A measuring apparatus and method of use thereof

Abstract

The present invention relates to a measuring apparatus and method of use thereof for determining one or more properties of a slurry. In one form, the measuring apparatus includes: at least one dielectric sensor for determining a dielectric permittivity of the slurry, said at least one dielectric sensor configured to introduce an incident wave signal into the slurry; and at least one processor operatively associated with the at least one dielectric sensor and configured to: measure a return wave signal relative to the incident wave signal and determine the dielectric permittivity of the slurry; and determine the one or more properties of the slurry based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

Description

A MEASURING APPARATUS AND METHOD OF USE THEREOFTECHNICAL FIELD

[0001] The present invention relates to a measuring apparatus and method of use thereof for determining one or more properties of a slurry.BACKGROUND

[0002] Over the last century, the volume of slurries being generated has exponentially increased. Accordingly, many techniques are being employed to try and reduce the area required for an effective settling pond, decrease dewatering time and / or increase a load of existing settling ponds. Typically, such techniques involve enhancing, or attempting to enhance, consolidation and / or dewatering rates through chemical and / or mechanical means, since natural dewatering can take several years, is unpredictable and leads to various outcomes.

[0003] Mechanical dewatering involves traversing the slurry with a vehicle configured to provide low ground pressure, such as, e.g., an Archimedes screw tractor. In use, the vehicle facilitates mechanical dewatering through the consolidation of the slurry material under a loading weight of the vehicle and the creation of surface drainage channels caused by the passage of the vehicle over the slurry. Generally, the drainage channels are orientated along the angle of repose of the slurry to afford natural drainage under gravity. Typically, as the slurry material consolidates, fluid is released into the drainage channels and drains away.

[0004] Operation of the vehicle is directly dependent on the physical characteristics of the slurry. For example, the speed, buoyancy and regularity with which the vehicle traverses the slurry is directly dependent on such physical characteristics, including water saturation and density of the slurry.

[0005] Current practice is to determine the physical characteristics of a slurry based on estimates from slurry production data or by manual sampling followed by laboratory characterisation. Problems with the current practice is that the former is wildly inaccurate and not generally representative of the entire slurry and the latter is extremely slow, typically delaying mechanical dewatering from commencing while incurring costs.

[0006] An ongoing problem with current practice is that manual samples have to be periodically taken throughout the mechanical dewatering process, meaning adjustments to the vehicle and its use are always delayed while awaiting the return of the laboratory characterisation of the samples.

[0007] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.SUMMARY OF INVENTION

[0008] Embodiments of the present invention provide a measuring apparatus and methods of use thereof, which may at least partially address one or more of the problems or deficiencies mentioned above or which may provide the public with a useful or commercial choice.

[0009] According to a first aspect of the present invention, there is provided a measuring apparatus for measuring one or more properties of a density of a slurry, said device including: at least one dielectric sensor for determining a dielectric permittivity of the slurry, said at least one dielectric sensor configured to introduce an incident wave signal into the slurry; and at least one processor operatively associated with the at least one dielectric sensor and configured to: measure a return wave signal relative to the incident wave signal and determine the dielectric permittivity of the slurry; and determine the one or more properties of the slurry based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

[0010] According to a second aspect of the present invention, there is provided a measuring apparatus for use with a mechanical dewatering vehicle for measuring one or more properties of a slurry in a settling pond, said apparatus including: at least one dielectric sensor for determining a dielectric permittivity of the slurry, said at least one dielectric sensor configured to introduce an incident wave signal into the slurry at predetermined intervals and measure a return wave signal so as to define a plurality of measurements points along a length of the settling pond as the mechanical dewatering vehicle traverses the slurry; and at least one processor operatively associated with the at least one dielectric sensor and configured to: measure the return wave signal relative to the incident wave signal and determine the dielectric permittivity of the slurry at each of the plurality measurement points; and determine the one or more properties of the slurry at each measurement point based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

[0011] According to a third aspect of the present invention, there is provided a dewatering vehicle for mechanically dewatering a slurry, said vehicle including: a chassis; at least two auger cylinders fitted to the chassis for propulsion of the chassis through or over the slurry; and at least one measuring apparatus according to the first or second aspects for monitoring and collecting data corresponding to at least slurry density.

[0012] Advantageously, the measurement apparatus of the present invention enables contactless, continuous and autonomous slurry parameters to be determined in real time, including slurry density, water saturation and moisture content. The collection of the slurry parameters enables a database to be formed and used to develop a dewatering model for a settling pond, which is orders of magnitude greater than and more accurate than parameters obtained by manual estimation techniques.

[0013] As indicated, the measuring apparatus and apparatus of the present invention is for use with a mechanical dewatering vehicle for measuring one or more properties of a slurry in a settling pond, particularly slurry density, water saturation and / or moisture content. It will therefore be convenient to hereinafter describe the device and apparatus with reference to this example application. However, a person skilled in the art will appreciate that the measuring apparatus and apparatus is capable of broader applications and may be used in related fields, such as, e.g., dredged materials management and land reclamation.

[0014] The present invention is at least in part predicated on the principle that the dielectric properties, or relative permittivity, of a material, such as, e.g., a slurry, are intrinsic electrical properties that characterize the interaction between the electrical field of an electromagnetic wave and the material and in part on the principle that a dielectric constant of a material is closely related to its density thus enabling the density, moisture content and / or water saturation of a slurry to be determined based on its relative permittivity.

[0015] More specifically, the emission of an incident wave signal into the slurry enables the dielectric properties of the slurry to be characterized based on a reflected return wave signal and the density, moisture content and / or water saturation of the slurry to be determined based on a predetermined dielectric constant for the slurry.

[0016] The dielectric properties of a material may be represented by s = s' - js", where s' is the dielectric constant, s" is the loss factor, which represents the loss of electric-field energy in the material, and j =is the imaginary unit. Both s' and s" are dependent on frequency,temperature, water content and the composition of the material.

[0017] As used herein, the term “settling pond” may refer to any reservoir open to the atmosphere and used to collect slurry-like material. The term may encompass tailings dams, waterlogged marshes, dredge materials impoundments and the like.

