RU2085743C1 - Method for subsurface clarification of circulating water and dewatering of coal slurry - Google Patents

Abstract

FIELD: mining industry. SUBSTANCE: according to method, coal slurry is delivered from cutting face to sorting screen, and under-screen slurry is divided into two flows. One flow containing larger coal fractions is directed to horizontal clarifier for formation of filter, and water with coal slurry is directed to horizontal polarizer and then to water distribution manifold of clarifier. Taking place in clarifier is water filtration at unlike charges of coal of renewed filter and of small particles contained in slurry water and subjected to treatment in polarizer. Filtration course in clarifier is renewed by removing coal from upper part of filter in the form of thickened slurry which is delivered under liquid level in thickening slurry collector. Clarified water from clarifier and overflow from thickening slurry collector are directed to contact-type water collector, and water from bottom part of it is delivered to cutting faces with continuous miners. Overflow from contact-type water collector is forwarded to hydraulic giant cutting face. EFFECT: high efficiency. 5 cl, 1 dwg

Description

 The invention relates to mining, in particular, to dehydration of minerals and clarification of process water, can be used both in underground coal mining by hydraulic and mechanical-hydraulic methods, and on the surface when conducting opencast mining.

A known method of underground coal processing, which consists in dehydration of coal and clarification of process water [1]
According to this method, the coal pulp through the gutters enters a screen, the over-sieve product of which (coal with a grain size of more than 13 mm with a moisture content of less than 8%) is sent to the hopper, and the under-screen product of the screen is sent to an arc sieve. From subgrid coal with a particle size of 1-13 mm, a filter layer is formed on a moving perforated surface. Under-water with coal fineness less than 1 mm in a uniform flow enters the moving filter bed. When passing through the formed coal layer, the bulk of the solid particles are retained in the layer, as a result, the process water is clarified. The precipitate obtained by filtration with a moisture content of 25-30% is fed into the wind tunnel, where the precipitate is subjected to the dynamic action of the air stream. After that, the dehydrated sludge from coal of class 0-13 mm is mixed with coal of class +13 mm and sent to the surface. Technological water enters the sump and partially closes in the mine, or is pumped to the surface by coal pumps.

 The disadvantages of this method are the low throughput of the formed coal layer and the quality of clarification of process water, due to the compaction of the filtration layer and its low height.

There is also a method of underground coal processing [2]
According to this method, coal pulp from the faces goes to a scraper conveyor, in which the bottom is made in the form of a sieve with a slot size of 13 mm. Coal is separated on the conveyor and fed into the hopper. Under-coal and water by gravity flow to a plate feeder, in which shaltite sieves with a slit size of 0.5 mm are built into the plates. Oversize coal of the feeder is the middle class of coal and its supply for dehydration to the centrifuge and then to the mine shaft transport system, and the under-coal of the plate feeder and centrifuge centrifuge, which is the third small product, are sent to the sump of industrial water, where the flocculant solution is supplied.

 Dehydrated coals are fed from the hopper using a rocking feeder to a plate feeder with a slot width of 0.5 mm. A filter layer is formed on the feeder, the height of which is controlled by changing the speed of the chain of the plate feeder and the frequency of the swing of the tray of the swinging feeder, and the width of the layer is regulated by the moving sides. Fine coal slurry thickened in a hydrocyclone is fed to the formed layer, taken from a sump of industrial water. The discharge from the hydrocyclone enters the sump of clarified water, from where it is again fed into the face. To ensure uniformity of the supply of fine coal sludge from the hydrocyclone to the moving layer, its release is carried out using a slotted nozzle. The width of the condensed stream is regulated by turning the slotted nozzle. The filtrate from the feeder enters the sump of clarified water. Overflow of clarified water from the sump of process water also enters the sump of clarified water.

 On a joint layer of fine and large coal, air is supplied by a fan to a diffusion casing with slots along the entire length. The pressure drop across the bed accelerates the filtration process and air strips moisture from solid particles.

 The disadvantages of this method are: the use of flocculants; the relatively high humidity of coal obtained after filtration and processing by air flow and the complexity of the process of regulation of the formed filtration layer.

 The objective of the invention is to improve the quality of clarification of process water and coal dehydration in underground conditions.

This object is achieved by the fact that in the method of underground clarification of recycled water and coal dehydration, including pressureless hydraulic transport, screen, horizontal type polarizer, horizontal clarifier, thickening pulp collector and filtering centrifuge is carried out:
separation of the sieve pulp of the screen into a pulp containing solid fractions of coal and sludge water;
non-reagent treatment of slurry water in a horizontal type polarizer, with a change in the polarity of the fine coal particles contained in the slurry water;
the formation of large fractions of coal filtration layer in a horizontal clarifier;
clarification of sludge water by filtration with simultaneous electrocoagulation of oppositely charged particles of solid, which is part of the sludge water and the formed filtration layer;
removal of spent filtration layer in the form of a thickened pulp; additional thickening of the pulp in the thickening pulp collector;
feeding condensed pulp to a filtering centrifuge for coal dehydration.

