AU2019216882B2 - Method and system for use in positioning a mill liner - Google Patents

Abstract

The present disclosure relates to a system for use in positioning a mill liner during liner installation, the system including: a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes; a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes; and at least one electronic processing device for: determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor; comparing the orientation of each sensor using the sensor data; and determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

Description

METHOD AND SYSTEM FOR USE IN POSITIONING A MILL LINER

Background of the Invention

[0001] The present invention relates to a method and system for use in positioning a mill liner, and in particular for orienting a liner to a mill shell during liner installation.

Description of the Prior Art

[0002] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

[0003] Mill liners are sacrificial wear components used to protect the shell of a grinding mill from damage and to provide a mechanism to lift the ore charge during mill operation, for grinding the ore charge down to the required size. The mill liners need to be replaced at regular intervals, because the ore charge wears the liners down to the point where the mill shell is at risk of damage, or the grinding process efficiency has reduced significantly.

[0004] Mill liners are secured to the inside of grinding mills using fasteners known as liner bolts which are inserted through bolt holes in the liner and mill shell. Mill liners are manipulated within the mill using a mill reline machine (MRM) that is controlled by a mill reline operator.

[0005] During typical liner installation, a spotter is present within the mill to provide feedback to the mill reline operator regarding the orientation of the liner with respect to the mill shell where the liner is being placed. This feedback is important to ensure that the liner is oriented appropriately for accurate and fast placement. When correctly oriented, the liner bolt holes (and/or liner bolts) will be aligned with the shell bolt holes allowing reline personnel outside of the mill to efficiently install a nut and washer onto the bolt and tighten it using various torque tools.

[0006] This current installation method exposes the spotter on the inside of the mill to many hazards. The inside of the mill is classified as a confined space, the floor of the mill is uneven, there is poor visibility, there is the potential for falling objects to strike the spotter (steel balls and rocks wedged in the liners), the atmosphere is hot and humid, communication is difficult, the spotters are in close proximity to working machinery and suspended loads and, in order to provide visual feedback of liner orientation to the mill reline operator, the spotter is often required to climb up the mill shell and work at heights.

[0007] To enhance safety it would therefore be desirable to remove the need for the spotter inside the mill.

[0008] It is against this background, and the problems and difficulties associated therewith, that the present invention has been developed.

Summary of the Present Invention

[0009] In one broad form an aspect of the present invention seeks to provide a system for use in positioning a mill liner during liner installation, the system including:

a) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes;

b) a second orientation sensor positioned on a liner inside the mill in alignment with a row of liner bolt holes; and,

c) at least one electronic processing device for:

i) determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor;

ii) comparing the orientation of each sensor using the sensor data; and, iii) determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

[0010] In one embodiment, the system further includes a display for displaying a representation of the at least one alignment indicator to a mill reline operator.

[0011] In one embodiment, the display is at least one of:

a) an light emitting diode (LED) display;

b) a liquid crystal display (LCD); c) a picture in picture (PIP) display; and,

d) a heads up display (HUD).

[0012] In one embodiment, the display includes at least one of:

a) a linear array of LEDs;

b) a circular array of LEDs;

c) a two dimensional (2D) representation of the alignment indicator; and, d) a three dimensional (3D) representation of the alignment indicator.

[0013] In one embodiment, the display is co-located with the second orientation sensor.

[0014] In one embodiment, the at least one electronic processing device is for providing the at least one alignment indicator to a mill reline machine.

[0015] In one embodiment, the at least one alignment indicator is indicative of an alignment about at least one of:

a) a single axis;

b) two axes; and,

c) three axes.

[0016] In one embodiment, the alignment indicator is indicative of an angle between the liner and mill shell with respect to at least one axis.

[0017] In one embodiment, the system includes:

a) a first orientation sensor unit having a first housing including:

i) the first orientation sensor; and,

ii) a first electronic processing device coupled to the first orientation sensor; and, b) a second orientation sensor unit having a second housing including:

i) the second orientation sensor; and,

ii) a second electronic processing device coupled to the second orientation sensor.

[0018] In one embodiment, the first and second orientation sensor units are respectively attached to the mill shell and liner using at least one of:

a) an adhesive; b) magnets; and,

c) mechanical engagement.

[0019] In one embodiment, the second orientation sensor unit is a sacrificial member that remains attached to the liner after liner installation.

[0020] In one embodiment, the first and second orientation sensor units communicate wirelessly.

[0021] In one embodiment, the wireless communication is via at least one of:

a) radio;

b) optical;

c) electrical; and,

d) acoustic.

[0022] In one embodiment, the second electronic processing device is for:

a) receiving signals wirelessly from the first orientation sensor unit;

b) receiving signals from the second orientation sensor;

c) processing the received signals to determine orientation data;

d) determining a difference in alignment between the orientation sensor units using the processed orientation data; and,

e) causing feedback to be provided to a mill reline operator indicative of the determined difference.

