WO2014063188A1

WO2014063188A1 - A system for, and a method of, controlling charging of a blast hole with explosives

Info

Publication number: WO2014063188A1
Application number: PCT/AU2013/001220
Authority: WO
Inventors: Charles Benjamin McHUGH; Eric William Nettleton
Original assignee: Technological Resources Pty Ltd
Current assignee: Technological Resources Pty Ltd
Priority date: 2012-10-23
Filing date: 2013-10-22
Publication date: 2014-05-01
Anticipated expiration: 2015-04-23

Abstract

A system (10) for controlling charging of a blast hole with explosives includes a charging controller (14) for controlling an explosives charging operation to charge a blast hole with the explosives. A sensor (16) is configured to monitor an initial condition of the blast hole and to monitor, during the explosives charging operation, the blast hole and parameters associated with the explosives charging operation. The sensor (16) is in communication with the charging controller (14) and the charging controller (14) is responsive to data received from the sensor (16) to alter, where necessary, the parameters associated with the explosives charging operation during the explosives charging operation.

Description

"A system for, and a method of, controlling charging of a blast hole with explosives" Cross-Reference to Related Applications

[1 ] The present application claims priority from Australian Provisional Patent

Application No 2012904622 filed on 23 October 2012, the contents of which are incorporated herein by reference.

Field

[2] This disclosure relates, generally, to the charging of blast holes with explosives and, more particularly, to a system for, and a method of, controlling charging of a blast hole with explosives.

Background

[3] At present, a technique known as "dipping" is used to determine the depth of a blast hole prior to charging explosives into the blast hole. Dipping involves a person manually lowering a weighted rope or line down the blast hole to check the depth of the drilled hole. This is a time-consuming, tedious process. In addition, there are large variations in accuracy depending on the person carrying out the dipping process.

[4] The information obtained from the dipping process is not automatically linked to the charging process and it is only performed before charging and not during the charging process.

[5] There is also the problem that, because dipping is a manual process, it may not be performed on every hole due to time constraints. It will be appreciated that a blast pattern is subject to accurately charging every blast hole with a predetermined "recipe" of explosives. If every hole is not dipped so that the correct recipe of explosives is charged into each hole, unforeseen variations in the blasting pattern could occur potentially leading to under-recovery of ore or resulting in less satisfactory grades of ore. [6] There is also the problem that, when a blast hole anomaly is detected by dipping, a drill blast engineer may not be available on site to determine what variations to the charging recipe need to be made to account for the anomaly.

Summary

[7] In a first aspect, there is provided a system for controlling charging of a blast hole with explosives, the system including

a charging controller for controlling an explosives charging operation to charge a blast hole with the explosives; and

a sensor configured to monitor an initial condition of the blast hole and to monitor, during the explosives charging operation, the blast hole and parameters associated with the explosives charging operation, the sensor being in communication with the charging controller and the charging controller being responsive to data received from the sensor to alter, where necessary, the parameters associated with the explosives charging operation during the explosives charging operation;

[8] In this specification, the term "explosives" is to be understood to include various different mixtures of blasting materials charged into the blast hole in different layers, as well as other material associated with the charging of the blast hole such as emulsions if water is present in the blast hole and stemming charged into a top of the blast hole after charging the explosive materials into the blast hole.

[9] The "parameters" associated with the explosives charging operation may include parameters associated with the blast hole such as hole depth, hole integrity (i.e. presence of voids and/or blow outs) or the presence of water or other detritus in the blast hole. The "parameters" may further include parameters associated with the actual charging of the explosives into the blast hole. Such parameters may include the composition of materials to be charged into the blast hole, the quantity of explosive materials to be charged into the blast hole, the flow rate of the explosive materials, etc.

