Patent Description:
The present disclosure relates to an apparatus for measuring elements within a mineral slurry. In particular, the present disclosure relates to an analyser for measuring elements within a mineral slurry by utilising X-ray fluorescence (XRF).

Ores are extracted from the earth through mining and the ores are then processed, using mineral processing, to separate commercially valuable minerals from their respective ores. Mineral processing may involve a number of different sequential steps to identify and separate various minerals from raw material extracted from a mine. Such steps depend on the particular mineral to be extracted and the mining operation, but may include, for example, crushing, vibrating, flotation, and the like.

During mineral processing, it is common to form a slurry from mixing crushed raw material with water, as slurries are a convenient way by which to transport and handle bulk materials.

At the beginning of a mineral processing arrangement, it is important to identify the amount of various elements in the slurry to be processed. After the slurry has been processed and the valuable mineral content has been extracted, the waste product is known as tailings. It is important to identify the amount of elements remaining in the slurry tailings, so that the efficiency of the mineral processing can be assessed.

<CIT> discloses an X-ray fluorescence spectrometer for real-time wear metal analysis of lubricating oils.

Thus, a need exists to provide an improved apparatus for measuring elements in a mineral slurry.

The present disclosure relates to an analyser for the measurement of elements in a mineral slurry using XRF.

A first aspect of the present disclosure provides a measurement probe as defined in the claims appended hereto.

A second aspect of the present disclosure provides an analyser for measurement of elements in a mineral slurry as defined in the claims appended hereto.

One or more embodiments of the present disclosure will now be described by way of specific example(s) with reference to the accompanying drawings, in which:.

Method steps or features in the accompanying drawings that have the same reference numerals are to be considered to have the same function(s) or operation(s), unless the contrary intention is expressed or implied.

The present disclosure provides an apparatus suitable for use in measuring elements in a mineral slurry by utilising X-ray fluorescence (XRF) analysis. The apparatus of the present disclosure is an analyser that is adapted to be positioned on a pipe containing a slurry, such that an X-ray source of the analyser is directed through an X-ray window of the analyser to be incident on the slurry within the pipe. An X-ray detector of the analyser detects scattered and emitted X-rays and the analyser processes data derived from the detected X-rays to determine the quantity of one or more elements of interest in the mineral slurry.

<FIG> is a schematic representation of an X-ray fluorescence (XRF) apparatus <NUM>. The XRF apparatus <NUM> includes an X-ray source <NUM> that is used to generate X-rays, which are a form of electromagnetic radiation. X-rays typically have a wavelength ranging from <NUM> to <NUM> nanometres and energies in the range <NUM> eV to <NUM> keV. The X-ray source <NUM> is positioned relative to a sample <NUM>, such that X-rays emitted from the X-ray source <NUM> are incidence on the sample <NUM>.

In the example of <FIG>, the XRF apparatus includes filters <NUM>, which are positioned between the X-ray source <NUM> and the sample <NUM> so as to attenuate X-rays emitted from the X-ray source <NUM>. Filtering the X-rays may be used to filter out X-rays that are not of the appropriate wavelength and/or energy for the element(s) in the sample to be studied. The XRF apparatus <NUM> also includes an X-ray detector <NUM>, which is adapted to receive and detect X-rays scattered from or emitted from the sample <NUM>. Further, the XRF apparatus <NUM> includes collimators <NUM>, which restrict X-rays emitted from the X-ray source <NUM> so that those emitted source X-rays are directed towards the sample <NUM>, and also restricts X-rays from the sample <NUM> so that those emitted sample X-rays are directed towards the X-ray detector <NUM>.

