Apparatus for sorting ore lumps containing minerals with weak magnetic susceptibility and non-magnetic minerals

Abstract

A device for sorting lump ore containing minerals with low magnetic susceptibility and non-magnetic minerals, comprising a device for metered feeding of ore pieces to a conveyor, a device for electromagnetically irradiating the pieces, a system for identifying raw material pieces according to the criterion of the presence of a useful component, and a system for separating the pieces into material streams, one of which comprises the useful component and another of which represents a non-usable component, characterized in that the device comprises a 3D scanner arranged above the conveyor belt and designed to pre-identify the ore pieces according to the criterion of their geometric parameters, their spatial orientation, and their coordinate position on the conveyor belt, the device further comprising a sorting controller, a sensor unit, a human-machine interface,an encoder and a compressed air valve unit, wherein the sensor unit comprises a signal processing unit, a data interface and a sensor matrix in which sensors are arranged in a special coordinate grid designed to measure the magnetic susceptibility of the pieces with paramagnetic properties, wherein each sensor is designed in the form of an induction coil contained in a measuring oscillator connected to a Schmitt trigger and a signal processing unit connected to an oscillator by means of an activation key, wherein the sorting control comprises a computing unit, a valve control unit and a synchronization unit, wherein the computing unit comprises a module for storing output data and constants, a module for measuring the geometric parameters of the pieces and for generating coil activation delays,a module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt, a module for eliminating the mutual influence of the individual pieces and for measuring the electromagnetic background, a unit for processing data and control signals for the sensor unit, and connection interfaces, wherein the synchronization unit comprises a digital synchronization signal input, a command and synchronization signal processing unit, digital synchronization signal outputs, and a data interface, wherein the valve control unit comprises a command processing unit and a data interface, and the human-machine interface comprises an input / output (I / O) interface and a data interface, wherein the 3D scanner is connected to the lumpy ore on the conveyor belt via an optical input,is connected via a synchronization input to the digital synchronization outputs of the synchronization unit and is connected at one output via a data interface to the unit for processing data and control signals for the sensor unit, wherein in the computing unit the module for storing output data and constants, the module for measuring the geometric parameters of the pieces, the module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt, the module for eliminating the mutual influence of the individual pieces and for measuring the electromagnetic background are connected to the unit for processing data and control signals for the sensor unit, which is connected to two data interfaces, one of which is connected to the data interface of the sensor unit,wherein the other data interface of the computing unit is connected to the output of the 3D scanner and via a data interface to the I / O interface of the human-machine interface, wherein in the synchronization unit, a data interface is connected to the data interface of the computing unit and to the command and synchronization signal processing unit, which is connected to the digital synchronization signal outputs and to the digital synchronization input connected to an encoder of the device connected to the conveyor, wherein the data interface of the valve control unit is connected to a data interface of the computing unit and to the command processing unit, which is connected to the digital synchronization signal outputs of the synchronization unit and to the compressed air valve unit,wherein the unit of digital synchronization signal outputs is connected via the signal processing unit of the sensor unit to the sensor matrix which interacts with the lump ore on the conveyor belt, wherein a data interface of the sensor unit is connected to the signal processing unit.

Description

[0001] The proposed utility model relates to the mining and mineral processing industry, in particular to devices for the pre-processing of ores containing a useful component which has a low concentration and a low mass fraction in the rock mass and which, in terms of its distribution, has a correlation with minerals of low magnetic susceptibility or with non-magnetic minerals.

[0002] The proposed utility model can be used particularly effectively in the sorting of ores with paramagnetic properties, which are characterized by particularly low magnetic susceptibility. An ore mass containing a useful component correlated with paramagnetic elements or with non-magnetic ore minerals contained in paramagnetic gangue is practically impossible to separate or sort using conventional means and devices used in mining and processing plants.

[0003] A device for sorting an ore mass is known, which is an X-ray luminescence separator and comprises: a means for transporting the separated material, a source of pulsed excitation X-rays located above the surface of the transport material and capable of irradiating it on the portion of its free-fall trajectory close to the point where it leaves the means of transport, a photodetector for recording the luminescence, which is located on the same side as the source of pulsed excitation X-rays with respect to the surface of the transport material to be irradiated, the region for recording the luminescence of the transport material being capable of being aligned with the portion of its free-fall trajectory coinciding with the irradiation region, an element for setting a threshold value for the intensity of the luminescence signal and threshold values for separation parameters,a synchronization unit, a device for digitally processing the luminescence signal, which is equipped with functions for determining the separation parameters, comparing the obtained parameter values with corresponding predetermined threshold values and issuing a command to an actuating mechanism, an actuating mechanism and receiving containers for usable and non-usable material.

[0004] The photodetector allows for simultaneous amplification of the recording signal with different gain coefficients. Separation parameters for the device for digital processing of the luminescence signal can be determined by determining characteristic values of the luminescence signal properties, such as the normalized autocorrelation function, the ratio of the total intensity of the fast and slow signal components to the intensity of its slow component, the luminescence decay time constant after the excitation pulse, and the intensity value of the fast component of the luminescence signal [1].

[0005] A shortcoming of the known device is that the selectivity is not high enough when extracting weakly luminescent minerals whose luminescence intensity of the slow component is below the threshold. This is because the photodetector records the total intensity generated during the X-ray luminescence pulse, which includes both the intensity of the fast component of the mineral luminescence and the light signal intensity of air, various vapors, rock particles, and accompanying minerals. The intensity of this light signal is subject to strong fluctuations, resulting in a relatively high threshold for the intensity of the fast component of the luminescence signal.

[0006] Also known is a device for sorting lumpy mineral raw materials for the dry pre-selection and selection of ferrous and non-ferrous metals as well as other ores and raw materials.

[0007] The design of the known device provides for the presence of a receiving container filled with lump ore, which is then conveyed by a loading device to a transport element in the form of a conveyor. The loading device is designed to ensure even distribution of the lump ore on the conveyor belt without the formation of piles. An X-ray source is located in the area of horizontal movement of the lumps perpendicular to the plane of the conveyor belt, and an X-ray receiver is located below the conveyor belt.

[0008] When the ore pieces on the conveyor belt are irradiated with X-rays, the radiation is partially absorbed by each piece. The X-ray absorption coefficient varies depending on the mass fraction of the useful component in the ore piece. The mass fraction of the useful component in the ore piece is assessed based on the radiation intensity. If the mass fraction of the useful component in the ore piece is below a predetermined threshold, the ore piece is exposed to a directed air stream based on a control command, which transports the worthless rock to the appropriate collecting container. If the mass fraction of the useful component is not below the threshold, the ore piece is not exposed to the air stream, does not change its trajectory after leaving the conveyor, and enters the container for usable rock [2].

[0009] A shortcoming of the known device is that the presence of X-ray radiation requires a number of measures to ensure the safety of the operating personnel.

[0010] In order to obtain a correct picture of the mass fraction of the useful component, it must be evenly distributed in the ore piece; furthermore, a precisely specified range of the grain size distribution of the material to be separated must be maintained.

[0011] Determining the degree of absorption by the conveyor belt material leads to errors in measuring the mass fraction of the useful component in the ore piece.

[0012] The closest technical solution selected as a prototype for the proposed utility model is a device for separating lumpy raw materials, which includes: a device for metered feeding of raw material pieces to a conveyor, a device for preliminary electromagnetic irradiation of the raw material pieces, a system for identifying the raw material pieces and a system for separating the raw material pieces into material streams, one of which includes the useful component and another of which represents the non-usable component [3].

[0013] The device includes a mechanism for the metered feeding of primary raw material pieces, comprising: a receiving container, a feeder with an electric drive and a control system for the electric drive of the feeder and a roller distributor; a conveyor with an electric drive and a control system for the electric drive of the conveyor; a microwave irradiation unit with a control system and a microwave heating chamber; a thermographic system with temperature sensors; an input interface; a computing device; an output interface; a pulse shaper for controlling electropneumatic valves, a time delay unit, a comparison device; a highly focused light emitter, a photodetector; a position sensor, and a device for separating worthless rock from concentrate. An output of the thermographic system is connected to a first input of the input interface.whose output is connected via the computing device to an input of the output interface; a first output of the output interface is connected to a first input of the comparing device, the second input of which is connected to an output of the photodetector of the light emitter, the output being connected via the time delay unit and the pulse shaper to an input of the electropneumatic valve; a second output of the output interface is connected to the control system of the electric drive of the device for the metered feeding of primary raw material pieces; a third output of the output interface is connected via the control system to an input of the microwave irradiation unit connected to the microwave heating chamber; a fourth output of the output interface is connected to the control system of the electric drive of the conveyor, on whose shaft the position sensor is positioned,which is connected to a second input of the input interface. The primary raw material pieces, which comprise a useful component and a non-usable component (gangue),are exposed to an electromagnetic field in the microwave heating chamber. During the heating period, the useful component and the gangue heat up to different temperatures. After irradiation in the electromagnetic microwave field, the heat transfer process between the useful component and the gangue causes the temperatures of the useful component and the gangue to equalize. The nature of this process and its parameters are determined based on the properties of the useful component and the gangue, as well as the ratio of their mass fractions. By measuring the characteristics of the heat exchange process using temperature sensors and the thermographic system, the mass fraction of the useful component in the rock sample under investigation is determined and compared with the limit value. Based on the comparison results, the rock sample under investigation is subjected to an appropriate sorting process.