[0018] As used herein, the term “slurry” and variations such as “slurries” may refer to emplaced tailings, slimes, leach residues, slickens, dredge materials and other like material and / or materials having slurry-like properties.

[0019] In some embodiments, the measuring apparatus may be configured to be hand held.

[0020] In other embodiments, the measuring apparatus may be mounted on a mount, such as, e.g., a pole.

[0021] In preferred embodiments, the measuring apparatus may be for use with a mechanical dewatering vehicle.

[0022] As used herein, the term “dewatering vehicle” may encompass any vehicle configured to traverse over slurries and slurry-like mediums and provide low ground pressure, preferably the vehicle may be an Archimedes Screw Tractor.

[0023] Generally, the vehicle may include a chassis and at least two auger-like cylinders fitted to the chassis. Each cylinder may include at least one outwardly extending helical spiral flange. Each cylinder and helical spiral flange may collectively be referred to hereafter as a “scroll”.

[0024] In use, the vehicle may be propelled by the rotation of the scrolls such that the respective outwardly extending helical spiral flanges may engage with a medium through or over which the vehicle traverses. Usually, the at least two scrolls may extend beneath and / or along each side of the chassis. Of the at least two scrolls, a first said scroll may have at least one helical spiral flange extending clockwise along a length of the scroll, and a second said scroll may have the at least one helical spiral flange extending counterclockwise along the length of the scroll.

[0025] The vehicle may further include one or more motors to counter-rotate the scrolls such that a first scroll rotates clockwise and a second scroll rotates counterclockwise. Any lateral movement of the vehicle may be cancelled out by the counter-rotation of the scrolls thereby allowing the vehicle to be propelled either forwards or backwards in a direction substantially parallel with the axes of rotation of the scrolls.

[0026] As indicated, the apparatus includes a dielectric sensor for introducing an incident wave signal into the slurry and for receiving a return wave signal reflected from the slurry.

[0027] The sensor may be of any suitable size, shape and construction and may be formed from any suitable material or materials.

[0028] In some embodiments, the sensor may include a transmitter, a receiver and at least one antenna for emitting and receiving wave signals. The transmitter and receiver may be in the form of a transceiver.

[0029] In other embodiments, the sensor may include a vector network analyser (“VNA”) and at least one antenna for emitting and receiving wave signals.

[0030] The at least one antenna may be directional or omnidirectional.

[0031] The antenna may include any one of parabolic reflectors, horns and parasitic elements for directing a radio frequency wave signal into a desired radiation pattern.

[0032] The antenna may be a dipole antenna.

[0033] In some embodiments, the antenna may be a flat, microstrip, patch antenna.

[0034] In other embodiments, the antenna may be a dielectric resonator antenna (“DRA”).

[0035] In yet other embodiments, the antenna may include two or more antenna arranged in a phased array.

[0036] In yet other embodiments, the antenna may include a Vivaldi antenna. The Vivaldi antenna may include a co-planar sheet having first end and an opposed second end and a tapered slot, or notch, defined at the first end and extending at least partially towards the opposed second end, the slot may widen in width from a minimum at or near the opposed second end to a maximum at the first end.

[0037] The sheet may include sheet metal, a printed circuit board or a dielectric plate metalized on one or both sides.

[0038] In some embodiments, the antenna may be configured to emit and receive radio waves.

[0039] In other embodiments, the antenna may be configured to emit and receive microwaves.

[0040] The antenna may be configured to emit and receive incident wave signals ranging from about 0.1 GHz to about 1 ,000 GHz, typically from about 01 GHz to about 100 GHz, preferably from about 0.1 GHz to about 10 GHz, more preferably from about 0.6 GHz to about 1 GHZ.

[0041] Advantageously, both radio wave or microwave incident and reflected wave signals are non-destructive and contactless, meaning the dielectric permittivity of the slurry can be safely measured.

[0042] The transmitter, or transceiver, may be configured to transmit a radio frequency signal corresponding to a desired wave signal frequency. The radio frequency signal may be applied to the antenna, which radiates the energy as the incident wave signal. Typically, the transmitter may include an incident wave signal circuit for use with the at least one antenna which operates at a desired incident wave signal frequency, preferably a single incident wave signal frequency.

[0043] The receiver, or transceiver, may be configured to receive a return wave signal intercepted by the at least one antenna. Like the transmitter, the receiver may include a return wave signal circuit for use with the at least one antenna in intercepting the return wave signal.

[0044] In preferred embodiments, the at least one dielectric sensor may include at least one antenna as previously described and a vector network analyser (“VNA”) electrically connected to the at least one antenna by coaxial cables and configured to transmit and receive the incident wave signal and the return wave signal, respectively. Advantageously, the VNA may measure both the magnitude and phase properties of the return wave signal.

[0045] The VNA may have multiple ports to permit simultaneous measurement of different parameters and thus improving the accuracy of the measurements.

[0046] In embodiments in which the measuring apparatus is used with the mechanical dewatering vehicle, the at least one dielectric sensor may be mounted in any suitable location on the vehicle, preferably at least at one of the front and rear ends of the vehicle, more preferably both.

[0047] The sensor may be mounted to the vehicle in any suitable way such that it is suspended above the slurry in the settling pond as the vehicle traverses the slurry, preferably such that at least the at least one antenna is suspended above the slurry. The sensor may be directly or indirectly mounted to the vehicle.

[0048] For example, in some embodiments, the at least one dielectric sensor, or partthereof, may be mounted to a side of chassis of the vehicle such that the at least one antenna extends out from and is suspended over the slurry.

[0049] In other embodiments, the at least one dielectric sensor, or part thereof, may be mounted to the vehicle by at least one mount, preferably an adjustable mount for adjusting a height of the sensor, or at least the at least one antenna relative to a surface of the slurry. Advantageously, this may assist in moving the sensor, or at least the at least one antenna clear when loading and unloading the vehicle. Likewise, this may assist in calibrating the sensor, which will be discussed in detail later.

[0050] The at least one mount may be of any suitable size, shape and construction.

[0051] In some embodiments, the at least one mount may include an arm having a pair of opposed ends and an elongate body extending therebetween. The arm may be of unitary construction or may be formed from two or more arm pieces joined or coupled together.