[10] Throughout the explosives charging operation, the sensor may monitor the blast hole and parameters associated with the explosives charging operation at least periodically (whether at regular intervals or irregular intervals) or continuously. [11] The system may include a data store containing data relating to a plurality of blast holes to be charged with the explosives and an explosives charging schedule, the charging controller being able to communicate with the data store to use the data received from the sensor to update the data in the data store. The data store may be a remotely located data store, the data store communicating with the charging controller via a systems controller, the systems controller further being configured to load the data from the data store into the charging controller prior to commencement of the explosives charging operation and to receive updated data from the charging controller.

[12] The system may include an explosives carrying vehicle for sequentially charging a plurality of blast holes, the explosives carrying vehicle including the charging controller and the charging controller being configured to control dispensing of the explosives from the vehicle.

[13] The sensor may be mounted on the vehicle. The sensor may be mounted on the vehicle to be positioned in line of sight of a bottom of the blast hole during the explosives charging operation. The vehicle may include an explosives dispensing device having a discharge opening proximate a free end of the device, the sensor being mounted proximate the discharge opening.

[14] In a second aspect, there is provided a method of controlling charging of a blast hole with explosives, the method including

monitoring the condition of the blast hole prior to the commencement of an explosives charging operation

using a charging controller to charge the blast hole with explosives and, during the explosives charging operation, monitoring the blast hole and parameters associated with the explosives charging operation; and

causing the charging controller, where necessary, to alter the parameters during the explosives charging operation.

[15] Throughout the explosives charging operation, the monitoring of the blast hole and parameters associated with the explosives charging operation may occur periodically (whether at regular intervals or at irregular intervals) or continuously. [ 16] The method may include altering the parameters substantially in real time. By "real time" is meant that the charging controller is operable to alter the parameters substantially as soon as the charging controller detects a change from a loaded explosives data specification and that a change to the parameters is required.

[17] The method may include updating a data store responsive to altering the parameters associated with the explosives charging operation.

[18] The method may include monitoring the condition of the blast hole and the explosives charging operation using a sensor.

[ 19] The method may include effecting charging of the blast hole using an explosives charging vehicle on which the sensor is mounted and feeding information from the sensor to the charging controller. . -

[20] Further, the method may include mounting the sensor on the vehicle in a position in which the sensor is able to be placed in line of sight of the blast hole during the explosives charging operation. The method may include mounting the sensor proximate a discharge opening of an explosives dispensing device carried by the vehicle.

[21] In a third aspect, there is provided an explosives charging vehicle which includes a vehicle body defining at least one storage compartment for containing explosives; an explosives dispensing device mounted on the vehicle body, the explosives dispensing device being in communication with the at least one storage compartment; and a sensor mounted on the vehicle in a position to monitor a blast hole to be charged with the explosives, the sensor being configured to monitor the condition of the blast hole and to monitor during an explosives charging operation the blast hole and parameters associated with the explosives charging operation and to relay data gathered during the monitoring operation to a charging controller to enable the charging controller, where necessary, to alter the parameters associated with the explosives charging operation during the explosives charging operation. Brief Description of Drawings

[22] An embodiment of the disclosure is now described by way of example with reference to the accompanying diagrammatic drawings in which:-

[23] Fig. 1 shows a schematic block diagram of an embodiment of a system for controlling charging of a blast hole with explosives;

[24] Fig. 2 shows a schematic side view of an embodiment of an explosives charging vehicle used with the system of Fig. 1 ;

[25] Fig. 3 shows a schematic representation of a user interface forming part of the system of Fig. 1 ; and

[26] Fig. 4 shows a flow chart of the steps of an embodiment of a method of controlling charging of a blast hole with explosives.

