RU2506582C2 - Industrial metal detector for determination of percentage content of ferromagnetic in ore - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention relates to ore dressing industry and is used to determine percentage content of ferromagnetic in ore. The device comprises excitation coils, an AC generator, which develops AC excitation magnetic field, a receiving coil, arranged in parallel to the transmitting ones in the middle, a summator, a DAC signal of compensation of x.x. receiving coil, an ADC, a speed sensor, an additional receiving coil, connected in parallel with the transmitting ones, weights, a unit of a central processor, a calibration loop, arranged in parallel to the receiving coil, at the same time high evenness of measurement of the response value is achieved due to usage of several transmitting coils for creation of the even field, a processing logic with account of a signal of an additional coil, arranged in parallel to the transmitting one, generation of a signal of compensation x.x. with account of re-distribution of harmonics of the main frequency and compensation of the signal x.x. with account of the varying environment (climatic, mechanical changes) dynamically, i.e. without drop of sensitivity in the mode of real time.

EFFECT: increased evenness of measurement of a value of magnetising field response.

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Description

The invention is intended for use in the mining and processing industry and is used to determine the percentage of ferromagnet in mining ore.

State of the art

To measure the content of a ferromagnet, metal detectors are used, consisting of transmitting and receiving coils that record a change in the magnitude of the magnetic field, for example, invention SU No. 1078384 "Conveyor metal detector". Achieving a high uniformity in measuring the magnitude of the response is not always possible, since it is limited by the actual magnetic environment, and by the fact that it is necessary to “magnetize” the entire layer of rock.

The problem is solved:

- using multiple transmitting coils to create a uniform field;

- using data processing from receiving sensors with a coefficient obtained by closing an additional coil located parallel to the transmitter, which allows you to measure the real magnetizing field, taking into account external factors.

In the metal detector under consideration, the following are used: field coils 1 connected to an alternating current generator, which create an alternating magnetic field of excitation, affecting the object under examination, moving through the control zone. The receiving coil 2, located parallel to the transmitter, inside it. The signal from the receiving coil is fed to the input of the amplifier 3, the signal from the amplifier is fed to the adder 4, where it is added to the “compensation” signal coming from the DAC 5, which allows you to compensate for the chemical signal, then the signal is fed to the ADC 6. Also the processing unit receives information from the speed sensor 7 and data from the balance 8. In parallel with the transmitting coil, a calibration loop 9 is also included, which is periodically closed, which allows the device to independently perform auto-testing and auto-calibration. To control the current of the transmitting coil, a current sensor 10 and a separate ADC are used 11. The signal processing module 12 contains: a band-pass filter 13, a synchronous detector 14, an low-pass filter 15, a pulse shape processor 16. To control the signal processing module, the generation and compensation control module 17 is used. For communication between the device modules and the computer interface 18, a central processor 19 is used.

The main difference between this device and similar metal detectors is:

1. The number of transmitting coils.

2. The presence of an automatic compensation system x.x. receiving coil, which eliminates the time-consuming process of tuning the sensor, and also eliminates the effect of "aging" of the element base due to the constant auto-tuning of optimal parameters.

3. The presence of a “loop”, which is a periodically closed coil located parallel to the transmitting one, allows the device to independently perform auto-testing and auto-calibration.

4. Monitoring the speed of the conveyor to change the signal processing parameters can significantly reduce the influence of interference due to the fact that only a signal with a given rate of change is recognized as a useful signal.

5. The presence of an input for connecting the scales (mass information) allows you to programmatically calculate the percentage of ferrum in ore.

Claims (1)

An industrial metal detector for determining the percentage of a ferromagnet in mining ore, consisting of excitation coils, an alternating current generator that creates an alternating magnetic field of an excitation, a receiving coil located parallel to the transmitting middle, an adder, a DAC of a compensation signal x.x. receiving coil, ADC, speed sensor, additional receiving coil connected in parallel to the transmitting unit, balance, central processor unit, calibration loop located parallel to the receiving coil, characterized by high uniformity of measurement of the response value through the use of several transmitting coils to create a uniform field, processing algorithm with taking into account the signal of an additional coil located parallel to the transmitter, generating a compensation signal x.x. taking into account the redistribution of harmonics of the fundamental frequency and signal compensation x.x. taking into account the changing environment (climatic, mechanical changes) dynamically, i.e. without loss of sensitivity in real time.