Waste Disposal During Pit Mining

• US 20080290718A1
• Filed: 06/30/2008
• Published: 11/27/2008
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Bhp Billiton Innovation Pty., Ltd. (BHP Group Ltd.)
• Original Assignee: Bhp Billiton Innovation Pty., Ltd. (BHP Group Ltd.)
• Inventors: Stone, Peter Mitchell, Zukerberg, Mark
• Granted Patent: US 8,103,364 B2
• Time in Patent Office: Days
• US Class Current: 299/1.9
• CPC Class Codes: B09B 1/00 Dumping solid waste
• CPC Class Codes: B09B 1/006 Shafts or wells in waste dumps
• CPC Class Codes: E21C 41/32 Reclamation of surface-mined areas machines or methods for treating or working soil for agricultural purposes A01B77/00, A01B79/00; machines for back-filling E02F5/22

Abstract

A method, apparatus and computer program for pit mining with waste dumping is disclosed, in which material is extracted from an open pit and some of that material is sent to waste. The method optimises a joint extraction and waste refill schedule.

Claims

1. A method of open pit mining with waste dumping, comprising:

extracting material from the open pit and determining whether the material is sent to any one or more of stockpiling, waste and processing;

defining a road network interconnecting a plurality of zones;

determining waste movement along the network from its origin being the zone in which the waste was produced to a destination being the zone in which the waste is to be dumped, to provide a joint extraction and waste movement strategy which optimises the net value of a joint extraction and waste movement schedule; and

each zone containing a plurality of blocks, material extracted from one of the blocks in a zone being sent to a predetermined entry point on the road network, moving the material across the network and depositing the waste material in at least one external waste dump, and some of the waste material being moved on the road network to terminate at one of the zones within the pit, and allocating the material moved to one of the zones within the pit proportionally to an in pit waste dump defined by a refill aggregate that overlaps with that zone, the refill aggregate being a space formed after extraction of material from that aggregate and therefore cleared of original material and after any refill aggregate which sits below that aggregate has been completely refilled.

2. The method of claim 1 wherein some of the waste is also dumped in an in-pit zone.

3. A method of open pit mining with waste dumping, comprising:

extracting material from an open pit and determining some proportion of the extracted material to go to waste;

defining a road network having a plurality of nodes, at least some of the nodes defining entry points to a plurality of waste dumps, and wherein the waste dumps are selected from the group of at least one in pit waste dump and at least one external waste dump; and

moving the material to go to waste along the network of roadways from a location in the pit to an entry node relating to one of the waste dumps and depositing the material to go to waste at the waste dump, to provide a joint extraction and waste movement strategy which optimises the net value of a joint extraction and waste movement schedule.

4. The method of claim 3 wherein the step of extracting material comprises extracting material based on a block model extraction schedule, and wherein the waste dump comprises an in pit waste dump defined by a space in the pit which is determined from one or more blocks of the block model which have already been subject to extraction.

5. The method of claim 4 wherein the space comprises a block aggregation determined by aggregating a plurality of blocks in the block model.

6. The method of claim 4 wherein the shape of the spaces is chosen to ensure that the spaces may be independently scheduled for refilling with waste, subject to precedent rules, without violating maximum waste repose slope constraints.

7. The method of claim 3 wherein the pit is divided into a plurality of zones, each zone containing a plurality of blocks and potential refill spaces which form in pit waste dumps.

8. The method of claim 7 further comprising moving waste from a zone in the pit, along the road network, to an external waste dump, and eventually from that external waste dump to an in pit waste dump.

9. The method of claim 8 wherein a cost of extraction of material and its movement to waste is determined from the zone from which the waste is removed in the pit, the path the waste is moved on the road network via the nodes and to the waste dump in which the waste is dumped.

10. The method of claim 3 wherein the pit is divided into a plurality of zones, each zone containing a plurality of blocks, material extracted from one of the blocks in a zone being sent to a predetermined entry point on the road network, moving the material across the network and depositing the waste material at at least one external waste dump, and some of the waste material being moved on the road network to terminate at one of the zones within the pit, and allocating the material moved to one of the zones within the pit proportionally to an in pit waste dump defined by a refill aggregate that overlaps with that zone, the refill aggregate being a space formed after extraction of material from that aggregate and therefore cleared of original material and after any refill aggregate which sits below that aggregate has been completely refilled.

11. An apparatus for scheduling open pit mining with waste dumping, wherein material is extracted from an open pit and a determination is made that some proportion of the extracted material is to go to waste, a road network is provided having a plurality of nodes, at least some of the nodes defining entry points to a plurality of waste dumps, and wherein the waste dumps are selected from the group of at least one in pit waste dump and at least one external waste dump, and material to go to waste is moved along the network of roadways from a location in the pit to an entry node relating to one of the waste dumps and depositing the material to go to waste at the waste dump, the apparatus comprising:

a processor for dividing the pit into a plurality of zones, and for allocating the material to be moved to one of the zones within the pit proportionally to an in pit waste dump defined by a refill aggregate that overlaps with that zone, the refill aggregate being a space formed after extraction of material from that aggregate and therefore cleared of original material and after any refill aggregate which sits below that aggregate has been completely refilled, to thereby provide a joint extraction and waste movement strategy which optimises the net value of a joint extraction and waste movement schedule.

12. A computer program for scheduling open pit mining with waste dumping, wherein material is extracted from an open pit and some proportion of the extracted material is to go to waste, comprising:

code for defining a road network having a plurality of nodes, at least some of the nodes defining entry points to a plurality of waste dumps, and wherein the waste dumps are selected from the group of at least one in pit waste dump and at least one external waste dump, so material to go to waste is moved along the network of roadways from a location in the pit to an entry node relating to one of the waste dumps and depositing the material to go to waste at the waste dump;

code for dividing the pit into a plurality of zones, each zone containing a plurality of blocks so material extracted from one of the blocks in a zone is sent to a predetermined entry point on the road network and moved across the network and deposited at at least one external waste dump, and some is sent on the road network to terminate at one of the zones within the pit; and

code for allocating the material moved to one of the zones within the pit proportionally to an in pit waste dump defined by a refill aggregate that overlaps with that zone, the refill aggregate being a space formed after extraction of material from that aggregate and therefore cleared of original material and after any refill aggregate which sits below that aggregate has been completely refilled, to thereby provide a joint extraction and waste movement strategy which optimises the net value of a joint extraction and waste movement schedule.

13. The program of claim 12 wherein the program further comprises code for scheduling extraction of material based on a block model extraction schedule, and code for determining an in pit waste dump defined by a space in the pit which is determined from one or more blocks of the block model which have already been subject to extraction.

14. The program of claim 12 wherein the program further comprises code for determining a cost of extraction of material and its movement to waste, from the zone from which the waste is removed in the pit, the path the waste is moved on the road network via the nodes and to the waste dump in which the waste is dumped.