[0023] In one embodiment, the orientation sensor units include a magnetic sensor for detecting an external magnet, the respective electronic processing device being for at least one of activating and configuring the unit in response to detection of the external magnet.

[0024] In one embodiment, the first and second orientation sensors include at least one of: a) an accelerometer;

b) a magnetometer; and,

c) a gyroscope. [0025] In another broad form an aspect of the present invention seeks to provide a method for use in positioning a mill liner during liner installation, the method including in at least one electronic processing device:

a) determining sensor data indicative of signals from:

i) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes; and,

ii) a second orientation sensor positioned on a liner inside the mill in alignment with a row of liner bolt holes, the sensor data at least partially indicative of the orientation of each sensor;

b) comparing the orientation of each sensor using the sensor data; and,

c) determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

[0026] In one embodiment, the method further includes, in the at least one electronic processing device, causing a representation of the at least one alignment indicator to be displayed on a display so as to provide visual feedback to a mill reline operator of the alignment between the mill liner and mill shell.

[0027] In one embodiment, the method further includes, in the at least one electronic processing device, causing a mill reline machine to adjust the position of the mill liner based on the determined alignment indicator.

[0028] In a further broad form an aspect of the present invention seeks to provide a method for positioning a mill liner during liner installation, the method including:

a) attaching a first orientation sensor unit to an outer surface of a mill shell in alignment with a row of shell bolt holes;

b) attaching a second orientation sensor unit to the mill liner in alignment with a row of liner bolt holes; and,

c) adjusting the position of the mill liner in response to feedback from a controller that determines the alignment of the mill liner relative to the mill shell using sensor data from the sensor units, the sensor data indicative of the orientation of each sensor unit. [0029] In one embodiment, the position of the mill liner is adjusted by a mill reline machine that is operated by a mill reline operator.

[0030] In one embodiment, the controller provides visual feedback of the alignment to the mill reline operator via a display.

[0031] In one embodiment, the position of the mill liner is adjusted by a mill reline machine that is operated by an at least partially automated control system.

[0032] In one embodiment, the position of the liner is adjusted until at least one of:

a) the liner bolt holes are co-axially aligned with the shell bolt holes; and, b) one or more liner bolts retained in the liner are co-axially aligned with the shell bolt holes.

[0033] In one embodiment, the liner is secured to the mill shell via the one or more liner bolts.

[0034] In one embodiment, the method further includes:

a) removing the second orientation sensor unit from the secured liner; and, b) attaching the second orientation sensor unit to another liner to be positioned.

[0035] In one embodiment, for another liner in a different row to the secured liner, the method includes:

a) removing the first orientation sensor unit from the mill shell; and,

b) attaching the first orientation sensor unit to the mill shell in alignment with a row of shell bolt holes in the different row.

[0036] In one embodiment, the first and second orientation sensor units are respectively attached to the mill shell and liner using at least one of:

a) an adhesive;

b) magnets; and,

c) mechanical engagement.

[0037] In one embodiment, the second orientation sensor unit is a sacrificial member that remains attached to the liner after liner installation. [0038] In a further broad form an aspect of the present invention seeks to provide a system for use in positioning a mill liner during liner installation, the system including:

a) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes;

b) a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes; and,

c) at least one electronic processing device for:

i) determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor; and,

ii) providing at least some of the sensor data to a control system of a mill reline machine for adjusting the position of the mill liner based on the at least some of the sensor data.

[0039] It will be appreciated that the broad forms of the invention and their respective features can be used in conjunction, interchangeably and/or independently, and reference to separate broad forms is not intended to be limiting.

Brief Description of the Drawings

[0040] Various examples and embodiments of the present invention will now be described with reference to the accompanying drawings, in which: -

[0041] Figure 1A is a schematic sectional view of an example of a system for use in positioning a mill liner during liner installation;

[0042] Figure 1B is a schematic perspective view of the system shown from within the grinding mill;

[0043] Figure 1C is a schematic side view of the system shown from outside the mill;

[0044] Figures 2A to 2G provide sequential views of an example of a display of an orientation sensor unit and corresponding alignment between the liner and mill shell;

[0045] Figure 3A is a schematic sectional view of a an example of a system for use in positioning a mill liner during liner installation illustrating wireless connectivity between first and second orientation sensor units;

[0046] Figure 3B is a schematic diagram of apparatus for use in positioning a mill liner during installation; [0047] Figure 4 is a flowchart of an example of a method for use in positioning a mill liner during liner installation; and,

[0048] Figure 5 is a flowchart of an example of a method of positioning a mill liner during liner installation.

Detailed Description of the Preferred Embodiments

[0049] An example of a system for use in positioning a mill liner during liner installation shall now be described with reference to Figures 1A to 1C.

