Combined centrifugal stirring mill disc

Abstract

The combined type centrifugal stirring mill disc comprises a disc body, a plurality of wear-resistant sleeves and a plurality of axial arc-shaped strips, the disc body is provided with a shaft mounting hole, a plurality of overflowing holes and a plurality of first assembling holes, the overflowing holes are evenly distributed in the circumferential direction, and the thickness between the outer edges of the overflowing holes and the outer edge of the disc body is reduced; the wear-resistant sleeves are arc-shaped sleeves, are provided with axial second assembly holes, are assembled on the thinned part of the disc body through bolts and the assembly holes, and are assembled to completely wrap the thinned part and the side edge of the disc body; the axial arc-shaped strip is provided with an axial third assembling hole, one end in the axial direction is a plane, the other end in the axial direction is an arc face, the axial arc-shaped strip is assembled on the disc body through a bolt and the assembling hole, and the arc face end of the axial arc-shaped strip is far away from and protrudes out of the disc body. The invention has the advantages of light weight, long service life, easiness in replacement and high ore grinding medium speed; and the superfine mill using the invention has the advantages of high power density, high treatment capacity, high operation rate and easiness in replacement of accessories.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical equipment technology, and relates to mills for mineral processing, and particularly to a combined centrifugal stirred mill disc. Background Technology

[0002] With the gradual depletion of easily beneficiated ores, refractory ores have become the main source of mineral processing. The useful components in refractory ores are mostly encapsulated in associated minerals in the form of micron-sized fine particles. To recover these useful components, the encapsulation must be broken open and exposed. Breaking open the encapsulation requires grinding to achieve individual particle dissociation, which necessitates the use of micron-sized ultrafine grinding mills.

[0003] The centrifugal stirred mill currently used in the market is a horizontal high-speed stirred mill. The mill mainly consists of 8 discs mounted on a shaft, which is driven to rotate by a motor and gearbox. During operation, the outer edge linear velocity of the discs is 5-23 m / s, which drives the grinding media to move at high speed and greatly increases the chance of high-speed collisions between the grinding media and mineral particles, thus enabling true ultrafine grinding.

[0004] The mill disc is a porous disc with 4-6 flow holes evenly distributed in addition to the central spindle mounting hole. These flow holes agitate the grinding media and provide it with initial velocity. See the attached diagram for its structure. Figure 1 and Figure 2 .

[0005] The main problem with this type of disc is that its agitation effect on the grinding media is only radial centrifugal velocity, lacking axial velocity. To maintain the movement speed of the grinding media between the discs, the only solution is to limit the disc spacing. However, with a fixed grinding volume, limiting the disc spacing can only be achieved by increasing the disc thickness and the number of discs. Increasing the disc thickness and the number of discs inevitably leads to a higher total disc weight. Since the centrifugal stirred mill's main shaft is a cantilever structure, the increased total disc weight places higher demands on the main shaft's strength. Simulation using EDME coupled with FLUNT showed that the optimal disc spacing is three times the disc thickness. The simulation results are shown below. Figure 3 .

[0006] Simulation results show that the optimal disk spacing is three times the disk thickness. It was also observed that even when the disk spacing was reduced to twice the disk thickness, there were still dark blue particles between the cylinder and the outer edge of the disks, with a movement speed close to zero.

[0007] Secondly, this disc structure provides no agitation for the grinding media between the outer edge of the disc and the cylinder. The grinding media between the outer edge of the disc's flow hole and the outer edge of the disc are only agitated by friction on the side of the disc, resulting in weak agitation. As a cylindrical cylinder, the volume occupied is larger closer to the outer edge. The space between the inner diameter of the cylinder and the outer edge of the flow hole accounts for about 50% of the net volume. The typical grinding media volume filling rate is 60-70%, which means that most of the grinding media cannot be fully agitated, resulting in weak grinding effect.