[0052] The opposed ends may include a first end pivotally coupled to the chassis of the vehicle and an opposed second end coupled to the dielectric sensor, or at least the at least one antenna of the sensor, optionally pivotally coupled.

[0053] The elongate body may be of fixed length or may be of an adjustable length. If of adjustable length, the elongate body may include two or more body segments arranged in a sliding or telescopic arrangement and moveable between an extended and retracted position relative to each other.

[0054] The at least one mount may further include an actuating mechanism for moving the at least one mount relative to the chassis of the vehicle and adjusting a height of the sensor, or at least the at least one antenna relative to the surface of the slurry.

[0055] Any suitable actuating mechanism may be used. The actuating mechanism may be manually actuated or by using a drive. Movement may be linear, although non-linear movement, such as, e.g., rotary movement is also envisaged.

[0056] For example, if manually actuated, the actuating mechanism may include one or more of a lever, a ram, an operable handle, a sliding arrangement, a hinged arrangement or pivoting arrangement for pivoting the arm relative to the chassis of the vehicle and adjusting a height of the sensor relative to a surface of the slurry.

[0057] If using a drive, the drive may be a hydraulic or pneumatic ram, or an electric motor for pivoting the arm relative to the chassis of the vehicle and adjusting a height of the sensorrelative to a surface of the slurry.

[0058] In some such embodiments, the actuating mechanism may include one or more linear actuators each extending between the chassis and the arm and capable of moving between an extended position and a retracted position. The extended and retracted positions may correspond with lowered and raised positions of the sensor, or at least the at least one antenna of the sensor, relative to a surface of the slurry, respectively.

[0059] The one or more linear actuators may include a pneumatic ram, a hydraulic ram or a rigid chain actuator (also known as a linear chain actuator, a push-pull actuator, an electric chain actuator, a zip chain actuator or a column forming chain actuator).

[0060] In other such embodiments, the actuating mechanism may be a servomotor or stepper motor configured to pivot the arm between the raised and lowered positions.

[0061] In yet other such embodiments, the actuating mechanism may be a manually, pneumatically or electrically powered screw jack or screw motor.

[0062] In yet other such embodiments, the actuator or actuating mechanism may include a drive motor, such as, e.g., an electric motor or combustion engine, operatively associated with a winch, a cable and at least one pulley for raising and lowering the arm and thus the sensor, or at least the at least one antenna of the sensor, relative to a surface of the slurry.

[0063] In preferred such embodiments, the actuating mechanism may be in the form of a pneumatic ram that may extend between the chassis of the vehicle and the arm for pivoting the arm relative to the chassis between a raised position in which the sensor, or at least the at least one antenna of the sensor, is moved away from the surface of the slurry and a lowered position in which the sensor, or at least the at least one antenna of the sensor, is moved towards from the surface of the slurry.

[0064] The actuating mechanism may be pivotally coupled to each of the chassis and the arm for pivoting the arm.

[0065] In other embodiments, the at least one mount may include, or be in the form of, a linear actuator extending between the chassis and the antenna and capable of moving between an extended position and a retracted position, preferably in a vertical orientation. The extended and retracted positions may correspond with the lowered and raised positions of the sensor, or at least the at least one antenna of the sensor, relative to a surface of the slurry, respectively.

[0066] The linear actuator may include an upper end mounted to the chassis and a lowerend operatively coupled to the sensor, or at least the at least one antenna of the sensor.

[0067] The linear actuator may include a pneumatic ram, a hydraulic ram or a rigid chain actuator as previously described. In preferred such embodiments, the linear actuator may include a screw jack actuator.

[0068] In some such embodiments, that at least one mount may further include a housing for at least partially housing the sensor, or at least the at least one antenna of the sensor, when in the raised position.

[0069] In some embodiments, the measuring apparatus may include at least one global navigation satellite system (“GNSS”) antenna and at least one modem. In other embodiments, mechanical dewatering vehicle may include at least one GNSS antenna and at least one modem.

[0070] The GNSS antenna may be configured to receive radio waves from artificial satellites for determining positional coordinates of the measuring apparatus or the vehicle, preferably GNSS satellites, more preferably at least four GNSS satellites. Preferably, the GNSS antenna may be a Global Positioning System (“GPS”) antenna.

[0071] The apparatus or the vehicle may further include a GNSS receiver associated with the at least one GNSS antenna for receiving output from the antenna, preferably a GPS receiver.

[0072] Advantageously, the inclusion of positional data together with the dielectric permittivity data obtained by the measuring apparatus or apparatus enables the density, water saturation and / or moisture content data to be subsequently derived as a function of its geographical location relative to the slurry.

[0073] As indicated, the apparatus includes at least one processor configured to measure a return wave signal relative to the incident wave signal, determine the dielectric permittivity of the slurry and based on a predetermined dielectric constant for the slurry, determine at least the density of the slurry, preferably the density, water saturation and / or moisture content.

[0074] The measuring of the return wave signal relative to the incident wave signal may include determining an attenuation and phase shift of the return wave signal relative to the incident wave signal.

[0075] Attenuation may be considered a difference between power levels of the incident and return wave signals.

[0076] Phase shift may characterize the delay in propagation caused by the slowing of aspeed of propagation of the wave signal interacting with the slurry. The phase shift may be determined by calculating a difference between the phase in the incident wave signal and in the return wave signal.

[0077] The attenuation and phase shift may be measured by the VNA.

[0078] The dielectric permittivity of the slurry may be calculated based on the determined attenuation and phase shift of the return wave signal (see, e.g., Bussey, 1967. Measurement of the RF properties of materials, a survey. Proc. IEEE, 55(6), 1064-53; Von Hippel, 1954. Dielectrics and Waves. John Wiley & sons, New York; Nyfors and Vainikainen, 1989. Industrial Microwave Systems. Artech House, Norwood, Mass., 351 pp; all of which are herein incorporated by reference).

[0079] The slurry density, water saturation and moisture content may be derived based on the calculated dielectric permittivity and the predetermined dielectric constant for the slurry (see, e.g., US Patent No. 6,147,503; Trabelsi et aL, 2004 Universal dielectric calibration method and apparatus for moisture content determination in particulate and glandular materials, USA, US Patent No. 6,691 ,563; all of which are herein incorporated by reference).

