Three-product micro-fine particle rotational flow-reverse flow grading equipment

Abstract

The invention belongs to the technical field of mineral processing, and aims to solve the problems of universality of an underflow clamping phenomenon, low separation precision and high separation energy consumption of an existing classification cyclone. The invention provides three-product micro-fine particle rotational flow-reverse flow grading equipment which comprises an ore pulp distributor, an overflow collecting box, a reverse flow grading box and a plurality of grading hydrocyclones. The ore pulp distributor is used for uniformly distributing ore pulp to each grading cyclone; fine materials enter an overflow collecting box through an overflow pipe of the grading cyclone; a countercurrent grading area, a coarse-grain material collecting area and a middle-grain material collecting area are arranged in the countercurrent grading box, and the countercurrent grading area is used for separating coarse-grain materials and middle-grain materials through an arc-shaped rising structure and rising water flow. Secondary classification of the bottom flow of the cyclone can be achieved, the content of the thin bottom flow is effectively controlled, the design of the water seal of the bottom flow pipe is adopted, no air column exists in the cyclone process, the classification effect and stability are guaranteed, and meanwhile energy consumption can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to a three-product micro-fine particle cyclone-countercurrent classification equipment. BACKGROUND

[0002] In the field of coal washing and processing, coarse slime separation is a key link connecting heavy medium separation and flotation process. Usually, coal slime water is pumped to a classification cyclone by a slurry pump for classification, the overflow (-0.25 mm fine slime) is sent to the flotation process, and the underflow (1-0.25 mm coarse slime) is sent to the coarse slime separation process. The classification cyclone is a key equipment for coarse / fine slime classification, and its separation efficiency directly affects the subsequent process effect. Under ideal conditions, the content of -0.25 mm particles in the underflow should be less than 15%, but in actual operation, the following problems exist: Underflow fine particle inclusion is common: with the deterioration of raw coal quality, the proportion of -0.25 mm particles in the slime increases from the traditional 15%-20% to 30%-40%. The intensified turbulence in the cyclone causes the intermediate size particles and the residual fine particles (especially 0.1-0.25 mm particles) to enter the underflow due to insufficient centrifugal force, and the inclusion rate can reach 20%-40%.

[0003] Separation precision and processing capacity conflict: to reduce the underflow fine particle inclusion, a small diameter cyclone (Φ150 mm or less) or a reduced feed pressure (<0.15 MPa) is required, but this leads to a 50%-70% reduction in single processing capacity, the increase in equipment number causes the increase in capital cost, and at the same time, it poses new challenges to the space optimization of the equipment layout of the coal preparation plant.

[0004] Air column causes energy consumption to increase and classification particle size to be unstable: the central region of the traditional classification cyclone has an air column, research has proved that this air column is unnecessary for work, but due to its unstable size and position, it causes excessive energy consumption and the classification particle size is also greatly affected by the air column.

[0005] Classification particle size is easily affected by the feed conditions: flow field fluctuation caused by unstable feed pressure and particle mismatch caused by unstable concentration have a significant impact on the classification effect. The existing classification cyclone lacks effective adjustment means when dealing with conditions such as unstable pressure, unstable concentration, or deteriorating coal quality. SUMMARY

[0006] The present application provides a three-product micro-fine particle cyclone-countercurrent classification equipment to solve at least one of the above technical problems in the prior art.