[0014] A disadvantage of the known device is the low productivity of the process, which is due to the time required for treating the ore piece with ultrahigh frequency radiation and the time required for carrying out the heat exchange processes to create the thermal image.

[0015] The effective operation of the device is ensured in the narrowest possible grain size range of the ore mass to be separated, so that uniform heating of the pieces in the area of ultrahigh frequency irradiation is ensured.

[0016] An increase in the device's productivity is accompanied by higher energy costs for the separation process. Furthermore, the device requires measures to ensure occupational safety and protect personnel from exposure to high-frequency radiation.

[0017] Effective operation of the device is limited to ores whose useful component has significantly different physical properties than the unusable rock.

[0018] The device is only of limited use for the separation of ores whose useful component is finely dispersed and present in low concentration, since the determination of their mass fraction is difficult when irradiated with ultrahigh frequency.

[0019] The proposed utility model is based on the object of improving a sorting device, for example for lump ore containing minerals with low magnetic susceptibility and non-magnetic minerals, in order to increase its sensitivity, the accuracy of measuring the magnetic susceptibility of individual pieces of ore and its productivity as follows: - Using a 3D laser to create an initial data set for identifying each piece of the ore mass based on its geometric parameters and the spatial coordinates of the geometric centers of the pieces with respect to a coil system of a sensor unit; - Use of a system of electromagnetic (EM) sensors comprising a system of induction coils arranged in a matrix as a measuring device, the coils being arranged in rows perpendicular to the direction of movement of the conveyor belt, the coils of a subsequent row being diagonally offset from the coils of the previous row with respect to the direction of movement of the conveyor belt, the distance between the coils in each row and diagonally being determined by means of a special matrix; - Possibility of measuring magnetic susceptibility based on the pulse method using an oscillator, where the 3D laser data set is a controlling data set on the basis of which the measurements of the individual sensors of the matrix are controlled, and the sensor matrix data set is a controlled data set; - Possibility of obtaining a measurement result formed from the difference between two signals - a signal from the measurement of a piece of ore and a signal from the measurement of the electromagnetic background in the absence of a piece - using special digital signal processing methods to suppress the background; - Creating conditions for consolidated operation of the 3D laser and EM sensor array, creating a 3D EM precision sorting system with new properties such as extremely high sensitivity, high measurement accuracy, and high productivity, which will allow the processing of not only ores containing weakly magnetic and non-magnetic minerals, but also a range of ore types containing strong and weak paramagnetic, diamagnetic, and non-magnetic minerals that have not previously been processed at all or whose processing results have not been effective. These include: a) Ores containing minerals with close atomic masses, for which high-resolution instruments are required for sorting, for example ferromanganese ores with a massive texture, b) Ores with extremely low concentrations of the useful component correlated with non-magnetic or weakly magnetic separable minerals, for example fine gold dislocated in deposits with narrow quartz veins, (c) ores containing separable minerals whose useful component has a low atomic mass, such as mineral resources for which X-ray methods are not sufficiently effective, d) Ores containing rare earth elements whose useful component is correlated with disseminated or vein-like minerals dislocated in acid or ultra-acidic gangue, for which highly sensitive instruments are required for sorting, such as rare earth elements in pegmatite ores.

[0020] To operate the proposed device, the following information is loaded into the memory of a computing device in the form of a sorting controller: geometric parameters of the matrix of induction coils belonging to the sensors of the sensor unit, speed of movement of the ore pieces on the conveyor belt, synchronization clocks in the form of a pulse sequence that determine the relationship between the movement of the conveyor belt and the data on the ore pieces, normalized correction functions for reducing the sensor output signal depending on the grain size of the ore pieces to be sorted, the distance from the geometric center of the piece to the center of the induction coil, the geometric position of the ore piece axis relative to the measuring axis of the coil, the specifics of the geometric parameters of the piece and the fractional composition of the ore by size classes, sorting criteria taking into account the threshold values orthe lower and upper values of the magnetic susceptibility of the ore piece, the sensors being arranged in the sensor unit on the basis of the required sensitivity of the individual induction coils, the coils being arranged in rows perpendicular to the direction of movement of the conveyor belt at a distance between the coil edges of the matrix rows which is determined by the following formula:. C=R1−D / 2, with C- distance between the coil edges of adjacent matrix rows; R1 - radius defining the circular area within which, during the active state of the n-coil, neighboring coils in the same row must be inactive; D - outer diameter of the induction coil, the coils in each matrix row being arranged at a distance from the edges of adjacent coils, which is determined using the following formula: C1=(2R1−3D) / 4, where C1 is the distance between the edges of adjacent coils in the same row, where, relative to the direction of movement of the conveyor belt, the coils in each subsequent row are arranged with respect to the previous row with an offset determined by the following condition: B≤0.3⋅D, with B - offset of adjacent coils across the diagonal of the matrix, where the geometric parameters of the matrix are related to the size of the ore to be sorted by the following conditions: B≤1.4⋅Fmin C≥1.1⋅Fmax, with F min , F max - minimum and maximum ore size, wherein the lump ore is fed to the conveyor belt by means of a feeding device, wherein the geometric parameters of each piece are subsequently recorded using a 3D scanner in an area where the speed of the ore pieces corresponds to the speed of movement of the conveyor belt, and a sorting controller is used to calculate a data set comprising the area of each piece, its volume, its geometric centers, other geometric parameters of its rectangular model, and its spatial position on the conveyor belt. On the basis of this data set and the data set containing the geometric parameters of the sensor unit matrix, the sorting controller determines the following: the sequence of measurements of the magnetic susceptibility of the individual pieces, taking into account the activation delay of the individual coils, using the following formula: ΔZi=(ΔXi)2+(±ΔYi)2 with ΔZ i- absolute displacement of the center of the i-ore piece to the center of the n-coil, ±ΔY i - Coordinates of the control shift relative to Y n-axis, which is negative if the activation command for the coil is delayed and positive if the activation command is advanced, the number of the coil to be activated for the measurement, further generating control commands for measuring the magnetic susceptibility of the ore pieces and the electromagnetic background, which are forwarded to the sensor unit, wherein, when generating the command for measuring the magnetic susceptibility of the ore piece, the coordinates of its geometric center with respect to the centers of the coils, the coordinates of the activation delay of the coils and the number of synchronization cycles for the movement of the ore piece on the conveyor belt via the induction coils, as well as the number of the sensor to be activated and the numbers of the clock signal at which the sensor must be activated, are taken into account,After counting the synchronization cycles, the corresponding sensor is activated for the measurement process. The measurement of the signal from the piece is carried out by the n-coil of the sensor, while the adjacent coils located in the same matrix row are deactivated, and is carried out in a pulsating manner for a certain period of time, which is determined by the activation duration of the n-coil, taking into account the size of the pieces and their quantity per unit area of the conveyor belt. To measure a piece of ore in the area of its interaction with the induction coil, the latter is activated using an oscillator generating sinusoidal signals with a frequency of 5 - 10 kHz.To avoid errors due to amplitude and frequency instabilities, 7-10 start-up oscillations and 5-7 decay oscillations after the oscillator shutdown command are disregarded, and only a set of 5-30 measured sinusoidal oscillations is used, which are converted into rectangular pulses using the Schmitt trigger, from which the predetermined measurement interval of the direct measurement is formed, which is filled with high-frequency pulses of 0.3-1.5 GHz. The signal from the measurement of the ore piece is determined based on the number of high-frequency pulses, which is proportional to the magnetic susceptibility of the piece. This signal is corrected to ensure high measurement accuracy using the following equation: U^s=f(K1,K2,K3,K4,K5)⋅Us, with Û s - corrected signal from the measured ore piece, U s - Signal from the measured ore piece before the correction operations, K1 - Function of dependence on piece size, K2 - function of dependence on the distance of the geometric center of the piece to the center of the coil, K3 - Function of dependence on the geometric position of the axis of the piece relative to the measuring axis of the coil, K4 - Function of dependence on the geometric shape characteristics of the piece, K5 - Function of dependence on the influence of neighboring pieces near the measured piece when measuring it with coil n, where the minimum measured value of the electromagnetic background signal of coil n is ensured by: deactivation of neighboring coils located in the same matrix row within the radius R1, determination of the area of the zone on the moving conveyor belt with minimal influence of other parts by the circle diameter using the following equation D2≥1.15⋅D where D2 - diameter of the circle defining the area within which no whole pieces of ore or parts thereof may be located on the moving conveyor belt, and reducing the low-frequency component of the background spectrum by observing the condition that the time between the measurements of the signal from the ore piece and the signal from the electromagnetic background should be minimal, limited by the conveyor belt cutout, according to the equation E=D+C, with E- length of the conveyor belt section that limits the area within which the electromagnetic background is measured, and reduction of the high-frequency component of the background spectrum by using a digital exponential filter, for which several measurements are carried out before and after the measurement of the piece, from these measurements the one with the minimum value is selected and taken as the current background value, which is used together with the previous measurements to calculate the current average value of the background, which is taken as the resulting signal of the electromagnetic background, according to the equation U^b(i)=α⋅min(Ub(i))+(1−α)⋅U^b(i−1), with Û b (i) - current mean value of the electromagnetic background, relative to the time of measurement of the i-piece of ore by the coil n, min(U b(i)) - minimum value of the background from several last measurements by coil n, carried out before and after the measurement of the ore piece i by this coil, U b (i-1) - mean value of the electromagnetic background, relative to the time of measurement of the previous piece of ore (i-1) by the coil n, α - smoothing factor of the exponential filter (0 < α < 1), corresponding to a certain number of high-frequency pulses proportional to the magnetic susceptibility of the environment, including the conveyor belt. Subsequently, the actual value of the magnetic susceptibility of the ore piece, corresponding to the maximum sensitivity and accuracy of the measuring system, is determined as the difference between two signals using the following equation: ΔU=U^s−U^b, with ΔU- signal of the actual value of the magnetic susceptibility of the piece, U s- corrected signal from the measurement of the ore piece by the coil n, U b- electromagnetic background signal measured by the same coil without a piece of ore to be measured above it and under minimal influence of electromagnetic factors. After calculating the difference between the corrected signal from the piece of ore and the signal of the minimum electromagnetic background value, the signal of the actual value of the magnetic susceptibility of the piece and, accordingly, the correlated or uncorrelated mass fraction of the useful component is obtained, which is compared with the sorting criteria. Depending on the result, sorting control commands are generated for the compressed air valve system. If the piece does not meet the sorting criteria, it is discarded, and if it does meet the sorting criteria, control commands are generated based on which the pieces are fed to the collecting container by applying compressed air.The pneumatic valve is given the control command based on its position relative to the conveyor belt, the speed of movement of the conveyor belt, the duration of movement of the piece along the free-fall trajectory, the size of the piece, the number of the pneumatic valve, the number of the synchronization clock corresponding to the opening time of the valve, and the duration of the open state, whereby the piece is ejected by means of compressed air and fed to the corresponding sorting container.