[0008] like Figure 4 and Figure 5 As shown, the grinding media is only stirred within the flow holes, achieving a high initial velocity v. The grinding media between the outer edge B of the disc and the outer edge C of the flow holes only generates a lower initial velocity v1 through friction between the disc and the media. The media in the region between the inner diameter A of the cylinder and the outer edge B of the disc can only obtain an initial velocity v3 through collisions between the media moving at a low speed between B and C. Obviously, v3 is very low. Since the grinding effect of a stirred mill relies on the high-speed collision between the grinding media and mineral particles, this disc structure severely affects the grinding efficiency of the mill. Figure 4 and Figure 5 As can be seen from the data, v1 and v3 only have radial velocities and no axial velocities. Only the v generated by the flow orifice on the grinding media has a certain radial velocity, which also explains the results of the simulation calculation.

[0009] In addition, the disc-type plates are made of integral steel plates with rubber or polyurethane lining. The plates at the inlet end are usually the most severely worn, located at the innermost part of the mill. The front-end classifying wheel and the discs must be completely removed before replacement, which involves a large amount of maintenance work and a long maintenance time, seriously affecting the equipment's operating rate. Summary of the Invention

[0010] In order to overcome the shortcomings of the prior art, the present invention aims to provide a combined centrifugal stirred mill disc to solve one or more of the problems of disc wear resistance, insufficient axial speed / movement speed of grinding media, and dense disc installation.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A combined centrifugal stirred mill disc includes a disc body, multiple wear-resistant sleeves, and multiple axial arc-shaped strips; The disk body has a shaft mounting hole, multiple flow holes and multiple first assembly holes. The shaft mounting hole is located in the center, and the multiple flow holes are evenly distributed circumferentially. The portion between the outer edge of the flow holes and the outer edge of the disk body is thinned. The wear-resistant sleeve is an arc-shaped sleeve with an axial second mounting hole. It is assembled to the thinned part of the disk body by bolts and mounting holes. The assembly of each wear-resistant sleeve completely covers the thinned part and side edge of the disk body. The axial arc-shaped strip has a third axial mounting hole. One end of the axial strip is flat, and the other end is arc-shaped. It is mounted to the disk body by bolts and mounting holes. The arc-shaped end is far away from and protrudes from the disk body.

[0012] In one embodiment, the flow passage is an arc-shaped hole, with both the inner and outer arcs concentric with the disk body. The outer edge of the hole has a chamfer to reduce the thickness, and the angle of the chamfer is between 1° and 45°.

[0013] In one embodiment, the disk body is made of ultra-high density polyethylene, and the wear-resistant sleeve and the axial arc strip are made of alumina ceramic, tungsten carbide, silicon carbide ceramic or wear-resistant steel.

[0014] In one embodiment, the wear-resistant sleeve is composed of a first wear-resistant plate, a second wear-resistant plate, and a third wear-resistant plate. The first and second wear-resistant plates are arc-shaped flat plates with the same shape and size and are arranged in parallel. Their thicknesses are equal to the thickness of the single-sided thinning of the disk body. The third wear-resistant plate is an arc-shaped plate with its inner side attached to the side edge of the disk body. Its upper edge is connected to the outer arc edge of the first wear-resistant plate, and its lower edge is connected to the outer arc edge of the second wear-resistant plate. The second assembly holes are symmetrically opened on the first and second wear-resistant plates and are used for assembly with the first assembly holes of the disk body by bolts.

[0015] In one embodiment, the inner arc radius of the first wear-resistant plate and the second wear-resistant plate is equal to the outer edge radius of the flow hole on the disk body; Both ends of the first and second wear-resistant plates have notches on the side near the inner arc edge, which are used to accommodate the installation of the axial arc strip.

[0016] In one embodiment, the axial arc strips are installed between adjacent wear-resistant sleeves, and multiple axial arc strips are distributed along one or more circumferential directions on the surface of the disk body.

[0017] In one embodiment, the axial direction of the axial arc strip is the radial direction of the disk body, or has the same included angle as the radial direction of the disk body. The axial arc strip is composed of a cuboid and an arc strip. The thickness of the cuboid is equal to the thickness of the wear-resistant sleeve. The bottom surface of the arc strip is attached to the side of the cuboid that is flush with the surface of the disk body, and the top surface is the arc surface. The arc strip refers to the arc shape of its cross-section, and the arc apex of the arc has the maximum distance from the disk body.