[0007] The application adopts the technical scheme as follows: a three-product micro-fine particle cyclone-counterflow grading equipment, comprising a pulp distributor, an overflow collection tank, a counterflow grading tank and a plurality of grading cyclones; the pulp distributor is provided with a pulp feeding port at the upper end, and a plurality of grading cyclones are arranged at intervals along the outer periphery of the pulp distributor; the feeding port of the grading cyclone is connected to the outer wall of the pulp distributor and communicates with the inner cavity of the pulp distributor, and the pulp distributor is used for uniformly distributing the pulp to each grading cyclone; the overflow collection tank is arranged at the lower end of the pulp distributor, and the upper end of the grading cyclone is provided with an overflow pipe, the discharge end of the overflow pipe being located inside the overflow collection tank, and the overflow collection tank is used for collecting fine particle materials in the pulp, which enter the inside of the overflow collection tank through the overflow pipe of the grading cyclone; the counterflow grading tank is arranged at the lower end of the overflow collection tank and is supported on the ground by a rack, and the discharge port at the bottom of the grading cyclone is located inside the counterflow grading tank and is water-sealed; the inside of the counterflow grading tank is provided with a counterflow grading zone, a coarse particle material collection zone and an intermediate particle size material collection zone, wherein the counterflow grading zone is used for separating the coarse particle materials and the intermediate particle size materials in the pulp through an arc-shaped upward structure and an upward water flow, the coarse particle material collection zone is used for collecting the separated coarse particle materials, and the intermediate particle size material collection zone is used for collecting the separated intermediate particle size materials; the overflow collection tank, the coarse particle material collection zone and the intermediate particle size material collection zone are all provided with ports for unloading materials.

[0008] Preferably, the grading cyclone comprises a cyclone column segment, a cyclone cone segment and an underflow pipe arranged in sequence from top to bottom, the feeding port of the grading cyclone communicates with the cyclone column segment, the end of the cyclone cone segment and the underflow pipe are located inside the counterflow grading tank, and the bottom of the overflow pipe located in the grading cyclone is located in the middle of the cyclone column segment.

[0009] Preferably, the counterflow grading zone comprises a primary grading zone and a secondary grading zone, the arc-shaped upward structure is a distribution arc at the bottom of the primary grading zone, the distribution arc is located below the grading cyclone, and the distribution arc is used for preliminarily grading the coarse particle materials and the intermediate particle size materials in the pulp under the action of inertia; the secondary grading zone comprises an upward water flow entering zone and an upward water flow grading zone, the upward water flow entering zone and the upward water flow grading zone are separated by an inclined plate provided with flow holes, the inclined plate with flow holes is used for adjusting the speed of the upward water flow, the bottom of the upward water flow entering zone is provided with a water inlet pipe, and each grading cyclone corresponds to one water inlet pipe; the upward water flow grading zone is used for secondarily grading the coarse particle materials and the intermediate particle size materials in the preliminarily graded pulp, and the secondarily graded coarse particle materials and intermediate particle size materials enter the coarse particle material collection zone and the intermediate particle size material collection zone respectively.

[0010] Preferably, the upper middle part of the upward water flow classification zone is located above one side of the discharge side of the distribution arc, an overflow weir is arranged between the upper part of the upward water flow classification zone and the intermediate particle size material collection zone, a gap for the overflow of the intermediate particle size material is left between the top end of the overflow weir and the top end of the countercurrent classification tank, the lower part of the upward water flow classification zone is located below one side of the discharge side of the distribution arc, the coarse particle material collection zone is located on one side of the bottom of the inclined surface of the inclined plate and is arranged at the same angle as the inclined plate, a bottom flow discharge port is arranged at the bottom of the coarse particle material collection zone, and all classification cyclones share one bottom flow discharge port.

[0011] Preferably, the intermediate particle size material collection zone comprises an overflow tank and an intermediate particle size material discharge port, wherein the overflow tank is located on one side of the overflow weir away from the upward water flow classification zone and is in communication with the upward water flow classification zone, and the intermediate particle size material discharge port is arranged at the bottom end of the overflow tank.

[0012] Preferably, the distance between the top end of the arc-shaped top of the overflow weir and the top end of the countercurrent classification tank is a, the distance between the bottom end of the arc-shaped top of the overflow weir and the top end of the countercurrent classification tank is m, and the value of a is in the range of 0.8m-0.9m, so as to avoid coarse overflow; the horizontal distance between the center of the arc bottom of the distribution arc and the overflow weir is L, and the value of L is in the range of 1 / 2-2 / 3 of the width f of the countercurrent classification zone, so as to ensure that the intermediate particle size material is fully separated and then enters the overflow tank.