Detailed Description of Exemplary Embodiment

[27] In the drawings, reference numeral 10 generally designates an embodiment of a system for controlling charging of a blast hole with explosives. The system 10 employs an explosives charging vehicle in the form of an explosives charging truck 12. The truck 12 includes a charging controller 14 for controlling an explosives charging operation to charge a blast hole with explosives. A sensor 16 is mounted on the truck 12 and is configured to monitor an initial condition of a blast hole and also to monitor, continuously during the explosives charging operation, the blast hole and parameters associated with the explosives charging operation. In other embodiments, throughout the explosives charging operation, the sensor 16 may monitor the blast hole and parameters associated with the explosives charging operation periodically, whether at regular intervals or at irregular intervals.

[28] While the described embodiment discloses the charging controller 14 being mounted on the truck 12, in other embodiments the charging controller 14 is mounted remotely from the truck 12 and communicates with the truck 12 via a suitable communications link such as, for example, a wireless communications link. [29] The sensor 16 communicates sensed data to the charging controller 14 and the charging controller 14 is responsive to the received data to alter, where necessary, the parameters associated with the explosives charging operation substantially in real time.

[30] The system 10 is intended particularly for use in charging explosives into blast holes drilled in a drill bench in an open-cut mine, quarry, or the like. It will be appreciated that such blast holes are drilled in a predetermined drill hole pattern in the drill bench and that the holes are each charged with a predetermined composition of explosives to effect a desired blast pattern by detonating the explosives.

[31 ] Generally, each blast hole is charged with a mixture of explosives in different proportions. For ease of description, the composition or mixture of explosives and related materials charged into each blast hole will be referred to as a "recipe". The recipe includes, in addition to different compositions of blasting material, emulsions used to separate the blasting material from any water present in a blast hole and stemming. Types of blasting materials include, for example, ammonium nitrate fuel oil (ANFO) and/or heavy ammonium nitrate fuel oil (HANFO). The ANFO and HANFO which are charged into the blast hole are charged into the blast hole in different proportions based on a predetermined explosives charging schedule and blast pattern to be achieved.

[32] The explosives charging schedule governs the grade and the quantity of material recovered following blasting operations and having one or more drill blast holes significantly out of specification could adversely affect the overall blasting pattern resulting in under- recovery of material and/or the grade of such recovered material.

[33] The system 10 includes a user interface 18 mounted in a cabin 20 (Fig. 2) of the truck 12. In addition, the system 10 includes a systems controller 22 arranged remotely. The systems controller 22 communicates with a data store or information store, such as a database 24, in which, inter alia, an explosives charging schedule is stored. A user interface 26 is associated with the systems controller 22.

[34] As described above, the systems controller 22 and its associated components are arranged remotely from the truck 12. The systems controller 22 may, for example, be located in a mine office or even more remotely, such as off site from the mine at a remote operations centre. The systems controller 22 communicates with the truck 12 via a wireless

communication network indicated schematically by antennas 28 and 30, the antenna 30 being associated with the truck 12.

[35] The truck 12 has a plurality of storage compartments 32, 34 and 36. The storage compartment 32 contains a quantity of ammonium nitrate. The storage compartment 34 contains emulsion and the storage compartment 36 contains fuel oil, such as diesel, which is mixed with the ammonium nitrate from the storage compartment 32 to form ANFO or HANFO, as desired, prior to being charged into the blast hole in accordance with the recipe. The mixing of materials occurs according to known techniques using pumps, valves and one or more programmable logic controllers on the truck 12. As this is all known technology in the art, these components are not described further in any detail in this specification.

[36] The truck 12 may include further storage compartments which are not shown in Fig. 2 of the drawings for storage of other consumables associated with the blasting operation such as, for example, stemming.

[37] The truck 12 includes an explosives dispensing device in the form of an auger 38. The auger 38 comprises a boom or arm 40 pivotally mounted on a body of the truck 12 to be rotatable about a vertical axis. The auger 38 further includes a discharge nozzle 42 located proximate a free end of the boom 40.

[38] To facilitate accurate measuring of the blast hole and, more particularly, the depth of the blast hole prior to commencing charging of explosives into the blast hole, the sensor 16 is mounted on the discharge nozzle 42 so that there is line of sight between the sensor 16 and the bottom of the blast hole in use.