[0021] Productivity is increased by introducing a lump volume correction function, which allows the sorting system to operate over a wide range of ore lump sizes. A further productivity increase is achieved by controlling the activation timing of the coils for measuring the ore lumps in close proximity, which allows for an increase in their arrangement density on the conveyor belt (number of lumps per unit area of the conveyor belt).

[0022] The technical result that can be achieved by implementing the proposed utility model is the creation of conditions for increasing the sensitivity of measuring the magnetic susceptibility of individual ore pieces through the joint (consolidated) operation of a 3D laser and a sensor matrix (EM) by: - Use of a special matrix of induction coils, - Use of a 3D laser to create an output data set of the geometric dimensions and the position of the ore pieces relative to the coil centers of the sensor unit, - Control of the sequence of measurements by the individual sensors, taking into account the control time shifts during coil activation, - Ensuring measurement operation of a single coil while preventing simultaneous measurements on adjacent coils located in the same row, - Application of the pulse measurement method, in which a measurement interval is formed which is then filled with stable high-frequency pulses, the number of which corresponds to an estimate of the signal level, - Possibility of measuring the magnetic susceptibility of the ore piece as the difference between two signals: a signal from the ore piece and a signal from the electromagnetic background measured by the same coil without ore pieces on it, - Application of digital signal processing techniques to reduce the level of the electromagnetic background separately for low-frequency and high-frequency parts of its spectrum.

[0023] The accuracy of the magnetic susceptibility measurement is improved by introducing correction functions for the measured signal value: - a function for correcting the measurement depending on the actual volume of the piece - implemented according to a monotonically decreasing dependence on the measured volume of the piece, with normalization to the piece volume corresponding to the maximum size, - a function for correcting the measurement depending on the deviation caused by the fact that the actual coordinates of the geometric center of the piece do not coincide with the coordinates of the center of the induction coil - implemented according to a monotonically decreasing dependence on the measured deviation, with normalization to the geometric position of the ideal coincidence of both centers, - a function for correcting the measurement depending on the geometric position of the longitudinal axis of the piece and the measuring axis of the coil, - a function for correcting the measurement depending on the geometric characteristics of the ore piece, - a function to minimize the influence of the magnetic properties of other ore pieces located near the measured piece.

[0024] The nature of the proposed device is illustrated by the drawings. They show: Fig. 1 -the arrangement of the induction coils in the matrix of the sensor unit using the example of a piece i and a measuring coil n (for a better understanding of the graphic representation, the coordinate X n considered at two equivalent positions), Fig. 2 (excerpt from Fig. 1) - the geometric coordinates of the activation and deactivation of the coil n as well as the geometric position of a model of the piece i relative to the induction coil system, Fig. 3 (excerpt from Fig. 2) - the process of additional coordinate shift of the activation time of the coil n along the Y-axis when introducing a control time shift, Fig. 4 - an area of the moving conveyor belt in which the measurement of the electromagnetic background of the coil n is carried out, Fig. 5 and Fig. 6 - Time diagrams of the formation of the measurement interval during operation of the electronic elements of the sensor, Fig. 7 - a schematic representation of the interaction of the components of the device, Fig. 8 - a structural diagram of the device, Fig. 9 and Fig. 10 - a block diagram of the device, Fig. 11 - a block diagram of the electronic elements of the sensor.

[0025] Reference symbols in Fig. 1 - 6: X - current coordinates on the abscissa axis, perpendicular to the direction of movement of the piece, Y- current coordinates on the ordinate axis, parallel to the direction of movement of the piece, Y n - Coordinate of the coil n on the ordinate axis, which is called the measuring axis and serves as the origin for the coordinates Y 1(n), Y 2(n), Y A ', Y A '', ΔY i , Y 2(n-5) , Y 1n , Y 2nand the angle α i and furthermore the measurement of the maximum signal U s of the piece, where the number of measuring axes is equal to the number of coil rows ( Fig. 4), X n - Coordinate of coil n on the X-axis, n - number of the coil activated for measuring the magnetic susceptibility of the piece, i - number of the piece to be measured, X i - Coordinate of piece i on the X-axis, Y i - Coordinate of the geometric center A of a model of piece i on the Y-axis, D- Outer diameter of the induction coil, B - Offset of adjacent coils across the diagonal, C - distance between the edges of coils arranged in adjacent rows, C1- Distance between the edges of coils arranged in the same row, R1 - radius defining the area of the circle within which, during the active state of coil n, the neighboring coils located in the same row must be inactive, D2 - diameter of the circle defining the area of the conveyor belt zone within which no other whole pieces of ore or parts thereof may be located during the measurement of the electromagnetic background, E- length of the area on the conveyor belt within which the level of the electromagnetic background for coil n is measured before and after the measurement of piece i by coil n, V- movement speed of piece i on the conveyor belt, S i - Area of a rectangular model of piece i, which is equal to the projection area of piece i onto the XY plane (when processing the data sets, the geometric parameters of its rectangular model are used as the geometric parameters of the piece), L i - length of the rectangular model of piece i, W i - Width of the rectangular model of piece i, A - geometric center of the rectangular model of piece i, α i - Angle of inclination of the longitudinal axis along L i to the axis with the coordinate Y i , n-5 - serial number of the adjacent coil preceding coil n in the same row (using the example of a 5-row matrix), n+5 - consecutive number of the adjacent coil following coil n in the same row (using the example of a 5-row matrix), ΔX i - Deviation of the coordinate X i of the piece i from the coordinate X n of the coil n, fixed for the state Y i = Y n , Y 1(n) - Coordinate of the start of activation of coil n (switching on the oscillator), Y 2(n)- Coordinate of the activation end of coil n (switching off the oscillator), Y A '- coordinate of the beginning of the direct measurement of the magnetic susceptibility, Y A ''- Coordinate of the end of the direct measurement of the magnetic susceptibility, ΔY i - Coordinates of the control time shift with respect to Y n when the activation time of the coil n is delayed, Y 2(n-5) - Coordinate of the activation end of coil n-5, Y 1n - Coordinate of the activation start of the coil n taking into account the control shift by ΔY i (under condition Y i # Y n ), Y 2n - Coordinate of the activation end of the coil n taking into account the control shift by ΔY i (under condition Y i # Y n ), ΔZ i- absolute displacement between the geometric centers of coil n and piece i under the condition ΔY i > 0 (if ΔY i = 0, the condition ΔZ i = ΔX i automatically fulfilled), Q - area of the conveyor belt zone limited by the dimensions D2 · E and within which the measurement of the electromagnetic background is carried out, u - voltage axis of the signal, t - current time axis, Pos. 34 - Oscillogram of the oscillator output voltage, Pos. 35 - Oscillogram of the output voltage of the Schmitt trigger, Δt - measurement interval (duration of direct measurement), Δt1 - duration of the oscillator switch-on signal, Δt2- duration of the oscillator switch-off signal, Δt1', Δt2'- duration of the pulse packets that are not taken into account when determining the measurement interval Δt. t n- Duration of a packet of sinusoidal oscillations in the coil n.