[0013] Preferably, the height e of the countercurrent classification zone is in the range of 300mm-500mm, and the central angle j of the distribution arc is in the range of 60 degrees-150 degrees; the height i of the distribution arc is in the range of 1 / 3-1 / 2 of the height e of the countercurrent classification zone. The width f of the countercurrent classification zone is 1.0-1.2 times the width G of the distribution arc, the width G of the distribution arc is 1.2-1.5 times the diameter d2 of the bottom flow pipe, the diameter d2 of the bottom flow pipe is determined according to the diameter D of the cyclone column segment, and is 0.2-0.35 times the diameter D of the cyclone column segment. The insertion depth of the overflow pipe is h1, the insertion depth h1 of the overflow pipe refers to the length of the insertion of the overflow pipe into the interior of the classification cyclone, and the insertion depth h1 of the overflow pipe is 0.3-0.7 times the diameter D of the cyclone column segment.

[0014] Preferably, the diameter of the flow distribution hole on the inclined plate is in the range of 5mm-10mm, and the distance between adjacent flow distribution holes is 2-3 times the diameter of the flow distribution hole; the flow distribution hole adopts annular array distribution, so as to ensure that the upward water flow uniformly covers the countercurrent classification zone.

[0015] Compared with the prior art, the present application has the following beneficial effects: The device can reduce the underflow fine rate. On the basis of a conventional hydrocyclone, the underflow directly enters the annular gap of the reverse flow classification box, and the underflow material of the classification cyclone is subjected to secondary classification by the action of the rising water flow. The intermediate particle size material enters the overflow tank with the rising water flow, and the coarse particle material falls into the coarse particle material collection area.

[0016] The device can reduce the overflow coarse running phenomenon. Since the underflow of the classification cyclone is directly inserted into the reverse flow classification tank, a "water seal type cyclone" is formed, which weakens the influence of the air column on the separation effect and reduces the overflow coarse running phenomenon.

[0017] The device can improve the stability of the particle size range of the coarse coal slime separation system. On the basis of the existing classification cyclone, a reverse flow classification box is added. When the underflow of the classification cyclone is severely fine due to fluctuations in the working conditions such as feed pressure, concentration, and coal quality, the rising water flow rate can be adjusted to strengthen the classification of the underflow of the classification cyclone, effectively ensuring the stability of the particle size range of the feed material supplied to the coarse coal slime separation system.

[0018] Compared with the two-stage cyclone in series or the cyclone + screening process, the existing classification cyclone underflow tank is directly transformed into a reverse flow classification tank without improving the original ore slurry pumping system, which has limited impact on the plant area and low additional power consumption (due to the rising water flow pump).

[0019] In the beneficiation process, the ore particles are usually ground to a certain particle size to release valuable minerals from the ore particles. After grinding, the mineral particles are returned to the classification cyclone for classification. The intermediate particle size material (classification cyclone overflow) enters the subsequent flotation process, and the coarse particle material (classification cyclone underflow) is returned to the ball mill for grinding. However, due to the structure of the classification cyclone, the underflow often contains 10%-30% of intermediate particle size material. Due to the incomplete classification efficiency, this part of intermediate particle size material that has reached the required particle size enters the ball mill with the underflow, resulting in reduced grinding efficiency, increased overgrinding rate, reduced processing capacity, and increased energy consumption for the same processing capacity. The patent performs secondary reverse flow classification on the underflow of the cyclone, and by adjusting the rising water flow rate, this part of intermediate particle size material can be removed from the coarse particle material, greatly reducing the content of intermediate particle size material entering the subsequent grinding process, which is beneficial to improving the grinding efficiency and reducing the grinding energy consumption.