 The technological scheme of the method of underground clarification of circulating water and dewatering of coal sludge is shown in the drawing.

 The technological scheme includes a screen 1, a hydrocyclone or a pulp divider 2, a clarifier 3, made in a horizontal mining, inside of which there is a vertical loading pipe 4 for inputting the incoming pulp, a water distribution manifold 5, laid in the lower part of the clarifier and serving for supply and uniform distribution throughout the filter area of clarified water; a horizontal suction device 6 located above the water distribution manifold and designed to exchange the filtration layer; a drainage collector 7 for collecting and draining clarified water. In the clarifier, a filter layer is formed from coal from the incoming pulp. In addition, the technological scheme includes: a horizontal polarizer of type 8; two water collectors 9 and 10; thickening pulp collector 11 with a loading pipe 12 and a horizontal 9 and 10; thickening pulp collector 11 with a loading pipe 12 and a horizontal suction device 13; filtering centrifuge 14, conveyor 15 and loading hopper 16.

 The method is as follows.

 the ulpa coming from the face falls on screen 1, where coal with a grain size of more than 6 mm is dehydrated and sent with a moisture content of up to 8%, and under-water with coal with a grain size of less than 6 mm is separated in a hydrocyclone 2, or pulp divider, into a pulp with large fractions of coal and sludge water. One of the streams containing large fractions of coal enters the vertical loading pipe 4 of the horizontal clarifier 3.

 The stream of slurry water with small particles of coal from the hydrocyclone, or pulp divider, is directed to a horizontal type 8 polarizer, where the coal particles contained in the slurry water passing through the metal loading of the polarizer, as a result of interaction with it, change their charge to the opposite. Sludge water formed in the polarizer 8 is supplied through the water distribution collector 5 of the horizontal clarifier 4 under the filter layer and, passing through it in the upward direction created by the difference in levels of the polarizer and clarifier, is clarified. Clarification of sludge water is carried out by filtration through a coal layer with simultaneous electrocoagulation of oppositely charged solid particles that are part of the slurry water and formed in the clarifier of the filter layer. The clarified water with a solid content of less than 1 g / l is discharged to the contact water collector 9. Water is drawn from the contact water collector using horizontal suction devices and fed to the combine faces. The overflow of the contact catchment enters the second catchment 10, from where high-pressure pumps, with a solids content of less than 0.5 g / l, are fed into the hydraulic face.

 Coal accumulated in a horizontal clarifier, using a horizontal suction device 6, is taken from the top of the filtration layer and is sent in the form of condensed pulp to the vertical loading pipe 12 of the thickening pulp collector 11. The vertical loading pipe 12 allows a buried input of the incoming pulp under the liquid level, and split it on a solid precipitate and clarified water. The clarified water, with a content of up to 1.5 g / l, is discharged into the contact water collector 9. From the thickening pulp collector, the pulp with a concentration of 50-60% is taken by a horizontal suction device, the pulp with a concentration of 50-60% is taken by a horizontal suction device 13 and fed to the filtering centrifuge 14. Coal dehydrated in a centrifuge with a moisture content of 10-12% is sent via conveyor 15 to the feed hopper 16, where it is mixed with coarse coal beaten off at screen 1. The centrifuge filter centrifuge is fed to polarizer 8 and then clarified body together with sludge water.

 Using the proposed method of underground clarification of recycled water and coal dehydration can improve the quality of process water clarified in a mine without using chemical reagents, get dehydrated coal in underground conditions, and greatly simplify the technological scheme and apparatus design.

Claims (6)

 1. A method of underground clarification of recycled water and coal dehydration, including hydrotransport of coal, screening, thickening and separating the under-sieve pulp into pulp with a large fraction and coal sludge water, forming a filtration layer, filtering water and dehydrating the thickened pulp, characterized in that the filtering the layer is formed in a horizontal clarifier from sublattice pulp containing large fractions, and water with coal sludge is sent to polarization and then to the horizon water distribution collector cial clarifier.  2. The method according to p. 1, characterized in that the filtering of the circulating water is carried out with opposite charges of large fractions of coal and coal sludge that have passed polarization.  3. The method according to claims 1 and 2, characterized in that the thickened pulp is taken from the top of the filter bed of the horizontal clarifier and served under the liquid level of the thickening pulp collector.  4. The method according to PP.1 to 3, characterized in that the thickened pulp of the thickening pulp collector is taken from the bottom of the horizontal suction device and with a concentration of 50 to 60% is fed to a filtering centrifuge.  5. The method according to PP.1 to 4, characterized in that the centrate of the filter centrifuge is directed to polarization.  6. The method according to claims 1 to 5, characterized in that the filtered water and the overflow of the thickening pulp collector are sent to the contact water collector, from the bottom of which the water is supplied to the combine faces, and the overflow is sent to the second water collector, from where it is fed to the hydraulic monitor face.