[0026] A device for separating lump ore with low magnetic susceptibility comprises a feeder for the metered feeding of ore pieces to a conveyor 27, a sorting system with a 3D scanner 1, a sorting controller 2, and a sensor unit 3, a human-machine interface 4, and a separation system in the form of a compressed air valve unit 28 for separating the ore into concentrate and unusable rock. The device's 3D scanner 1 is arranged above the conveyor 27 at the beginning of the section after the pieces have settled; the sensor unit is arranged below the conveyor 27 at the beginning of the belt section where the 3D scanner has already scanned the settled pieces. The human-machine interface 4 comprises an interface 8 for the input and output of information and an interface 9 for data exchange.

[0027] The sorting control 2 comprises a computing unit 10, a valve control unit 18 and a synchronization unit 21.

[0028] The computing unit 10 comprises a module 11 for storing output data and constants, a module 12 for measuring the geometric parameters of the pieces and generating coil activation delays, a module 13 for compensating the geometric parameters of the pieces and their arrangement on the conveyor belt, and a module 14 for eliminating the mutual influence of the individual pieces and measuring the electromagnetic background. These modules are connected to a unit 15 for processing data and control signals for the sensor unit, which is connected to two data interfaces 16, 17. Interface 16 is connected to data interface 7 of sensor unit 3. Interface 17 is connected to the 3D scanner 1 and data interface 9, which is connected to I / O interface 8 of the human-machine interface 4.

[0029] The synchronization unit 21 comprises a digital synchronization signal output unit 23, a command and synchronization signal processing unit 24, a digital synchronization signal input unit 25 and a data interface 22. The data interface 22 of the synchronization unit 21 is connected via the command and synchronization signal processing unit 24 to the unit 25, whose digital input is connected to an encoder 26 that is mechanically connected to the roller axis of the conveyor.

[0030] The valve control unit 18 includes a command processing unit 20 and a data interface 19. The data interface 19 of the valve control unit 18 is connected to the command processing unit 20, which is connected to the digital synchronization signal output unit 23 of the synchronization unit 21 and to the pneumatic valve unit 28. The digital synchronization signal output unit 23 is connected to the matrix 6 of sensors that interact with the lump ore on the conveyor belt. The data interface 7 of the sensor unit 3 is connected to the signal processing unit 5.

[0031] The 3D scanner 1 is connected to the ore pieces via an optical input, to the digital synchronization signal output unit 23 via a synchronization input, and to the data interface 17 via an output, and records the position of the ore pieces on the conveyor belt. The data interface 16 of the computing unit 10 is connected to the data interface 22 of the synchronization unit 21 and to the data interface 19 of the valve control unit 18.

[0032] The sensor unit 3 comprises a signal processing unit 5, a sensor matrix 6 and a data interface 7. The signal processing unit 5 is connected to the computing unit 10 and to the synchronization unit 21 via the data interface 7.

[0033] The human-machine interface 4 comprises an input / output (I / O) interface 8 and a data interface 9. The interface 8 is connected to the interface 9, which is coupled via the interface 17 to the unit 15 for processing data and control signals for the sensor unit.

[0034] The main functional elements of the device for separating ores with low magnetic susceptibility perform the following tasks: The 3D scanner 1 scans the ore pieces transported by the conveyor and tracks them via the following external communication options: an optical input, a synchronization input and a digital data output.

[0035] Sorting Control 2 includes the following main components: The computing unit 10 processes the data from the 3D scanner 1, controls the operation of the sensor unit 3, the valve control unit 18 and the synchronization unit 21 and performs mathematical calculations.

[0036] Module 11 for output data and constants is used to store output information for performing calculations.

[0037] Module 12 for measuring the geometric parameters of the pieces and generating a delay (or anticipation) of coil activation performs calculations of the geometric parameters of the ore pieces and their rectangular models, determines the numbers of the sensors to be activated and the activation delay or anticipation of the other sensors.

[0038] Module 13 for compensating the geometric dimensions of the pieces and their arrangement corrects the measured value of the magnetic susceptibility depending on the following factors: volume of the pieces, distance between the center of the piece and the center of the sensor coil, arrangement in the plane and shape characteristics of the piece.

[0039] Module 14 for eliminating mutual influences of individual pieces and measuring the electromagnetic background compensates for the influence of neighboring ore pieces on the piece to be measured, measures the electromagnetic background and performs calculations to ensure its minimum value.

[0040] The unit 15 for processing data and control signals for the sensor unit is the main element of the computing unit 10. It performs current calculations, coordinates the operation of additional computing elements (modules 11 to 14) and is responsible for analyzing the data and making sorting decisions according to the sorting criteria.

[0041] The RS-422 data interface is used for data exchange within the sorting control 2, with the computing unit 10 and between the sensor unit 3, the valve control unit 18 and the synchronization unit 21.

[0042] The Ethernet data interface is used for data exchange within the sorting control 2, with the 3D scanner 1 and the human-machine interface 4.

[0043] The valve control unit 18 is part of the sorting control 2 and controls the operation of the compressed air valve unit 28.

[0044] The command processing unit 20 is responsible for controlling the operation of the compressed air valves.

[0045] The synchronization unit 21 is part of the sorting control 2 and generates synchronization signals (clock signals) for the entire sorting system.

[0046] The digital synchronization signal outputs 23 are the synchronization outputs (clock outputs) for the sensor unit 3, the valve control unit 18 and the 3D scanner 1.

[0047] The command and synchronization signal processing unit 24 reads the numbers of the clock signals from the encoder 26 and can also generate synchronization test signals if necessary.

[0048] The digital synchronization signal input 25 is the input for connection to the encoder.

[0049] The sensor unit 3 carries out measurements of the magnetic susceptibility of the ore pieces transported on the conveyor belt and essentially comprises the following parts: 1). The signal processing unit 5 is used to control the sensors of the sensor unit 3, digitally process the signals from the sensors, store the measurement data, and communicate with the sorting control 2. It enables the following: - Generating, sending and receiving measurement commands from the sorting controller 2, generating a job comprising a clock number from the synchronization unit 21 and a sensor number, - Counting the high-frequency pulses during the direct measurement interval, storing the measurement results in the working memory until receiving a readout command. 2). Sensor matrix 6 is a system of inductive sensors whose coils are arranged in a special coordinate grid used to measure the magnetic susceptibility of ore pieces with paramagnetic properties.

[0050] A sensor 29 comprises the following functional units: - The induction coil 30 is part of a resonant circuit that determines the frequency of the oscillator 31. - Oscillator 31 generates a signal with a nearly harmonic waveform. When a piece of ore with paramagnetic properties is placed above the coil, the coil's inductance changes, resulting in a change in the oscillator's frequency. - The activation key 32 serves to activate the oscillator 31 and the sensor as a whole according to a command from the signal processing unit 5. - The Schmitt trigger 33 generates pulse signals which are then transmitted to the signal processing unit 5.

[0051] The human-machine interface 4 is used to enter sorting criteria and to monitor and control the operation of the units and modules of the device.

[0052] The I / O interface 8 is used to display operating information and to enter system parameters and sorting criteria.