[0080] The at least one processor may typically form part of a processing device, including one or more processors and a memory. The one or more processors may include multiple inputs and outputs coupled to electronic components of the apparatus.

[0081] For example, the processors may have at least one output coupled to the transmitter or the VNA, typically at least one output and at least one input. Likewise, the processors may have at least one input coupled to the receiver, or the VNA. Further, the processors may have at least one input coupled to the GNSS antenna and receiver.

[0082] The processing device may include a microcomputer, an external processing device, such as, e.g., a computer, a tablet, a smart phone, a PDA or at least one remotely accessible server.

[0083] In other embodiments, the processing device may include a dedicated microprocessor operatively associated with one or both of the receiver and transmitter, or the VNA, of the at least one dielectric sensor.

[0084] The processing device may be operatively associated with the transmitter and receiver, or the VNA, of the at least one dielectric sensor for at least collecting data corresponding to the determined permittivity of the slurry as a function of time and geographic location.

[0085] As indicated in some embodiments in which the measuring apparatus is used with a mechanical dewatering vehicle, the at least one dielectric sensor may be configured to determine a dielectric permittivity of the slurry along a plurality of measurement points along a length of the settling pond as the vehicle traverses the slurry. In such embodiments, the at least one processor may collect data corresponding to the determined permittivity of the slurry at each measurement point as a function of time and geographic location.

[0086] Generally, each measurement point may be defined as a function of the predetermined interval at which the sensor introduces an incident wave signal into the slurry. For example, the sensor may be configured to emit the incident wave signal at intervals of about 2s, about 4s, about 6s, about 8s, about 10s, about 12s, about 14s, about 16s, about 18s, about 20s, about 22s, about 24s, about 26s, about 28s, about 30s, about 32s, about 34s, about 36s, about 38s, about 40s, about 42s, about 44s, about 46s, about 48s, about 50s, about 52s, about 54s, about 56s, about 58s, about 60s, about 62s, about 64s, about 66s, about 68s, about 70s, about 72s, about 74s, about 76s, about 78s, about 80s, about 82s, about 84s, about 86s, about 88s, about 90s, about 92s, about 94s, about 96s, about 98s, about 100s, about 102s, about 104s, about 106s, about 108s, about 110s, about 112s, about 1 14s, about 116, about 118s, about 120s, about 150s, about 180s, about 210s, about 240s, about 270s, about 300s, about 330s, about 360s, about 390s, about 420s, about 450s, about 480s, about 510s, about 540s, about 570s or even about 600s. Typically, the predetermined interval may be between about 5s and about 30s, preferably between about 5s and about 20s, more preferably about 10s.

[0087] Preferably, each measurement point may further be defined as a function of the geographic location at which the incident wave signal is introduced relative to the settling pond.

[0088] In some embodiments, the data corresponding to the dielectric permittivity, timing and / or geographic location relative to the slurry at each said measurement point may be collected and stored to form a database of dielectric permittivity along a length of the settling pond, preferably a remote database.

[0089] In other embodiments, one or more of the slurry density, water saturation and moisture content may be derived from the dielectric permittivity for each measurement point and may be collected and stored together with the timing and / or geographic location relative to the slurry to form a database of measurements along a length of the settling pond, preferably a remote database.

[0090] The data may be continuously, or periodically, collected and the database updated as the vehicle traverses the slurry. The database may be used to develop a dewatering model for a settling pond. Preferably, the data may be collected continuously in real time.

[0091] In some embodiments, the apparatus may further include a communications module for connecting the apparatus to an external device, such as, e.g., an external processing device, a controller, an external display or a storage device. The apparatus may be connected to the external device in any suitable way.

[0092] For example, in some such embodiments, the communications module may be in the form of an access port or point (e.g., a USB or mini-USB port) such that the apparatus may be connected to the external device using a suitable cable.

[0093] In other such embodiments, the communications module may be in the form of a wireless communications module, such as, e.g., a wireless network interface controller, such that the apparatus may wirelessly connected to the external device via a wireless network, e.g., a Wi-Fi (WLAN) communication, Satellite communication, RF communication, infrared communication or Bluetooth™). In such embodiments, the communications module may include at least one modem, such as, e.g., a cellular or radio modem.

[0094] In some embodiments, the apparatus may include a power supply for powering the electrical components, including the receiver, the transmitter or the VNA.

[0095] The power source may include an on-board power source, such as, e.g., one or more batteries. In other embodiments, the power source may include an external power source, such as, e.g., a mains supply or generator. In yet other embodiments in which the apparatus is used with a mechanical dewatering vehicle, the apparatus may draw power from the vehicle.

[0096] In some embodiments, the apparatus may further include a controller for controlling operation of the at least dielectric sensor. The controller may be operatively connected to the dielectric sensor. The controller may be wired or wirelessly connected to the apparatus.

[0097] The controller may preferably be a remote controller. The remote controller may be of any suitable size, shape and form.

[0098] The remote controller may include one or more keys, buttons and / or switches for an operator to control operation of the apparatus.

[0099] In some embodiments, the remote controller may include at least one display for displaying data transmitted from the apparatus, such as, e.g., measured permittivity, preferably as a function of time and geographic location.

[0100] In some embodiments, the remote controller may be an external computing device, such as, e.g., a laptop desktop. In such embodiments, the device may include softwareconfigured to be run on the computing device for controlling operation of the apparatus, or at least aspects thereof. The software may preferably be interactive and allow an operator to interact and control operation of the apparatus.

[0101] In other embodiments, the remote controller may be a mobile computing device, such as, e.g., a smart phone, a tablet or a smart watch. In such embodiments, the remote controller or device may further include software in the form of an application (i.e., an app) configured to be run on the mobile computing device and allow an operator to interact with and control the apparatus, or at least aspects thereof.

[0102] In some embodiments, the apparatus may be addressable and may report recorded dielectric permittivity, derived slurry density, water saturation and / or moisture content as a function of geographic location and / or timing to the remote controller, or an external computing device, when polled.

[0103] In other embodiments, the apparatus may immediately, or periodically, upload recorded dielectric permittivity, derived slurry density, water saturation and / or moisture content as a function of geographic location and / or timing to at least one remotely accessible server in communication with the remote database.

