Mining method for steeply dipping ore bodies

• US 6,857,706 B2
• Filed: 12/04/2002
• Issued: 02/22/2005
• Est. Priority Date: 12/10/2001
• Status: Expired due to Fees

• Current Assignee: Her Majesty The Queen In Right of Canada As Represented By The Minister of National Defence
• Original Assignee: Placer Dome Technical Services Limited
• Inventors: Dimock, Timothy B., Anwyll, Edward William Drew, Delabbio, Fredric Christopher, Young, Donald Duncan, Hames, Marilyn Patricia Ann, Jackson, Simon Mark, Jackson, Eric
• Primary Examiner(s): KRECK, JOHN J
• Application Number:
  US10/309,237
• Publication Number:
  US 20030173819A1
• Time in Patent Office: 811 Days
• Field of Search: 299/18, 299/19, 299/1.1, 299/1.2, 299/1.6, 299/1.8, 299/29, 299/36.1, 299/42, 299/95, 299/34.01, 299/63
• US Class Current: 299/18
• CPC Class Codes: E21C 25/16 Machines slitting solely by one or more rotating saws, cutting discs, or wheels
• CPC Class Codes: E21C 35/24 Remote control specially adapted for machines for slitting or completely freeing the mineral control in general G05
• CPC Class Codes: E21C 41/16 Methods of underground mining winning machines therefor E21C25/00 - E21C39/00; Layouts therefor

Abstract

The present invention is directed to a mining method for steeply dipping orebodies. In the method, an excavator 152 is tethered to a deployment system 120 by one or more cables/umbilicals 144. The excavator 152 excavates slices 172a-h of the orebody 100 by moving generally up-dip, down-dip or a combination thereof. The excavator can be automated.

Claims

1. A method for mining a valuable material in a steeply dipping deposit, comprising:

(a) in a deposit of a material to be excavated, the deposit having a dip of at least about 35° and

a plurality of intersecting excavations, the plurality of intersecting excavations including at least first and second spaced apart excavations extending at least substantially in a direction of a strike of the deposit and at least a third excavation intersecting the first and second excavations and extending at least substantially in a direction of the dip of the deposit, the first, second, and third excavations defining a block of the deposit,

deploying an articulated excavator in the third excavation, the articulated excavator comprising a rotating boom, at least one excavating device positioned on an end of the rotating boom, and a plurality of actuators positioned on the excavator, the plurality of actuators engaging the hanging wall and footwall of the third excavation to maneuver the excavator into a desired position and orientation relative to the block, wherein the articulated excavator is deployed in the third excavation using a mobile deployment system positioned in the first excavation;

(b) remotely transmitting electronic commands to the articulated excavator to control the position and orientation of the articulated excavator;

(c) the articulated excavator removing a first segment of the block, the first segment extending at least substantially the length of a side of the block and being adjacent to and accessible by the third excavation; and

(d) the articulated excavator thereafter removing a second segment of the block, the second segment extending at least substantially the length of the side of the block and being adjacent to the first segment before the removing step (c).

2. The method of claim 1, wherein the deposit is a hard rock deposit of igneous or metamorphic origin and wherein, the mobile deployment system is operatively engaged with the excavator during steps (c) and (d).

3. The method of claim 1, wherein the deposit is not of sedimentary origin.

4. The method of claim 1, wherein the first and second segments are removed by the articulated excavator while the excavator is movably suspended in the third excavation.

5. The method of claim 1, wherein the first excavation is located at a shallower depth than the second excavation and wherein removing step (c) comprises:

positioning the articulated excavator at a first location near the first excavation;

moving the excavator progressively downwards while the excavator removes progressively the first segment;

when the excavator reaches a second location near the second excavation, repositioning the excavator at or near the first location; and

moving the excavator progressively downwards while the excavator removes progressively the second segment.

6. The method of claim 5, wherein the excavated material moves under the force of gravity to a drawpoint located at or near the second excavation.

7. The method of claim 5, wherein, after the excavator reaches the second location, the method includes repositioning the mobile deployment system operationally engaged with the excavator by at least one flexible support member, wherein the mobile deployment system is a mobile winch, and wherein the at least one flexible support member is attached to the excavator during steps (c) and (d).

18. The method of claim 1, further comprising:

(e) providing hydraulic fluid to the articulated excavator using an umbilical extending from the first excavation to the articulated excavator.

