CN114713363B - Separation and recovery system and process for non-slime-formation fine-particle coal - Google Patents

Abstract

The invention relates to a system and a process for sorting and recovering non-slime-formation fine-particle coal, belongs to the technical field of coal sorting and processing, and solves the problems of poor coal slime sorting effect and high energy consumption in the prior art. The invention comprises a first flotation machine, a sedimentation type filtering centrifuge, a second flotation machine and a first ultrahigh pressure filter, wherein the first flotation machine is a four-tank flotation machine, flotation clean coal formed by ash reduction and dehydration of flotation clean coal in the last two tanks of the first flotation machine is subjected to ash reduction and dehydration by the sedimentation type filtering centrifuge, flotation clean coal obtained by ash reduction and dehydration of flotation clean coal in the last two tanks of the first flotation machine is subjected to centrifugal liquid obtained by the second flotation machine, and flotation clean coal in the first two tanks of the first flotation machine enters the first ultrahigh pressure filter together. The sorting and recycling system and the process have good sorting effect and low energy consumption.

Description

Separation and recovery system and process for non-slime-formation fine-particle coal

Technical Field

The invention relates to the technical field of coal sorting processing, in particular to a sorting and recycling system and process for non-coal-slime-formation fine-particle coal.

Background

Coal is one of important industrial raw materials in China, and is an important guarantee for energy safety in China. Although the current coal separation technology has made great progress, as the coal to be collected is increasingly lean, fine and miscellaneous, and more fine materials need to be separated and classified, the coal slime flotation refining is realized, the green development and clean and efficient utilization of the coal are realized, and the coal separation plant obtains the best economic benefit, social benefit and environmental benefit.

Flotation is one of the most economical and effective methods for treating fine coal slime, while flotation is a comprehensive process with multiple factors, and the main factors influencing the process effect include the nature of the coal slime, the working performance of flotation equipment, the flotation process flow and the like. The traditional coal slime treatment process is low in separation efficiency, high in cost, high in energy consumption and high in product moisture, further influences the form of a sold product to reduce economic benefits, and therefore, higher requirements are provided for separation and recovery of coal slime.

The traditional coal slime flotation process comprises the following steps: the floating coal slime is fed from the bottom of the stirring barrel for pretreatment, the modified fine coal automatically flows into a flotation machine for flotation, and the product is dehydrated through a pressure filter or a quick-open filter press and then is sold. The process only carries out one-time separation, and partial coarse particles adhered to the foam are separated from the foam due to the interference of external factors such as water flow, vibration and the like and enter tailings, so that the coarse phenomenon is serious, and the loss of clean coal is high.

The flotation coal slime is subjected to two-stage separation in a coal preparation plant aiming at the problem, namely, the flotation coal slime enters a first-stage flotation machine through a stirring barrel, flotation clean coal passes through a sedimentation type filtering centrifuge, and centrifuge centrifugate enters a second-stage flotation machine for separation after being subjected to size mixing through a second-stage stirring barrel. The process ensures the recovery rate of products by adding two-stage flotation of scavenging, and ensures the water content of the products to be qualified by utilizing a sedimentation type filtering centrifuge to replace a pressure filter or a quick-opening pressure filter. Although the floating coal slurry is stirred and modified by the stirring barrel, the pre-mineralization effect is still poor, which directly causes medicament waste and the separation effect of the flotation machine is not ideal. The first-stage clean coal is subjected to secondary flotation completely, and the secondary flotation treatment capacity is large, so that more flotation equipment is needed, and the production cost is increased. In addition, the ash content difference of the flotation clean coal in the front two tanks and the flotation clean coal in the rear two tanks of the first-stage flotation machine is large. The first-stage clean coal is completely dehydrated by a sedimentation filter centrifuge, so that the separation precision of the first-stage flotation machine is reduced indirectly, and the products in the first two tanks are seriously back-ash; the obtained clean coal moisture (higher than 20%) and tail coal moisture (nearly 30%) are both high, so that the blending and selling forms of products are influenced; on the other hand, all the ore pulp enters the sedimentation equipment to ensure that the solid-liquid concentration of the ore pulp is high, the sedimentation equipment needs to be added, and the unit energy consumption of the equipment is high, so that the production cost is increased.

In the face of the current situation of resources with increasing coal slime yield and the coal slime separation process with low separation efficiency and low product quality, a new coal slime separation process with strong processing capacity, high separation efficiency, high separation precision, low cost, low energy consumption and low product moisture and without falling to the ground is urgently needed to be developed.

Disclosure of Invention

In view of the above analysis, the embodiments of the present invention provide a system and a process for sorting and recovering non-coal-slime-derived fine coal, so as to solve the problems of poor sorting effect and high energy consumption of the existing coal slime.

In one aspect, the invention provides a system for sorting and recovering non-slime fine coal, which comprises a first flotation machine, a sedimentation type filtering centrifuge, a second flotation machine and a first ultrahigh pressure filter, wherein the first flotation machine is a four-tank flotation machine, flotation clean coal formed by ash reduction and dehydration of flotation clean coal in the last two tanks of the first flotation machine is subjected to ash reduction and dehydration by the sedimentation type filtering centrifuge, flotation clean coal obtained by ash reduction and dehydration of flotation clean coal in the last two tanks of the first flotation machine is subjected to centrifugal liquid obtained by ash reduction and dehydration of flotation clean coal in the second flotation machine and flotation clean coal in the first two tanks of the first flotation machine enter the first ultrahigh pressure filter together.