[0104] The at least one remotely accessible server may be any appropriate sever computer, distributed server computer, cloud-based server computer, server computer cluster or the like.

[0105] The server may include one or more processors and one or more memory units containing executable instructions / software to be executed by the one or more processors, such as, e.g., generate a heat map of the settling pond indicating any one of the derived slurry density, water saturation and / or moisture content as a function of geographic location and timing.

[0106] Generally, the at least one remotely accessible server may be in communication with the remote database.

[0107] For example, in some embodiments, the server may be linked to or may maintain all data within the remote database. The server may collect and record data output from each measuring apparatus or apparatus in the remote database, preferably against an apparatus record corresponding to each respective apparatus.

[0108] The at least one remotely accessible server may be configured to transmit communications to and receive communications from the remote controller and / or at least one external processing device over a communications network, which may include, amongst others, the Internet, LANs, WANs, GPRS network, a mobile communications network, a radio network(UHF-band), etc. and may include wired and / or wireless communications links, preferably the latter.

[0109] According to a fourth aspect of the present invention, there is provided a method of determining one or more properties of a slurry, said method including: providing a measuring apparatus according to the first aspect of the present invention; emitting an incident wave signal into the slurry; measuring a return wave signal relative to the incident wave signal and determining the dielectric permittivity of the slurry; determining the one or more properties of the slurry based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

[0110] The method may include one or more features or characteristics of the measuring apparatus and / or the dewatering vehicle as hereinbefore described.

[0111] The one or more properties may include slurry density, water saturation and / or moisture content.

[0112] In some embodiments, the method may include an initial step of obtaining a sample of the slurry and determining the dielectric constant for the slurry from the sample obtained.

[0113] In some embodiments, the method may further include another initial step of calibrating the measuring apparatus prior to use.

[0114] The calibrating may include performing a zero calibration of the dielectric sensor with a dedicated absorbing material to provide a baseline dielectric permittivity reading. The dedicated absorbing material may be a foam material of particular design configured to return a zero reading.

[0115] The calibrating may further include calibrating the dielectric sensor relative to the slurry. The calibrating may include obtaining dielectric permittivity measurements of the slurry at varying heights relative to the surface of the slurry with the adjustable mount and then determining and applying a correction coefficient. The correction coefficient may be input into and stored within the VNA.

[0116] According to a fifth aspect of the present invention, there is provided a method of generating a heat map displaying one or more properties of a settling pond, said method including: determining at least a dielectric constant of a slurry contained in the settling pond;measuring and collecting a dielectric permittivity of the slurry with at least one dielectric sensor mounted to a mechanical dewatering vehicle, said dielectric permittivity measured and collected across a plurality of measurement points along the settling pond as the mechanical dewatering vehicle traverses the slurry; determining the one or more properties of the slurry at each of the plurality of measurement points based on the dielectric permittivity measured and collected and the dielectric constant determined; and generating the heat map of the settling pond displaying the one or more properties of the settling pond determined at the plurality of measurement points.

[0117] Again, the method may include one or more features and / or characteristics of the measuring apparatus, the vehicle and the method as hereinbefore described.

[0118] Again, the one or more properties may include slurry density, water saturation and / or moisture content.

[0119] The generating may include transposing the one or more properties data to a map of the settling pond and representing individual values within the data on the map in colour or as a shade. Variation in colour may be represented by hue or intensity.

[0120] The heat map may be generated to concurrently or alternatively display slurry density data, water saturation data and / or moisture content data.

[0121] According to a sixth aspect of the present invention, there is provided a heat map displaying one or more properties data of a settling pond when generated according to the method of the fifth aspect of the present invention.

[0122] Any of the features described herein can be combined in any combination with any one or more of the other features described herein within the scope of the invention.

[0123] The reference to any prior art in this specification is not, and should not be taken as an acknowledgement or any form of suggestion that the prior art forms part of the common general knowledge.BRIEF DESCRIPTION OF DRAWINGS

[0124] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will makereference to a number of drawings as follows:

[0125] Figure 1 is a schematic showing a measuring apparatus according to an embodiment of the present invention being used with a mechanical dewatering vehicle;

[0126] Figure 2 is an illustration of the measuring apparatus as shown in Figure 1 ;

[0127] Figure 3 is a photograph of the measuring apparatus as shown in Figure 1 mounted to a mechanical dewatering vehicle;

[0128] Figure 4 is an illustration of a measuring apparatus according to another embodiment of the present invention;

[0129] Figure 5 is a flowchart showing steps in a method of determining one or more properties of a slurry according to an embodiment of the present invention; and

[0130] Figure 6 is a flowchart showing steps in a method of generating a heat map displaying one or more properties of a settling pond according to an embodiment of the present invention.DETAILED DESCRIPTION

[0131] Figures 1 to 3 show an embodiment of a measuring apparatus (100) for use with a mechanical dewatering vehicle (900) for measuring one or more properties of a slurry (800; shown in Figures 1 & 3 only) in a settling pond (700; shown in Figure 1 only).

[0132] Referring to Figure 1 , the measuring apparatus (100) for use with a mechanical dewatering vehicle (900) includes: at least one dielectric sensor (110) for determining a dielectric permittivity of a slurry (800); a processing device (140; i.e., at least one processor), including one or more processors and a memory; and a mount (150) for adjustably mounting the dielectric sensor (110) to the mechanical dewatering vehicle (900).

[0133] The at least one dielectric sensor (1 10) includes a Vivaldi antenna (120) electrically coupled to a vector network analyser (“VNA”; 130). The at least one dielectric sensor (110) is configured to introduce an incident radio wave signal into the slurry (800) at predetermined intervals and measure a return radio wave signal reflected from the slurry (800) so as to define a plurality of measurement points along a length of the settling pond (700) as the mechanical dewatering vehicle (900) traverses the slurry (800).

[0134] The processing device (140) is electrically connected to the VNA (130) and receives measurement data consisting of the attenuation and phases shift of the return radio wave signalrelative to the incident radio wave signal and calculates and collects data corresponding to the dielectric permittivity of the slurry (800) at each measurement point as a function of time and geographic location.

