RU2069100C1 - Mineral raw material separator - Google Patents

Abstract

FIELD: material separation. SUBSTANCE: device has one feeder, one conveyor to deliver raw material to check zone 1, two sources of ionizing irradiation 3, two secondary radiation registers 4, two protective casings 5, one conveyor 6 to deliver material to sorting out zone, one threshold unit 8, one actuator control unit 9, two concentrate receivers 10, 11. EFFECT: enlarged operating capabilities. 1 dwg

Description

 The invention relates to a device for the separation of mineral raw materials, mainly diamond-containing, and can be used to detect and sort minerals luminescent under the action of x-ray radiation.

 The essence of the invention lies in the fact that the probability of detecting a useful mineral in the separation process is not reduced, because the magnitude of the radiation power of the sources of exciting radiation and the sensitivity of the registrars of secondary radiation remain unchanged. This is due to the lack of a physical relationship between the zone of action of the exceptional mechanism and the zone of detection of the signal from the useful mineral.

It is known that the degree of ε extraction of diamonds during ore separation can be determined by the formula
e = P _o • P _and , (1)
where P is _the probability of detecting diamonds,
P _{and the} probability of separation of diamonds into concentrate by the actuator.

As follows from the expression (1), the closer the characteristics _{of the} P and P _{and the} unit is, the higher the extraction of diamonds, and hence the quality of separation.

The signal U at the input of the threshold element of the registrar of secondary radiation is determined by the expression
UR x I x G x K _n x K _y x K _f , (2)
where R is the radiation power of the exciting radiation source,
I intensity of the luminescent (secondary) radiation of the mineral,
G geometric attenuation factor of the system: source of exciting radiation, secondary radiation recorder,
K _p the transmittance of the optical windows of the source of exciting radiation and the registrar of secondary radiation,
K _y , K _f gain and filtering of the secondary radiation recorder.

If the magnitude of the signal (2) U≥U _{n is the} voltage of the threshold of the threshold element of the secondary radiation recorder, then the mineral is detected with a probability P ' _about . In this case, an actuator control signal is generated, which, when triggered, separates the useful mineral into concentrate.

 If the zone of irradiation of the material with exciting radiation and the registration of secondary radiation and the separation zone of the mineral in the concentrate are not physically separated (as in the prototype device), the actuation of the actuator leads to contamination, clogging and shading (hollows) of the surface of the optical windows of the exciting radiation source and a secondary radiation recorder. During prolonged ore separation, neither mechanical nor hydraulic methods of protecting optical windows provide the specified efficiency (this is shown by practical experience of more than 5 years of operation in industry).

. Согласно выражению (1) произойдет уменьшение извлечения алмазов, а следовательно, качество сепарации ухудшится. При этом, чем больше производительность сепарации, тем интенсивнее происходит загрязнение оптических окон, и, следовательно, в большей степени снижается извлечение алмазов.When the optical windows of the source of the exciting radiation and the secondary radiation detector are contaminated, the values of R and K _{p of} expression (2) decrease. Moreover, from a portion of useful minerals, the luminescence signal U of expression (2) will be less than U _n , i.e. registration of useful material will not happen. Probability of detection in this case

. According to expression (1), diamond recovery will decrease, and therefore, the quality of separation will deteriorate. Moreover, the greater the separation performance, the more intense the contamination of the optical windows occurs, and, consequently, the recovery of diamonds is reduced to a greater extent.

 The drawing shows a block diagram of a device for separation.

The device contains a feeder (not shown in the drawing), an inclined conveyor 1 for moving the material flow into the irradiation zone 2 and recording secondary radiation, the width l of which is chosen to be equal to l T x V, where T is the period of repetition of the pulses of the exciting radiation, V is the flow velocity material. Sources of exciting radiation 3 and registrars 4 of secondary radiation are placed in a protective casing 5 and are installed at the discharge end of the conveyor 1 from two opposite sides of the material flow. The secondary radiation recorders 4 are made of a photodetector and a threshold device. A conveyor 6 for moving the material flow from the irradiation zone 3 and registering the secondary radiation to the material cutoff zone 7 is mounted obliquely with respect to the conveyor 1 with a gap equal to the width of the irradiation zone 2 and recording the secondary radiation. The conveyor 6 relative to the conveyor 1 in a vertical plane is located at a distance equal to the maximum deviation of the material flow path during free fall, the value of which is determined experimentally. Delay control signal device 8 is connected to the threshold device registrar secondary radiation 4, the delay time t _of the signal for which the formula is determined by V x t _z L, where L the length of the conveyor 6, V the velocity of the material on the conveyor 6. The actuator 9, for example pnevmoezhektor , connected to the delay device 8 and installed at the discharge end of the conveyor 6 at a distance l _o equal to half the width of the cut-off zone 7 of the material flow, which is determined from the condition l _o = l _he + ΔV • t ₃ , where l _{he is the} width of the cut-off zone, defined the required force of the air jet for guaranteed deflection of a batch of material at a stable speed V of the material flow, ΔV instability of the material flow rate due to the spread of the coefficient of friction of grains on the material of the conveyor tray 6, t _s the delay time of the signal by the delay device 8. The device also contains concentrate receivers 10 and tails 11, respectively.

 The device operates as follows.

 The flow of the separated material in the form of pulp with coarse and fine fractions in the scheme with an inclined conveyor 1 from two opposite sides is irradiated by a source of exciting radiation 3, for example, x-ray radiation. Secondary radiation signals, for example luminescence, from two opposite sides for a time equal to the period between the irradiation pulses of the exciting radiation source 3, are recorded by the secondary radiation recorder 4, for example a photodetector, and converted into electrical signals. Electrical luminescence signals exceeding the threshold value of the luminescence signal from the threshold device of the secondary radiation recorders 4 are supplied to the delay device 8 of the signal. The material stream after passing through the irradiation zone 2 and registering the secondary radiation enters the inclined conveyor 6 and, as the last one, moves in the form of a monolayer into the cut-off zone 7 created by the actuator, for example, an air ejector. After the delay time, the delay device 8 includes an actuator 9, which cuts off a portion of the material with useful mineral in the concentrate receiver 10, the tail product enters the receiver 11.

 The device allows for high average operational recovery with high separation performance of sludge-containing diamond ores, that is, to improve the quality of separation by eliminating the contamination of optical windows of excitation sources and secondary radiation detectors.

Claims (1)

 A device for the separation of mineral raw materials, comprising a feeder, a conveyor mounted at an angle to the vertical plane for supplying raw materials to the control zone, ionizing radiation sources and secondary radiation detectors located on opposite sides of the feed stream, the outputs of the secondary radiation recorders through the threshold block are connected to the inputs of the control unit an actuator, characterized in that, in order to improve the quality of separation, it is equipped with a conveyor for feeding raw materials to the sorting zone, made with a gap after the conveyor for feeding raw materials to the control zone and at an angle to the vertical plane less than the angle of inclination of the conveyor for feeding raw materials to the control zone, the gap being equal to the width of the irradiation zone and recording secondary radiation, the distance between the conveyors in the vertical plane is equal to the maximum deviation of the trajectory movement of the flow of raw materials during free fall, and the actuator is installed at the discharge end of the conveyor to feed the raw materials into the sorting zone at a distance equal to half e cutoff zone width.