The device further comprises a first forced stirring quality-improving machine which is arranged at the upstream of the first flotation machine.

And further, the floating coal slurry is fed from the bottom of the first forced stirring upgrading machine, and the upgraded fine-grained coal automatically flows into the first flotation machine for sorting.

The system further comprises a second forced stirring and modifying machine, wherein the second forced stirring and modifying machine is arranged at the downstream of the sedimentation type filtering centrifuge and is positioned at the upstream of the second flotation machine.

And further, centrifugal liquid formed after ash falling and dehydration of the sedimentation type filtering centrifuge is fed from the bottom of the second forced stirring upgrading machine, and the fine-grained coal after upgrading automatically flows into the second flotation machine for separation.

And further, a tail coal thickener is further included, and tail coal generated by the first flotation machine and the second flotation machine enters the tail coal thickener together for thickening.

Furthermore, a second ultrahigh pressure filter is arranged at the downstream of the tail coal thickener.

Further, the downstream of the first ultrahigh-pressure filter is provided with a first coal slime crusher, and the downstream of the second ultrahigh-pressure filter is provided with a second coal slime crusher.

Further, the first ultrahigh-pressure filter, the second ultrahigh-pressure filter and the tailing coal concentrator are communicated with the first forced stirring and upgrading machine.

On the other hand, the invention provides a separation and recovery process of non-slime fine-grained coal, which adopts the separation and recovery system of the non-slime fine-grained coal and comprises the following steps:

feeding float coal slime into a first forced stirring modification machine, adding a collecting agent and a foaming agent, performing size mixing modification, overflowing from the discharge end at the upper part of the first forced stirring modification machine, and entering a first flotation machine for separation;

defoaming the flotation foam clean coal in the two grooves behind the first flotation machine, and then feeding the foam clean coal into a sedimentation type filtering centrifuge to obtain low-moisture clean coal; the filtrate of the sedimentation type filtering centrifuge passes through a second forced stirring modification machine and then is sorted in a second flotation machine;

after defoaming, the foam clean coal floated by the second flotation machine, the foam clean coal, the clean coal in the front two tanks of the first flotation machine and the low-moisture clean coal obtained by the treatment of the rear two tanks of the first flotation machine are pumped into a first ultrahigh pressure filter together for strong dehydration, and then the clean coal is crushed by a first coal slime crusher to obtain a clean coal product;

and the tailing coal of the second flotation machine and the tailing coal of the first flotation machine enter a tailing coal thickener together for concentration, then enter a second ultrahigh pressure filter for dehydration, and then are crushed by a second coal slime crusher to obtain a tailing coal product.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

(1) The floating coal slime and the flotation reagent are conveyed to the bottom feeding end of the forced stirring modifying machine by the pump, the ore pulp flows into the modifying machine from bottom to top under the pressure of the pump, and the retention time of the ore pulp is increased under the double actions of impeller stirring and baffle rebounding, so that the reagent is dispersed uniformly and is fully mixed with the ore pulp. Thereby forming a better ore pulp environment and being beneficial to the improvement of the separation efficiency of the flotation machine.

(2) According to the invention, the low-ash clean coal in the front two tanks and the high-ash clean coal in the rear two tanks of the first-stage flotation machine are separately treated, so that the flotation precision can be greatly improved, and the product quality is ensured; only the clean coal of the last two grooves enters a sedimentation type filtering centrifuge, and the high-ash clean coal is subjected to ash reduction and dehydration independently by virtue of the sedimentation effect of the centrifuge; the clean coal quality is guaranteed, the production input cost is reduced, and the high-efficiency separation of the coal slime is realized.

(3) The invention adopts the flow of one-stage full flotation and two-stage partial flotation, and ensures the number quality of products on the premise of low energy consumption; all products are mixed and directly sold in a low-moisture state, so that the coal slime is sorted without falling to the ground, namely, the coal slime treatment is avoided.

(4) According to the invention, the clean coal of the front two tanks of the first-stage flotation machine and the clean coal of the second-stage flotation machine are dehydrated by means of the strong pressure of the ultrahigh pressure filter, so that the water content of the product is greatly reduced, and the economic benefit of the whole plant is improved; the solid-liquid ratio in the filtrate is small, and the filtrate can be used as circulating water to realize closed circulation of coal slime water in a coal preparation plant.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings, in which like reference numerals refer to like parts throughout, are for the purpose of illustrating particular embodiments only and are not to be considered limiting of the invention.

FIG. 1 is a schematic diagram of a sorting recovery system according to an embodiment;

FIG. 2 is a schematic structural view of a first forced stirring and upgrading machine according to an embodiment;

FIG. 3 is a block diagram of a sorting recovery process according to an embodiment.