[0020] In addition, the overflow coarse phenomenon exists in the coal separation link of the classification cyclone, which leads to poor subsequent flotation effect and increased flotation cost. Moreover, the fine inclusion of the underflow of the classification cyclone also has a great influence on the subsequent coarse slime separation, which leads to poor coarse slime separation efficiency. The three-product classification equipment proposed in the patent has a good solving effect on the overflow coarse and underflow fine inclusion of the slime. The overflow without coarse material can be ensured by changing the insertion depth of the overflow pipe, which will increase the probability of underflow fine inclusion. The intermediate size material mismatched in the underflow can be discharged by adjusting the upward water flow velocity due to the configuration of the secondary reverse flow classification link. The existence of the secondary reverse flow classification operation can weaken the overflow coarse phenomenon and the underflow fine inclusion phenomenon. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Fig. 1 It is the overall structure of the present application external schematic diagram; Fig. 2 It is the local structure sectional view of the reverse flow classification tank of the present application; Fig. 3 It is the structure sectional view of the classification cyclone of the present application; Fig. 4 It is the local enlarged schematic view of the overflow hole of the present application.

[0023] In the figure: 1-ore pulp distributor; 2-overflow collection tank; 3-reverse flow classification tank; 3.1-distribution arc; 3.2-inclined plate; 3.3-inlet pipe; 3.4-overflow weir; 3.5-underflow discharge port; 3.6-overflow groove; 3.7-intermediate size material discharge port; 3.8-flow distribution hole; 4-classification cyclone; 4.1-cyclone column section; 4.2-cyclone cone section; 4.3-underflow pipe; 4.4-overflow pipe; 5-rack. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application are described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] It is to be understood that the structures, proportions, sizes, etc. shown in the drawings of the present disclosure are merely used to illustrate the content disclosed in the present disclosure for the understanding and reading of those skilled in the art, and are not used to limit the defined conditions under which the present application can be implemented, and therefore do not have technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should fall within the scope of the technical content disclosed by the present application. It should be noted that in the present specification, relational terms such as first and second are only used to distinguish one entity from another entity, and do not necessarily require or imply that there is any actual relationship or order between the entities.

[0026] The present application provides an embodiment: As Figs. 1 to 4 shown, a three-product fine particle cyclone-counterflow classification equipment includes a pulp distributor 1, an overflow collection tank 2, a counterflow classification tank 3 and a plurality of classification cyclones 4; the upper end of the pulp distributor 1 has a pulp feed inlet 1.1, and a plurality of classification cyclones 4 are arranged along the outer periphery of the pulp distributor 1, the feed inlet of the classification cyclone 4 is connected to the outer wall of the pulp distributor 1 and communicates with the inner cavity of the pulp distributor 1, and the pulp distributor 1 is used to uniformly distribute the pulp to each classification cyclone 4; the overflow collection tank 2 is arranged at the lower end of the pulp distributor 1, the upper end of the classification cyclone 4 is provided with an overflow pipe 4.4, the discharge end of the overflow pipe 4.4 is located inside the overflow collection tank 2, the overflow collection tank 2 is used to collect fine particle materials in the pulp, and the fine particle materials enter the inside of the overflow collection tank 2 through the overflow pipe 4.4 of the classification cyclone 2; the counterflow classification tank 3 is arranged at the lower end of the overflow collection tank 2 and is supported on the ground by a rack 5, the discharge port at the bottom of the classification cyclone 4 is located inside the counterflow classification tank 3 and is water-sealed, and the counterflow classification tank 3 is provided with a counterflow classification zone, a coarse particle material collection zone and an intermediate particle size material collection zone, wherein the counterflow classification zone is used to separate the coarse particle materials and the intermediate particle size materials in the pulp through an arc-shaped upward structure and an upward water flow, the coarse particle material collection zone is used to collect the separated coarse particle materials, and the intermediate particle size material collection zone is used to collect the separated intermediate particle size materials; the overflow collection tank 2, the coarse particle material collection zone and the intermediate particle size material collection zone are all provided with ports for unloading materials.