The X-ray source <NUM> emits X-rays directed at the sample <NUM>. When an X-ray strikes the sample <NUM>, the incident X-ray may be absorbed by an electron in an atom of the sample <NUM>. If the electron is ejected during this process (known as the photoelectric effect), then a vacancy is created in an atomic orbital. When this vacancy in the atomic orbital is filled, via the transition of a higher orbital electron, the excess energy may be emitted as a characteristic X-ray whose energy is the difference between the corresponding atomic orbitals. Since each element has a unique set of orbitals, then the characteristic X-rays are unique for each element. The emitted characteristic X-rays are then received by the X-ray detector <NUM>, which may be implemented using an Energy Dispersive detector. In particular, a Silicon Drift Detector (SDD) is particularly suitable for such an analyser. The process of measuring the emissions of characteristic X-rays and determining the elemental abundances is typically called XRF analysis.

As shown in <FIG>, the XRF apparatus <NUM> includes collimators <NUM> and filters <NUM>, which may be used to condition the X-rays impinging on the sample <NUM> and the X-ray detector <NUM>. Differing combinations of X-ray sources <NUM>, filters <NUM>, collimators <NUM>, samples <NUM>, and X-ray detectors <NUM> are widely used in a variety of modern day commercial XRF instrumentation.

<FIG> shows a simplified X-ray spectrum <NUM> measured by an Energy Dispersive X-ray detector. The spectrum <NUM> consists of one or more characteristic X-ray peaks from the elements present in the sample, and additionally one or more Compton and Rayleigh peaks due the scattering of X-rays in the sample. In general, the heights of the characteristic X-ray peaks are related to their corresponding elemental abundances, whereas the Compton and Rayleigh peaks are more complexly related to the overall slurry composition.

XRF analysis techniques are particularly suitable for deployment in the mining industry, where timely characterisation of the elemental composition of a mineral slurry may result in vastly improved economics. For example, a mineral concentrator is where mineral bearing ore is processed. As part of this process, mined ore is crushed and milled, and water and chemicals are added to produce a slurry. The mineral bearing slurry is then processed via a variety of techniques, including flotation and gravity concentration, to produce a high grade slurry "concentrate", which is recovered. The waste slurry "tailings" typically exit the plant and are discarded. Timely characterisation of the slurry, via X-ray techniques, can yield much information regarding the operational state of the concentrator, resulting in much improved recovery of the valuable elements and minerals.

<FIG> is a schematic representation of an analyser <NUM> for measurement of the composition of a mineral slurry <NUM>, particularly in relation to the measurement of elements in the mineral slurry. The analyser <NUM> includes three components:.

The pipe measurement section <NUM> consists of a section of pipe <NUM> which transports the slurry and facilitates the mounting of the measurement probe <NUM>. The pipe measurement section <NUM> includes an aperture to a lumen of the pipe <NUM>, wherein the aperture is surrounded by a pipe mount adapted to couple the measurement probe <NUM> to the pipe <NUM>.

The pipe mount may be implemented in many ways, including, for example, but not limited to, a flange adapted to couple to a matching probe mount <NUM> on the measurement probe <NUM>. The pipe mount may optionally be secured to the probe mount <NUM> by one or more fasteners, wherein the fasteners may include, but are not limited to screws, bolts, threaded screw mounts, dowels, clamps, and the like, or any combination thereof. Embodiments may include a seal between the pipe mount and the probe mount <NUM>, such as an O-ring or the like, to prevent leakage of the mineral slurry through the coupling.

In the example of <FIG>, the measurement probe <NUM> includes a housing <NUM> for enclosing components of the measurement probe <NUM>. The housing <NUM> includes a slurry window <NUM> made from material of sufficiently low atomic number and thickness to allow transmission of X-rays of interest into the lumen of the pipe <NUM>. The slurry window <NUM> may be implemented using a material having a low atomic number (Z<<NUM> and in some embodiments Z<<NUM>), including, but not limited to, Poly Ether Ether Ketone (PEEK), boron carbide (B<NUM>C), polyester (Mylar), polycarbonate, polyamide (Nylon), polytetrafluoroethylene PTFE (Teflon), polystyrene, polyvinylchloride (PVC), magnesium alloy, aluminium alloy, quartz, or fused silica. In one or more embodiments, the slurry window <NUM> is implemented using multi-layered windows to provide protection for the equipment, in the case of a window failure.