[0135] Based on the calculated and collected dielectric permittivity data, the processing device (140) determines the one or more properties of the slurry (800) at each measurement point, including the slurry density, the water saturation and the moisture content.

[0136] The processing device (140) further includes a wireless communication module in the form of a radio or cellular modem (not shown) for wireless connecting the processing device (140) and thus the at least one dielectric sensor (1 10) to an external processing device (200) and a remotely accessibly server (300).

[0137] The dielectric permittivity data together with the derived slurry density, the water saturation and the moisture content data for each measurement point is continuously and in real time uploaded to a remote database (310) associated with the remotely accessibly server (300). The remote database (310) enables a dewatering model to be developed for the settling pond (700).

[0138] As well as accessing the dielectric permittivity data together with the derived slurry density, the water saturation and the moisture content data for each measurement point from the remote database (310) with the external processing device (200), a user (210) can also remotely address the measuring apparatus (100) to report recorded and collected data for each measurement point when polled. Software on the external processing device (200) can be used to transpose the data onto a map of the settling pond (700) and display the data as heatmap (220).

[0139] Referring to figures 2 and 3, and as indicated, the measuring apparatus (100) includes a dielectric sensor (110) comprising a Vivaldi antenna (120) and a VNA (130); a processing device (140); and a mount (150) for adjustably mounting the dielectric sensor (1 10) to the mechanical dewatering vehicle (900).

[0140] The Vivaldi antenna (120) includes a co-planar sheet having first end, an opposed second end and a tapered slot, or notch, defined at the first end and extending at least partially towards the opposed second end. The slot widens in width from a minimum at or near the opposed second end to a maximum at the first end.

[0141] The antenna (120) is configured to emit and receive radio frequency waves ranging from about 0.6 GHz to about 1 GHZ.

[0142] The VNA (130) is electrically connected to the antenna (120) by coaxial cables and configured to transmit and receive the incident radio wave signal and the return radio wave signals.

[0143] The VNA (130) has multiple ports to permit simultaneous measurement of different parameters and thus improving the accuracy of the measurements.

[0144] As shown in part in figure 3, the measuring apparatus (100) is mounted to the front and / or rear ends of the chassis of the mechanical dewatering vehicle (900) by mount (150) such that at least the antenna (120) is suspended above the slurry (800) as the vehicle (900) traverses the slurry (800).

[0145] Referring again to both figures 2 and 3, the mount (150) includes an arm (152) having a pair of opposed ends and an elongate body extending therebetween.

[0146] The opposed ends include a first end (154) pivotally coupled to the chassis of the vehicle (900) via bracket (155) and an opposed second end (156) to which the antenna (120) is coupled and extends outwardly therefrom.

[0147] The mount (150) further includes an actuating mechanism in the form of a linear actuator (160) extending between the bracket (155) and the arm (152) for pivoting the mount (150) relative to the chassis of the vehicle (900) and adjusting a height of the antenna (120) relative to a surface of the slurry (800; shown only in Figure 3).

[0148] Advantageously, movement of the antenna (120) relative to a surface of the slurry (800; shown only in Figure 3) assists in moving the antenna (120) clear when loading and unloading the vehicle (900) as well as when calibrating the sensor (110), which will be discussed in detail later.

[0149] Referring back to figure 1 , the mechanical dewatering vehicle (900) is an Archimedes screw tractor.

[0150] The vehicle (900) includes a chassis (910) and two auger-like cylinders fitted to the chassis (910). Each cylinder includes at least one outwardly extending helical spiral flange. Each cylinder and helical spiral flange may collectively be referred to hereafter as a “scroll” (920).

[0151] In use, the vehicle (900) is propelled by the rotation of the scrolls (920) such that the respective outwardly extending helical spiral flanges engage with the slurry (800) through or over which the vehicle (900) traverses.

[0152] The vehicle (900) further includes GPS system which is coupled to the processing device (140) for reporting positional information alongside the dielectric permittivity data reported for each measurement point.

[0153] As indicated, the dielectric sensor (1 10) is configured to determine a dielectric permittivity of the slurry (800) along a plurality of measurement points along a length of the settling pond (700) as the vehicle (900) traverses the slurry (800) during which the processing device (140) collects the data corresponding to the determined permittivity of the slurry (800) at each measurement point.

[0154] Each measurement point is defined as a function of the predetermined interval of 10s at which the sensor (1 10) introduces the incident radio wave signal into the slurry (800).

[0155] As previously mentioned, each measurement point is further defined as a function of the geographic location at which the incident radio wave signal is introduced relative to the settling pond (700) by way of positional data derived from the GPS system of the vehicle (800).

[0156] Figure 4 shows another embodiment of the measuring apparatus (100) using a different mount (450). For convenience, features that are similar or correspond to features of the aforementioned embodiment will be referenced with the same reference numerals.

[0157] Referring to Figure 4, the measuring apparatus (100) again includes the at least one dielectric sensor (1 10) for determining a dielectric permittivity of a slurry (800; not shown); the processing device (140), including one or more processors and a memory; and the mount (450) for adjustably mounting the dielectric sensor (1 10) to the mechanical dewatering vehicle (900).

[0158] However, in this embodiment, the mount (450) is in the form of a screw-jack actuator (460) extending between the chassis of the vehicle (900) and an antenna (120) of the sensor (1 10) and capable of moving between a retracted position (as shown) and an extended position in a vertical orientation. The retracted and extended positions correspond to raised and lowered positions of the sensor (1 10), or at least the antenna (120) of the sensor (1 10), relative to a surface of the slurry (800; shown only in Figure 3).

[0159] As shown, in this embodiment the measuring apparatus (100) further includes a housing (470) for at least partially housing the sensor (1 10).

[0160] A method (500) of using the apparatus (100) to measure one or more parameters of a slurry (800; not shown) will now be described in detail with reference to Figure 5.

[0161] At step 510, the dielectric sensor (110) is instructed by the processing device (140)to emit an incident radio wave signal into the slurry (800).

[0162] At step 510, the dielectric sensor (110) monitors for and measures a return radio wave signal reflected from the slurry (800).