Reference numerals:

1-a first flotation machine; 2-a decanter centrifuge; 3-a second flotation machine; 4-a first ultra-high pressure filter; 5-a first material pump; 6-second material pump; 7-a first forced stirring modification machine;

71-a stirring barrel body; 72-a barrel cover; 73-a motor; 74-stirring shaft; 75-a material inlet; 76-overflow port; 77-straight blade impeller; 78-pitched blade impeller; 79-stirring baffle; 710-stirring baffles; 711-slurry shear disk; 712-upper circulation port; 713-lower circulation port; 714-clear water replenishing port; 715-a medicament cartridge; 716-a circulation pump; 717-circulation pipe; 718-jet medicine suction throat;

8-a second forced stirring modification machine; 9-a third material pump; 10-a fourth material pump; 11-a first coal slime crusher; 12-a tail coal thickener; 13-a second ultra-high pressure filter; 14-a fifth material pump; 15-a second coal slime crusher; 16-a sixth material pump;

a-floating coal slime is filled; b-clean coal products; c-tailing products.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention and not to limit its scope.

In the description of the embodiments of the present invention, it should be noted that the term "connected" is to be understood broadly, and may be, for example, fixed, detachable, or integrally connected, and may be mechanically or electrically connected, and may be directly or indirectly connected through an intermediate medium, unless otherwise specifically stated or limited. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The terms "top," "bottom," "at 8230; \8230above," "below," and "at 8230; \8230above," and "above" are used throughout to describe relative positions of components with respect to the device, such as the relative positions of the top and bottom substrates inside the device. It will be appreciated that the devices are multifunctional, regardless of their orientation in space.

Example 1

One embodiment of the present invention, as shown in fig. 1, discloses a system for separating and recovering fine coal without slime (hereinafter referred to as "separating and recovering system"), which includes a first flotation machine 1, a decanter centrifuge 2, a second flotation machine 3 and a first ultra-high pressure filter 4, wherein the first flotation machine 1 is a four-tank flotation machine, flotation cleaned coal formed by subjecting flotation cleaned coal in the last two tanks of the first flotation machine 1 to ash reduction and dehydration by the decanter centrifuge 2, and flotation cleaned coal obtained by subjecting a centrifugal liquid formed by subjecting flotation cleaned coal in the last two tanks of the first flotation machine 1 to ash reduction and dehydration by the decanter centrifuge 2 to ash reduction and dehydration by the second flotation machine 3 enter the first ultra-high pressure filter 4 together with flotation cleaned coal in the first two tanks of the first flotation machine 1.

When the method is implemented, a four-trough flotation machine is adopted for one-section flotation of the coal slime, flotation clean coal obtained by the first two troughs of the four-trough flotation machine directly enters the ultrahigh pressure filter without two-section flotation, flotation clean coal obtained by the second two troughs directly enters the ultrahigh pressure filter after ash reduction and dehydration of the flotation clean coal through a sedimentation type filtering centrifuge, flotation clean coal obtained by the second two troughs directly enters the ultrahigh pressure filter through centrifugal liquid obtained after ash reduction and dehydration of the sedimentation type filtering centrifuge, two-section flotation is carried out on the flotation clean coal obtained by the first two troughs and the flotation clean coal obtained by the second two troughs.

Compared with the prior art, the separation and recovery system provided by the embodiment has the advantages that the first two tanks of low-ash clean coal subjected to first-stage flotation and the second two tanks of high-ash clean coal subjected to second-stage flotation are separately treated, so that the flotation precision can be greatly improved, and the product quality is ensured; only the high-ash clean coal in the last two tanks enters a sedimentation type filtering centrifuge, and the high-ash clean coal is subjected to ash reduction and dehydration by virtue of the sedimentation effect of the centrifuge, so that the clean coal quality is ensured, the production input cost is reduced, and the high-efficiency separation of the coal slime is realized.

A first material pump 5 is arranged between the front two grooves of the first flotation machine 1 and the first ultrahigh pressure filter 4, the inlet of the first material pump 5 is communicated with the front two grooves of the first flotation machine 1, and specifically, the front two grooves of the first flotation machine 1 are communicated with the inlet of the first material pump 5 through a material pipe. The outlet of the first material pump 5 is communicated with the first ultrahigh pressure filter 4 through a material pipe. The flotation clean coal produced by the front two tanks of the first flotation machine 1 enters the first ultrahigh pressure filter 4 through the material pipe under the action of the first material pump 5.

A second material pump 6 is arranged between the two rear tanks of the first flotation machine 1 and the sedimentation type filtering centrifuge 2, the inlet of the second material pump 6 is communicated with the two rear tanks of the first flotation machine 1, and specifically, the two rear tanks of the first flotation machine are communicated with the inlet of the second material pump 6 through material pipes. The outlet of the second material pump 6 is communicated with the sedimentation type filtering centrifuge 2 through a material pipe. The flotation clean coal produced in the rear two tanks of the first flotation machine 1 enters the sedimentation type filtering centrifuge 2 through the material pipe under the action of the second material pump 6.

The separation and recovery system further comprises a first forced stirring and modifying machine 7 and a second forced stirring and modifying machine 8, wherein the first forced stirring and modifying machine 7 is arranged at the upstream of the first flotation machine 1, and the second forced stirring and modifying machine 8 is arranged at the downstream of the sedimentation type filtering centrifuge 2 and is positioned at the upstream of the second flotation machine 3.