[0050] In this example, the system 100 includes a first orientation sensor 130 positioned on an outer surface of a mill shell 120 in alignment with a row of shell bolt holes 122. A second orientation sensor 140 is positioned on a liner 110 inside the mill 101 in alignment with a row of liner bolt holes 112. In this regard, it is to be appreciated that the row of shell bolt holes 122 correspond to the position where the liner 110 is to be placed so that when positioned, the liner bolt holes 112 will be aligned with the shell bolt holes 122 so that liner bolts (not shown) can be inserted through the shell to fasten the liner 110 thereto.

[0051] As will be described in further detail below, the orientation sensors 130, 140 provide orientation or angular position data for use in correctly aligning the liner 110 to the mill shell 120. Typically, the orientation sensors include accelerometers; however magnetometers and gyroscopes may also be employed along with optical enhancement in some examples.

[0052] The system 100 further includes at least one electronic processing device for determining sensor data indicative of signals from each of the first and second orientation sensors 130, 140, the sensor data at least partially indicative of the orientation of each sensor. The processing device then compares the orientation of each sensor 130, 140 using the sensor data, and, determines at least one alignment indicator at least partially indicative of an alignment between the mill liner 110 and the mill shell 120 in accordance with results of the comparison.

[0053] The alignment indicator can then be used to provide feedback to a mill reline operator enabling them to adjust the position of the liner in an appropriate manner in order to align it with the mill shell. In this regard, it is to be understood that typically the operator is in control of a mill reline machine (MRM) which lifts the liner into position and is controllable to orient the liner in response to instructions from the operator.

[0054] The above described system provides a number of advantages.

[0055] Firstly, it enables the operator to correctly orient the liner with respect to the mill shell without requiring a spotter to be present inside the mill to provide feedback of the liner orientation. Safety of mill reline operations is therefore improved by removing the need for the spotter inside the mill which is a dangerous and confined space.

[0056] Furthermore, the use of orientation sensors to estimate the alignment of the liner with respect to the mill shell provides more accurate feedback compared to estimation of liner orientation based on visual inspection by a human spotter. The accuracy and speed of liner positioning can therefore be improved by use of the system enabling faster installation of liner bolts through the liner and mill shell. The feedback could also be used in an autonomous or semi- autonomous liner installation system whereby a machine manipulates the orientation of the liner in response to the determined alignment indicator.

[0057] A number of further features will now be described.

[0058] Typically, the system further includes a display for displaying a representation of the at least one alignment indicator to a mill reline operator. In this regard, the alignment indicator can be displayed to the operator as part of a graphical, numerical, symbolic representation and the like. The representation may be displayed substantially in real-time which allows faster positioning of the liner and therefore quicker mill relines.

[0059] Any suitable display technology may be used to display the representation of the alignment indicator including for example an light emitting diode (LED) display; a liquid crystal display (LCD); a picture in picture (PIP) display, and, a heads up display (HUD).

[0060] In one example, the display includes at least one of a linear array of LEDs, a circular array of LEDs, a two dimensional (2D) representation of the alignment indicator, and, a three dimensional (3D) representation of the alignment indicator which may include a representation of the liner and shell. [0061] Whilst the display could be located in any position visible to the mill reline operator (for example on a console or the like), more typically it is co-located with the second orientation sensor. In one example, the sensor and display are packaged in the same housing attached to the liner.

[0062] Alternatively, the at least one alignment indicator may be provided to a mill reline machine. The mill reline machine may include a controller configured to autonomously or semi-autonomously adjust the position of the mill liner based on the at least one alignment indicator. In some examples, the sensor data may be provided to the mill reline machine for use by the controller as required.

[0063] In any event, the alignment indicator may be indicative of an alignment about at least one of a single axis, two axes and three axes. In the simplest arrangement, only a single axis is used, corresponding to the liner orientation that is most difficult for the mill reline operator to observe. In this regard, it will be appreciated that it is often difficult for the operator to observe the angular position of the liner about a lengthwise axis of rotation. In other arrangements, angular alignment feedback is measured about two or three axes so that the operator is given feedback enabling them to rotate the liner about any desired axis.

[0064] In one example, the alignment indicator is indicative of an angle between the liner and mill shell with respect to at least one axis. In the example described herein, a circular array of LEDs is used to represent the angle, with each LED corresponding to a liner angle or range of liner angles.

[0065] In one implementation, the system includes a first orientation sensor unit having a first housing including the first orientation sensor and a first electronic processing device coupled to the first orientation sensor; and, a second orientation sensor unit having a second housing including the second orientation sensor, and, a second electronic processing device coupled to the second orientation sensor. Each orientation sensor unit may therefore include its own processing device such as a controller or microprocessor in order to process signals from the sensors. The first orientation sensor unit attached to the mill shell does not necessarily require a processing device however, as signals from the sensor may be transmitted directly to the second orientation sensor unit without processing. [0066] Alternatively, the first orientation sensor unit may include an ADC (Analogue to Digital Converter), for sampling analogue signals indicative of the orientation of the first orientation sensor to thereby generate sampled signal values, as well as a filter for filtering the analogue signals and/or an amplifier. This can be performed to remove unwanted artefacts, such as noise interference from remote equipment, noise generated by the sensors, as well as to prevent aliasing due to the sampling rate of the ADC, or the like. It will be appreciated that filtering and digitising can be performed in any order, so that filtering can be performed on either or both of the analogue or digitised signals. In the above example, the processing devices may incorporate ADC and filtering functionality such that separate ADCs and filters are not required.