[0053] The encoder 26 generates setpoint signals for system synchronization.

[0054] The conveyor is used to transport the ore pieces.

[0055] The compressed air valve unit 28 changes the trajectory of the ore pieces using compressed air.

[0056] The sorting device is used to sort lump ore with paramagnetic properties depending on the magnetic susceptibility of the individual ore pieces as a sorting criterion.

[0057] The device is implemented using the following equipment as an example: - laser-based 3D scanner 1 Gorator 2491A, - Computing unit 10: Data and signal processing unit 15 for controlling the sensor unit based on a Matrix MVP-5101 / M16G computer; additional computing modules 11-14 based on STM32F103 microcontrollers, - Signal processing unit 5, consisting of two subunits: command generation and transmission based on an STM32F103; high-frequency pulse counting based on an FPGA Cyclone IV, - Sensor matrix 6: using the example of ore to be sorted with a grain size of 10 - 80 mm on a conveyor belt with a belt width of 1,500 mm; flat structure of 96 coils forming 5 rows and arranged in 18 complete diagonals with 5 coils each and 2 incomplete diagonals with 3 coils each (with the following matrix parameters ( Fig. 1): D = 48.0 mm, B = 14.0 mm, R1 = 113.2 mm, C = 89.2 mm, C1 = 20.6 mm, D2 = 55.2 mm, E = 137.2 mm); each coil is connected to electronic components as shown in Fig. 11, wherein the induction coil 30 is connected to the electronic components 31 - 33, which together form the sensor 29, -Induction coil 30: has a round shape, is wound with thin copper wire and provided with a ferrite core.

[0058] As an example of the operation of the proposed device, the sorting of lumpy gold-bearing ore with quartz mineralization is considered. The useful component is fine gold, the grain size and concentration of which do not allow effective detection in the ore piece using direct methods; the gold exhibits a positive correlation with the quartz vein; both components (gold and quartz) are non-magnetic. The gangue of the ore is paramagnetic and contains diorite, granitoids, and other minerals with a magnetic susceptibility χ = 10 -6 - 10 -3 SI units.

[0059] The proposed device comprises a set of functional units that allow the determination of the geometric parameters of each piece of ore, the determination of its spatial position relative to the nearest electromagnetic sensor, the accurate measurement of the piece's magnetic susceptibility and its subsequent feeding into a material stream for usable or worthless rock depending on the expected concentration of the useful component in the sorted material.

[0060] Functioning of the proposed device.

[0061] First, the following information is stored in the sorting control: - geometric parameters of the coil matrix of the sensor unit ( Fig. 1), - speed of movement of the ore pieces on the conveyor belt and synchronization parameters of the system, - standardized correction functions for reducing the sensor output signal depending on the grain size range of the ore pieces to be sorted, the distance from the geometric center of the piece to the center of the coil, the geometric position of the axis of the ore piece relative to the measuring axis of the coil and the geometric shape characteristics of the piece, - fractional composition of the ore by size classes, - Sorting criteria that take into account the threshold value or the lower and upper values of the magnetic susceptibility of the ore piece based on known correlation functions of the mass fractions of the useful component contained therein.

[0062] The geometric parameters of the matrix of the sensor unit ( Fig. 1) are determined by the required sensitivity of the individual induction coils, which, given a known diameter D, is determined by the radius R1, within which only the measuring coil may be activated, while during its activation, the other neighboring coils in the same row must be inactive. The following equations apply to the relationship of radius R1 to the XY coordinates: on the Y axis, R1 = D / 2 + C, and on the X axis, R1 = (3D + 4C1) / 2. The arrangement of the sensors in the sensor unit is determined taking these equations into account based on the calculation parameters using the following formulas: - Distance C between the edges of induction coils arranged in adjacent rows: C=R1−D / 2 - Distance C1 between the edges of coils arranged in the same row: C1=(2R1−3D) / 4 - Condition for the offset B across the diagonal of the coils: B≤0.3⋅D - Conditions for the relationship between the parameters B and C and the size of the sorted material F min - F max : B≤1.4⋅Fmin, C≥1.1⋅Fmax, with B - offset step on the X-axis between adjacent coils across the diagonal, the smaller value of B being selected from equations (3) and (4).

[0063] Before the ore is fed into the sorting system, all systems of the facility are commissioned and synchronized with the operation of the units. The starting ore is fed to the conveyor belt using a feeder. The 3D scanner is positioned at the beginning of the area to steady the ore pieces and adjust their speed to the belt speed. It scans the ore pieces on the conveyor and generates a 3D dataset containing the geometric parameters of the pieces, which are used by the sorting control system to guide the measurement by the sensor unit.The 3D data is fed to the sorting controller, which calculates a data set for each piece, including the volume, area, geometric centers, other geometric parameters of the rectangular model, and the spatial position of the piece on the conveyor belt. Based on this data set and the data set containing the geometric parameters of the sensor unit matrix, the sorting controller determines the order of measuring the magnetic susceptibility of each piece, taking into account the activation delay of each coil and the number of the coil to be activated for the measurement. The activation of the coils and the generation of the activation delays are now described in more detail.

[0064] The activation process is illustrated by the example of the coordinates of the coil n to be activated and the piece i to be measured in Fig. 2, which is an excerpt from Fig. 1.

[0065] The piece i with the geometric center at A moves with the velocity V perpendicular to the rows of the sensor unit. Since ΔX = |X n - X i | is minimal for coil n, this coil must be activated for the measurement. The signal from the piece is measured relative to the measuring axis of coil n with the coordinates Y n . The piece i with the variable coordinate Y i of the geometric center A of the model of the piece moves along the constant coordinate X i . If it is the position Y i = Y 1(n) reaches, the activation of the coil n begins, which after the time τ n ends when the model reaches position Y i = Y 2(n) reached.

[0066] The method for generating the activation delay for coil n is described in Fig. 3, which is a section of Fig. 2.

[0067] To improve the productivity of the sorting system, a coordinate shift of the activation moment of coil n along the Y-axis is performed, which is accompanied by a time delay or anticipation. Essentially, this is as follows: With an increasing number of pieces per unit area, it becomes more and more common for, for example, coil n-5 to still be in the active state when coil n needs to be activated. The simultaneous activation of both coils in an area with radius R1 leads to a violation of the condition that only one measuring coil n may be active within area R1. To ensure compliance with this condition, the active modes of coils n and n-5 are separated in time, as shown in Fig. 3 is shown.

[0068] Assume that the coil n-5 is at the coordinate Y 2(n-5)is already deactivated. In this case, the coil n should not start its activation process until the coordinate Y 1n The geometric center of piece i is additionally shifted by ΔY i shifted, whereupon the absolute displacement of the center of the ore piece i with respect to the center of the coil n can be calculated as follows: ΔZi=(ΔXi)2+(±ΔYi)2 with ΔZ i - absolute displacement of the center of the ore piece i with respect to the center of the coil n, ±ΔY i - Coordinates of the control shift relative to Y n which is negative if the activation command for the coil is delayed and positive if the activation command is advanced.

[0069] The sorting controller also generates orders for measuring the magnetic susceptibility of the ore pieces, taking into account the absolute displacements. These orders are passed on to the sensor unit, which in turn generates control commands to perform the measurement. Command generation is based on the known coordinates of the geometric centers of the pieces relative to the centers of the coils, their absolute displacements, and the calculation of the synchronization cycles determined by the movement of the piece on the conveyor belt above the coil matrix. The command includes the number of the sensor to be activated and the number of the clock signal at which activation should occur. The synchronization cycles are counted, the desired sensor is activated, and the measurement process is started.

[0070] The measurement is carried out using a pulse method, the functionality of which is Fig. 5 and Fig. 6 is shown in detail.

[0071] The coils n are activated by starting up the oscillator, which generates sinusoidal signals. The peculiarity of the oscillator is that initial amplitude and frequency instabilities occur during its start-up, which cannot be exploited in the measurement. Therefore, the duration τ n divided into individual time periods depending on the functional purpose: direct measurement duration Δt = (Y A' - Y A'' ) / V, duty cycle of the oscillator Δt1= (Y 1(n) - Y A' ) / V and off time of the oscillator Δt2 = (Y A'' - Y 2(n) ) / V.

[0072] Studies have shown that a correct measurement mode is achieved when the first 5–10 sinusoidal oscillations (Δt1) after the command to start the oscillator and the last 5–7 decay oscillations (Δt2) after the command to turn the oscillator off are ignored during the measurement, and when only the 5–30 oscillations that make up the measurement interval Δt are considered as measurement periods. The choice of the interval value (the number of oscillations) depends on the size and number of pieces per unit area of the conveyor belt. Determining Δt is also a question of optimization, since its maximum value enables maximum system sensitivity and its minimum value enables maximum productivity. A range of Δt = 0.3–2.5 milliseconds was determined empirically.