As shown in fig. 2, the first forced stirring modification machine 7 is a space-time non-uniform circulation jet flow coupled slurry mixing device (hereinafter referred to as slurry mixing device), and includes a stirring barrel 71 and a circulation jet flow assembly, the stirring barrel 71 is an inverted frustum structure, the circulation jet flow assembly is disposed outside the stirring barrel 71 and is used for jet flow dosing, and the circulation jet flow assembly is communicated with the stirring barrel 71 to form a jet flow circulation path.

According to the pulp mixing device provided by the embodiment, the stirring barrel body is of the inverted frustum structure, and a flow field in the stirring barrel is in a spatially non-uniform state along with the flow of ore pulp, so that the turbulence degree of the ore pulp can be improved, the collision of granular reagents in the ore pulp is increased, and the subsequent flotation recovery of granules is facilitated; adopt circulation efflux to inhale the medicine, the medicament is by negative pressure suction ore pulp, and the effective dispersion emulsification of pressure drop when the stirring barrel body of falling frustum shape is got into along with rivers, is favorable to the homodisperse of medicament, improves medicament and the abundant integration of ore pulp.

In order to avoid the slurry in the stirring barrel body 71 from overflowing from the upper end of the stirring barrel body 71 and carrying the power unit, a barrel cover 72 is arranged at the upper end of the stirring barrel body 71. The upper end of the barrel cover 72 is provided with a power unit for providing power for ore pulp stirring. The power unit includes a motor 73 and a power transmission mechanism, and the motor 73 transmits power to a stirring shaft 74 provided in the stirring barrel body 71 through the power transmission mechanism. One end of the stirring shaft 74 penetrates through the barrel cover 72 to be connected with the power transmission mechanism, and the other end is positioned in the stirring barrel body 71 and is in a cantilever shape. Specifically, a through hole is formed in the middle of the barrel cover 72, a bearing is arranged in the through hole, and the stirring shaft 74 penetrates through the bearing and is connected with the power transmission mechanism.

The power transmission mechanism can be a gear transmission mechanism, a chain wheel transmission mechanism or a belt transmission mechanism, and preferably, the power transmission mechanism is a belt transmission mechanism. In this embodiment, motor 73 passes through belt drive mechanism and gives (mixing) shaft 74 with power transmission, compares with the meshing transmission, and belt drive mechanism simple structure, low in manufacturing cost, installation maintenance is convenient, because the belt is rich in elasticity, can alleviate impact and vibration for the device of sizing mixing operates steadily at the size mixing in-process, and the during operation noise is lower.

The motor 73 is a variable frequency motor, the motor 73 rotates at a non-uniform speed, and the speed changes from 600r/s to 800r/s in a reciprocating mode to form a time-nonuniform flow field. And because the stirring barrel body 71 is a reverse-taper table type barrel body, the ore pulp flows unevenly in the stirring barrel body 71 in space, a time uneven flow field formed by the non-uniform rotation of the motor 73 is combined with a space uneven flow field formed by the reverse-taper table type stirring barrel body 71 to form a space-time uneven flow field, and the space-time uneven flow field is coupled to circulate jet flow to suck the medicine, so that the stirring and dispersing of the medicine are enhanced, the energy transmission and distribution gradient is increased, and the electricity is saved.

Considering that the ore pulp in the stirring barrel body 71 needs to be diluted sometimes, the phenomenon that the slurry is sticky and affects the slurry mixing effect is avoided, and the rotation of the stirring shaft 74 is not facilitated, the clear water replenishing port 714 is formed in the barrel cover 72, the clear water replenishing pipe is communicated with the clear water replenishing port 714, a valve is arranged on the clear water replenishing pipe, and when the clear water needs to be replenished into the stirring barrel body 71, the valve is opened.

Understandably, in order to feed the slurry raw material into the stirring barrel 71 and output the stirred slurry out of the stirring barrel 71, the stirring barrel 71 is provided with a feeding port 75 and an overflow port 76, specifically, the feeding port 75 is located at the lower part of the stirring barrel 71, and the overflow port 76 is located at the upper part of the stirring barrel 71.

In this embodiment, because the ore pulp in the stirring barrel body 71 is from the upward movement of below, when the ore pulp of below is enough many, the ore pulp just upwards flows, and the ore pulp needs ascending thrust promptly, and for the better upward movement of ore pulp, pan feeding mouth 75 is located the centre of the lower extreme of stirring barrel body 71, and the centre that pan feeding mouth 75 is located the little bottom surface of back taper platform promptly.

In this embodiment, the overflow port 76 is located at the upper end of the cylindrical surface of the stirring barrel 71 and is disposed adjacent to the barrel cover 72. A multi-section pulp mixing chamber is arranged from the feeding port 75 to the overflow port 76 in the stirring barrel body 71, and a stirring impeller is arranged in the pulp mixing chamber and is used for stirring ore pulp. Preferably, three sections of mixing chambers are arranged in the mixing barrel body 71.

The diameter of the stirring impeller is gradually reduced from top to bottom, the diameter ratio of the uppermost stirring impeller to the lowermost stirring impeller is between 4.

The stirring partition plate 710 is arranged in the stirring barrel body 71, and the stirring partition plate 710 is annular and horizontally arranged on the inner wall of the stirring barrel body 71. In this embodiment, the number of the stirring baffles 710 is 3, and the stirring barrel 71 is of an inverted cone table structure, so the outer diameters of the 3 stirring baffles 710 are not equal.

