GB2563550B

GB2563550B - A mining machine

Info

Publication number: GB2563550B
Application number: GB1815749.5A
Authority: GB
Inventors: Arnautov Maksim
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-09-27
Filing date: 2018-09-27
Publication date: 2019-08-28
Anticipated expiration: 2038-09-27
Also published as: GB201815749D0; GB2563550A

Description

A MINING MACHINE

FIELD OF THE INVENTION

The present invention relates to a mining machine, and in particular to a mining machine comprising a mining head at an end of a mining cable.

BACKGROUND OF THE INVENTION

Mining of mineral resources normally requires removal of large volumes of soil and/or rock before the depth of the resources is reached, and historically very large areas of the landscape have been excavated to reach relatively small areas of mineral deposits. The deeper the deposit, the further beyond the edges of the deposit the higher layer of soil/rock must be excavated to reach the deposit, often causing widespread damage to the local environment.

Publication US 4,319,784 discloses an apparatus for sub-terranean drilling and mining, in which waterjets are used to loosen and remove soil, and generally assist with the drilling and mining process. A casing pipe is used to drill vertically downwardly through the soil to the mineral deposit, and the water from the water jets returns back up the casing pipe along with the mineral deposits.

This apparatus avoids the need to excavate large areas of soil above the mineral deposits, however the area of the deposit that can be reached with the casing pipe is limited, and the casing pipe typically needs to be withdrawn and moved to a slightly different location to access different areas of the deposit on a fairly regular basis. Accordingly, once the deposit has been fully mined, a large number of holes from the surface down to the level of the deposit may be left behind.

It is therefore an object of the invention to provide an improved mining machine.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a mining machine, comprising a mining cable and a mining head at an end of the mining cable. The mining head comprises a plurality of nozzles which receive cutting fluid from one or more cutting fluid conduits passing along a length of the mining cable, the nozzles for ejecting the cutting fluid under pressure to perform subterranean mining. The mining head further comprises a return port connected to a return conduit passing along the length of the mining cable, the return port and the return conduit for carrying mined material and the cutting fluid back along the mining cable. The mining cable comprises a plurality of rigid length portions and a plurality of actuable bend portions, wherein each actuable bend portion is connected between two immediately adjacent ones of the rigid length portions so the rigid length portions and the actuable bend portions alternate with one another along the length of the mining cable. Each actuable bend portion is actuable to control a bend angle between the two immediately adjacent rigid length portions connected by the actuable bend portion, so the actuable bend portions are actuable to control movement of the mining head relative to another end of the mining cable opposite the mining head.

The alternate rigid length portions and actuable bend portions mean that the mining cable can be actuated to move the mining head to a wide variety of different subterranean locations. The mining cable can enter the subterranean area of interest at a single location on the surface, and the mining head can be moved beneath the ground to mine a much larger volume beneath the ground than was previously possible.

The cutting fluid may be supplied at very high pressure to cut though the subterranean substrate, and the high forces involved limit the maximum cross-sectional area of the one or more cutting fluid conduits, and limit the volume of cutting fluid that can be delivered. Therefore, in some situations, there may be an insufficient or sub-optimum volume of fluid for carrying the mineral deposits into the return port and along the return conduit. Accordingly, the mining head may further comprise a bulk fluid supply port connected to a bulk fluid supply conduit passing along the length of the mining cable, the bulk fluid supply conduit for supplying additional fluid to collect and sweep the mined material into the return port and along the return conduit.

Each actuable bend portion may comprise two rings that are respectively connected to the two immediately adjacent rigid length portions on either side of the actuable bend portion. The rings may be interspaced by at least one linear actuator extending from one ring to the other ring, each linear actuator controlling the distance between the rings at the location of the linear actuator, to control a bend angle between a central axis of one of the two immediately adjacent rigid length portions and a central axis of the other one of the two immediately adjacent rigid length portions. Each linear actuator may be a hydraulic cylinder, so that large loads can be supported by the linear actuator. The hydraulic cylinders may be spaced at regular intervals around an axis extending from a centre of one of the two rings to a centre of the other of the two rings.