The slurry window <NUM> is surrounded by the probe mount, such that when the pipe mount is coupled to the probe mount, the slurry window <NUM> is positioned to provide a transmission window for X-rays to pass between the measurement probe <NUM> and the lumen of pipe <NUM>.

The housing of the measurement probe <NUM> encloses: X-ray source(s) <NUM> positioned to emit X-rays towards the slurry window <NUM>; X-ray filter(s) <NUM> and collimator(s) <NUM> to condition the X-rays; X-ray detector(s) <NUM> to measure the X-rays from the direction of the slurry window <NUM>; control and processing electronics <NUM> and associated software which control the analyser and process the X-ray spectrum to yield compositional information regarding the slurry; and active cooling <NUM> to control the temperature inside the measurement probe <NUM>.

Various combinations of filters <NUM> and collimators <NUM> may be positioned in relation to either one or both of the X-ray source <NUM> and X-ray detector <NUM> so as to condition X-rays emitted from the source <NUM> and detected by the detector <NUM>. For example, particular filters <NUM> may be used when measuring a certain element, in order to increase the signal to noise ratio.

The control and processing electronics <NUM> may be implemented using a computing device, alone or in combination with other electrical components. Such electronic components may include, for example, a transceiver for communications with an external device, a display, a speaker for audible alerts, mechanical or electrical interlocks, one or more lights (such as LEDs) to act as status indicators, and the like.

The control and processing electronics <NUM> stores computer program instructions that when executed on a processor are adapted to: control operation of the X-ray source <NUM>, including turning off and on, and setting the voltage and power; control operation of the X-ray detector <NUM>, including turning off and on, and collecting x-ray spectra (i. e, <FIG>); and perform analysis of X-ray spectra to determine elemental abundances in the mineral slurry that is being analysed.

The measurement probe <NUM> may optionally include a transceiver (not shown) for remote communications facilities to allow upload/download of data. Such remote communications may be implemented using wired and/or wireless communications, including, for example, but not limited to, Ethernet, ADSL, optical fibre, <NUM>/<NUM>/<NUM> wireless mobile technologies, LoRa, Zigbee, Sigfox, Bluetooth, WiFi, and any combination thereof. In one implementation, the measurement probe <NUM> includes a wireless transceiver (such as a Bluetooth or WiFi transceiver) for local wireless communications with a mobile computing device, such as a tablet, phablet, laptop, or smartphone.

One embodiment of the measurement probe <NUM> uses a Moxtek X-ray source operating at 50kV and a source collimator to restrict X-rays emitted from the X-ray source <NUM> so that the emitted X-rays impinge only on the slurry window <NUM>. This embodiment also uses a source filter to maximise the relative intensity of <NUM> keV X-rays, an Amptek Silicon Drift Detector (SDD) to detect X-rays emitted from the slurry within the pipe <NUM>, and a Detector Collimator to ensure that the vast majority of detected X-rays originate from the direction of the slurry window <NUM>. The X-ray source <NUM> and X-ray detector <NUM> are arranged so the axial angle of the X-ray source tube <NUM> is equal to the axial angle of detection of the detector <NUM>, with respect to the slurry window <NUM>.

In one arrangement, active cooling is achieved through the use of Peltier cooling. Efficient heat transfer is achieved through the utilisation of a set of closely coupled fans on the Peltier surface. Insulation on the internal surface of the housing of the measurement probe <NUM> helps to achieve efficient cooling. A thermostat is optionally utilised to ensure that stable temperatures are achieved and maintained.