In order to achieve the purpose of better size mixing, an ore pulp shearing disc 711 is further arranged in the stirring barrel body 71, the ore pulp shearing disc 711 is horizontally arranged in the stirring barrel body 71 and is installed on the stirring shaft 74, and the ore pulp is sheared under the driving of the stirring shaft 74.

The ore pulp shearing disc 711 is of a circular disc-shaped structure and is fixedly arranged on the stirring shaft 74, and in order to improve the shearing effect on the ore pulp, a plurality of long holes are symmetrically formed in the ore pulp shearing disc 711, are formed in the radial direction of the ore pulp shearing disc 711 and are arranged in the circumferential direction. One side edge of the long hole is turned downwards, and the lower turning edge is lower than the lower surface of the pulp shearing disc 711.

In this embodiment, the slurry shearing disk 711 is provided with the long hole, so that the slurry can pass through the long hole, and the shearing force can be increased by using the edge of the long hole turned downward.

The number of the ore pulp shearing discs 711 is one less than that of the stirring partition plates 710, the ore pulp shearing discs 711 are arranged opposite to the stirring partition plates 710 from the lower end of the stirring barrel body 71, and a gap is reserved between the ore pulp shearing discs 711 and the stirring partition plates 710 for coarse particles in the ore pulp to pass through, so that the phenomenon that the stirring impeller is blocked by the coarse particles in the ore pulp is avoided.

In this embodiment, there are 2 ore pulp shearing disks 711, which are respectively disposed opposite to the two stirring partitions 710 disposed at the inner lower portion of the stirring barrel 71. It should be noted that, on the stirring shaft 74, the stirring impellers and the slurry shearing disk 711 are alternately arranged, the stirring impeller is arranged at the end of the stirring shaft 74, and the slurry shearing disk 711 and the stirring impeller are sequentially and alternately arranged upward. The stirring barrel body 71 is divided into a plurality of mixing chambers by the stirring partition plates 710 and the pulp shearing discs 711, namely, adjacent mixing chambers are separated by the stirring partition plates 710 and the pulp shearing discs 711.

In order to effectively reduce the diameter of the liquid drops of the chemical and promote the dispersion of the chemical, the stirring impeller in the slurry mixing chamber located at the lowermost end in the stirring barrel body 71 is a straight-blade impeller 77, and the other slurry mixing chambers are inclined-blade impellers 78. Adjusting device adopts the design of little space high shear to make the medicament at the very first time that gets into stirring barrel body 71, and the medicament liquid drop is as little as possible, and the medicament disperses as far as possible, then through the lower turbulent flow that follows, the even effective mixed medicament of stirring in great space and ore pulp improve medicament effect.

In this embodiment, the three sections of the slurry mixing chambers in the stirring barrel body 71 are a first slurry mixing chamber, a second slurry mixing chamber and a third slurry mixing chamber from bottom to top, a straight blade impeller 77 is arranged in the first slurry mixing chamber to form sufficient preliminary turbulence, inclined blade impellers 78 are arranged in the second slurry mixing chamber and the third slurry mixing chamber to cooperate with the slurry shearing disk 711 to form circulation in the slurry mixing chamber, and the high-energy straight blade impeller 77 can effectively reduce the diameter of the liquid drops of the reagent to promote the dispersion of the reagent, and the reagent is fully mixed with the slurry.

Stirring baffle 79 is also arranged in stirring barrel 71, the stirring baffle 79 and the same gradient of the inner wall of stirring barrel 71 are provided with 4 stirring baffles 79, the stirring baffles are uniformly distributed along the circumferential direction of the inner wall of stirring barrel 71, and the stirring baffles 79 are positioned between the stirring partition plates 710. In this embodiment, the stirring baffle 79 is disposed in the second slurry mixing chamber and the third slurry mixing chamber, and the stirring baffle 79 cooperates with the inclined blade type impeller 78 to enhance the stirring effect on the slurry.

In order to circulate the ore slurry in the stirring barrel 71, an upper circulation port 712 and a lower circulation port 713 are further formed in the stirring barrel 71. The upper circulation port 712 is arranged on the side wall of the uppermost size mixing chamber and is not lower than the mounting height of the stirring impeller in the size mixing chamber, and the lower circulation port 713 is arranged on the side wall of the lowermost size mixing chamber and is positioned below the stirring impeller in the size mixing chamber. In this embodiment, the upper circulation port 712 is not lower than the height of the stirring impeller in the homodyne slurry chamber, which means that the center of the upper circulation port 712 is not lower than the horizontal symmetry plane of the stirring impeller.

In this embodiment, the upper circulation port 712 is disposed on the sidewall of the third slurry mixing chamber and is not lower than the pitched blade impeller 78 in the third slurry mixing chamber, and the lower circulation port 713 is disposed on the sidewall of the first slurry mixing chamber and is located below the straight blade impeller 77 in the first slurry mixing chamber.

It should be noted that the inner cavity of the stirring barrel 71 is divided into two parts, the upper region is a non-stirring region, and the lower region is a stirring region, i.e. a multi-stage mixing chamber, that is, in this embodiment, the upper portion of the third mixing chamber is a non-stirring region.