[0067] In use, the first and second orientation sensor units are respectively attached to the mill shell and liner using at least one of an adhesive, magnets, and, mechanical engagement. Typically, magnetic engagement is used for rapid installation and removal of the units thereby enabling the units to be re-used throughout the mill reline. Alternatively, the second orientation sensor unit may be a sacrificial member that remains attached to the liner after liner installation. In this regard, the second orientation sensor unit may be disposable and permanently attached to each liner.

[0068] Typically, the first and second orientation sensor units communicate wirelessly in order to share orientation data. Any suitable means of wireless communication may be used including for example radio, optical, electrical or acoustic. Typically, sensor data from the first orientation sensor unit is transmitted to a wireless receiver on the second orientation sensor unit. As the units are in close proximity in use, the transmitter on the first orientation sensor unit may have low power consumption and a wireless protocol such as Bluetooth may be employed. However this is not essential and in other embodiments the wireless protocol may include any one or more of wireless, Zigbee, radio frequency, mobile network, and the like.

[0069] Although the use of wireless communications between the orientation sensor units will generally be preferred for practical reasons, this is not essential and any other suitable communication method may be used. For instance, in alternative implementations the orientation sensor units may be directly connected by a physical communication medium for allowing data to be transferred between the units. For example, an electrical connection may be used to allow data transfer via electrical signal transmissions, or in another example, a fiber optic transmission cable may be used.

[0070] It should also be appreciated that dedicated cable connections for providing communication between the orientation sensor units will not necessarily be required. In some implementations, communication may be achieved by having the orientation sensor units “piggy-back” or superimpose the necessary communications signals on existing power wiring or other communications wiring.

[0071] It should also be understood that a combination of different communication methods could be used. For example, an orientation sensor unit may be connected by cable to a remote mounted wireless transmitter/receiver/transceiver, which could in turn facilitate wireless communication either directly to another orientation sensor unit or another transmitter/receiver/transceiver associated with the other orientation sensor.

[0072] It will be appreciated that the second electronic processing device associated with the second orientation sensor unit on the liner may be configured to perform most of the signal processing. In this regard, the second electronic processing device may be configured to receive signals wirelessly from the first orientation sensor unit, receive signals from the second orientation sensor, process the received signals to determine orientation data, determine a difference in alignment between the orientation sensor units using the processed orientation data; and, cause feedback to be provided to a mill reline operator indicative of the determined difference.

[0073] In some implementations, the orientation sensor units may include a magnetic sensor for detecting an external magnet, the respective electronic processing device being for at least one of activating and configuring the unit in response to detection of the external magnet. This can be used to allow a user to interact with the unit even if the unit is completely sealed within its housing.

[0074] A method for use in positioning a mill liner during liner installation is also provided, the method including in at least one electronic processing device, determining sensor data indicative of signals from a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes; and, a second orientation sensor positioned on a liner inside the mill in alignment with a row of liner bolt holes, the sensor data at least partially indicative of the orientation of each sensor. The method further includes comparing the orientation of each sensor using the sensor data; and, determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

[0075] In one example, the method further includes, in the at least one electronic processing device, causing a representation of the at least one alignment indicator to be displayed on a display so as to provide visual feedback to a mill reline operator of the alignment between the mill liner and mill shell. As previously described the representation may be displayed to the operator as part of a graphical, numerical, symbolic representation and the like.

[0076] In an alternative example, the method may include, in the at least one electronic processing device, causing a machine to manipulate the orientation of the liner based on the determined alignment indicator.

[0077] In another broad form, a method for positioning a mill liner during liner installation is provided, the method including attaching a first orientation sensor unit to an outer surface of a mill shell in alignment with a row of shell bolt holes, attaching a second orientation sensor unit to the mill liner in alignment with a row of liner bolt holes; and, adjusting the position of the mill liner in response to feedback from a controller that determines the alignment of the mill liner relative to the mill shell using sensor data from the sensor units, the sensor data indicative of the orientation of each sensor unit.

[0078] Typically, the position of the mill liner is adjusted by a mill reline machine (MRM) that is operated by a mill reline operator. The liner is attached to an arm of the MRM and able to be manipulated via controls so as to move and orient the liner in any desired manner.