Each bend portion may comprise a plurality of stabiliser pistons between the plurality of linear actuators, each stabiliser piston extending from one of the two rings to the other of the two rings and configured to resist rotation of the two rings relative to one another. Then, the position of the mining head can be controlled more accurately.

Each actuable bend portion may comprise an exterior defined by a flexible skirting pipe that extends from one of the two immediately adjacent rigid length portions to another of the two immediately adjacent rigid length portions. The skirting pipe helps prevent any unwanted earth/rock material from entering between the immediately adjacent rigid length portions and damaging the linear actuators.

The mining machine may further comprise a rigid cable that is not bendable connected to the mining cable, wherein the rigid cable is connected to the mining cable at an end of the mining cable opposite from the mining head, the rigid cable being formed of rigid cable length portions that are attachable and removable from the rigid cable to define a length of the rigid cable. Then the mining head can first be used to drill vertically downward, with additional rigid cable length portions being added at the surface until the mining cable and head reaches the desired depth where the minerals to be extracted are located.

The mining machine may further comprise a cutting fluid pumping station for pressuring the cutting fluid, and a return fluid pumping station for sucking up the mined material and the cutting fluid via the return conduit.

DETAILED DESCRIPTION

Embodiments of the invention will now be described by way of non-limiting example only and with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic diagram of a mining machine according to an embodiment of the invention being used to mine subterraneaneously;

Fig. 2 shows an enlarged schematic diagram of the mining machine of Fig. 1;

Fig. 3 shows a schematic diagram of a mining cable and mining head of the mining machine of Figs. 1 and 2;

Fig. 4 shows a schematic diagram of a front of the mining head of Fig. 3; and

Fig. 5 shows a schematic diagram of part of an actuable bend portion of the mining cable of Fig. 3.

The figures are not to scale, and same or similar reference signs denote same or similar features.

The schematic diagram of Fig. 1 shows a subterranean excavation machine according to an embodiment of the invention, being used to mine gold from an alluvial soil layer 2. The machine comprises a cutting (mining) head 10 at an end of a bendable cable 15, and a rigid cable 20 connected at an opposite end of the bendable cable 15 from the cutting head 10. The end of the rigid cable 20 opposite from the end where the bendable cable 15 is connected, is held in place by a support structure 25. The support structure 25 is positioned in place by a vehicle 30.

The cutting head 10 comprises nozzles and at least one return port. The nozzles eject cutting fluid into a hole 5 in the alluvial soil layer 2, cutting through the soil and creating a turbulent slurry of soil and cutting fluid, that is sucked up through the return port. The bendable and rigid cables 15 and 20 define a cutting fluid conduit that delivers cutting fluid from the support structure 25 to the nozzles, and a return conduit that carries the slurry of soil and cutting fluid from the return port up to the support structure 25.

The cutting fluid conduit is connected to a cutting fluid pumping station 7 at the surface, and the cutting fluid pumping station pumps the cutting fluid down to the nozzles at high pressure, via the support structure 25. In this embodiment, the cutting fluid is water, however other cutting liquids could be used in alternate embodiments. The cutting fluid pumping station 7 is held on a vehicle 26 for easy transportation.

The return conduit is connected to a return fluid pumping station 8 at the surface, which pumps the slurry of soil and cutting fluid up to the surface from the cutting head, through sluices 9a on a vehicle 27 to extract the gold from the slurry. The slurry is then passed into a gravitational separator 9b on a vehicle 28, which separates out the largest solid particles 4b from the slurry, so they can be transferred into a previously mined hole 4. The remaining liquids and smaller particles are passed to a water purifier 9c on a vehicle 29 that extracts the water from the slurry so that it can be sent to the cutting fluid pumping station 7 and reused as cutting fluid.