The upper circulation port 712 is arranged in the multi-section pulp mixing chamber and is positioned at the upper end of the multi-section pulp mixing chamber, so that the problem that when the machine is stopped due to the fact that the upper circulation port 712 is arranged in a non-stirring area, pulp can flow backwards to the circulation port to block a medicament passage to cause serious faults is solved, and the problem that partial short circuit and incomplete circulation of the pulp are caused by the fact that the upper circulation port 712 is arranged below the uppermost stirring impeller (the inclined blade type impeller 78 in the third pulp mixing chamber in the embodiment) is also solved.

The central axis of the lower circulation port 713 and the side wall of the stirring barrel body 71 form an included angle of 30-45 degrees, and the included angle is directly opposite to the feeding port 75 to form opposite-impact flow to increase the turbulence degree of ore pulp.

The circulating jet assembly comprises a circulating pump 716, a circulating pipe 717 and a jet medicine suction throat 718, and an upper circulating port 712, the circulating pipe 717, the circulating pump 716, the jet medicine suction throat 718 and a lower circulating port 713 are sequentially connected to form a jet circulation passage. The jet flow medicine suction throat pipe 718 is also provided with a medicine barrel 715, the jet flow medicine suction throat pipe 718 is a venturi tube, the inlet end of the venturi tube is communicated with the upper circulation port 712 through a circulation pump 716 and a circulation pipe 717, and the diffusion end lower circulation port 713 of the venturi tube is communicated.

In this embodiment, adopt circulation efflux to inhale the medicine, the ore pulp is inhaled by the negative pressure to the medicament, along with rivers effectively disperse the emulsification by the pressure drop when entering stirring barrel body 71, straight leaf formula impeller 77 forces the stirring to improve medicament dispersion degree, improves granule medicament contact probability, reduces the medicament quantity.

In order to improve the stirring effect of the ore slurry, 2 circulation jet assemblies are symmetrically distributed on two sides of the stirring barrel body 71, and understandably, two groups of upper circulation ports 712 and two groups of lower circulation ports 713 are symmetrically arranged.

In this embodiment, the pulp enters from the feeding port 75, and is strongly stirred and dispersed by the straight blade impeller 77 of the first pulp mixing chamber, and then is transported by the inclined blade impeller 78 to enter the next pulp mixing chamber through the gap between the pulp shearing disc 711 and the stirring partition plate 710, when reaching the third pulp mixing chamber, a part of the pulp flows out from the upper overflow port 76 to become a stirring product, a part of the pulp is sucked into the circulating jet section from the upper circulating port 712, and the chemical is sucked in from the chemical tank 715 by the jet medicine suction throat 718 at a negative pressure, and is ejected into the stirring tank 71 from the lower circulating port 713 to form convection enhanced chemical dispersion with the feeding port 75.

The mixing of thick liquid device of this embodiment utilizes back taper stirring staving 71 fully to improve the rotational speed dispersion medicament, when promoting the even contact of mineral particle and medicament, protects (mixing) shaft 74 as far as possible, reduces (mixing) shaft 74 moment of torsion and reduces the fault incidence. The design of the inverted cone-shaped barrel body and the impellers with the large upper part and the small lower part can ensure that the medicament is fully dispersed in a smaller cavity space under the dual actions of the straight blade type impeller and the circulating jet flow, so that the medicament is effectively emulsified, and then the whole ore pulp is driven to flow under the action of the larger inclined blade type impeller, so that the medicament ore pulp is uniformly contacted, and the torque substep is met, the stirring shaft 74 is protected, and the fault occurrence rate is reduced.

In the embodiment, the floating coal slurry is fed from the bottom of the first forced stirring modifying machine 7, the floating coal slurry and the flotation reagent are fully mixed and modified and discharged through overflow under the forced layering and high-speed stirring of the three-layer impeller, and the modified fine coal automatically flows into the first flotation machine 1 to complete separation.

The second forced stirring and modifying machine 8 has the same structure as the first forced stirring and modifying machine 7, and has the same beneficial effects, which are not described in detail herein. The centrifugal liquid formed after ash reduction and dehydration of the sedimentation type filtering centrifuge 2 is fed from the bottom of the second forced stirring modification machine 8, the centrifugal liquid and the flotation reagent are fully mixed and modified and discharged from overflow under the forced layering and high-speed stirring of the three-layer impeller, and the modified fine-grained coal automatically flows into the second flotation machine 3 to complete separation.

A third material pump 9 is arranged between the sedimentation type filtering centrifuge 2 and the second forced stirring modification machine 8, the inlet of the third material pump 9 is communicated with the sedimentation type filtering centrifuge 2 through a material pipe, and the outlet of the third material pump 9 is communicated with a feeding port at the bottom of the second forced stirring modification machine 8. The centrifugate formed by the sedimentation type filtering centrifuge 2 enters a second forced stirring modification machine 8 through a material pipe under the action of a third material pump 9.