[39] Because the diameter of a blast hole is of the order of 300 millimetres, it is required that the truck 12 be accurately positioned relative to the blast hole prior to commencing charging of that blast hole via the auger 38.

[40] For this purpose, the truck 12 includes one or more position determining units 44. Preferably, each of these position determining units 44 is a GPS unit. The GPS units 44 may, if desired, be high precision GPS (HPGPS) units 44. It will be appreciated that the resolution 0

8 of the GPS units 44 is insufficient to position the discharge nozzle 42 of the auger 38 with sufficient accuracy relative to the blast hole to be charged. For this purpose, the auger 38 carries an encoder 46. The encoder 46 is used to determine the position of the free end of the auger 38 accurately relative to the body of the truck 12. This, together with the GPS units 44, facilitates sufficiently accurate positioning of the discharge nozzle 42 above a blast hole to be charged.

[41 ] Although the sensor 16 has been described as being mounted on the discharge nozzle 42 of the auger 38, the sensor 16 could, instead, be mounted in any other suitable position where there is line of sight between the sensor 16 and the bottom of the blast hole. Thus, for example, the sensor 16 could be mounted on its own pivot arm (not shown) instead of being mounted on the auger 38.

[42] The sensor 16 is a laser, radar or other suitable electromagnetic sensor that provides range data. Instead, the sensor 16 could be a mechanically implemented system such as a mechanically fed probe or line which is lowered into the blast hole to measure the depth of the blast hole. The sensor 16 could also be an acoustic sensor.

[43] In use, two data sets are stored in the database 24. The first data set relates to blast hole data and comprises data relating to the blast hole pattern and the depth of each blast hole in the pattern. It will be appreciated that the blast hole pattern comprises positional information which can be used by the truck 12 for positioning the truck 12 relative to each blast hole to be charged, i.e. the blast hole pattern comprises co-ordinate data of each blast hole in the pattern.

[44] The second data set is an explosives data specification. The explosives data specification contains the recipe for each blast hole and this recipe is generated by drill and blast engineers, prior to the charging operation, in dependence on various factors such as, for example, the geological makeup of the drill bench in question.

[45] The database 24 also includes charging rules associated with the charging operation. These rules may be related to what is required if a drilled blast hole is significantly out of specification in comparison with the recorded data of that hole. Thus, the rules could specify that if the drilled hole is too deep, it should be back filled, if a drilled hole is too shallow it may need to be redrilled and if the water level in the hole is above a predetermined threshold, the hole is to be charged with an emulsion to inhibit absorption of the water by the explosive material.

[46] Once the data have been loaded into the database 24 and the truck 12 has been provisioned with materials to be used in the explosives charging operation, the systems controller 22 loads the data relating to the explosives charging operation to be carried out into the charging controller 14 of the truck 12. The truck 12 then travels to the drill bench, the blast holes of which are to be charged with explosives and commences the charging operation.

[47] As an initial step, as shown at step 48 in Fig. 4 of the drawings, the sensor 16 is operated to sense the depth of the blast hole to be charged. The charging controller 14 then determines whether or not the sensed depth of the blast hole corresponds with the stored data relating to that specific blast hole. If not, the charging controller 14, substantially in real time, adjusts the recipe to cater for the revised depth of the blast hole as measured by the sensor 16.

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[48] Simultaneously, the sensor 16, or another sensor, determines whether or riot any water is present in the blast hole. If so, the sensor 16 conveys this information to the charging controller 14. The charging controller 14 then, further, alters the recipe at step 52 so that, if necessary, an emulsion from the compartment 34 of the truck 12 is firstly charged into the blast hole prior to the explosives material being charged into the blast hole.