[0018] In one embodiment, the axial arcuate strip protrudes from the disk body in a size that is 1 to 10 times the diameter of the grinding media.

[0019] The present invention also provides a centrifugal stirred mill for stirring grinding media of refractory ores, which adopts the combined centrifugal stirred mill discs described in the present invention.

[0020] In one embodiment, multiple combined centrifugal stirred mill discs are installed on the stirring shaft, with the spacing between adjacent discs being 5 to 10 times the disc thickness.

[0021] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention adopts a modular structure and is connected by bolts, making it easy to replace.

[0022] 2. The disc body of this invention is made of ultra-high density polyethylene, which has good wear resistance and is lightweight, only 1 / 4 the weight of steel discs, thus greatly reducing the load on the spindle.

[0023] 3. The outer edge of the arc-shaped hole in the disc body of the present invention is chamfered, which increases the axial velocity of the grinding medium through the flow hole and improves the grinding effect.

[0024] 4. The wear-resistant sleeve of this invention is made of silicon carbide or wear-resistant steel, which has good wear resistance and long service life, more than twice that of rubber or polyurethane materials.

[0025] 5. The axial arc strip of this invention increases the axial velocity of the grinding media, and the disk spacing can be increased to 5 times the disk thickness. At the same time, the spindle length can be reduced to reduce the number of disks.

[0026] 6. The combined discs of this invention can significantly increase the movement speed of the grinding media within the grinding chamber, thereby greatly improving the grinding effect. When the required fineness of the ground product is constant, the grinding time can be shortened, and the mill's processing capacity increased. Attached Figure Description

[0027] Figure 1 This is a schematic diagram (front view) of a disc-type platter in the prior art.

[0028] Figure 2 This is a schematic diagram (axial section view) of a disc-type plate in the prior art.

[0029] Figure 3 The results are from existing technology's simulation calculations of disk spacing.

[0030] Figure 4 This is a schematic diagram (front view) of the velocity analysis of existing disc-type grinding media.

[0031] Figure 5 This is a schematic diagram (axial section view) of the velocity analysis of existing disc-type grinding media.

[0032] Figure 6 This is a schematic diagram (front view) of the combined disk structure of the present invention.

[0033] Figure 7 yes Figure 6 View from AA.

[0034] Figure 8 yes Figure 6 Partial sectional view.

[0035] Figure 9 This is a schematic diagram (front view) of the disk body structure of the present invention.

[0036] Figure 10 This is a schematic diagram (axial section view) of the disk body structure of the present invention.

[0037] Figure 11 This is a schematic diagram (front view) of the wear-resistant sleeve structure of the present invention.

[0038] Figure 12 This is a schematic diagram of the wear-resistant sleeve structure of the present invention (cross-sectional view). Figure 1 ).

[0039] Figure 13 This is a schematic diagram of the wear-resistant sleeve structure of the present invention (cross-sectional view). Figure 2 ).

[0040] Figure 14 This is a schematic diagram (front view) of the axial arc-shaped strip structure of the present invention.

[0041] Figure 15 This is a schematic diagram of the axial arc-shaped strip structure of the present invention (cross-sectional view). Figure 1 ).

[0042] Figure 16 This is a schematic diagram of the axial arc-shaped strip structure of the present invention (cross-sectional view). Figure 2 ).

[0043] Figure 17 This is a schematic diagram (front view) of the combined disk assembly of the present invention.

[0044] Figure 18 This is a schematic diagram of the combined disk assembly of the present invention (cross-sectional view). Figure 1 ).

[0045] Figure 19 This is a schematic diagram of the combined disk assembly of the present invention (cross-sectional view). Figure 2 ).

[0046] Figure 20 This is a schematic diagram of the multi-plate assembly structure of the combined disk of the present invention.