The flotation clean coal formed after ash reduction and dehydration of the sedimentation type filtering centrifuge 2 is converged into the first ultrahigh pressure filter 4 through the flotation clean coal in the material pipe connected with the outlet of the first material pump 5 through the material pipe. The centrifugate formed by the sedimentation type filtering centrifuge 2 enters the second flotation machine 3 for separation through a third material pump 9 and a second forced stirring modification machine 8, and the flotation clean coal formed by the second flotation machine 3 is converged with the flotation clean coal and then enters the first ultrahigh pressure filter 4. Specifically, a fourth material pump 10 is arranged between the second flotation machine 3 and the first ultrahigh pressure filter 4, an inlet of the fourth material pump 10 is respectively communicated with the front two grooves and the rear two grooves of the second flotation machine 3 through material pipes, an outlet of the fourth material pump 10 is communicated with the first ultrahigh pressure filter 4 through material pipes, and the front two grooves and the rear two grooves of the second flotation machine 3 both enter the first ultrahigh pressure filter 4 through material pipes under the action of the fourth material pump 10.

The first ultra-high pressure filter 4 carries out dehydration to the flotation cleaned coal that gets into, and the low reaches of first ultra-high pressure filter 4 is equipped with first coal slime breaker 11, and the flotation cleaned coal after the filtration gets into first coal slime breaker 11 and smashes the blending.

The first flotation machine 1 and the second flotation machine 3 are both communicated with the tailing coal thickener 12 through material pipes, and tailing coal generated by the first flotation machine 1 and the second flotation machine 3 enters the tailing coal thickener 12 together for thickening. A second ultrahigh pressure filter 13 is arranged at the downstream of the tailing thickener 12, a fifth material pump 14 is arranged between the tailing thickener 12 and the second ultrahigh pressure filter 13, the inlet of the fifth material pump 14 is communicated with the tailing thickener 12 through a material pipe, the outlet of the second material pump 14 is communicated with the second ultrahigh pressure filter 13 through a material pipe, and the bottom flow of the tailing thickener 12 is pumped into the second ultrahigh pressure filter 13 through the fifth material pump 14 for dehydration.

And a second coal slime crusher 15 is arranged at the downstream of the second ultrahigh-pressure filter 13, and the tailings dehydrated by the second ultrahigh-pressure filter 13 enter the second coal slime crusher 15 to be crushed and then sold.

The first ultrahigh-pressure filter 4, the second ultrahigh-pressure filter 13 and the tailing thickener 12 are communicated with the first forced stirring and modifying machine 7 through material pipes, and filtrate of the first ultrahigh-pressure filter 4 and the second ultrahigh-pressure filter 13 and overflow of the tailing thickener 12 are used as circulating water.

A sixth material pump 16 is further arranged upstream of the first forced stirring and upgrading machine 7 and used for supplying the floating coal slurry and the circulating water into the first forced stirring and upgrading machine 7.

Example 2

Another embodiment of the present invention is, as shown in fig. 3, a non-slime fine-grained coal sorting and recycling process, which uses the non-slime fine-grained coal sorting and recycling system of embodiment 1, and includes the steps of:

the float coal slurry is fed into the first forced stirring upgrading machine 7 from the bottom by a sixth material pump 16, and the concentration of the ore pulp is set to be 500g/L. According to the characteristics of the float coal mud, a certain amount (500 g/t) of collecting agent (kerosene, diesel oil and the like) and a certain amount (200 g/t) of foaming agent (sec-octanol, MIBC and the like) are added. The ore pulp is fully mixed and modified, overflows from the discharge end at the upper part of the first forced stirring and modifying machine 7 and continuously, uniformly and stably enters the first flotation machine 1 for separation.

The flotation foam clean coal in the front two tanks of the first flotation machine 1 is defoamed and then is pumped into a first ultrahigh pressure filter 4 through a first material pump 5. At 100kg/cm ² Filtering for about 30 minutes under the ultrahigh pressure to finally obtain a clean coal product with the water content below 18 percent; the filtrate of the first ultrahigh pressure filter 4 has less solid content and can be used as circulating water.

The flotation froth clean coal in the two grooves behind the first flotation machine 1 is defoamed and then is pumped into a sedimentation type filtering centrifuge 2 through a second material pump 6. The sedimentation type filtering centrifuge 2 rotates at a high speed to increase the sedimentation speed of particles to be sedimentated to the inner wall, and then the particles are hung out of a sedimentation area along the inclined plane by a spiral scraper to obtain low-moisture clean coal; the overflow filtrate contains part of high ash fine mud, so that the ash content of clean coal obtained by filtering is reduced by 2-4%. The filtrate of the sedimentation type filtering centrifuge 2 is stably transported to a second forced stirring modifier 8 by a third material pump 9, and the pre-mineralized ore pulp is separated in a second flotation machine 3.

After defoaming, the foam clean coal floated by the second flotation machine 3, the foam clean coal, clean coal in the front two grooves of the first flotation machine 1 and the flotation clean coal with slightly high ash content in the rear two grooves of the first flotation machine 1 are subjected to ash reduction by a sedimentation type filtering centrifuge 2, and the cleaned coal after dehydration is pumped into a first ultrahigh pressure filter 4 together for strong dehydration. And then the clean coal product obtained by crushing the coal slime through the first coal slime crusher 11 is directly sold, so that the coal slime is sorted without falling to the ground, namely, the coal slime is not treated.