[49] At step 54, if the explosives charging data has been revised following measurement by the sensor 16 or if the data measured by the sensor 16 agrees with the data initially stored in the charging controller 14, the charging controller 14 causes the recipe as stored or as revised to be charged into the blast hole. While the material is being charged into the blast hole, the sensor 16 continues to monitor the charging of the blast hole as shown at step 56.

[50] During the monitoring procedure, the charging controller 14 receives the sensed data from the sensor 16 and, as shown at step 58, continuously and substantially in real time, compares the sensed data with the stored data relating to that blast hole, whether as initially loaded from the database 24 or as revised. Should the charging controller 14 detect that there is a difference between the sensed data and the stored data, the charging controller 14 is operable to adjust the charging rate as shown at step 60. [51] Data sensed by the sensor 16 during the charging operation include, for example, the flow rate of explosives charged into the blast hole, the quantity of explosives charged into the blast hole, or the like. A discrepancy between the quantity of explosives charged into the blast hole and the stored data relating to the quantity that should be charged into the blast hole may arise due to voids or blow outs being present in the blast hole. This could result in overcharging of the blast hole.

[52] With continuous monitoring by the sensor 16 and the charging controller 14 being responsive to the sensor 16, this problem is, largely, obviated. As soon as a discrepancy is detected by the charging controller 14, the charging controller 14 is operative to stop the charging operation thereby inhibiting over-charging of the blast hole.

[53] As shown at step 62, should the charging controller 14 determine that there is no change to the charging date needed, the charging controller 14 determines whether or not the hole has been charged as per specification or as revised using data received from the sensor 16. If the hole has been charged to the required height, the charging procedure ends at step 64. If not, the charging procedure continues from step 54.

[54] Fig. 3 shows the user interface 18 as carried in the cabin 20 of the truck 12. The user interface 18 is a graphical user interface including a haptic or touch display 66. A window 68 is displayed showing the position of the truck 12 on a drill bench 70 as well as the hole pattern 72 on the drill bench 70. In addition, the display 66 shows the state of charge of a blast hole 74. The blast hole information contains different coloured legends indicative of the material charged into the blast hole 74.

[55] The illustrated example shows a blast hole 74 having an initial charge 76 of ANFO, an upper charge of HANFO 78 and is topped off by stemming 80.

[56] Should the blast hole have had water in it, the initial material charged into the blast hole is the emulsion which is injected prior to the charge of ANFO 76.

[57] A graphic representation of the auger 38 is also displayed on the display and, when the blast hole is being charged, a representation of material flow is shown in the representation of the auger 38. [58] The user interface 18 enables the operator of the truck 12 to monitor the charging operation. Should the operator detect any problems with the charging operation at any time, the operator is able, using the user interface 18, to override the automated charging operation.

[59] Data collected by the charging controller 14 are fed back to the systems controller 22 which, in turn, revises the data stored in the database 24 with the updated data from the charging controller 14. This is useful for subsequent analysis purposes. The transfer of data from the truck 12 can occur during the charging operation if the communications link, via the antennas 28 and 30, between the truck 12 and the systems controller 22 is adequate. If not, the data can be loaded from the charging controller 14 into the systems controller 22 when the truck 12 returns to base, either after completion of the charging operation or to be replenished with charging materials and any other consumables.

[60] It is possible for the systems controller 22 to be omitted and for the charging controller 14 to communicate directly with the database 24 if the wireless communication link is adequate or, if not, when the truck 12 is within range of the database 24.