[0047] Figure 21 This is a schematic diagram of the velocity analysis of the combined disc grinding media of the present invention.

[0048] Figure 22 This is a simulation comparison diagram of the combined disk of the present invention and the existing circular disk technology. Detailed Implementation

[0049] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings and examples.

[0050] To address the shortcomings of existing technologies, this invention provides a combined disc that is lightweight, has a long lifespan, is easy to replace, and has a high grinding media speed.

[0051] like Figure 6 , Figure 7 and Figure 8 As shown, the combined centrifugal stirred mill disc of the present invention preferably adopts a detachable combined structure, mainly including a disc body 1, multiple wear-resistant sleeves 2 and multiple axial arc strips 3. In practical applications, only these parts are generally needed to assemble the mill disc of the present invention. Apart from bolts and other connecting parts, no additional components are required.

[0052] refer to Figure 9 and Figure 10 The disc body 1 of the present invention has a shaft mounting hole 11, multiple flow holes 12, and multiple first assembly holes 13. The shaft mounting hole 11 is located in the center and is used for assembly with the stirring shaft. The multiple flow holes 12 are evenly distributed along the circumference of the disc body 1, and the number can generally be selected as 4-8. They are distributed between the shaft mounting hole 11 and the outer edge of the disc body 1. The thickness of the portion between the outer edge of the flow hole 12 and the outer edge of the disc body 1 is reduced to facilitate the installation of the wear-resistant sleeve 2.

[0053] refer to Figure 11 , Figure 12 and Figure 13 The wear-resistant sleeve 2 is an arc-shaped sleeve installed on the thinned portion and side edge of the disk body 1. Specifically, the arc-shaped sleeve has a C-shaped cross-section and axial second mounting holes 23 on two opposite sides. It is assembled to the thinned portion of the disk body 1 by bolts, the second mounting holes 23, and part of the first mounting holes 13. Each wear-resistant sleeve 2 is assembled circumferentially, so that after assembly, it can completely cover the thinned portion and side edge of the disk body 1. The side edge refers to the side wall of the disk body 1, which is connected to the disk surface.

[0054] refer to Figure 14 , Figure 15 and Figure 16An axial arc-shaped strip 3 is mounted circumferentially on the surface of the disk body 1. It has a third axial mounting hole 33, with one end being flat and the other arc-shaped. It is mounted to the surface of the disk body 1 via bolts, the third mounting hole 33, and part of the first mounting hole 13, with the arc-shaped end protruding from and away from the disk body 1. In this invention, the axial direction of the "axial arc-shaped strip 3" is the radial direction of the disk body 1, or it may have the same angle as the radial direction of the disk body 1, i.e., arranged in a "spiral" form. The axial directions mentioned elsewhere all refer to the axial direction of the disk body 1, that is, the length direction of the mill's stirring shaft, typically such as the "second axial mounting hole 23," the "third axial mounting hole 33," and "one end of the axial direction," etc.

[0055] In this invention, to improve wear resistance, the disc body 1 is made of ultra-high density polyethylene, which is more than 70% lighter than steel discs. At the same time, due to the extremely high wear resistance of ultra-high density polyethylene, the service life can reach 6 months. The materials of the wear-resistant sleeve 2 and the axial arc strip 3 include, but are not limited to, alumina ceramic, tungsten carbide, silicon carbide ceramic or wear-resistant steel.

[0056] In this invention, the wear-resistant sleeve 2 and the axial arc strip 3 are connected to the disc body 1 by bolts. The outer edge height of the axial arc strip 3 is greater than the thickness of the wear-resistant sleeve 2, and it protrudes on the disc surface of the disc body 1, so that it has an axial stirring effect on the grinding medium and provides an axial speed. This can increase the disc spacing and reduce the number of discs.

[0057] Furthermore, the flow passage of the present invention is an arc-shaped hole, with both the inner and outer arcs being concentric with the disk body 1. The outer edge of the arc-shaped hole has a chamfer to reduce its thickness, which facilitates the installation of the wear-resistant sleeve 2. The chamfer design can increase the axial velocity of the flow passage relative to the grinding media. The recommended chamfer angle is between 1° and 45°.