[0079] In one example, the controller provides visual feedback of the alignment to the mill reline operator via a display as previously described. Whilst a visual display is described herein, it is to be appreciated that the feedback could also be aural and the alignment indicator could be communicated to the operator via voice information in the form of instructions or the like. [0080] However, in alternative implementations, the position of the mill liner may be adjusted by a mill reline machine that is operated by an at least partially automated control system. In this regard, the control system may be configured to respond to the alignment feedback by generating control signals to autonomously or semi-autonomously move and orient the liner to achieve the required positioning of the mill liner relative to the mill shell.

[0081] Typically, the position of the liner is adjusted until at least one of the liner bolt holes are co-axially aligned with the shell bolt holes; and, one or more liner bolts retained in the liner are co-axially aligned with the shell bolt holes. In this regard, the liner bolts may be retained in the liner prior to transportation into the mill so that mill reline personnel are not required to be inside the mill to install the bolts.

[0082] Once correctly aligned, the liner is secured to the mill shell via the one or more liner bolts which are installed through the liner and mill shell and secured by an operator outside the mill.

[0083] After a liner has been positioned and subsequently secured, the method may further include removing the second orientation sensor unit from the secured liner; and, attaching the second orientation sensor unit to another liner to be positioned. For another liner in a different row to the secured liner, the method includes removing the first orientation sensor unit from the mill shell, and, attaching the first orientation sensor unit to the mill shell in alignment with a row of shell bolt holes in the different row. For another liner in the same row, the first orientation sensor unit does not need to be re-positioned.

[0084] As previously described, the first and second orientation sensor units are typically respectively attached to the mill shell and liner using at least one of an adhesive, magnets; and, mechanical engagement, although in some examples the second orientation sensor unit is a sacrificial member that remains attached to the liner after liner installation.

[0085] In another broad form, a system for use in positioning a mill liner during liner installation is provided, the system including a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes, a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes, and at least one electronic processing device for determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor, and providing at least some of the sensor data to a control system of a mill reline machine for adjusting the position of the mill liner based on the at least some of the sensor data.

[0086] Referring back to Figures 1A to 1C, the system 100 shall be described in further detail. In Figures 1A to 1C, there is shown a grinding mill 101 during a mill reline during which worn liners in the mill are removed and replaced with new liners. A mill reline machine 102 is operated inside the mill to lift each liner plate to its mounting position against the mill shell. Each liner 110 includes a plurality of liner bolt holes 112 that must be aligned correctly with corresponding shell bolt holes 122 where the liner is to be placed. Correct alignment will assist in the installation of liner bolts through the liner and mill shell.

[0087] The system 100 includes a first orientation sensor 130 which is attached to the outside of the mill shell 120, for example via magnetic attachment. As shown in Figure 1C, the first orientation sensor 130 is aligned with a row of shell bolt holes 122 along a horizontal plane AA through the centres of the bolt holes 122. The first orientation sensor 130 typically forms part of a sensor unit including a housing which houses the sensor and a processing device such as a controller or microprocessor. In one example, the housing includes an arrow or the like which must point upwards and be at 90 degrees to the horizontal plane through the shell bolt holes. This ensures that the orientation sensor 130 is oriented correctly for reference and calibration.

[0088] A second orientation sensor 140 is attached to the liner 110 to be replaced so that it is aligned with the row of liner bolts along a horizontal plane through the centres of the bolt holes 112. The second orientation sensor 140 typically forms part of a sensor unit including a housing which houses the sensor and a processing device such as a controller or microprocessor. In one example, the housing includes an arrow or the like which must point upwards and be at 90 degrees to the horizontal plane through the liner bolt holes. This ensures that the orientation sensor 140 is oriented correctly for purposes of calibration with orientation sensor 130.

[0089] The respective sensor units can be turned on and synced together via wireless communication as will be described in further detail below so that the units can begin sharing orientation data. Any suitable orientation sensors may be used including for example accelerometers, magnetometers and gyroscopes.

[0090] A controller on-board the second orientation sensor unit determines sensor data indicative of signals from each of the first and second orientation sensors 130, 140, the sensor data at least partially indicative of the orientation of each sensor 130, 140. The controller then compares the orientation of each sensor using the sensor data and determines an alignment indicator at least partially indicative of an alignment between the mill liner 110 and the mill shell 120 in accordance with results of the comparison.

[0091] A representation of the alignment indicator is then displayed to a mill reline operator on a display 200, for example an LED array on the second orientation sensor unit. Various representations of the alignment indicator are shown by way of example in Figures 2A to 2G along with examples of the alignment that the representation indicates.

[0092] In Figure 2 A, the second orientation sensor 140 is aligned with the first orientation sensor 130 along at least one axis so that the liner bolt holes are co-axially aligned with the shell bolt holes along axis BB. In this example, the three main lights 201 in the middle of the circular array illuminate green and the three FEDs 202 either side of the main lights will also light up green. This indicates to the operator that the liner 110 is parallel to the mill shell 120.