The measurement probe <NUM> is powered by the power cabinet <NUM>. In the example of <FIG>, the power cabinet <NUM> is configured to receive AC mains power, such as in the range of <NUM>-240V AC. A transformer <NUM> and other electrical circuitry (not shown), such as a rectifier, convert the AC mains power to a low voltage output power supply to power the measurement probe <NUM>. The power cabinet <NUM> may optionally provide a set of one or more power outlets for general use, wherein the power outlets may provide power at mains voltage, low voltage, or any other voltage value.

In the example of <FIG>, the low voltage output power supply is in the range of <NUM> to 24V and is coupled to the measurement probe <NUM> via an outlet using a user-friendly detachable coupling that is readily used by an operator to connect and disconnect the power cabinet <NUM> to and from the measurement probe <NUM> as desired. The power cabinet <NUM> may also optionally be actively cooled. Depending on the implementation, the outlet may connect power and communications between the measurement probe <NUM> and the power cabinet <NUM>. The outlet may be implemented using a single connector or multiple connectors, depending on the particular application.

In one arrangement, the power cabinet <NUM> outlet provides wired communications to an internal communications module in the measurement probe <NUM>. The internal communications module may be part of the control and processing electronics module <NUM> or may be implemented using a separate transceiver.

In one example, an analyser in accordance with the present disclosure is utilised to measure palladium (Pd) content within a slurry. Software running on the control and processing electronics module <NUM> receives data derived from X-rays detected by the X-ray detector <NUM>, the data forming X-ray spectra corresponding to the quantity of elements present in the mineral slurry. Irradiation of a palladium bearing slurry results in a characteristic Pd X-ray peak detected at <NUM> keV. After processing by the control and processing electronics module <NUM>, consisting of steps including normalisation and correction for attenuation effects, the Pd composition of the slurry is calculated.

In one implementation, two analysers are utilised in a mining concentrator. A first analyser is attached to a first pipe carrying feed slurry and a second analyser is attached to a second pipe carrying tailings after mineral content has been extracted from the feed slurry. The first and second analysers are used to measure feed and tailings grade continuously, and hence determine mineral recovery in real time.

Other embodiments may utilise an X-ray source operating at higher or lower target voltages. Similarly, the X-ray detector may be oriented at greater or lesser angles than the X-ray source, dependent on the operating voltage, collimators, filters, and targeted accuracies for a given slurry measurement application.

Other embodiments may utilise multiple X-ray sources, operating at the same or different voltages and powers, with the same or different filters and collimators.

Other embodiments may utilise multiple detectors, with the same or different filters and collimators.

Other embodiments may utilise multiple X-ray sources and detectors, with the same or different filters and collimators.

Whilst XRF instrumentation has been used to make measurements on pipes, the analyser of the present disclosure is different, since it contains the processing electronics (including computer and spectral analysis software) and any other (optional) components such as remote communications and Bluetooth connectivity in the measurement probe, and is directly mounted onto the pipe. This has the advantage of ensuring that when the measurement probe leaves the factory, it will have the correct calibration for its particular X-ray source(s), detector(s), filter(s), collimator(s) and any other small changes in geometry typically seen across multiple instances of the same analyser design.

The incorporation of active cooling, such as Peltier, to control the temperature inside the measurement probe ensures increased reliability. This is particularly important for mining sites located in remoted areas, where the maximum possible reliability is of great value. The increased cost and complexity of active cooling is more than offset by the advantages of improved reliability.

The incorporation of low atomic number (Z<<NUM> and in some embodiments Z<<NUM>) X-ray windows in the measurement probe allows the measurement of base metals and other elements that emit characteristic X-rays less than approximately <NUM> keV. Such low energy characteristic X-rays are unable to penetrate higher atomic number windows, especially in a mineral processing environment, where slurry pressures as great as <NUM> atm are expected, and hence necessitate the use of sufficiently thick windows to withstand the pressure. Depending on the application, the window thickness may be, for example, in the order of approximately <NUM> to <NUM>, but the actual thickness will depend on the rated pressure required for the pipe and the particular materials used. Examples of suitable windows include PEEK (Poly Ether Ether Ketone), boron carbide (B<NUM>C), polyester (Mylar), polycarbonate, polyamide (Nylon), polytetrafluoroethylene PTFE (Teflon), polystyrene, polyvinylchloride (PVC), magnesium alloy, aluminium alloy, quartz, fused silica, or similar low atomic number materials. As indicated with reference to <FIG>, the X-ray windows may be implemented using multi-layered windows to provide protection for the equipment, in the case of a window failure.