[0058] Further reference Figure 11 , Figure 12 and Figure 13The wear-resistant sleeve 2 has a C-shaped cross section and is specifically composed of a first wear-resistant plate 21, a second wear-resistant plate 22, and a third wear-resistant plate 25. The first wear-resistant plate 21 and the second wear-resistant plate 22 are arc-shaped flat plates with the same shape and size and are arranged in parallel. They are used to attach to the front and rear surfaces of the disk body 1, respectively. The thickness of the first wear-resistant plate 21 and the second wear-resistant plate 22 is equal to the thickness of the single-sided thinning of the disk body 1, so that they can be flush with the disk surface after installation. The third wear-resistant plate 25 is an arc-shaped plate, with its inner side attached to the side edge of the disk body 1. Its upper and lower edges connect to the outer arc edges of the first wear-resistant plate 21 and the second wear-resistant plate 22, respectively. Two sets of second mounting holes 23 are symmetrically opened on the first wear-resistant plate 21 and the second wear-resistant plate 22, respectively. These holes should obviously correspond to the first mounting holes 13 on the disk body 1, allowing the wear-resistant sleeve 2 to be assembled with the disk body 1 via bolts, the first mounting holes 13, and the second mounting holes 23. During maintenance, the wear-resistant sleeve 2 can be replaced simply by removing the bolts. Clearly, the first wear-resistant plate 21 and the second wear-resistant plate 22 do not have axial plates at both ends; adjacent wear-resistant sleeves 2 are directly overlapped or connected by axial arc-shaped strips 3.

[0059] Furthermore, the inner arc radius of the first wear-resistant plate 21 and the second wear-resistant plate 22 is equal to the outer edge radius of the flow hole 12 on the disk body 1, that is, the wear-resistant sleeve 2 covers the outer edge of the flow hole 12.

[0060] Furthermore, both ends of the first wear-resistant plate 21 and the second wear-resistant plate 22 have notches 24 on the side near the inner arc edge, which are used to accommodate the installation of the axial arc-shaped strip 3. That is, an axial arc-shaped strip 3 is installed between adjacent wear-resistant sleeves 2. The axial arc-shaped strip 3 of the present invention can be distributed along one or more circumferential directions on the surface of the disk body 1, that is, distributed in one or more circles on the surface of the disk body 1. The preferred embodiment of the present invention is one circle distributed between adjacent wear-resistant sleeves 2. Its tail end can be flush with the side edge of the disk body 1.

[0061] Further reference Figure 14 , Figure 15 and Figure 16 The axial arc-shaped strip 3 consists of a cuboid and an arc-shaped strip. The cuboid is mainly used for the thinned portion embedded in the surface of the disk body 1, while the arc-shaped strip is used for the protrusion formed on the surface of the disk body 1. When the axial arc-shaped strip 3 is installed between adjacent wear-resistant sleeves 2, the thickness of the cuboid is equal to the thickness of the wear-resistant sleeve. When embedded, the first surface is in contact with the surface of the disk body 1, and the second surface opposite to the first surface is flush with the surface of the disk body 1. The shape of the arc-shaped strip refers to its arc-shaped cross-section and rectangular bottom surface. The rectangular bottom surface is in contact with the second surface, and the top surface of the arc-shaped strip is the arc surface of the axial arc-shaped strip 3. The arc-shaped top of the arc-shaped cross-section has the maximum distance from the disk body 1.

[0062] Furthermore, the arc-shaped strip is preferably a semi-cylindrical structure, protruding from the disk body 1 in a size 1 to 10 times the diameter of the grinding media, thereby improving the stirring effect of the grinding media. The axial arc-shaped strip 3 is connected to the disk body 1 by bolts and is further fixed by wear-resistant sleeves 2 on both sides to prevent rotation.

[0063] The arc-shaped strip of this invention can also be directly adopted as a spherical crown structure.