[0027] In the present embodiment, the classification cyclone 4 includes a cyclone column segment 4.1, a cyclone cone segment 4.2 and an underflow pipe 4.3 arranged in sequence from top to bottom, the feed inlet of the classification cyclone 4 communicates with the cyclone column segment 4.1, the end of the cyclone cone segment 4.2 and the underflow pipe 4.3 are located inside the counterflow classification tank 3, and the bottom of the overflow pipe 4.4 in the classification cyclone 4 is located in the middle of the cyclone column segment 4.1.

[0028] The countercurrent classification zone comprises a primary classification zone and a secondary classification zone, the arc-shaped upthrow structure is a distribution arc 3.1 at the bottom of the primary classification zone, the distribution arc 3.1 is located below the classification cyclone 4, and the distribution arc 3.1 is used for preliminarily classifying coarse-grained material and medium-grained material in the ore pulp under the action of inertia; the secondary classification zone comprises an upward water flow entering zone and an upward water flow classification zone, the upward water flow entering zone and the upward water flow classification zone are separated by an inclined plate 3.2 provided with flow distribution holes 3.8, the inclined plate 3.2 is used for adjusting the speed of the upward water flow, the bottom of the upward water flow entering zone is provided with a water inlet pipe 3.3, and each classification cyclone 4 corresponds to one water inlet pipe 3.3; the upward water flow classification zone is used for secondarily classifying the coarse-grained material and the medium-grained material in the ore pulp after preliminary classification, and the coarse-grained material and the medium-grained material after secondary classification enter the coarse-grained material collecting zone and the medium-grained material collecting zone respectively.

[0029] The middle upper part of the upward water flow classification zone is located above one side of the discharge side of the distribution arc 3.1, an overflow weir 3.4 is arranged between the upper part of the upward water flow classification zone and the medium-grained material collecting zone, a gap for overflow of the medium-grained material is left between the overflow weir 3.4 and the top end of the countercurrent classification tank 3, the lower part of the upward water flow classification zone is located below one side of the discharge side of the distribution arc 3.1, the coarse-grained material collecting zone is located on one side of the bottom of the inclined surface of the inclined plate 3.2 and is arranged to be inclined at the same angle as the inclined plate 3.2, the bottom of the coarse-grained material collecting zone is provided with an underflow discharge port 3.5, and all the classification cyclones 4 share one underflow discharge port 3.5.

[0030] The medium-grained material collecting zone comprises an overflow tank 3.6 and a medium-grained material discharge port 3.7, the overflow tank 3.6 is located on the side, away from the upward water flow classification zone, of the overflow weir 3.4 and communicates with the upward water flow classification zone, and the medium-grained material discharge port 3.7 is arranged at the bottom end of the overflow tank 3.6.

[0031] The following is a specific setting of the structural parameters of the present application: The distance between the top end of the arc-shaped top of the overflow weir 3.4 and the top end of the countercurrent classification tank 3 is a, the distance between the bottom end of the arc-shaped top of the overflow weir 3.4 and the top end of the countercurrent classification tank 3 is m, the value range of a is 0.8m-0.9m, so as to avoid coarse overflow, and the horizontal distance between the arc bottom center of the distribution arc 3.1 and the overflow weir 3.4 is L, and the value range of L is 1 / 2-2 / 3 of the width f of the countercurrent classification zone, so as to ensure that the medium-grained material is fully separated and then enters the overflow tank 3.6.