[0073] The frequency f lowThe frequency of the oscillator is approximately 7-15 kHz; it is stable during the period Δt and depends on the inductance of the oscillator's tuned circuit, to which the measuring induction coil is connected. The inductance of the coil n depends on the magnetic susceptibility of the piece of ore i moving over it. Thus, the duration Δt of a packet of sinusoidal oscillations is a function of the magnetic susceptibility.

[0074] In order to correctly record the beginning and end of the measurement interval Δt, a packet of sinusoidal oscillations of duration τ n fed to a Schmitt trigger, which generates rectangular pulses ( Fig. 6). The sensor unit forms a measuring interval Δt from the pulse packet, which is filled with pulses of a stable high frequency f high of approximately 0.3 - 1.5 GHz, which are counted. The number of high-frequency pulses is the result of the measurement of the ore piece i and is determined using the following equation: Us=f(k) with U s - signal of the measurement of the ore piece i by the coil n, k - number of high frequency pulses.

[0075] In this way, a high sensitivity is achieved in measuring the duration of the measurement interval and, accordingly, the magnetic susceptibility of an ore piece with paramagnetic and non-magnetic properties of the minerals it contains.

[0076] To ensure high accuracy of the measured signal U s To achieve this, its value is corrected using empirical coefficients based on the following equation: U^s=f(K1,K2,K3,K4,K5)⋅Us with Û s - corrected signal from the measured ore piece taking into account the influence of the conveyor belt and the environment; U s - Signal from the measured ore piece before the correction operations, K1 - Function of dependence on piece size, K2 - function of dependence on the distance of the geometric center of the piece to the center of the coil (absolute displacement), K3 - Function of dependence on the geometric position of the axis of the piece relative to the measuring axis of the coil, K4 - Function of dependence on the geometric shape characteristics of the piece, K5 - function of dependence on the influence of neighboring pieces near the measured piece when measuring it with coil n.

[0077] The nature of the correction functions can be described in detail as follows: K1 allows the compensation of the geometric size of a piece by correcting U s using a monotonically decreasing function depending on its size in the range F max - F min The correction serves the following purpose: Suppose two pieces with the limiting sizes F max and F mincontain the same mineral composition and are successively deposited at the same point (e.g. X i = X n ) on the measuring axis Y n for the coil n. In this case, the measured signal U s for F min always be smaller than for F max , even if both consist of the same minerals. This fact can lead to an error in determining whether a piece of ore is usable or unusable. To compensate for this possible error, the correction coefficient K1 is introduced: Us(1)=K1⋅Us, with K1 = f(F i ) - coefficient which changes in a monotonically decreasing dependence on the size of the piece i, its normalization is carried out on F max .

[0078] K2 allows the compensation of the output signal U sof the sensor using a monotonically decreasing function depending on the deviation of the geometric center of the piece from the center of the coil. The correction serves the following purpose: Suppose one and the same piece is successively measured at two different points (for example, with the coordinates X n and X n + ΔX i ) on the measuring axis Y n In this case, the measured signal U s for the coordinates X n + ΔX i always smaller than that for the coordinates X n, even though the same piece is being measured. This fact can also lead to an incorrect decision. To compensate for a possible error, the correction coefficient K2 is introduced: Us(2)=K2⋅Us, with K2 = f(ΔX i)- coefficient which changes in a monotonically decreasing dependence on the deviation of the geometric center of the piece i with respect to the center of the coil n, its normalization is carried out based on the position of the piece in the coordinates X i = X n ,

[0079] K3 allows the compensation of the output signal U s of the sensor using a monotonically decreasing function depending on the inclination angle α i the longitudinal axis L i of the piece to axis Y n To compensate for a possible error due to the geometric position of the piece, the correction coefficient K3 is introduced: Us(3)=K3⋅Us, with K3 = f(α i ) - coefficient which is a function of the angle α i = |0°±90°|, its normalization is done to the position of the piece at α i = 90°.

[0080] K4 allows the compensation of the output signal U sof the sensor depending on the characteristics of the flat shape of the piece (ratio of length L i and width W i of the piece) with constant area S i To compensate for a possible error, the correction coefficient K4 is introduced: Us(4)=K4⋅Us, with K4 = f(L i / W i ), its normalization is done to the shape of the piece corresponding to the square L i = W i corresponds.

[0081] K5 allows compensation for the influence of neighboring ore pieces within a circular area with diameter D2 near piece i. To compensate for a possible error, the correction coefficient K5 is introduced: Us(5)=K5⋅Us, with K5 = f(U' s 'U' s , Δr i ) ensures the minimization of the influence of another piece of ore located near piece i.

[0082] The process of interactions between the piece i to be measured and another nearby (neighbouring) piece can be described in detail as follows.

[0083] In this case, the coefficient is determined depending on the measurement result U' s for the piece i when influenced by the neighboring piece, from the measurement result U'' s for the neighboring piece when influenced by piece i and by the distance Δr i between the edges of the pieces. Both U' s as well as U'' s It is a bilinear combination of the signals from both pieces without mutual influence, which allows calculations to be performed in reverse order (by solving a system of two equations) and the degree of their mutual influence to be determined. The influence of the ore pieces is determined with increasing distance Δr ibetween them weaker, which can be expressed empirically by a decreasing exponential function.

[0084] When sorting ores containing minerals with low magnetic susceptibility, the measurement and processing of very weak signals from paramagnetic elements takes place under conditions characterized by interference and harmful industrial electromagnetic background. The signal levels are so weak that they are comparable to the strength of a signal from an empty conveyor belt. It is therefore important to minimize the influence of the magnetic properties of the belt and the environment, and in particular to suppress the electromagnetic background and interference.

[0085] In parallel (before and after the measurement of piece i) to the measurement of the signal from the piece of ore, a measurement of the signal level of the electromagnetic background is carried out, which consists of the sum of the influence of three factors: Ub=Uc+Ul+Ue with U b - electromagnetic background signal; U c - signal caused by the electromagnetic influence of adjacent coils near coil n in the same row; U l - Signal caused by the magnetic properties of other pieces located within the conveyor belt area where the background is measured; U e - Fluctuating signal of the electromagnetic background due to the presence of external industrial electromagnetic disturbances, whose spectral characteristics include low-frequency and high-frequency spectral ranges.

[0086] When measuring the background level U b ( Fig. 4) to minimize the influence of electromagnetic factors U c and U l, which are disturbing factors that increase the overall background level, the following empirical conditions apply: - for U c : R1=D / 2+C where R1 - radius of the circle within which, when the measuring coil n is activated, the neighboring coils n-5 and n+5 located in the same row (using the example of a 5-row matrix) must be inactive; - for U l : D2≥1.15⋅D where D2 - diameter of the circle defining the area of the zone on the moving conveyor belt within which no whole pieces of ore or parts thereof may be located.

[0087] To reduce the influence of the electromagnetic factor U e To minimize the effects of noise, conditions of minimal influence of the low-frequency and high-frequency regions of the background spectrum must be ensured.

[0088] To reduce the influence of the low frequency component of the spectrum U eTo minimize the signal U s and U b must be minimal, limited by section E of the conveyor belt: E=D+C with E- length of the conveyor belt section that limits the area Q within which the electromagnetic background is measured, the measurements being made along the coordinate X'' over the section E with coordinates of Y n + (D + C) / 2 to Y'' - (D + C) / 2.

[0089] In the general case (e.g., to increase the productivity of the sorting system), it is permissible to increase the parameter E, which entails an increase in the low-frequency component of the background spectrum and, consequently, a decrease in the sensitivity of the system (according to the criterion of the relationship U s / U b). This is an optimization issue that depends on the required productivity and sensitivity as well as the background level under the specific application conditions of the method.

[0090] To minimize the influence of the high-frequency background component U e To minimize this, a suppression method is used using an exponential filter according to the following recursion formula: U^b(i)=α⋅min(Ub(i))+(1−α)⋅U^b(i−1) with Û b (i) - current mean value of the electromagnetic background (relative to the time of measurement of the ore piece i by the coil n), min(U b (i)) - minimum value of the background from several last measurements by coil n, carried out before and after the measurement of the ore piece i by this coil, U b(i - 1) - mean value of the electromagnetic background, relative to the time of measurement of the previous piece of ore (i - 1) by the coil n, α - smoothing factor of the exponential filter (0 < α < 1),where several measurements are taken before and after the measurement of the piece of ore, from these measurements the one with the minimum value is selected and taken as the current background value, which is used together with the previous measurements to calculate the current average value of the background, which corresponds to a certain number of radio frequency pulses proportional to the magnetic susceptibility of the environment, including the conveyor belt.