[0064] like Figure 17 , Figure 18 and Figure 19 As shown, the assembly of this invention involves installing the wear-resistant sleeve 2 onto the disc body 1 and securing it with bolts. Then, the axial arc-shaped strip 3 is installed onto the disc body 1 and secured with bolts. After the combined discs are assembled, the discs are installed on the mill spindle at intervals five times the disc thickness. Finally, the classifying wheel is installed, and the cylinder is installed, completing the installation of the centrifugal stirred mill. This mill can be used for grinding media stirring of refractory ores. Its main form can be referred to... Figure 20 As shown.

[0065] The mill is used as follows: Grinding media are added through the feed inlet, filling the mill to 70% of its net volume. The ball inlet is closed, and the feed inlet is opened. During operation, the slurry enters the mill through the feed inlet. The main shaft drives the discs to rotate, agitating the grinding media at high speed, causing them to collide with the feed particles at high speed, resulting in a crushing effect.

[0066] like Figure 21 As shown, according to the structure of the present invention, the grinding media is not only stirred in the flow hole 12, having a high initial velocity v, but also the grinding media between the outer edge B of the disc and the outer edge C of the flow hole, generating a high axial initial velocity v1 through stirring by the axial arc strips 3 on the disc. The media in the region between the inner diameter A of the cylinder and the outer edge B of the disc obtains a high initial velocity v3 through the collision of the high-speed moving media between B and C. At the same time, because the outer edge of the flow hole has a chamfer, it provides a high axial velocity v2 to the grinding media in the nearby region, thereby making the grinding media in the entire grinding chamber at a high speed. The grinding effect of the stirred mill is achieved by the high-speed collision between the grinding media and mineral particles. Therefore, this disc structure greatly improves the grinding efficiency of the mill. Through simulation using EDME and FLUNT coupling, the contrasting effects of the two discs can be clearly seen, such as... Figure 22 As shown.

[0067] To verify the effectiveness of the present invention, specific processing embodiments are provided as follows: Example 1 The gold concentrate from a Kyrgyz mine was processed. It was a powdery material with a specific gravity of 3.2 and a D90 (90% sieve particle size) of 86 μm.

[0068] The fineness of the product was determined using a BT9300HT laser particle size analyzer, and the concentration was determined using a concentration vessel.

[0069] The aforementioned mineral powder was processed using a 15L ultrafine mill equipped with the combined discs of this invention, referred to as Mill A. The discs have a diameter of φ180mm, a thickness of 15mm, a spacing of 75mm, and five discs are installed. The mill cylinder has a diameter of φ210mm, a length of 525mm, and a net volume of 15L. 23.5kg of 2mm diameter alumina ceramic balls are added, ensuring a filling rate of 70%. The matching motor is a 15kW permanent magnet motor with a speed of 2900 rpm, and a frequency converter is configured to control the mill speed.

[0070] The mill was replaced with a disc-type mill, and a comparison was conducted under the same conditions; this mill was designated Mill B. The mill used for comparison was equipped with 7 disc-type mills, each with a diameter of φ180mm, a thickness of 15mm, and a spacing of 45mm. Everything else remained unchanged.

[0071] The feed pump is an RGB-20 hose pump with a rated flow rate of 0.6 m³ / h. 3 The flow rate is [value missing] / h, rated head 40m, motor power 1.1kw, and equipped with a frequency converter to control the flow rate. Specific conditions are as follows: Step 1: First, add the mineral powder to the φ1200×1500 mixing tank, then add clean water to prepare a slurry with a mass percentage concentration of 55%, connect it to the feed pump and start the agitator; Step 2: Turn on the RGB-20 feed pump and measure the flow rate at 50Hz, 40Hz and 30Hz respectively. The results are shown in the table below.

[0072] Step 3: Connect the feed pump to mill A. First, turn on the feed pump at a frequency of 15 Hz and a flow rate of 0.225 m³ / h. 3 / h, then start mill A at a frequency of 22Hz and run for 60 minutes. The ground product is then fed into a φ1200×1200 mixing tank. Samples are taken every 10 minutes to test the fineness of the ground product; the mill power is recorded.