[0032] The height e of the countercurrent classification zone ranges from 300 mm to 500 mm, and a height that is too low can result in insufficient particle residence time and poor classification effect, and a height that is too high can increase the size of the equipment and energy consumption; the central angle j of the distribution arc 3.1 ranges from 60 degrees to 150 degrees, and a smaller arc results in a steeper angle of the upward movement of the ore slurry and a more obvious effect of inertial separation of coarse particles; a larger arc, such as 120 degrees, results in a more gentle trajectory of the ore slurry, prolonging the residence time of the particles and being suitable for fine particle classification; the height i of the distribution arc 3.1 is 1 / 3 to 1 / 2 of the height e of the countercurrent classification zone, avoiding insufficient lift or excessive turbulence; The width f of the countercurrent classification zone is 1.0 to 1.2 times the width G of the distribution arc 3.1, ensuring smooth transition of the ore slurry flow field; the width G of the distribution arc 3.1 is 1.2 to 1.5 times the diameter d2 of the underflow pipe 4.3, to ensure uniform distribution of the ore slurry; the diameter d2 of the underflow pipe 4.3 is determined according to the diameter D of the cyclone column 4.1, being 0.2 to 0.35 times the diameter D of the cyclone column 4.1.

[0033] The diameter of the flow distribution hole 3.8 on the inclined plate 3.2 ranges from 5 mm to 10 mm, and the distance between adjacent flow distribution holes 3.8 is 2 to 3 times the diameter of the flow distribution hole 3.8; the flow distribution holes 3.8 are arranged in a ring array to ensure that the upward water flow uniformly covers the countercurrent classification zone; the upward water flow velocity is between the settling velocities of the coarse and intermediate particle materials.

[0034] The invention adjusts the ore slurry feeding method on the basis of the traditional classification cyclone, adds a countercurrent classification box 3, and realizes three-product classification. The underflow of the classification cyclone 4 is mainly coarse and intermediate particle materials in the countercurrent classification box 3, which are distributed by the distribution arc 3.1 and lifted upward at a certain speed in the countercurrent classification box. At this time, the coarse and intermediate particle materials are lifted to different heights under the action of inertia, realizing preliminary classification.

[0035] At the same time, the intermediate particle materials are further pushed into the overflow tank 3.6 by the upward water flow, and the coarse particle materials pass through the countercurrent classification zone under the action of gravity and enter the underflow discharge port 3.5.

[0036] In operation, the selected particles -1.5mm are fed into the slurry distributor 1 under a certain pressure, and the slurry distributor 1 evenly distributes the slurry to the feed inlet of each classification cyclone 4 through the distribution function of the slurry distributor 1; the fine particles -0.25mm are discharged from the overflow pipe 4.4 of the classification cyclone 4 and enter the overflow collection tank 2 as fine particle products; the classification cyclone 4 classifies the slurry, and the underflow of the classification cyclone 4 is lifted by the distribution arc 3.1, and then the intermediate size particles in the underflow of the classification cyclone 4 are further moved upward into the overflow tank 3.6 under the action of the top water; the relatively coarse particles in the underflow sink through the countercurrent classification zone under the action of gravity to the vicinity of the underflow discharge hole 3.5; the underflow discharge hole 3.5 is provided with a periodically opening and closing valve, which can realize periodic discharge, so as to promote the coarse particles in the vicinity of the underflow discharge hole 3.5 to be discharged out of the equipment as coarse particle products.

[0037] The present application proposes a three-product micro-fine particle cyclone-countercurrent classification equipment, which realizes three-product classification of coarse slime; one of the cores is to control the diameter d2 of the underflow pipe 4.3 and the insertion depth h1 of the overflow pipe 4.4; the diameter d2 of the underflow pipe 4.3 is determined and adjusted according to the size of the classification cyclone 4; the insertion depth h1 of the overflow pipe 4.4 refers to the length of the overflow pipe 4.4 inserted into the classification cyclone 4, which refers to the distance from the bottom of the overflow pipe 4.4 to the top cover of the classification cyclone 4; reducing the insertion depth h1 of the overflow pipe 4.4 makes the classification size finer; increasing the insertion depth h1 of the overflow pipe 4.4 makes the classification size coarser; the insertion depth h1 of the overflow pipe 4.4 is generally 0.3-0.7 times the diameter D of the cyclone column section 4.1; adjusting the insertion depth h1 of the overflow pipe 4.4 within this range can promote the classification cyclone 4 to realize classification under the action of cyclone in a water seal environment; the second core is to design a special distribution arc 3.1, which promotes the underflow of the classification cyclone 4 to be lifted upward under the guidance of the distribution arc 3.1, forming a primary countercurrent classification; the third core is to design a special countercurrent classification tank 3, the upward water flow can move upward uniformly at a certain speed under the action of the flow distribution hole, forming a countercurrent classification zone, and forming a secondary strengthened countercurrent classification.