Other embodiments may use higher atomic number windows if the measurement of characteristic X-rays less than approximately <NUM> keV is not desirable.

The control and processing electronics module <NUM> of the measurement probe <NUM> may be practised using a computing device, such as a general-purpose computer or computer server. <FIG> is a schematic block diagram of a system <NUM> that includes a general-purpose computer <NUM>. The general-purpose computer <NUM> includes a plurality of components, including: a processor <NUM>, a memory <NUM>, a storage medium <NUM>, input/output (I/O) interfaces <NUM>, and input/output (I/O) ports <NUM>. Components of the general-purpose computer <NUM> generally communicate using one or more buses <NUM>.

The memory <NUM> may be implemented using Random Access Memory (RAM), Read Only Memory (ROM), or a combination thereof. The storage medium <NUM> may be implemented as one or more of a hard disk drive, a solid state "flash" drive, an optical disk drive, or other storage means. The storage medium <NUM> may be utilised to store one or more computer programs, including an operating system, software applications, communications protocols for mining concentrator data systems, and data. In one mode of operation, instructions from one or more computer programs stored in the storage medium <NUM> are loaded into the memory <NUM> via the bus <NUM>. Instructions loaded into the memory <NUM> are then made available via the bus <NUM> or other means for execution by the processor <NUM> to implement a mode of operation in accordance with the executed instructions.

One or more peripheral devices may be coupled to the general-purpose computer <NUM> via the I/O ports <NUM>. In the example of <FIG>, the general-purpose computer <NUM> is coupled to each of a speaker <NUM>, a display device <NUM>, an input device <NUM>, a printer <NUM>, and an external storage medium <NUM>. The speaker <NUM> may be implemented using one or more speakers, and may function to provide audible alerts in relation to the analyser. In the example in which the general-purpose computer <NUM> is utilised to implement the control and processing module <NUM> of the measurement probe <NUM> of <FIG>, one or more peripheral devices may relate to a speaker or external display screen connected to the I/O ports <NUM>.

The display device <NUM> may be a computer monitor, such as a cathode ray tube screen, plasma screen, or liquid crystal display (LCD) screen. The display <NUM> may receive information from the computer <NUM> in a conventional manner, wherein the information is presented on the display device <NUM> for viewing by a user. The display device <NUM> may optionally be implemented using a touch screen to enable a user to provide input to the general-purpose computer <NUM>. The touch screen may be, for example, a capacitive touch screen, a resistive touchscreen, a surface acoustic wave touchscreen, or the like. For example, the display screen may be an LCD screen located on an external surface of the housing of the measurement probe <NUM> for displaying a status of the probe <NUM>, operating parameters of the probe <NUM>, and composition data relating to X-ray spectra of mineral slurry in the pipe <NUM>.

The input device <NUM> may be a keyboard, a mouse, a stylus, drawing tablet, touchscreen, or any combination thereof, for receiving input from a user.

The I/O interfaces <NUM> facilitate the exchange of information between the general-purpose computing device <NUM> and other computing devices. The I/O interfaces may be implemented using an internal or external modem, an Ethernet connection, or the like, to enable coupling to a transmission medium. In the example of <FIG>, the I/O interfaces <NUM> are coupled to a communications network <NUM> and directly to a computing device <NUM>. The computing device <NUM> is shown as a personal computer, but may be equally be practised using a smartphone, laptop, or a tablet device. Direct communication between the general-purpose computer <NUM> and the computing device <NUM> may be implemented using a wireless or wired transmission link. Such a wired or wireless transmission link may be used, for example, to enable a technician or plant operator to monitor data relating to performance of the measurement probe <NUM> itself or the composition of slurry in the pipe <NUM>.

