RU2170629C2 - Method of formation of distributed supply of lump material - Google Patents

Abstract

FIELD: concentration of mineral materials; applicable in radiometric separators for grading of lump materials. SUBSTANCE: method includes simultaneous supply of wet lump material sizing less than 5 mm and conveying water in volume to attain moisture content of transported material in excess of 40%. Under action of gravity and washing-off water, material particles are accelerated on conical surface and fall freely in sliding off the conical surface. EFFECT: extended limit of use of method of distributed supply of lump materials to side of reduction of particle sizes of 5+1 mm. 2 dwg

Description

 The invention relates to the field of mineral processing and can be used in radiometric separators to implement a pokusny mode of sorting wet bulk materials with a particle size of less than 5 mm

 A known method of forming a dispersed supply of bulk material [1, p. 44, Fig. 14 (b)], providing the required distance between the pieces, carried out by scattering pieces of material under the action of centrifugal forces.

 The disadvantages of this method are: high energy consumption, the distribution of particles in space by a fan, and the width of the fan depends on the difference in the densities and sizes of the pieces, which reduces the sorting efficiency, since the distance from the radiation source to the pieces of material changes.

 The closest technical solution to the proposed one is the method of gravitational layout of wet material supplied to a radiometric separator [2], in which wet bulk material with a particle size of 2-5 mm is fed into the loading hopper together with transport water added in the amount necessary to achieve the ratio T: W = 2.32-2.35 (i.e., ≈30% humidity) of the sorted material, is formed using an annular flow former, where the flow acquires a section in the form of a ring and enters a cone feeder, where the flow is distributed camping on the surface and in the zone of detection and registration becomes layered.

 However, the method of gravitational layout of wet bulk material allows you to implement only a batch sorting mode when, when a valuable component is detected, a batch containing a valuable component is rejected from the material flow and cannot be used to form a piecewise supply of wet materials with a particle size of less than 5 mm in order to implement a batch sorting mode when, when a valuable component is detected from the material stream, a piece representing this component or its intergrowth with associated breed; Wet bulk material with a particle size of less than 5 mm at a moisture content of W ≈ 30% sticks together due to film tension of water on the surface of the pieces under the action of adhesion forces and enters the detection and registration zone of a valuable component and the portion removed from the material stream.

 The purpose of the invention is the expansion of the use of the method of forming a piecewise supply of moist bulk material in the direction of reducing particle sizes to a particle size of 5 + 1 mm.

 This goal is achieved by the fact that in the hopper with wet material with a particle size of less than 5 mm, transport water is additionally supplied to the amount necessary to achieve a moisture content of the transported material of more than 40% (see Fig. 2).

 The authors did not find solutions with features similar to the distinguishing features of the proposed solution, on the basis of which we can conclude that the proposed solution meets the criterion of "significant differences".

 The essence of the proposed method is illustrated by the following description.

 In the hopper 1 of the radiometric separator (see Fig. 1), simultaneously with wet bulk material with a particle size of less than 5 mm, transport water is supplied in the amount necessary to achieve a moisture content of the transported material of more than 40%. Material with water from the hopper 1 falls onto a conical surface 3. Particles, under the influence of gravity and the action of washing away transport water, accelerate to a predetermined speed on the conical surface and, after leaving the conical surface 3, fall freely, providing the distance between the particles necessary for implementing feeding the material into the detection and registration zone of the valuable component 4 and into the zone of separation from the material stream 5. Increasing the circumference of the base of the conical surface in the direction of movement of the mat iala and transport water reduces the water film thickness and stretching of the particles transversely to the direction of movement of the material. Performance control occurs by changing the position of the gate 2.

In FIG. Figure 2 shows the experimental dependence of the efficiency of the formation of a stream of bulk material with a particle size of less than 5 mm on the moisture content in it. The initial portion of the curve, up to about W ≈ 3%, is a slightly inclined segment of the curve. Changing the humidity of the transported material in this range does not significantly affect the efficiency of the formation of an ordered flow, which in this case depends mainly on the design features of the power distribution device. The point W _cr ≈ 3% is critical, since after it there is a sharp decrease in the efficiency of formation of the material flow due to the coalescence of particles. In the range from W ≈ 6% to W ≈ 40%, the transportation of material almost completely stops - almost all of the original material remains in the hopper and adheres to the surface of the power distribution device. With a further increase in the humidity of the material (over 40%) - the process efficiency rises again.

 Along with an experimental study to determine the effect of moisture of a material on the efficiency of its formation in an ordered flow in order to eliminate its cohesion, a patent and bibliographic review of existing solutions to eliminate the coalescence of wet particles with a particle size of less than 5 mm was carried out. The review showed that the adhesion of wet material with a particle size of less than 5 mm is eliminated to increase screening efficiency by increasing its moisture content, i.e. adding extra water.

Bibliography
1. Kravets B.N. Special and combined enrichment methods. Textbook for high schools. - M .: Nedra, 1986 - 304 p.

 2. RF patent N 2034673, cl. B 07 C 5/346 (prototype).

Claims (1)

 A method of forming a dispersed supply of wet bulk material into a radiometric separator, comprising simultaneously supplying transport water to a hopper with wet bulk material with a particle size of less than 5 mm, accelerating particles of the material under the influence of gravity and washing water on a conical surface and free falling of particles upon leaving the conical surface characterized in that the transport water is supplied in an amount necessary to achieve a moisture content of the transported material of more than 40%.

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