[0073] Step 4: Connect the feed pump to mill B. First, turn on the feed pump at a frequency of 15 Hz and a flow rate of 0.225 m³ / h. 3 / h, then start mill A at a frequency of 22Hz and run for 60 minutes. The ground product is then fed into a φ1200×1200 mixing tank. Samples are taken every 10 minutes to test the fineness of the ground product; the mill power is recorded.

[0074] The running data is shown in the table below: Operational data shows that, using the mill A of this invention, the number of grinding discs was reduced from 7 to 5. Under the same feed rate and rotation speed, the -10μm content in the product increased from 73.6% to 90.65%. The grinding effect was greatly improved. While the grinding effect was greatly improved, the power consumption per ton of ore only increased slightly, showing obvious advantages.

[0075] Example 2 The gold concentrate from a Kyrgyz mine was processed. It was a powdery material with a specific gravity of 3.2 and a D90 of 86 μm.

[0076] The fineness of the product was determined using a BT9300HT laser particle size analyzer, and the concentration was measured using a concentration vessel. The above-mentioned mineral powder was processed using a 15L ultrafine mill equipped with the combined discs of this invention, referred to as mill A. The discs have a diameter of φ180mm, a thickness of 15mm, a spacing of 75mm, and 5 discs are installed. The mill cylinder has a diameter of φ210mm, a length of 525mm, and a net volume of 15L. 23.5kg of alumina ceramic balls with a diameter of 2mm are added, ensuring a filling rate of 70%. The matching motor is a 15kW permanent magnet motor with a speed of 2900rpm, and a frequency converter is configured to control the mill speed.

[0077] The feed pump is an RGB-20 hose pump with a rated flow rate of 0.6 m³ / h. 3 The flow rate is [value missing] / h, rated head 40m, motor power 1.1kw, and equipped with a frequency converter to control the flow rate. Specific conditions are as follows: Step 1: First, add the mineral powder to the φ1200×1500 mixing tank, then add clean water to prepare a slurry with a mass percentage concentration of 55%, connect it to the feed pump and start the agitator; Step 2: Turn on the RGB-20 feed pump and measure the flow rate at 50Hz, 40Hz and 30Hz respectively. The results are shown in the table below.

[0078] Step 3: Connect the feed pump to mill A. First, turn on the feed pump at a frequency of 15 Hz and a flow rate of 0.225 m³ / h. 3 / h, then start mill A at a frequency of 22Hz, and feed the ground product into a φ1200×1200 mixing tank. Adjust the feed pump frequency and check the product fineness until the product fineness reaches D90=17μm. Run for 60 minutes, and take samples every 10 minutes to check the fineness of the ground product; record the mill power.

[0079] Since the flow rate is dynamically adjusted and not pre-calibrated, the flow rate is calculated based on the actual frequency and the pre-calibrated frequency and flow rate curve.

[0080] The running data is shown in the table below: Operational data shows that, using mill A of this invention, the number of mill discs was reduced from 7 to 5. Under the same rotational speed and product fineness conditions, the throughput increased from 4.78 t / d to 7.96 t / d, and the power consumption per ton of ore decreased from 47.74 kWh / t to 33.77 kWh / t. The throughput increased by 67%, and the power consumption decreased by 29%, demonstrating significant advantages.

[0081] In summary, the present invention has the advantages of being lightweight, having a long service life, being easy to replace, and having a high grinding media speed. The ultrafine mill using the present invention has the advantages of high power density, large processing capacity, high operating rate, and easy replacement of parts.