[0093] In Figure 2B, FED 203 at the top of the array illuminates red indicating that the liner is not parallel to the mill shell and that the liner angle is over 105 degrees to the mill shell. When an FED in the top half of the array illuminates, in this example, it indicates that the top of the sensor is further away from parallel so the operator knows which way to rotate the liner in order to bring it closer to parallel. Fikewise, an FED illuminating the bottom half of the array may indicate that the bottom of the sensor is further away from parallel.

[0094] In Figure 2C, FEDs 204 illuminate red indicating that the liner is not parallel to the mill shell and that the liner angle is between 105 and 30 degrees to the mill shell. In Figure 2D, FEDs 205 illuminate orange indicating that the liner is not parallel to the mill shell and that the liner angle is between 30 and 23 degrees to the mill shell. As the alignment gets closer to parallel the lights may change colour for example from red to orange to yellow to green to provide further feedback to the operator. In Figure 2E, FEDs 206 illuminate orange indicating that the liner is not parallel to the mill shell and that the liner angle is between 23 and 15 degrees to the mill shell. In Figure 2F, LEDs 207 illuminate yellow indicating that the liner is not parallel to the mill shell and that the liner angle is between 15 and 9 degrees to the mill shell. In Figure 2G, LEDs 208 illuminate orange indicating that the liner is not parallel to the mill shell and that the liner angle is between 9 and 3 degrees to the mill shell.

[0095] It is to be appreciated that the above described display 200 is an example only of how the alignment indicator may be represented and displayed to the operator. Any other suitable representation may be used including for example a graphical, numerical, symbolic representation and the like. Instead of using an LED display, the display could be an LCD display or an element of another display technology including picture in picture (PIP) or part of a wearable heads up display (HUD).

[0096] Referring now to Figures 3 A and 3B, there is shown an example of system 300 for use in positioning a mill liner 310 during liner installation. The system 300 includes a first orientation sensor unit 330 aligned with a row of shell bolt holes 322 of the mill shell 320 and a second orientation sensor unit 340 aligned with a row of corresponding liner bolt holes 312. In use, the first and second orientation sensor units 330, 340 wirelessly communicate in order to share orientation sensor data.

[0097] An example of the hardware for each sensor orientation unit is shown in Figure 3B.

[0098] In this example, the first orientation sensor unit 330 includes a housing having a first electronic processing device such as a microprocessor 331, a memory 332, a first orientation sensor 333, and one or more interfaces 334, such as a wireless transmitter, interconnected via a bus 335. In use, the microprocessor 331 receives signals from the first orientation sensor 334, optionally storing these in the memory 332. The microprocessor 331 may then process the signals in accordance with instructions stored in the memory 332, for example in the form of software instructions, to digitize or filter the sampled signal before causing the first orientation sensor data to be transmitted via the wireless transmitter 334 to the second orientation sensor unit 340.

[0099] However, this is for the purpose of example only, and it will be appreciated that the electronic processing device 331 can include any form of electronic processing device that can receive and process signals from the first orientation sensor 333. Accordingly, the electronic processing device can include any one or more of a microprocessor, microchip processor, logic gate configuration, firmware optionally associated with implementing logic such as an FPGA (Field Programmable Gate Array), a suitably configured computer system, tablet, smartphone, or any other electronic device, system or arrangement capable of receiving and processing the signals.

[0100] The second orientation sensor unit 340 includes a housing having a second electronic processing device such as a microprocessor 341, a memory 342, input/output (I/O) device 343, such as a keyboard and display, a second orientation sensor 344, and one or more interfaces 345, such as a wireless receiver, interconnected via a bus 346. In use, the microprocessor 341 receives signals from the second orientation sensor 344 and sensor data from the first orientation unit 330 via the wireless receiver 345, optionally storing these in the memory 342. The microprocessor 341 may then process the signals in accordance with instructions stored in the memory 342, for example in the form of software instructions to compare the orientation data, to thereby generate the alignment indicator. The alignment indicator can then be provided as an output, for example via the display 343 or to a remote processing system in the console or the like.

[0101] However, this is for the purpose of example only, and it will be appreciated that the electronic processing device 341 can include any form of electronic processing device that can receive and process signals from the first orientation sensor unit 330 and second orientation sensor 334. Accordingly, the electronic processing device can include any one or more of a microprocessor, microchip processor, logic gate configuration, firmware optionally associated with implementing logic such as an FPGA (Field Programmable Gate Array), a suitably configured computer system, tablet, smartphone, or any other electronic device, system or arrangement capable of receiving and processing the signals.

[0102] In some embodiments, the orientation sensor units 330, 340 may be constructed so that the above described hardware elements are completely encapsulated within the respective housing. In one example, the orientation sensor units 330, 340 may include a magnetic sensor that can allow activation and/or configuration of the units using an external magnet, without requiring any externally accessible controls. [0103] This magnetic configuration functionality can be used to turn on the units and then access various configurations or modes as required. For example, after a unit is turned on using an external magnet acting as an activation switch, the unit may then wait for a period of time for a further magnetic input to allow further configuration of the unit. For instance, a north or south pole of the external magnet may be brought into proximity of the magnetic sensor to determine whether the unit should be configured as a first orientation sensor 330 or a second orientation sensor 340.