The tailing coal of the second flotation machine 3 and the tailing coal of the first flotation machine 1 enter a tailing coal thickener 12 to be concentrated; through the sedimentation and concentration of the tailing thickener 12, ore pulp containing a large amount of solid underflow is pumped into a second ultrahigh pressure filter 13 by a fifth material pump 14 for dehydration, and then crushed by a second coal slime crusher 15 to obtain tailing products for direct sale; the overflow of the tail coal thickener 12 and the solid content in the filtrate of the first ultrahigh pressure filter 4 and the second ultrahigh pressure filter 13 are almost zero, and the tail coal thickener can be used as circulating water to realize closed circulation of coal slurry water in a coal preparation plant.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims (10)

1. The separation and recovery process of the non-slime-formation fine-particle coal is characterized in that a separation and recovery system of the non-slime-formation fine-particle coal is adopted, and the steps comprise:

feeding float coal slime into a first forced stirring modification machine (7), adding a collecting agent and a foaming agent, performing size mixing modification, overflowing from the discharge end at the upper part of the first forced stirring modification machine (7), and entering a first flotation machine (1) for separation;

defoaming the flotation foam clean coal in the two grooves behind the first flotation machine (1), and then feeding the foam clean coal into a sedimentation type filtering centrifuge (2) to obtain low-moisture clean coal; the filtrate of the sedimentation type filtering centrifuge (2) passes through a second forced stirring modification machine (8) and then is sorted in a second flotation machine (3);

after defoaming, the foam clean coal floated by the second flotation machine (3) is pumped into a first ultrahigh-pressure filter (4) together with the clean coal in the front two tanks of the first flotation machine (1) and the low-moisture clean coal obtained by treatment in the rear two tanks of the first flotation machine (1) for strong dehydration, and then crushed by a first coal slime crusher (11) to obtain a clean coal product;

the tailing coal of the second flotation machine (3) and the tailing coal of the first flotation machine (1) enter a tailing coal thickener (12) together for concentration, then enter a second ultrahigh-pressure filter (13) for dehydration, and then are crushed by a second coal slime crusher (15) to obtain a tailing coal product;

wherein, first compulsory stirring upgrading machine (7) are equipped with ore pulp shearing disc (711) including stirring barrel body (71) in stirring barrel body (71), are first accent thick liquid room, second accent thick liquid room and third accent thick liquid room respectively from bottom to top in stirring barrel body (71), are equipped with straight leaf formula impeller (77) in the first accent thick liquid room for form preliminary turbulent flow, and it is indoor oblique leaf formula impeller (78) to be in second accent thick liquid room and the third accent thick liquid room, is used for cooperating ore pulp shearing disc (711) to form the indoor circulation of transferring thick liquid.

2. The separation and recovery process of the non-slime fine coal according to claim 1, wherein the separation and recovery system of the non-slime fine coal comprises a first flotation machine (1), a sedimentation type filtering centrifuge (2), a second flotation machine (3) and a first ultra-high pressure filter (4), the first flotation machine (1) is a four-tank flotation machine, the flotation clean coal formed after the flotation clean coal of the second tank of the first flotation machine (1) is subjected to ash reduction and dehydration by the sedimentation type filtering centrifuge (2), and the centrifugal liquid formed after the flotation clean coal is subjected to ash reduction and dehydration by the sedimentation type filtering centrifuge (3) enters the first filter (4) together with the ultra-high pressure clean coal of the first two tanks of the first flotation machine (1).

3. The process for separation and recovery of non-slimmed fine coal according to claim 2, further comprising a first forced agitation upgrading machine (7), the first forced agitation upgrading machine (7) being provided upstream of the first flotation machine (1).

4. The separation and recovery process of non-slime fine coal according to claim 3, characterized in that the floating coal slime is fed from the bottom of the first forced stirring upgrading machine (7), and the upgraded fine coal automatically flows into the first flotation machine (1) for separation.

5. The process for separation and recovery of non-slime-slimmed coal according to claim 2, further comprising a second forced agitation upgrading machine (8), said second forced agitation upgrading machine (8) being arranged downstream of said decanter centrifuge (2) and upstream of said second flotation machine (3).

6. The process for separating and recovering non-slime fine coal as claimed in claim 5, wherein the centrifugate formed by ash falling and dehydration of the decanter centrifuge (2) is fed from the bottom of the second forced stirring upgrading machine (8), and the upgraded fine coal automatically flows into the second flotation machine (3) for separation.

7. The process for separating and recovering non-slime fine coal according to claim 3, further comprising a tailing thickener (12), wherein the tailing generated by the first flotation machine (1) and the second flotation machine (3) enters the tailing thickener (12) together for concentration.

8. The process for separating and recovering non-slimmed fine coal according to claim 7, wherein a second ultra-high pressure filter (13) is provided downstream of the tailing thickener (12).

9. The process for separation and recovery of non-slime-slimmed coal according to claim 8, wherein a first slime crusher (11) is arranged downstream of the first ultra-high pressure filter (4) and a second slime crusher (15) is arranged downstream of the second ultra-high pressure filter (13).

10. The separation and recovery process of non-slimmed fine coal according to claim 8, wherein the first ultra-high pressure filter (4), the second ultra-high pressure filter (13) and the tailing thickener (12) are communicated with the first forced stirring upgrader (7).

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