[0091] The following explanations serve to reveal in detail the operating principle of the exponential filter. By factoring out and rearranging the terms, one arrives at the recursion formula (12) for calculating the current mean background value in the following form: U^b(i)=U^b(i−1)+α⋅(min(Ub(i)−U^b(i−1)) This means that the smoothing factor α represents the ratio between the pulsation level achieved by smoothing and the original (unsmoothed) pulsation level. Therefore, the smaller the value α, the more the influence of random electromagnetic factors is suppressed. Repeated application of the recursion formula to calculate the smoothed mean results in the following expression for the current mean background value: U^b=α⋅[min(Ub(i))+(1−α)⋅min(Ub(i−1))+(1−α)2⋅min(Ub(i−2))+…+(1−α)i−1⋅min(Ub(1))]+(1−α)i⋅min(Ub(O)) ie, as time progresses, the smoothed value becomes the weighted average of an increasing number of previous measurements min(U b (i-1)), min(U b (i-2)), ..., min(U b (1)), min(U b (0)) to which the weighting factors α, (1 - α), (1 - α) 2 , ..., (1 - α) iwhich form a geometric progression, which is a discrete representation of the exponential function.

[0092] Reducing the coefficient α not only improves the degree of smoothing, but also increases the influence of previous measurements (especially the initial measurement) on the current value of the smoothed mean to be calculated, which can lead to a delayed response to changes in the background level. Therefore, the rational choice of the coefficient α is also a matter of optimization.

[0093] Consequently, the actual value of the magnetic susceptibility of the ore piece, measured taking into account the electromagnetic background, is determined as the difference between two signals – the corrected signal from the measurement of the ore piece and the signal from the electromagnetic background under minimal influence of three electromagnetic factors – using the following formula: ΔU=U^s−U^b, where ΔU- actual value of the magnetic susceptibility of the ore piece, U s - corrected signal from the measurement of ore piece i, U b - Signal from the electromagnetic background, measured by the same coil without an ore piece to be measured above it and with minimal influence of electromagnetic factors.

[0094] The data obtained from the ΔU = f(k) calculation are compared with the sorting criteria, and based on the comparison result, a decision is made regarding the need to eject the ore piece. If the piece does not meet the sorting criteria (e.g., granitoids with low magnetic susceptibility, which is characteristic of paramagnetic rocks), no further action is taken. If the piece does meet the sorting criteria (e.g., non-magnetic quartz correlated with fine gold), control commands are generated for the pneumatic valve system, which eject the pieces from the quartz vein using compressed air. The control commands are based on a command that includes the pneumatic valve number, its opening duration (activation), and the synchronization clock number.All processes are synchronized, from scanning to magnetic susceptibility measurement, further processing, data transmission, and ejection. Under the influence of compressed air from the activated valves, the piece is fed into the desired container. The sorting process is complete when all pieces have been separated according to the sorting criteria and are in their respective containers.

[0095] By using a special matrix of coils of the sensor unit, the introduction of targeted control orders during its operation in a consolidated 3D EM system and the pulse method for measuring the signals from the ore piece and the electromagnetic background, a precise sorting system with the highest possible sensitivity and accuracy in measuring the magnetic susceptibility at high sorting performance is realized.

[0096] The proposed device for sorting lump ore containing minerals with low magnetic susceptibility and non-magnetic minerals comprises a device for metered feeding of ore pieces to a conveyor, a device for electromagnetically irradiating the pieces, a system for identifying raw material pieces according to the presence of a useful component, and a system for separating the raw material pieces into material streams, one of which contains the useful component and the other represents the non-usable component. According to the proposed utility model, the device comprises a 3D scanner arranged above the conveyor belt and designed to pre-identify the ore pieces according to their geometric parameters, spatial orientation, and coordinate position on the conveyor belt. Furthermore, the device comprises a sorting controller, a sensor unit,a human-machine interface, an encoder, and a pneumatic valve unit, wherein the sensor unit comprises a signal processing unit, a data interface, and a sensor matrix in which the sensors are arranged in a special coordinate grid designed to measure the magnetic susceptibility of the pieces with paramagnetic properties, each sensor being in the form of an induction coil contained in a measuring oscillator connected to a Schmitt trigger and a signal processing unit connected to an oscillator by means of an activation key, wherein the sorting control comprises a computing unit, a valve control unit, and a synchronization unit, wherein the computing unit comprises a module for storing output data and constants, a module for measuring the geometric parameters of the pieces, and for generating coil activation delays,a module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt, a module for eliminating the mutual influence of the individual pieces and for measuring the electromagnetic background, a unit for processing data and control signals for the sensor unit, and connection interfaces, wherein the synchronization unit comprises a digital synchronization signal input, a command and synchronization signal processing unit, digital synchronization signal outputs, and a data interface, wherein the valve control unit comprises a command processing unit and a data interface, and wherein the human-machine interface comprises an input / output (I / O) interface and a data interface, wherein the 3D scanner is connected to the lumpy ore on the conveyor belt via its optical input,is connected via a synchronization input to the digital synchronization outputs of the synchronization unit and is connected at one output via the data interface to the unit for processing data and control signals for the sensor unit, wherein in the computing unit the module for storing output data and constants, the module for measuring the geometric parameters of the pieces, the module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt, and the module for eliminating the mutual influence of individual pieces and for measuring the electromagnetic background are connected to the unit for processing data and control signals for the sensor unit, which is connected to two data interfaces, one of which is connected to the data interface of the sensor unit,wherein the other data interface of the computing unit is connected to the output of the 3D scanner and via a data interface to the I / O interface of the human-machine interface, wherein in the synchronization unit, a data interface is connected to the data interface of the computing unit and to the command and synchronization signal processing unit, which is connected to the digital synchronization signal outputs and to the digital synchronization signal input connected to an encoder of the device connected to the conveyor, wherein the data interface of the valve control unit is connected to a data interface of the computing unit and to the command processing unit, which is connected to the digital synchronization signal outputs of the synchronization unit and to the compressed air valve unit,wherein the unit of digital synchronization signal outputs is connected via the signal processing unit of the sensor unit to the sensor matrix which interacts with the lump ore on the conveyor belt, wherein a data interface of the sensor unit is connected to the signal processing unit.

[0097] The technical result of the implementation of the proposed utility model is as follows: - The device enables the identification of the useful component in the ore that is correlated with weakly magnetic or non-magnetic minerals, thus allowing the inclusion in the pre-processing process of mineral resources that have not been previously processed or whose processing has been ineffective. - The device enables the identification of the useful component in the ore piece regardless of its weight, shape and spatial orientation on the conveyor belt. - The device has low energy consumption and its operation has only a minor impact on the processing costs of mineral resources. - The device operates in a wide range of grain sizes, so that it can be used effectively both in smaller deposits and in ore deposits with smaller processing flows of mineral raw materials. - The device enables the processing of raw materials extracted from deposits of natural and technogenic origin. - Thanks to the short time required to decide whether the ore is usable or unusable based on the evaluation of the content of weakly magnetic or non-magnetic materials in the piece, high productivity of the device is ensured. - The device can be used in conjunction with technological units for processing ores with weak magnetic properties, which are characteristic of paramagnetic materials, or with non-magnetic properties, as well as ferromagnetic ores. - The device can be designed in stationary or mobile form depending on the required productivity and the location of the mineral deposits.

[0098] In the following, the operation of the device is described using the example of coil n ( Fig. 2 - 11) is considered, which is to measure the piece of ore i (it is assumed that the distance between the center of the coil n and the center of the piece i is minimal).

[0099] The operation of all functional units is synchronized using synchronization signals from the synchronization unit 21. The roller axis of the conveyor 27 is connected to the encoder 26, which generates synchronization signals received via the digital input of the synchronization unit 25. The synchronization signal output unit 23 synchronizes the operation of the 3D scanner, the sensor unit 3, and the valve control unit. Each functional unit counts the synchronization pulses (clocks), which allow the pieces to be tracked on the conveyor. The arithmetic unit 10 does not include a synchronization signal input, as the synchronization clock count is transmitted to it from the command and synchronization signal processing unit 24 via the data interface 22.