[0104] Similar functionality could be used to enter a code to make the unit enter a calibration mode by alternating the poles of the external magnet in a certain pattem/timing or go into a proprietary update or configuration mode to allow a laptop or another device wirelessly communicate with the unit to update software/parameters/algorithms, or the like. This system could also be used to control the type of data output by the unit, which may vary depending on whether this will be for providing feedback to a manual operator or for autonomous control of a mill reline machine. It will be appreciate that this provides a capability for a user to interact with the unit, whilst allowing the unit to be completely sealed and waterproof.

[0105] However, this is not essential, and in other examples, the orientation sensor units 330, 340 include external switches and/or may be controlled remotely via wireless communications. In some implementations, the orientation sensor units 330, 340 may be wirelessly reconfigured using an over-the-air (OTA) update.

[0106] Referring now to Figure 4, a flowchart of an example method for use in positioning a mill liner during liner installation shall now be described. For the purpose of illustration, it is assumed that the steps are performed by the second electronic processing device 341 forming part of the second orientation sensor unit 340 attached to the liner 310.

[0107] At step 400, sensor data from the first and second orientation sensors 333, 344 is determined by the second electronic processing device 341. This may include receiving sensor data from the first orientation sensor unit 330 via a wireless transmitter/receiver, receiving signals from the second orientation sensor 344 via the bus 346 and processing the sensor data/signals. At step 410, the orientation of each sensor is compared using the sensor data and at step 420, the method includes determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison. In one example, the alignment indicator may represent a determined difference in angular position between the liner and mill shell which is then displayed to the operator for use in adjustment of the liner orientation using a mill reline machine.

[0108] In Figure 5, there is shown a flowchart of an example of a method for positioning a mill liner during liner installation.

[0109] In this example, at step 500 the method includes attaching a first orientation sensor unit 330 to an outer surface of a mill shell 320 in alignment with a row of shell bolt holes 322. At step 510, the method includes attaching a second orientation sensor unit 340 to the mill liner 310 in alignment with a row of liner bolt holes 312. The method then includes adjusting the position of the mill liner at step 520, in response to feedback from a controller 341 that determines the alignment of the mill liner relative to the mill shell using sensor data from the sensor units, the sensor data indicative of the orientation of each sensor unit.

[0110] Accordingly, in at least one example, there is provided a method and system for use in positioning a mill liner during liner installation which obviates the need for a spotter to be inside the mill to provide feedback of liner orientation to a mill reline operator controlling a mill reline machine. In addition to improving safety for mill relines, the system and method enable a liner to be correctly oriented with respect to the mill shell in an expedient manner allowing for accurate and fast placement of liners. This in turn minimises mill shutdown time during relines which presents a significant cost saving to mine operators.

[0111] Throughout this specification and claims which follow, unless the context requires otherwise, the word“comprise”, and variations such as“comprises” or“comprising”, will be understood to imply the inclusion of a stated integer or group of integers or steps but not the exclusion of any other integer or group of integers.

[0112] Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons skilled in the art, should be considered to fall within the spirit and scope that the invention broadly appearing before described.

Claims (1)

1. THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

   1) A system for use in positioning a mill liner during liner installation, the system including: a) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes;

   b) a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes; and,

   c) at least one electronic processing device for:

   i) determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor;

   ii) comparing the orientation of each sensor using the sensor data; and,

   iii) determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

   2) The system according to claim 1, further including a display for displaying a representation of the at least one alignment indicator to a mill reline operator.

   3) The system according to claim 2, wherein the display is at least one of:

   a) a light emitting diode (LED) display;

   b) a liquid crystal display (LCD);

   c) a picture in picture (PIP) display; and,

   d) a heads up display (HUD).

   4) The system according to claim 3, wherein the display includes at least one of:

   a) a linear array of LEDs;

   b) a circular array of LEDs;

   c) a two dimensional (2D) representation of the alignment indicator; and,

   d) a three dimensional (3D) representation of the alignment indicator.

   5) The system according to any one of claims 2 to 4, wherein the display is co-located with the second orientation sensor.

   6) The system according to claim 1, wherein the at least one electronic processing device is for providing the at least one alignment indicator to a mill reline machine.

   7) The system according to any one of the preceding claims, wherein the at least one alignment indicator is indicative of an alignment about at least one of: a) a single axis;

   b) two axes; and,

   c) three axes.

   8) The system according to claim 7, wherein the alignment indicator is indicative of an angle between the liner and mill shell with respect to at least one axis.

   9) The system according to any one of the preceding claims, wherein the system includes: a) a first orientation sensor unit having a first housing including:

   i) the first orientation sensor; and,

   ii) a first electronic processing device coupled to the first orientation sensor; and, b) a second orientation sensor unit having a second housing including:

   i) the second orientation sensor; and,

   ii) a second electronic processing device coupled to the second orientation sensor.