[0038] Compared with the traditional classification cyclone group, the present application can realize secondary classification of the underflow of the classification cyclone 4, effectively control the content of the underflow, and effectively guarantee the quality of the underflow coarse particle products; the present application can adjust the characteristics of the upward water flow according to the physical properties of the underflow of the classification cyclone 4, and has strong adaptability to coal fluctuations.

[0039] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical scope disclosed by the present application, which can be easily thought by those skilled in the art, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A three-product micro-particle cyclone-countercurrent classification equipment, characterized in that: It includes a slurry distributor (1), an overflow collection box (2), a countercurrent classifier (3), and multiple classifiers (4). The upper end of the slurry distributor (1) has a slurry inlet (1.1), and a plurality of the classifying hydrocyclones (4) are arranged at intervals along the outer periphery of the slurry distributor (1). The inlet of the classifying hydrocyclone (4) is connected to the outer wall of the slurry distributor (1) and communicates with the inner cavity of the slurry distributor (1). The slurry distributor (1) is used to evenly distribute the slurry to each of the classifying hydrocyclones (4). The overflow collection box (2) is located at the lower end of the slurry distributor (1), and the upper end of the classifying hydrocyclone (4) is provided with an overflow pipe (4.4). The discharge end of the overflow pipe (4.4) is located inside the overflow collection box (2). The overflow collection box (2) is used to collect fine particles in the slurry. The fine particles enter the interior of the overflow collection box (2) through the overflow pipe (4.4) of the classifying hydrocyclone (2). The countercurrent classifier (3) is located at the lower end of the overflow collection box (2) and supported on the ground by the frame (5). The discharge port at the bottom of the classifier hydrocyclone (4) is located inside the countercurrent classifier (3) and is water-sealed. The countercurrent classifier (3) is provided with a countercurrent classification zone, a coarse material collection zone and an intermediate particle size material collection zone. The countercurrent classification zone is used to separate the coarse and intermediate particle size materials in the slurry through an arc-shaped upward structure and rising water flow. The coarse material collection zone is used to collect the separated coarse material, and the intermediate particle size material collection zone is used to collect the separated intermediate particle size material. The overflow collection box (2), the coarse material collection zone and the intermediate particle size material collection zone are all provided with ports for unloading materials.

2. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 1, characterized in that: The classifying hydrocyclone (4) includes a hydrocyclone column section (4.1), a hydrocyclone cone section (4.2), and an underflow pipe (4.3) arranged sequentially from top to bottom. The feed inlet of the classifying hydrocyclone (4) is connected to the hydrocyclone column section (4.1). The end of the hydrocyclone cone section (4.2) and the underflow pipe (4.3) are located inside the countercurrent classifying box (3). The bottom of the overflow pipe (4.4) in the classifying hydrocyclone (4) is located in the middle of the hydrocyclone column section (4.1).

3. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 1, characterized in that: The countercurrent classification zone includes a preliminary classification zone and a secondary classification zone. The arc-shaped upward structure is the distribution arc (3.1) at the bottom of the preliminary classification zone. The distribution arc (3.1) is located below the classification cyclone (4). The distribution arc (3.1) is used to perform preliminary classification of coarse and intermediate particle size materials in the slurry under the action of inertia. The secondary classification zone includes an upward water flow inlet zone and an upward water flow classification zone. The upward water flow inlet zone and the upward water flow classification zone are connected by inclined distribution holes (3). The inclined plate (3.2) of 8) is separated, and the inclined plate (3.2) with flow distribution hole (3.8) is used to adjust the speed of the rising water flow. The bottom of the rising water flow entry zone is provided with a water inlet pipe (3.3). Each classifying hydrocyclone (4) corresponds to a water inlet pipe (3.3). The rising water flow classification zone is used to perform secondary classification on the coarse and intermediate particle size materials in the slurry after the initial classification. The coarse and intermediate particle size materials after the secondary classification enter the coarse material collection zone and the intermediate particle size collection zone, respectively.

4. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 3, characterized in that: The upper part of the rising water flow classification zone is located above the discharge side of the distribution arc (3.1). An overflow weir (3.4) is provided between the upper part of the rising water flow classification zone and the intermediate particle size material collection zone. A gap is left between the overflow weir (3.4) and the top of the countercurrent classification box (3) for the intermediate particle size material to overflow through. The lower part of the rising water flow classification zone is located below the discharge side of the distribution arc (3.1). The coarse particle material collection zone is located on the bottom side of the inclined plate (3.2) and is inclined at the same angle as the inclined plate (3.2). The bottom of the coarse particle material collection zone is provided with a bottom flow discharge port (3.5). All the classifying hydrocyclones (4) share a bottom flow discharge port (3.5).

5. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 4, characterized in that: The intermediate particle size material collection area includes an overflow trough (3.6) and an intermediate particle size material discharge port (3.7), wherein the overflow trough (3.6) is located on the side of the overflow weir (3.4) facing away from the rising water flow classification area and is connected to the rising water flow classification area, and the intermediate particle size material discharge port (3.7) is located at the bottom end of the overflow trough (3.6).

6. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 5, characterized in that: The distance between the top of the arc-shaped top of the overflow weir (3.4) and the top of the countercurrent classifier (3) is set as a, and the distance between the bottom of the arc-shaped top of the overflow weir (3.4) and the top of the countercurrent classifier (3) is set as m, and the value of a is in the range of 0.8m~0.9m, so as to avoid overflow from running too far. The horizontal distance from the center of the bottom of the distribution arc (3.1) to the overflow weir (3.4) is set to L, and the value of L is 1 / 2 to 2 / 3 of the width f of the countercurrent classification zone, so as to ensure that the intermediate particle size material enters the overflow trough (3.6) after being fully separated.

7. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 6, characterized in that: The height e of the countercurrent grading zone ranges from 300 mm to 500 mm, and the central angle j of the distribution arc (3.1) ranges from 60 degrees to 150 degrees; the height i of the distribution arc (3.1) is 1 / 3 to 1 / 2 of the height e of the countercurrent grading zone. The width f of the countercurrent classification zone is 1.0 to 1.2 times the width G of the distribution arc (3.1), the width G of the distribution arc (3.1) is 1.2 to 1.5 times the diameter d2 of the underflow pipe (4.3), and the diameter d2 of the underflow pipe (4.3) is determined according to the diameter D of the hydrocyclone column section (4.1), which is 0.2 to 0.35 times the diameter D of the hydrocyclone column section (4.1). The insertion depth of the overflow pipe (4.4) is set to h1. The insertion depth h1 of the overflow pipe (4.4) refers to the length of the overflow pipe (4.4) inserted into the grading hydrocyclone (4). The insertion depth h1 of the overflow pipe (4.4) is 0.3 to 0.7 times the diameter D of the hydrocyclone column section (4.1).

8. The three-product micro-particle cyclone-countercurrent classification equipment according to claim 7, characterized in that: The diameter of the flow distribution holes (3.8) on the inclined plate (3.2) ranges from 5 mm to 10 mm, and the spacing between adjacent flow distribution holes (3.8) is 2 to 3 times the diameter of the flow distribution holes (3.8); the flow distribution holes (3.8) are arranged in a ring array to ensure that the rising water flow evenly covers the countercurrent grading zone.

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