The schematic diagram of Fig. 2 shows an enlarged schematic diagram of the subterranean excavation machine. As shown, the bendable cable 15 comprises a plurality of rigid length portions 16 that alternate with actuable bend portions 17. Each rigid length portion is formed of a rigid material such as metal or carbon fibre, and is substantially unbendable. Typically, each rigid length portion may be 1m to 1.5m long. Each actuable bend portion 17 is connected between two adjacent rigid length portions 16, and controls a bend angle between the two adjacent rigid length portions 16. The actuable bend portions are controlled by a controller at the support structure 25, to move the cutting head 10 within the hole 5 to target different areas of the alluvial layer 2. The rigid cable 20 is joined to the bendable cable 15 at a joint 19.

During installation, the support structure 25 is moved into position by the vehicle 30, and then the cutting head 10 is used to cut a hole vertically downwardly through the top soil layer 1 and into the alluvial layer 2 where the gold is located. Once the bendable cable is in the ground, successive length portions of rigid cable 20 are added to the end of the cable until the cutting head 10 reaches the required depth. A casing pipe 21 is inserted into the ground around the cable to hold back the surrounding soil from collapsing in around the cable, and preferably a collar 22 seals around the casing pipe at ground level.

Mining commences using the cutting head 10, and the hole 5 begins to form around the cutting head. The hole 5 is expanded to excavate more and more areas of the alluvial layer 2 by controlling the position of the cutting head 10 using the actuable bend portions 17. An air inlet pipe 23 connects to the cavity between the cable and the casing pipe 21, and pumping air into the cavity via the air inlet pipe raises the pressure inside the hole 5, and aids extraction of the alluvial layer up the bendable cable. The seal created by the collar 22 prevents the air that is pumped into the cavity from escaping at ground level.

The schematic diagram of Fig. 3 shows the bendable cable 15 and cutting head 10 in more detail. Each actuable bend portion 17 comprises two ends 40 and 50 for connecting between the two adjacent rigid length portions 16, the bend portion being actuable to adjust a bend angle 17b that is created between a central axis 17c of the end 40 of the rigid length portion 16a, and a central axis 17d of the end 50 of the rigid length portion 16b. The exterior of each actuable bend portion is formed by an expandable rubber skirt 18, which can flex to accommodate the changes in the bend angle, and which houses the cutting fluid conduit and the return conduit.

As seen in Fig. 3, the cutting head 10 comprises a ring of nozzles 60 that are spaced around a front circular face of the cutting head 10, and a return port 62 that is positioned centrally of the front circular face of the cutting head 10. Therefore, subterranean material that is dislodged by the cutting fluid from the nozzles 60 can be easily sucked up into the return port 62, and along the return conduit to the return fluid pumping station 8. In addition to the return port 62, further return ports connected to the return conduit may be positioned at the sides of the cutting head 10, to suck up further subterranean material and cutting fluid.

In this embodiment, a ring of bulk fluid supply ports 65 is arranged inside the ring of nozzles 60. The bulk fluid supply ports 65 are connected to a bulk fluid supply conduit passing along the lengths of the bendable and rigid cables. In use, the bulk fluid supply ports 65 supply a much larger volume of bulk fluid than the volume of the cutting fluid supplied by the nozzles 60, and the bulk fluid helps to sweep the subterranean material into the return port 62. The bulk fluid may for example be water, but other liquids could alternatively be used. The bulk fluid is pumped to the bulk fluid supply ports 65 from a pumping station (not shown in Figs) on the vehicle 26.

The schematic diagram of Fig. 4 shows an enlarged front view of the cutting head 10, which is intended for cutting through earth or soil substrates. The cutting head 10 comprises a fixed front ring 70, which is connected to the end-most rigid length portion 16, and is stationary with respect to that rigid length portion. The fixed front ring 70 has an aperture through its centre, the aperture defining the return port 62, through which the excavated material and cutting fluid is sucked up and along the return conduit to the return fluid pumping station 8.

The fixed front ring 70 has a plurality of holes at its exterior, in which nozzles 60 are located.