The communications network <NUM> may be implemented using one or more wired or wireless transmission links and may include, for example, a dedicated communications link, a local area network (LAN), a wide area network (WAN), the Internet, a telecommunications network, or any combination thereof. A telecommunications network may include, but is not limited to, a telephony network, such as a Public Switch Telephony Network (PSTN), a mobile telephone cellular network, a short message service (SMS) network, or any combination thereof. The general-purpose computer <NUM> is able to communicate via the communications network <NUM> to other computing devices connected to the communications network <NUM>, such as the mobile telephone handset <NUM>, the touchscreen smartphone <NUM>, the personal computer <NUM>, the cloud, and the computing device <NUM>.

One or more instances of the general-purpose computer <NUM> may be utilised to implement a control and processing electronics module <NUM> to implement a measurement probe in accordance with the present disclosure. In such an embodiment, the memory <NUM> and storage <NUM> are utilised to store data relating to X-ray spectra derived from measurement of mineral slurries in the pipe <NUM>. Software for implementing the mineral slurry analysis system is stored in one or both of the memory <NUM> and storage <NUM> for execution on the processor <NUM>. The software includes computer program code for implementing method steps to control operation of the X-ray source <NUM> and X-ray detector <NUM>, as well as performing analysis of X-ray spectra to determine slurry composition.

Whilst the embodiment described above refer to analysing mineral slurry in a pipe, a measurement probe in accordance with the present disclosure is suitable for use in detecting the quantity of one or more elements of interest in any vessel containing a slurry, such as a stirred slurry tank. Such a measurement probe may utilise the probe mount described above to secure the measurement probe to a vessel mount on the vessel, wherein the vessel mount is similar to the pipe mount describe above.

The arrangements described are applicable to the mining and mineral processing industries.

The foregoing describes only some embodiments of the present invention, and modifications and/or changes can be made thereto without departing from the scope of the invention, the embodiments being illustrative and not restrictive. Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

In the context of this specification, the word "comprising" and its associated grammatical constructions mean "including principally but not necessarily solely" or "having" or "including", and not "consisting only of". Variations of the word "comprising", such as "comprise" and "comprises" have correspondingly varied meanings.

Claim 1:
A measurement probe (<NUM>) for measurement of elements in a mineral slurry (<NUM>), said probe (<NUM>) comprising:
a housing (<NUM>) having an X-ray window (<NUM>), said housing (<NUM>) enclosing:
an electrically powered X-ray source (<NUM>) positioned to emit source X-rays at said X-ray window (<NUM>);
an X-ray detector (<NUM>) positioned to detect X-rays from said X-ray window (<NUM>); and
a control module (<NUM>) configured to:
control operation of said X-ray source (<NUM>) and said X-ray detector (<NUM>);
process X-rays detected by said X-ray detector (<NUM>) to generate X-ray spectra data; and
process said X-ray spectra data to determine the quantity of one or more elements of interest in the mineral slurry (<NUM>); and
a probe mount (<NUM>) located on an outer surface of said housing (<NUM>) and surrounding said X-ray window (<NUM>), said probe mount (<NUM>) being adapted to couple said measurement probe (<NUM>) to a pipe mount on a pipe (<NUM>) or a vessel mount on a vessel carrying said mineral slurry (<NUM>), said pipe mount or vessel mount surrounding an aperture to a lumen of said respective pipe (<NUM>) or vessel, such that when said probe mount (<NUM>) is coupled to said pipe mount or vessel mount the X-ray window (<NUM>) provides a transmission window for X-rays into said lumen of said pipe (<NUM>) or vessel.