   10) The system according to claim 9, wherein the first and second orientation sensor units are respectively attached to the mill shell and liner using at least one of:

   a) an adhesive;

   b) magnets; and,

   c) mechanical engagement.

   11) The system according to claim 10, wherein the second orientation sensor unit is a sacrificial member that remains attached to the liner after liner installation.

   12) The system according to any one of claims 9 to 11, wherein the first and second orientation sensor units communicate wirelessly.

   13)The system according to claim 12, wherein the wireless communication is via at least one of:

   a) radio;

   b) optical;

   c) electrical; and,

   d) acoustic.

   14) The system according to claim 13, wherein the second electronic processing device is for: a) receiving signals wirelessly from the first orientation sensor unit;

   b) receiving signals from the second orientation sensor;

   c) processing the received signals to determine orientation data; d) determining a difference in alignment between the orientation sensor units using the processed orientation data; and,

   e) causing feedback to be provided to a mill reline operator indicative of the determined difference.

   15)The system according to any one of claims 9 to 14, wherein the orientation sensor units include a magnetic sensor for detecting an external magnet, the respective electronic processing device being for at least one of activating and configuring the unit in response to detection of the external magnet.

   16) The system according to any one of the preceding claims, wherein the first and second orientation sensors include at least one of:

   a) an accelerometer;

   b) a magnetometer; and,

   c) a gyroscope.

   17) A method for use in positioning a mill liner during liner installation, the method including in at least one electronic processing device:

   a) determining sensor data indicative of signals from:

   i) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes; and,

   ii) a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes, the sensor data at least partially indicative of the orientation of each sensor;

   b) comparing the orientation of each sensor using the sensor data; and,

   c) determining at least one alignment indicator at least partially indicative of an alignment between the mill liner and the mill shell in accordance with results of the comparison.

   18) The method according to claim 16, wherein the method further includes, in the at least one electronic processing device, causing the at least one alignment indicator to be displayed on a display so as to provide visual feedback to a mill reline operator of the alignment between the mill liner and mill shell.

   19) The method according to claim 16, wherein the method further includes, in the at least one electronic processing device, causing a mill reline machine to adjust the position of the mill liner based on the determined alignment indicator. 20) A method for positioning a mill liner during liner installation, the method including: a) attaching a first orientation sensor unit to an outer surface of a mill shell in alignment with a row of shell bolt holes;

   b) attaching a second orientation sensor unit to the mill liner in alignment with a row of liner bolt holes; and,

   c) adjusting the position of the mill liner in response to feedback from a controller that determines the alignment of the mill liner relative to the mill shell using sensor data from the sensor units, the sensor data indicative of the orientation of each sensor unit.

   21) The method according to claim 19, wherein the position of the mill liner is adjusted by a mill reline machine that is operated by a mill reline operator.

   22) The method according to claim 19 or claim 20, wherein the controller provides visual feedback of the alignment to the mill reline operator via a display.

   23)The method according to claim 19, wherein the position of the mill liner is adjusted by a mill reline machine that is operated by an at least partially automated control system.

   24) The method according to any one of claims 19 to 22, wherein the position of the liner is adjusted until at least one of:

   a) the liner bolt holes are co-axially aligned with the shell bolt holes; and,

   b) one or more liner bolts retained in the liner are co-axially aligned with the shell bolt holes.

   25) The method according to claim 23, wherein the liner is secured to the mill shell via the one or more liner bolts.

   26) The method according to claim 24, wherein the method further includes:

   a) removing the second orientation sensor unit from the secured liner; and,

   b) attaching the second orientation sensor unit to another liner to be positioned.

   27) The method according to claim 25, wherein for another liner in a different row to the secured liner, the method includes:

   a) removing the first orientation sensor unit from the mill shell; and,

   b) attaching the first orientation sensor unit to the mill shell in alignment with a row of shell bolt holes in the different row.

   28) The method according to any one of claims 19 to 26, wherein the first and second orientation sensor units are respectively attached to the mill shell and liner using at least one of: a) an adhesive;

   b) magnets; and,

   c) mechanical engagement.

   29) The method according to claim 27, wherein the second orientation sensor unit is a sacrificial member that remains attached to the liner after liner installation.

   30) A system for use in positioning a mill liner during liner installation, the system including: a) a first orientation sensor positioned on an outer surface of a mill shell in alignment with a row of shell bolt holes;

   b) a second orientation sensor positioned on a mill liner inside the mill in alignment with a row of liner bolt holes; and,

   c) at least one electronic processing device for:

   i) determining sensor data indicative of signals from each of the first and second orientation sensors, the sensor data at least partially indicative of the orientation of each sensor; and,

   ii) providing at least some of the sensor data to a control system of a mill reline machine for adjusting the position of the mill liner based on the at least some of the sensor data.