The schematic diagram of Fig. 5 shows a sub-portion of one of the actuable bend portions 17 in more detail. Each actuable bend portion 17 comprises three sub-portions 17a (see Fig. 3) that are stacked on one another, to increase the angle that each actuable bend portion can bend through. Each sub-portion 17a comprises first and second rings 41 and 51, each ring being connectable to a ring of an adjacent sub-portion 17a, or to an end 40 or 50 of one of the rigid length portions 16. In this embodiment, the rings are made of metal, and are bolted to the rings of adjacent sub-portions or to the ends of the rigid length portions 16, but other materials and other methods of connecting the rings are possible in alternate embodiments. The expandable rubber skirt 18 and the various conduits running along the bendable cable are not shown in Fig. 5, for the sake of clarity.

The rings 41 and 51 are connected to one another by linear actuators in the form of hydraulic cylinders 45. Each hydraulic cylinder 45 extends from an annular face of the ring 41, to an annular face of the ring 51, to control the distance between the annular faces of the rings at the points where the hydraulic cylinder is connected to the rings. The annular faces of the rings face towards one another. The hydraulic cylinders are spaced evenly around the annular faces of the rings, and controlling the extension of each hydraulic cylinder controls the bend angle between the central axis of the ring 41 and the central axis of the ring 51, and therefore the bend angle 17b between the rigid length portions 16 that are connected to the acutable bend portion 17. The hydraulic cylinders are controlled via hydraulic pipes 48 that extend along the bendable 15 and rigid cables 20, up to a controller at the support structure 25. In this embodiment, there are 12 hydraulic cylinders spaced at equal angular intervals around the rings, but the numbers of cylinders may vary in alternate embodiments.

To help resist relative rotation of the rigid length portions 16 about the axes of the rings 41 and 51, each sub-portion 17a also has stabiliser pistons 53 that in this embodiment are spaced at equal angular intervals around the rings, in between the hydraulic cylinders. Each stabiliser piston 53 extends from the annular face of the ring 41, to the annular face of the ring 51, to prevent relative rotation between the rings.

Each stabiliser piston comprises a base plate 54 connected to a piston sheath 55, and a piston shaft 56 connected to a top plate 57. The base plate 54 is bolted to the annular face of the ring 51, and the top plate 54 is bolted to the annular face of the ring 41.

The piston shaft 56 is movable in directions in and out of the piston sheath 55, and the piston shaft 56 has a restraining pin 58 which extends through a slot 59 in the piston sheath 55, the slot 59 extending longitudinally along the piston sheath 55. The restraining pin 58 in the slot 59 prevents rotational movement of the piston shaft 56 relative to the piston sheath 55. The piston shaft 56 is free to move in and out of the piston sheath 55, under the influence of the hydraulic cylinders 45.

The hydraulic cylinders and stabiliser pistons are capable of flexing along their length as some of the hydraulic cylinders are extended and some of the hydraulic cylinders are retracted, to create the bend angle, and stacking three of the sub-portions together allows a larger bend angle to be created by the overall bend portion 17. Each one of the three sub-portions 17a bends through 1/3 of the angle 17b shown in Fig. 3, to together produce the angle 17b.

In use, the controller at the support structure is used to control which direction the mining head 10 points in, by controlling the actuable bend portions 17 via the hydraulic pipes 48. It will be appreciated that other types of actuable bend portion could be used in alternate embodiments.

Many other variations of the described embodiments falling within the scope of the invention will be apparent to those skilled in the art.

Claims

1. A mining machine, comprising a mining cable and a mining head at an end of the mining cable, wherein the mining head comprises a plurality of nozzles which receive cutting fluid from one or more cutting fluid conduits passing along a length of the mining cable, the nozzles for ejecting the cutting fluid under pressure to perform subterranean mining, wherein the mining head further comprises a return port connected to a return conduit passing along the length of the mining cable, the return port and the return conduit for carrying mined material and the cutting fluid back along the mining cable, wherein the mining cable comprises a plurality of rigid length portions and a plurality of actuable bend portions, wherein each actuable bend portion is connected between two immediately adjacent ones of the rigid length portions so the rigid length portions and the actuable bend portions alternate with one another along the length of the mining cable, wherein each actuable bend portion is actuable to control a bend angle between the two immediately adjacent rigid length portions connected by the actuable bend portion, so the actuable bend portions are actuable to control movement of the mining head relative to another end of the mining cable opposite the mining head.