[0163] At step 520, the VNA (130) calculates the attenuation and phase shift of the return radio wave signal relative to the incident radio wave signal and the processing device (140) determined the dielectric permittivity of the slurry (800).

[0164] At step 530, the processing device (140) determines the one or more properties of the slurry (800), including slurry density, water saturation and moisture content, based on the dielectric permittivity determined at step 520 and a predetermined dielectric constant for the slurry (800) obtained from an earlier manually obtained sample.

[0165] In preferred embodiments, the method (500) includes initial steps of performing a zero calibration on the dielectric sensor (110) with a dedicated absorbing material formed of foam and of a particular design to return a zero dielectric permittivity reading.

[0166] The method (500) further includes a subsequent initial step of calibrating the dielectric sensor (110) relative to the particular slurry (800). The calibrating includes obtaining dielectric permittivity measurements of the slurry (800) at varying heights relative to the surface of the slurry (800) with the adjustable mount (150) and then determining and applying a correction coefficient. The correction coefficient is input and stored in the VNA (130) for subsequent dielectric permittivity measurements.

[0167] A method (600) of generating a heat map displaying one or more properties of a slurry (800) with the apparatus (100) as shown in figure 1 will now be described in detail with reference to figure 6.

[0168] At step 610, the method (600) includes determining a dielectric constant for the slurry (800) from a sample obtained from the settling pond (700).

[0169] At step 620, the dielectric permittivity of the slurry (800) at a plurality of measurement points is determined by the dielectric sensor (110) mounted to the mechanical dewatering vehicle (900) at predetermined intervals, such as, e.g., 10s, as the vehicle (900) traverses a length of the settling pond (700).

[0170] At step 630, the one or more properties of the slurry (800), including slurry density, water saturation and moisture content, are determined for each measurement point by the processing device (140) of the apparatus (100) based on the dielectric permittivity datadetermined at step 620 and a predetermined dielectric constant for the slurry (800) obtained at step 610.

[0171] The step may additionally include uploading data in real time for each measurement point to a remote database (310) associated with a remotely accessibly server (300).

[0172] At step 640, a user (210) on an external processing device (200) retrieves the data either from the remote database (310) associated with the remotely accessibly server (300) or from the processing device (140) directly and transposes the data onto a map of the settling pond (700) to generate a heat map (220) displaying the one or more properties of the slurry (800).

[0173] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0174] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0175] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.

Claims

CLAIMS1 . A measuring apparatus for use with a mechanical dewatering vehicle for measuring one or more properties of a slurry in a settling pond, said apparatus including: at least one dielectric sensor for determining a dielectric permittivity of the slurry, said at least one dielectric sensor configured to introduce an incident wave signal into the slurry at predetermined intervals and measure a return wave signal so as to define a plurality of measurements points along a length of the settling pond as the mechanical dewatering vehicle traverses the slurry; and at least one processor operatively associated with the at least one dielectric sensor and configured to: measure the return wave signal relative to the incident wave signal and determine the dielectric permittivity of the slurry at each of the plurality measurement points; and determine the one or more properties of the slurry at each measurement point based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

2. The measuring apparatus of claim 1 , wherein the at least one dielectric sensor includes a transmitter, a receiver and at least one antenna for emitting and receiving wave signals.

3. The measuring apparatus of claim 1 , wherein the at least one dielectric sensor includes a vector network analyser (“VNA”) and at least one antenna for emitting and receiving wave signals.

4. The measuring apparatus of claim 2 or claim 3, wherein the at least one antenna includes any one of parabolic reflectors, horns and parasitic elements for directing a radio frequency wave signal into a desired radiation pattern.

5. The measuring apparatus of any one of claims 2 to 4, wherein the at least one antenna is a dielectric resonator antenna (“DRA”).

6. The measuring apparatus of any one of claims 2 to 4, wherein the at least one antenna includes two or more antenna arranged in a phased array.

7. The measuring apparatus of any one of claims 2 to 4, wherein the at least one antenna includes a Vivaldi antenna.

8. The measuring apparatus of claim 7, wherein the Vivaldi antenna includes a co-planar sheet having first end and an opposed second end and a tapered slot, or notch, defined at the first end and extending at least partially towards the opposed second end, the slot widens inwidth from a minimum at or near the opposed second end to a maximum at the first end.

9. The measuring apparatus of claim 8, wherein the co-planar sheet includes sheet metal, a printed circuit board or a dielectric plate metalized on one or both sides.

10. The measuring apparatus of any one of claims 2 to 9, wherein the at least one antenna emits and receives radio waves.11 . The measuring apparatus of any one of claims 2 to 9, wherein the at least one antenna emits and receives microwaves.

12. The measuring apparatus of any one of claims 2 to 9, wherein the at least one antenna emits and receives incident wave signals ranging from about 0.6 GHz to about 1 GHZ.

13. The measuring apparatus of any one of claims 2 to 12, wherein the transmitter includes an incident wave signal circuit for use with the at least one antenna.

14. The measuring apparatus of any one of claims 2 to 13, wherein the at least one antenna operates at a single incident wave signal frequency.

15. The measuring apparatus of any one of claims 2 to 14, wherein the receiver includes a return wave signal circuit for use with the at least one antenna.

16. The measuring apparatus of any one of claims 3 to 15, wherein the VNA is electrically connected to the at least one antenna by coaxial cables.

17. The measuring apparatus of claim 16, wherein the VNA has multiple ports to permit simultaneous measurement of both the magnitude and phase properties of a received return wave signal.

18. The measuring apparatus of any one of claims 1 to 17, wherein the at least one dielectric sensor is mounted by at least one mount on front and rear ends of the mechanical dewatering vehicle, and suspended above the slurry in the settling pond as the vehicle traverses the slurry.

19. The measuring apparatus of claim 18, wherein the at least one mount is an adjustable mount for adjusting a height of the sensor.

20. The measuring apparatus of claim 18 or claim 19, wherein the at least one mount includes an arm having a pair of opposed ends and an elongate body extending therebetween.21 . The measuring apparatus of claim 20, wherein the opposed ends include a first end pivotally coupled to the chassis of the vehicle and an opposed second end coupled to thedielectric sensor.

