claims, characterized by the fact that a plurality of disc cutters are arranged on the drive spindle. Cutting set according to claim 5, characterized in that the plurality of disc cutters is evenly spaced along the length of the drive spindle. Cutting set according to claim 6, characterized by the fact that the plurality of disc cutters is spaced by an interval measuring between 10 cm and 50 cm. Cutting set according to claim 6 or 7, characterized in that the gap between adjacent disc cutters is adjustable. Cutting set according to any one of the preceding claims, characterized in that at least one disk cutter is mounted perpendicularly around the drive spindle. Cutting set according to any one of claims 1 to 8, characterized in that at least one disc cutter is mounted non-perpendicularly around the drive spindle. Cutting set according to any one of the preceding claims, characterized in that the disc cutter additionally comprises one or more tool holders extending radially outwardly from the cutter body, a tool holder for each cutting element. Cutting set according to claim 11, characterized in that the tool holders are regularly spaced around the cutter body. 13. Cutting set according to claim 11, characterized in that the tool holders are irregularly spaced around the cutter body. Cutting set according to any one of the preceding claims, characterized in that the cutting element comprises a hard material selected from the group consisting of cemented carbide (eg tungsten carbide), cubic boron nitride, diamond, diamond-like material or combinations thereof. Cutting set according to claim 14, characterized in that the or each cutting element is a compact polycrystalline diamond (PDC). 16. Cutting set according to claim 15, characterized by the fact that each tool holder has a front face and a rear face, each cutting element being seated on the front face of the tool holder, facing the direction of rotation . 17. Long-walled mining system, characterized by the fact that it comprises a cutting set as defined in any of the preceding claims, a transport system for transporting mined rocks out from a cutting face and a collecting arm for collect mined rocks from the cut face and transfer it to the transport system. 18. Long-walled mining system according to claim 17, characterized in that it additionally comprises a secondary wedge tool.