19. The method of claim 18, wherein the umbilical further provides to the excavator at least one of electric power, water, and the electronic commands.

20. The method of claim 18, wherein the umbilical comprises a constant power hydraulic line, a hydraulic return line, an emergency hydraulic retract line, a hydraulic fluid case drain line, and a constant pressure hydraulic fluid line.

21. The method of claim 1, wherein the boom is extendable and retractable along a boom longitudinal axis and further comprising during removal of the second segment:

(e) determining whether the boom has a desired maximum degree of boom extension;

(f) when the boom has reached a desired maximum degree of boom extension, performing the substeps of;

(i) engaging actuators on the boom with the hanging wall of the third excavation;

(ii) disengaging actuators on the body from the hanging wall of the third excavation; and

(iii) retracting the boom to decrease the distance separating the body from the at least one excavating device;

(iv) engaging the actuators on the body with the hanging wall; and

(v) disengaging the actuators on the boom from the hanging wall;

(g) when the boom has not reached a desired degree of boom extension, further extending the boom; and

(h) thereafter rotating the boom to remove additional material in the second segment.

22. The method of claim 21, wherein the boom has a desired maximum degree of boom extension and further comprising, before substep (i), the substeps of:

(vi) rotating the boom relative to the body to position the longitudinal axis of the boom transversely to the longitudinal axis of the body; and

, after substep (iii) and before substep (iv); and

(vii) rotating the body relative to the boom to position the longitudinal axis of the boom in substantial alignment with the longitudinal axis of the body.

23. The method of claim 1, wherein the excavator has at least four degrees of movement.

24. The method of claim 1, wherein the excavator comprises a sensor array to assist in positioning the excavator, a navigation system to determine a current position of the excavator relative to a selected coordinate system, and a control system to receive input from the sensor array and navigation system and provide instructions responsive thereto to the excavator actuators and boom hydraulics.

25. The method of claim 24, wherein the sensor array comprises a geophysical sensor, excavator position sensors, excavator attitude sensors, and excavator component monitoring sensors.

26. The method of claim 25, wherein the attitude sensors determine the pitch and roll of the excavator and the component monitoring sensors comprise a plurality of a vibration sensor, electrical discharge sensor, cavity monitoring sensor, cylinder position sensor, cylinder force sensor, hydraulic fluid pressure sensor, end-of-stroke sensor, temperature sensor, fluid level sensor, boom position sensor, and excavation device wear sensor.

27. The method of claim 24, wherein the navigation system determines a current position of the excavator relative to a fixed three-dimensional reference and/or a geologic feature and following a prescribed trajectory or path.

28. The method of claim 24, wherein the navigation system determines a current position of the excavator relative to a digital map of the deposit.

8. A method for excavating a material, including:

(a) providing first and second excavations, at least a portion of the first excavation having a bearing generally in the direction of a dip of a hard rock deposit, the second excavation passing through the deposit, wherein the deposit has a dip of at least about 25°

, and wherein the first excavation is positioned transverse to the second excavation;

(b) deploying an articulated excavator in the second excavation, the articulated excavator comprising a rotating boom, at least one excavating device positioned on an end of the rotating boom, and a plurality of actuators positioned on the excavator, the plurality of actuators engaging the hanging wall and footwall of the second excavation to maneuver the excavator into a desired position and orientation relative to an exposed face of the deposit, wherein the articulated excavator is deployed in the second excavation using a mobile deployment system positioned in the first excavation;

(c) remotely transmitting electronic commands to the articulated excavator to control the position and orientation of the articulated excavator;

(d) in a first pass, moving the excavator in the second excavation along a first exposed portion of the deposit exposed by the second excavation to remove a first portion of the material in the deposit; and

(e) in a second, later, pass, moving the excavator in the second excavation along a second exposed portion to remove a second portion of the material, wherein the first and second exposed portions were adjacent to one another.

9. The method of claim 8, further including:

(f) at the end of the first pass, moving a mobile positioning device engaged with the excavator to reposition the excavator for the second pass; and

(g) raising the excavator to a starting position on the second exposed portion to begin the second pass.

10. The method of claim 8, further including:

(f) collecting excavated material at a position below first and second exposed portions; and

(g) transporting the collected excavated material to a location for processing.