22. The measuring apparatus of claim 20 or claim 21 , wherein the elongate body is of an adjustable length.

23. The measuring apparatus of claim 22, wherein the elongate body includes two or more body segments arranged in a sliding or telescopic arrangement and moveable between an extended and retracted position relative to each other.

24. The measuring apparatus of any one of claims 18 to 23, wherein the at least one mount includes an actuating mechanism for moving the at least one mount relative to a chassis of the vehicle and adjusting a height of the sensor.

25. The measuring apparatus of claim 18 or claim 19, wherein the at least one mount is a linear actuator extending between the mechanical dewatering vehicle and the at least one dielectric sensor and capable of moving between an extended position and a retracted position for adjusting a height of the sensor.

26. The measuring apparatus of claim 25, wherein the actuating mechanism is a screw jack actuator.

27. The measuring apparatus of any one of claims 1 to 26, wherein the measuring apparatus includes at least one global navigation satellite system (“GNSS”) antenna and at least one modem.

28. The measuring apparatus of claim 27, wherein the at least one GNSS antenna is a Global Positioning System (“GPS”) antenna.

29. The measuring apparatus of any one of claims 1 to 28, wherein the one or more properties of the slurry include the density, water saturation and moisture content of the slurry.

30. The measuring apparatus of any one of claims 1 to 29, wherein the measure of the return wave signal relative to the incident wave signal includes determining an attenuation and phase shift of the return wave signal relative to the incident wave signal.

31. The measuring apparatus of claim 30, wherein the attenuation is determined by a difference between power levels of the incident and return wave signals.

32. The measuring apparatus of claim 30, wherein the phase shift is determined by calculating a difference between the phase in the incident wave signal and in the return wave signal.

33. The measuring apparatus of any one of claims 30 to 32 when dependent on claim 3, wherein the attenuation and phase shift are measured by the VNA.

34. The measuring apparatus of any one of claims 30 to 33, wherein the dielectric permittivity of the slurry is calculated based on the attenuation and phase shift.

35. The measuring apparatus of claim 34, wherein the slurry density, water saturation and moisture content are derived based on the calculated said dielectric permittivity and the predetermined dielectric constant for the slurry.

36. The measuring apparatus of any one of claims 1 to 35, wherein the at least one dielectric sensor determines the dielectric permittivity of the slurry along the plurality of measurement points along a length of the settling pond.

37. The measuring apparatus of claim 36, wherein the at least one processor collects data corresponding to the determined permittivity of the slurry at each measurement point as a function of time and geographic location.

38. The measuring apparatus of claim 37, wherein each the measurement point is defined as a function of a predetermined interval at which the sensor introduces an incident wave signal into the slurry.

39. The measuring apparatus of claim 38, wherein the predetermined interval is about 10s.

40. The measuring apparatus of claim 38, wherein each the measurement point is further defined as a function of the geographic location at which the incident wave signal is introduced relative to the settling pond.41 . The measuring apparatus of any one of claims 37 to 40, wherein the data is collected and stored to form a database of dielectric permittivity along a length of the settling pond.

42. The measuring apparatus of any one of claims 37 to 41 , wherein the data is collected continuously in real time.

43. The measuring apparatus of any one of claims 1 to 42, wherein the apparatus further includes a wireless communications module for connecting the apparatus to an external device.

44. The measuring apparatus of any one of claims 1 to 43, wherein the apparatus is addressable and reports recorded dielectric permittivity, derived slurry density, water saturation and / or moisture content as a function of geographic location and / or timing to a remote controller.

45. The measuring apparatus of any one of claims 1 to 43, wherein the apparatus uploads recorded dielectric permittivity, derived slurry density, water saturation and / or moisture content as a function of geographic location and / or timing to at least one remotely accessible server in communication with a remote database.

46. A dewatering vehicle for mechanically dewatering a slurry, said vehicle including: a chassis; at least two auger cylinders fitted to the chassis for propulsion of the chassis through or over the slurry; and at least one measuring apparatus according to any one of claims 1 to 45 for monitoring and collecting data corresponding to at least slurry density.

47. A method of determining one or more properties of a slurry, said method including: providing a measuring apparatus according to any one of claims 1 to 45; emitting an incident wave signal into the slurry; measuring a return wave signal relative to the incident wave signal and determining the dielectric permittivity of the slurry; determining the one or more properties of the slurry based on the dielectric permittivity determined and a predetermined dielectric constant for the slurry.

48. The method of claim 47, wherein the one or more properties of the slurry include slurry density, water saturation and / or moisture content.

49. The method of claim 47 or claim 48, wherein the method includes an initial step of obtaining a sample of the slurry and determining the dielectric constant for the slurry from the sample obtained.

50. The method of claim 49, wherein the method further includes another initial step of calibrating the measuring apparatus prior to use.51 . The method of claim 50, wherein the calibrating includes performing a zero calibration of the dielectric sensor with a dedicated absorbing material to provide a baseline dielectric permittivity reading.

52. The method of claim 51 , wherein the calibrating further includes calibrating the dielectric sensor relative to the slurry.

53. The method of claim 52, wherein the calibrating includes obtaining dielectric permittivity measurements of the slurry at varying heights relative to a surface of the slurry with the adjustable mount and then determining and applying a correction coefficient.

54. A method of generating a heat map displaying one or more properties of a settling pond, said method including: determining at least a dielectric constant of a slurry contained in the settling pond; measuring and collecting a dielectric permittivity of the slurry with at least one dielectric sensor mounted to a mechanical dewatering vehicle, said dielectric permittivity measured and collected across a plurality of measurement points along the settling pond as the mechanical dewatering vehicle traverses the slurry; determining the one or more properties of the slurry at each of the plurality of measurement points based on the dielectric permittivity measured and collected and the dielectric constant determined; and generating the heat map of the settling pond displaying the one or more properties of the settling pond determined at the plurality of measurement points.

55. The method of claim 54, wherein the one or more properties include slurry density, water saturation and / or moisture content.

56. The method of claim 54 or claim 55, wherein the generating includes transposing the one or more properties data to a map of the settling pond and representing individual values within the data on the map in colour or as a shade.

57. The method of claim 56, wherein the heat map displays slurry density data, water saturation data and / or moisture content data.

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