[0100] The sorting process begins with the loading of ore pieces onto the conveyor 27. The 3D scanner 1 scans the ore pieces transported on the conveyor and generates a 3D data structure, which is forwarded to unit 15 of the computing unit 10 via the data interface 17. Unit 15 reads the output data from module 11 and then transmits it, along with the data received from the 3D scanner, to module 12 for calculating the geometric parameters of the pieces and the coil activation delay values. After performing the calculations, module 12 transmits the results to unit 15, which, based on the results received from module 12, generates a job for measuring the magnetic susceptibility of the pieces, which is transmitted to the sensor unit 3 via the data interface 16.The measurement order is received by the signal processing unit 5 and includes the number of the sensor to be activated and the number of the clock signal at which the activation should take place.

[0101] The signal Û s = f(k) is measured as follows.

[0102] When the signal processing unit 5 receives a request, its control subunit generates a command to activate the coil n of the sensor 29 using the activation key 32 ( Fig. 11). The oscillator 31 is put into operation and generates sinusoidal signals with a frequency f low = 9.2 kHz ( Fig. 5), which are fed to the input of the Schmitt trigger 33, which generates the pulses ( Fig. 6). The active state of sensor 29 is maintained for 32 oscillation periods of oscillator 31. The first 7 periods are disregarded in the measurements and are considered start-up periods, since the frequency and amplitude of oscillator 31 are unstable during its start-up. The following 17 periods are used to measure the magnetic susceptibility, whereas the last 8 periods correspond to the oscillation decay mode of oscillator 31 and are also disregarded. The oscillator-based sensor operates at a magnetic susceptibility of the minerals to be separated in the range of 10 -3 -10 -4 SI units are most effective. In the range of 10 -5 -10 -6 SI units, the sensor's circuitry can be changed in the presence of a high electromagnetic background.

[0103] The control subunit of unit 5 generates and transmits, at the onset of the edge of the 6th pulse (with the duration Δt1') from the Schmitt trigger 33, a command with the number of the sensor to be switched on for the measurement to the subunit for counting the high-frequency pulsesf high . The counting subunit of unit 5 counts the number k of high-frequency pulses (f high = 470 MHz, stabilized by a quartz oscillator) over 17 periods (measurement interval Δt). The counting result U s= f(k) is stored in the working memory until a command is received from the control subunit of unit 5 to read the data received by unit 15 via interfaces 7 and 16 (one pulse counting subunit can serve 16 sensors). The edges of the 24th and 25th pulses (with duration Δt2') are also disregarded when measuring the interval Δt, since upon receipt of the 24th pulse, the control subunit of unit 5 switches off oscillator 31 and the process for measuring U s is completed.

[0104] To ensure high measurement accuracy, a correction of the signal U sFor this purpose, unit 15 transmits the measurement results to module 13 and module 14. Module 13 performs a correction using coefficients K1, K2, K3, and K4, which are functions of the volume of the piece, its deviation from the center of the coil, the angle of inclination to the measuring axis, and the geometric shape features, respectively. Module 14 performs a correction using coefficient K5, which is a function for compensating for the influence of pieces located near piece i. After all correction calculations have been performed, the signal Û s = f(k) is generated.

[0105] The signal U b = f(k) is measured as follows: Module 12 excludes an active state of the adjacent coils n-5 and n+5 in the series by means of the activation delays. Module 14 calculates the range Q ( Fig.4), which is maximally free from other pieces. To minimize the influence of the low-frequency component of the electromagnetic background spectrum, the measurements are carried out at a minimum time interval before and after the measurement of the signal U s carried out. Several measurements U b from which the minimum measurement is selected and taken as the current background value. To reduce the high-frequency component of the background, calculations are performed using a digital exponential filter. The current background value and the results of previous background measurements (taking their weighting factors into account) are added to obtain the running average Û bof the electromagnetic background. The function of the exponential filter during the first measurement is ensured by performing several background measurements on an empty conveyor belt when the sorting system is switched on, thus filling the exponential filter with initial data.

[0106] The result of the measurement of the magnetic susceptibility of the ore piece ΔU is calculated by unit 15 as the difference between two signals: Û s , which is obtained with the coil n in the presence of the piece i, and Û b, obtained with the same coil in area Q of the conveyor belt. The calculations provide parameters with high sensitivity and measurement accuracy, enabling precise measurement of the magnetic susceptibility of paramagnetic ores. Unit 15 then compares the measurement result with the sorting criteria entered via human-machine interface 4. If the piece does not meet the sorting criteria, no further action is taken. If the piece does meet the sorting criteria, an order is generated for valve control unit 18, which is transmitted via data interfaces 16 and 19.

[0107] The valve control unit 18 receives the sorting order from the computing unit 10 via the data interface 19. The order includes the number of the pneumatic valve, the duration of its opening (activation), and the number of the synchronization cycle corresponding to the valve opening time. The synchronization cycles are counted by the command processing unit 20, and when the cycle number matches the cycle number corresponding to the order, the corresponding valves in the pneumatic valve unit 28 are opened, taking into account the movement time of the ore piece along its free-fall trajectory and the size of the piece. Under the influence of compressed air from the activated valves, the ore piece is fed to the desired container. Sources: 1. Russian patent for invention No. 2437725. 2. http: / / goldcilplant.com / Molybdenum-sorting-test-by-XRT-sorter.html 3. (US Patent 7,541,557 B2 “Method for thermographic lump separation of raw material (variants) and device for carrying out said method (variants)”, Volodymyr M. Voloshyn, Viktor Y. Zubkevych). QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] RU 2437725

[0107] US 7,541,557 B2

[0107] Cited non-patent literature

[0000] 2. http: / / goldcilplant.com / Molybdenum-sorting-test-by-XRT-sorter.

[0107] Method for thermographic lump separation of raw material (variants) and device for carrying out said method (variants)“, Volodymyr M. Voloshyn, Viktor Y. Zubkevych

[0107]

Claims

[1] Apparatus for sorting lump ore containing minerals with low magnetic susceptibility and non-magnetic minerals, comprising a device for metered feeding of ore pieces to a conveyor, a device for electromagnetic irradiation of the pieces, a system for identifying raw material pieces according to the criterion of the presence of a useful component, and a system for separating the pieces into material streams, one of which comprises the useful component and another of which represents a non-usable component, characterized bythat the device comprises a 3D scanner arranged above the conveyor belt and designed to pre-identify the ore pieces according to the criteria of their geometric parameters, their spatial orientation and their coordinate position on the conveyor belt, wherein the device further comprises a sorting control, a sensor unit, a human-machine interface, an encoder and a pneumatic valve unit, wherein the sensor unit comprises a signal processing unit, a data interface and a sensor matrix in which sensors are arranged in a special coordinate grid intended for measuring the magnetic susceptibility of the pieces with paramagnetic properties, wherein each sensor is designed in the form of an induction coil contained in a measuring oscillator connected to a Schmitt trigger and a signal processing unit,which is connected to an oscillator by means of an activation key, wherein the sorting control comprises a computing unit, a valve control unit and a synchronization unit, wherein the computing unit comprises a module for storing output data and constants, a module for measuring the geometric parameters of the pieces and for generating coil activation delays, a module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt, a module for eliminating the mutual influence of the individual pieces and for measuring the electromagnetic background, a unit for processing data and control signals for the sensor unit and connection interfaces, wherein the synchronization unit comprises a digital synchronization signal input, a command and synchronization signal processing unit, digital synchronization signal outputs and a data interface,wherein the valve control unit comprises a command processing unit and a data interface, and the human-machine interface comprises an input / output (I / O) interface and a data interface, wherein the 3D scanner is connected to the lumpy ore on the conveyor belt via an optical input, is connected to the digital synchronization outputs of the synchronization unit via a synchronization input, and is connected at an output via a data interface to the unit for processing data and control signals for the sensor unit, wherein the computing unit includes the module for storing output data and constants, the module for measuring the geometric parameters of the pieces, the module for compensating the geometric dimensions of the pieces and their arrangement on the conveyor belt,the module for eliminating the mutual influence of individual pieces and for measuring the electromagnetic background is connected to the unit for processing data and control signals for the sensor unit, which is connected to two data interfaces, one of which is connected to the data interface of the sensor unit, the other data interface of the computing unit being connected to the output of the 3D scanner and, via a data interface, to the I / O interface of the human-machine interface; in the synchronization unit, one data interface is connected to the data interface of the computing unit and to the command and synchronization signal processing unit, which is connected to the digital synchronization signal outputs and to the digital synchronization input connected to an encoder of the device connected to the conveyor;wherein the data interface of the valve control unit is connected to a data interface of the computing unit and to the command processing unit, which is connected to the digital synchronization signal outputs of the synchronization unit and to the compressed air valve unit, wherein the unit of the digital synchronization signal outputs is connected via the signal processing unit of the sensor unit to the sensor matrix that interacts with the lump ore on the conveyor belt, wherein a data interface of the sensor unit is connected to the signal processing unit.

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