[61] It is an advantage of the described embodiment that a system 10 is provided which enables more accurate charging of blast holes to be effected. This is achieved by integrating the sensor 16 with the explosive charging truck 12. The blast hole depth can be automatically recorded into the charging controller 14 and can be used automatically to calculate the amount of explosives to be charged into the blast hole and/or to revise the amount of explosives to be charged into the blast hole. Further, the ability to detect water in the bottom of the blast can also be used to change the recipe substantially in real time,

[62] It will further be appreciated that not only is the amount of charge in the specific blast hole altered should a revision be necessary by the charging controller but, as described above, alterations in the recipe for any one blast hole can affect the amount to be charged into neighbouring blast holes in the blast pattern so that the optimum result is able to be achieved. With the provision of the sensor 16 continuously monitoring and updating the charging controller 14 in real time, the charging controller 14 is able to make necessary revisions to recipes for the blast hole currently being charged and other blast holes without the presence or intervention of a drilling and blasting engineer. [63] Thus, a further benefit of the described disclosure is that updating to the blasting schedule can be effected by the charging controller 14 even when a drilling and blasting engineer is not present. It will be appreciated that the absence of the engineer when it is necessary to alter an explosives charging schedule can result in delays and, therefore, lead to reduced productivity. The ability to alter the charging data effectively in real time therefore speeds up the charging process and improves productivity.

[64] Still further, the provision of the system 10. results in a blasting process having fewer errors, more integrated data and reduced operator workload. This leads to greater repeatability and a more accurate and optimised blasting procedure.

[65] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A system for controlling charging of a blast hole with explosives, the system including

a sensor configured to monitor an initial condition of the blast hole and to monitor, during the explosives charging operation, the blast hole and parameters associated with the explosives charging operation, the sensor being in communication with the charging controller and the charging controller being responsive to data received from the sensor to alter, where necessary, the parameters associated with the explosives charging operation during the explosives charging operation.

2. The system of claim 1 which includes a data store containing data relating to a plurality of blast holes to be charged with the explosives and an explosives charging schedule, the charging controller being able to communicate with the data store to use the data received from the sensor to update the data in the data store.

3. The system of claim 2 in which the data store is a remotely located data store, the data store communicating with the charging controller via a systems controller, the systems controller further being configured to load the data from the data store into the charging controller prior to commencement of the explosives charging operation and to receive updated data from the charging controller.

4. The system of any one of the preceding claims which includes an explosives carrying vehicle for sequentially charging a plurality of blast holes, the explosives carrying vehicle including the charging controller and the charging controller being configured to control dispensing of the explosives from the vehicle.

5. The system of claim 4 in which the sensor is mounted on the vehicle.

6. The system of claim 5 in which the sensor is mounted on the vehicle to be positioned in line of sight of a bottom of the blast hole during the explosives charging operation.

7. The system of claim 6 in which the vehicle includes an explosives dispensing device, having a discharge opening proximate a free end of the device, the sensor being mounted proximate the discharge opening.

8. A method of controlling charging of a blast hole with explosives, the method including

9. The method of claim 8 which includes altering the parameters substantially in real time.

10. The method of claim 8 or claim 9 which includes updating a data store responsive to altering the parameters associated with the explosives charging operation.

1 1. The method of any one of claims 8 to 10 which includes monitoring the condition of the blast hole and the explosives charging operation using a sensor.

12. The method of claim 1 1 which includes effecting charging of the blast hole using an explosives charging vehicle on which the sensor is mounted and feeding information from the sensor to the charging controller.

13. The method of claim 12 which includes mounting the sensor on the vehicle in a position in which the sensor is able to be placed in line of sight of the blast hole during the explosives charging operation.

1 . The method of claim 13 which includes mounting the sensor proximate a discharge opening of an explosives dispensing device carried by the vehicle.

15. An explosives charging vehicle which includes

a vehicle body defining at least one storage compartment for containing explosives; an explosives dispensing device mounted on the vehicle body, the explosives dispensing device being in communication with the at least one storage compartment; and a sensor mounted_; on the vehicle in a position to monitor a blast hole to be charged with the explosives, the sensor being configured to monitor the condition of the blast hole and to monitor during an explosives charging operation the blast hole and parameters associated with the explosives charging operation and to relay data gathered during the monitoring operation to a charging controller to enable the charging controller, where necessary, to alter the parameters associated with the explosives charging operation during the explosives charging operation.