Claims

1. A combined centrifugal stirred mill disc, characterized in that, It includes a disk body (1), multiple wear-resistant sleeves (2) and multiple axial arc strips (3); The disk body (1) has a shaft mounting hole (11), multiple flow holes (12) and multiple first assembly holes (13). The shaft mounting hole (11) is located in the center, and the multiple flow holes (12) are evenly distributed in the circumferential direction. The portion between the outer edge of the flow hole (12) and the outer edge of the disk body (1) is thinned. The wear-resistant sleeve (2) is an arc-shaped sleeve with an axial second mounting hole (23). It is mounted on the thinned part of the disk body (1) by bolts and mounting holes. The assembly of each wear-resistant sleeve (2) completely covers the thinned part and side edge of the disk body (1). The axial arc strip (3) has a third axial mounting hole (33), one end of which is a plane and the other end is an arc surface. It is mounted to the disk body (1) by bolts and mounting holes, and its arc surface end is far away from and protrudes from the disk body (1).

2. The combined centrifugal stirred mill disc according to claim 1, characterized in that, The flow passage is an arc-shaped hole, with both the inner and outer arcs concentric with the disk body (1). The outer edge of the hole has a chamfer to reduce the thickness, and the angle of the chamfer is between 1° and 45°.

3. The combined centrifugal stirred mill disc according to claim 1, characterized in that, The disk body (1) is made of ultra-high density polyethylene, and the wear-resistant sleeve (2) and the axial arc strip (3) are made of alumina ceramic, tungsten carbide, silicon carbide ceramic or wear-resistant steel.

4. The combined centrifugal stirred mill disc according to claim 1, 2, or 3, characterized in that, The wear-resistant sleeve (2) is composed of a first wear-resistant plate (21), a second wear-resistant plate (22) and a third wear-resistant plate (25). The first wear-resistant plate (21) and the second wear-resistant plate (22) are arc-shaped flat plates with the same shape and size and are arranged in parallel. Their thicknesses are equal to the thickness of the single-sided thinning of the disk body (1). The third wear-resistant plate (25) is an arc-shaped plate. The inner side of the third wear-resistant plate (25) is attached to the side edge of the disk body (1). The upper edge is connected to the outer arc edge of the first wear-resistant plate (21), and the lower edge is connected to the outer arc edge of the second wear-resistant plate (22). The second assembly hole (23) is symmetrically opened on the first wear-resistant plate (21) and the second wear-resistant plate (22) for assembly with the first assembly hole (13) of the disk body (1) by bolts.

5. The combined centrifugal stirred mill disc according to claim 4, characterized in that, The inner arc radius of the first wear-resistant plate (21) and the second wear-resistant plate (22) is equal to the outer edge radius of the flow hole (12) on the disk body (1); The first wear-resistant plate (21) and the second wear-resistant plate (22) have notches (24) at both ends near the inner arc edge, which are used to accommodate the installation of the axial arc strip (3).

6. The combined centrifugal stirred mill disc according to claim 4 or 5, characterized in that, The axial arc strips (3) are installed between adjacent wear-resistant sleeves (2), and multiple axial arc strips (3) are distributed along one or more circumferential directions of the disk body (1) on the surface of the disk body (1).

7. The combined centrifugal stirred mill disc according to claim 1, characterized in that, The axial direction of the axial arc strip (3) is the radial direction of the disk body (1), or has the same included angle with the radial direction of the disk body (1). The axial arc strip (3) is composed of a cuboid and an arc strip. The thickness of the cuboid is equal to the thickness of the wear-resistant sleeve (2). The bottom surface of the arc strip is attached to the side of the cuboid that is flush with the surface of the disk body (1). The top surface is the arc surface. The arc strip refers to the shape of its cross-section being arc-shaped, and the arc top of the arc shape having the maximum distance from the disk body (1); or, the arc strip is a spherical crown.

8. The combined centrifugal stirred mill disc according to claim 1 or 7, characterized in that, The axial arc-shaped strip (3) protrudes from the disk body (1) and its size is 1 to 10 times the diameter of the grinding media.

9. A centrifugal stirred mill for stirring grinding media in refractory ores, characterized in that, The centrifugal stirred mill uses the combined centrifugal stirred mill discs as described in any one of claims 1 to 8.

10. The centrifugal stirred mill according to claim 9, characterized in that, Multiple composite centrifugal stirred mill discs are installed on the stirring shaft, with the spacing between adjacent discs being 5 to 10 times the disc thickness.

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