2. The mining machine of claim 2, wherein the mining head further comprises a bulk fluid supply port connected to a bulk fluid supply conduit passing along the length of the mining cable, the bulk fluid supply port for supplying additional fluid to collect and sweep the mined material into the return port and along the return conduit.

3. The mining machine of claim 1 or 2, wherein each actuable bend portion comprises at least one linear actuator which is actuable to control the bend angle between the two immediately adjacent rigid length portions connected by the actuable bend portion.

4. The mining machine of claim 1,2, or 3, wherein each actuable bend portion comprises two rings that are respectively connected to the two immediately adjacent rigid length portions on either side of the actuable bend portion.

5. The mining machine of claim 4, wherein each actuable bend portion comprises flexible pipes passing through the two rings, the flexible pipes defining the one or more cutting fluid conduits and the return conduit.

6. The mining machine of claim 4 when appended to claim 3, or claim 5 when claim 4 is appended to claim 3, wherein the at least one linear actuator is connected from a point on one of the two rings to a point on the other of the two rings, and is actuable to move the points closer and further from one another to control the bend angle.

7. The mining machine of claim 6, wherein the at least one linear actuator comprises a plurality of linear actuators, and the plurality of linear actuators are spaced around an axis extending from a centre of one of the two rings to a centre of the other of the two rings.

8. The mining machine of claim 7, wherein each bend portion comprises a plurality of stabiliser pistons between the plurality of linear actuators, each stabiliser piston extending from one of the two rings to the other of the two rings and configured to resist rotation of the two rings relative to one another.

9. The mining machine of claim 8, wherein each stabiliser piston comprises a piston sheath and a piston shaft which is movable in directions in and out of the sheath, wherein the piston shaft comprises a restraining pin which extends through a slot in the piston sheath, the slot extending longitudinally along the piston sheath and the restraining pin in the slot preventing rotational movement of the piston shaft relative to the piston sheath.

10. The mining machine of claim 3 or any one of claims 6 to 9, wherein each linear actuator is a hydraulic cylinder.

11. The mining machine of any preceding claim, further comprising a rigid cable that is not bendable connected to the mining cable, wherein the rigid cable is connected to the mining cable at an end of the mining cable opposite from the mining head, the rigid cable being formed of rigid cable length portions that are attachable and removable from the rigid cable to define a length of the rigid cable.

12. The mining machine of claim 11, further comprising a cutting fluid pumping station and a return fluid pumping station, wherein the rigid cable comprises pipes defining portions of the one or more cutting fluid conduits and the return conduit, wherein the cutting fluid pumping station is configured to pump cutting fluid under pressure into the one or more cutting fluid conduits, and the return fluid pumping station is configured to suck the mined material and the cutting fluid to the return fluid pumping station via the return conduit.

13. The mining machine of any preceding claim, wherein the mining head is substantially cylindrical, and wherein the nozzles for the cutting fluid are arranged in a ring shape at an end of the substantially cylindrical mining head.

14. The mining machine of claim 13, wherein the return port is positioned inside of the ring shape that is defined by the nozzles.

15. The mining machine of claim 13 or 14, wherein the mining machine comprises a plurality of the return ports, and where at least some of the plurality of return ports are arranged in a ring shape that surrounds the ring shape that is defined by the nozzles.

16. The mining machine of any preceding claim, wherein each actuable bend portion comprises an exterior defined by a flexible skirting pipe that extends from one of the two immediately adjacent rigid length portions to another of the two immediately adjacent rigid length portions.