11. The method of claim 8, wherein the excavator comprises at least one of one or more disc cutters, water jets, impact hammers, impact rippers, and pick cutters, a blasting system, and an electrical pulse discharge system and combinations thereof.

12. The method of claim 8, wherein the second excavation is a shaft and wherein the excavator is at least partly suspended in the shaft by an elongated flexible member and is connected to a power source by an umbilical line and wherein the elongated flexible member is attached to the mobile deployment system and the excavator during steps (d) and (e).

13. The method of claim 8, wherein the excavator includes a remote sensing system that detects the presence of material in the deposit and a navigation system that determines a position of the excavator.

14. The method of claim 13, wherein the remote sensing system is at least one of a sound monitor, a vibration monitor, a directional natural gamma detector, a camera, on-board geophysics, electrical discharge analyzer, chemical sensor, and seismo-electric sensor.

15. The method of claim 12, wherein the umbilical line comprises at least one of a conduit to supply water for cooling and flushing rock cuttings, hydraulics for maneuvering the excavator, signal conductors for conveying control signals from a remote operator to the excavator, and electrical conductors for supplying power to the excavator and wherein the umbilical is connected to the excavator during steps (d) and (e).

16. The method of claim 8, wherein the excavator includes a winch to raise and lower itself in the second excavation.

17. The method of claim 8, wherein the excavator includes at least one of hydraulic rams, pneumatic rams, rotational mounts and extendable arms, and tracks for multi-dimensional movement in the shaft.

29. The method of claim 8, further comprising:

(f) providing hydraulic fluid to the articulated excavator using an umbilical extending from the first excavation to the articulated excavator.

30. The method of claim 29, wherein the umbilical further provides to the excavator at least one of electric power, water, and the electronic commands.

31. The method of claim 29, wherein the umbilical comprises a constant power hydraulic line, a hydraulic return line, an emergency hydraulic retract line, a hydraulic fluid case drain line, and a constant pressure hydraulic fluid line.

32. The method of claim 8, wherein the boom is extendable and retractable along a longitudinal axis of the boom and further comprising during removal of the second segment:

(f) determining whether the boom has a desired maximum degree of boom extension;

(g) when the boom has reached a desired maximum degree of boom extension, performing the substeps of;

(i) engaging actuators on the boom with the hanging wall of the third excavation;

(ii) disengaging actuators on the body from the hanging wall of the third excavation; and

(iii) retracting the boom to decrease the distance separating the body from the at least one excavating device;

(iv) engaging the actuators on the body with the hanging wall; and

(v) disengaging the actuators on the boom from the hanging wall;

(h) when the boom has not reached a desired degree of boom extension, further extending the boom; and

(i) thereafter rotating the boom to remove additional material in the second segment.

33. The method of claim 32, wherein the boom has a desired maximum degree of boom extension and further comprising, before substep (i), the substeps of:

(vi) rotating the boom relative to the body to position the longitudinal axis of the boom transversely to the longitudinal axis of the body; and

(vii) after substep (iii) and before substep (iv), rotating the body relative to the boom to position the longitudinal axis of the boom in substantial alignment with the longitudinal axis of the body.

34. The method of claim 8, wherein the excavator has at least four degrees of movement.

35. The method of claim 8, wherein the excavator comprises a sensor array to assist in positioning the excavator, a navigation system to determine a current position of the excavator relative to a selected coordinate system, and a control system to receive input from the sensor array and navigation system and provide instructions responsive thereto to the excavator actuators and boom hydraulics.

36. The method of claim 35, wherein the sensor array comprises a geophysical sensor, excavator position sensors, excavator attitude sensors, and excavator component monitonng sensors.

37. The method of claim 36, wherein the attitude sensors determine the pitch and roll of the excavator and the component monitoring sensors comprise a plurality of a vibration sensor, electrical discharge sensor, cavity monitoring sensor, cylinder position sensor, cylinder force sensor, hydraulic fluid pressure sensor, end-of-stroke sensor, temperature sensor, fluid level sensor, boom position sensor, and excavation device wear sensor.

38. The method of claim 35, wherein the navigation system determines a current position of the excavator relative to a fixed three-dimensional reference and/or a geologic feature and following a prescribed trajectory or path.

39. The method of claim 35, wherein the navigation system determines a current position of the excavator relative to a digital map of the deposit.