Housing lining for a stirred mill and stirred mill

Abstract

A housing lining for a stirred mill and a stirred mill, which are configured to be removably mounted on the inner side of a mill housing in a grinding chamber of the mill. At least a part of a surface of the housing lining configured to be exposed in the grinding chamber constitutes a wear surface. The housing lining includes at least one polymer-ceramic panel having an elastic material layer and wear-resistant inserts held by the elastic material layer. An exposed surface of the wear-resistant inserts forms a part of the wear surface of the housing lining.

Description

Technical Field

[0001] This invention relates to improvements in stirred mills for grinding particles such as mineral ore. Background Technology

[0002] A stirred mill, also known as an atritor mill, is a type of mill used for grinding and mixing materials such as chemicals, ores, pyrotechnic materials, coatings, and ceramics. It comprises a vertical container with a central shaft and impellers that agitate the media in a specific manner.

[0003] Agitated bead mills are commonly used in mineral processing to grind mineral ore particles into smaller particles to facilitate subsequent downstream processing, such as separating valuable mineral particles from unwanted gangue. For example, mineral ore particles with diameters ranging from approximately 30 μm to 4000 μm can be ground into particles with diameters from 5 to 100 μm. This process is often referred to as fine grinding and ultrafine grinding.

[0004] Agitated bead mills typically have a fixed mill body or casing and an internal drive shaft. The casing and drive shaft can be arranged vertically within the mill; this type of mill is also known as a tower mill. The drive shaft has multiple agitating elements, such as rotor discs or rotors, such that rotation of the drive shaft also rotates the agitating elements, thereby agitating the suitable grinding media, through which mineral ore particles in the form of a feed slurry pass. The resulting agitation grinds the mineral ore particles into smaller particles. In other words, unlike roller mills such as ball mills (where motion is transmitted to the material via the rotation of the mill casing), in tower mills and agitated mills, motion is transmitted to the material via the movement of internal agitators, while the casing remains stationary.

[0005] Exemplary stirred bead mills can be found in WO2017 / 017315A1 and WO2018 / 138405A1.

[0006] In stirred media mills, shear forces are significant, and in fact, wear is unavoidable even in well-designed and manufactured equipment. The rotor disc and housing tend to suffer high wear, especially when the mill operates at high speeds due to the action of hard grinding media acting on the rotor disc. This accelerated wear of mill components results in a very short service life, necessitating replacements more frequently than expected. Replacement of mill components leads to downtime, reduces mill efficiency, and increases maintenance costs.

[0007] To protect the inner circumferential surface of the grinding mill housing from wear, a housing liner is typically used. This liner is installed on the inner circumferential surface and replaced when the wear becomes significant.

[0008] Despite these improvements, there is still a need to reduce wear on grinding machine components, reduce the time and labor required to replace parts, reduce downtime, and / or lower maintenance costs. Utility Model Content

[0009] The basic objective of this invention is to provide a housing liner for a stirred mill that offers a longer wear life than conventional liner ...

[0010] This objective is achieved through a shell liner and a stirring mill, respectively.

[0011] The present invention relates to a housing liner for a stirred mill, wherein the housing liner is configured to be removably mounted to the inside of a mill housing within the grinding chamber of the mill. The housing liner is configured such that at least a portion of its surface exposed within the grinding chamber constitutes a wear surface. The housing liner includes at least one polymer-ceramic panel comprising a layer of elastic material and a wear-resistant insert held by the elastic material layer, wherein the exposed surface of the wear-resistant insert forms part of the wear surface of the housing liner.

[0012] The material of the elastic material layer can be a polymer material, especially an elastomer material, such as rubber, isoprene, polybutadiene, butadiene, nitrile, ethylene, propylene, chloroprene rubber or silicone rubber, or a mixture thereof, including fillers or auxiliary materials and impurities comprising up to 30% by volume.

[0013] Inserts can be metallic or ceramic, or made of a metal-ceramic composite. If metallic, they can be iron-based metals, including metal carbides or oxides comprising up to 50% by volume. If ceramic, they can consist of carbides or oxides of metallic elements, such as aluminum, titanium, tantalum, tungsten, chromium, or zirconium, or mixtures thereof. If cermetic, they can include carbides or oxides of metallic elements (e.g., aluminum, titanium, tantalum, tungsten, chromium, or zirconium), or mixtures thereof, and a metallic binder, which is a pure metal or metal alloy and has cobalt, nickel, or iron as the main component of the binder.

[0014] Wear-resistant inserts can be attached to the elastic material layer by vulcanization (e.g., by vulcanizing ceramic inserts into a polymer-based material layer) or by adhesives or bonding agents. Alternatively or additionally, wear-resistant inserts can be mechanically held within the elastic material layer by press fitting and / or form fitting.

[0015] In summary, the combination of wear-resistant components (e.g., ceramic components) with elastic layers (e.g., rubber layers) is advantageous because ceramics are primarily suited for compensating for sliding or abrasive wear, while rubber is primarily suited for compensating for impact wear. Therefore, the housing liner of this invention provides a longer wear life than conventional steel liner liner. The reduction in wear will also reduce downtime required to replace worn components.

[0016] Ceramic-rubber composites are known in the art; for example, US3,607,606 discloses a composite material of natural or synthetic rubber and alumina-based ceramics, which can be used as a wear-resistant liner for ball mills, conveyors, chutes, etc. This composite material comprises a layer of rubber with a shaped body of closely spaced alumina-based ceramics embedded and bonded to its surface. WO-A1-2006 / 132582 also relates to wear-resistant liner elements for surfaces subjected to wear, having an outward-facing surface on which flake or granular materials such as crushed ore and crushed rock are used to move. Chutes and truck platforms are mentioned in the examples. This wear-resistant liner element comprises an elastomeric material primarily suited for absorbing impact energy and wear-resistant components primarily suited for resisting wear. These wear-resistant components are preferably made of ceramic materials. According to WO2008 / 087247A1, similar composite materials are used for wear components (e.g., distribution plates) of vertical shaft impactors, and WO2017 / 174147A1 describes a crusher (e.g., a rotary crusher or a cone crusher) having a protective liner comprising a layer of elastic material and wear-resistant inserts held by the layer of elastic material, wherein the outward surface of the wear-resistant inserts forms part of the wear surface of the housing liner.

[0017] To fit the shape of the housing being designed for installation, the housing liner of this invention can be bent into the shape of a section of a hollow cylinder. However, if the shape of the housing is not cylindrical, the shape of the housing liner will be adjusted accordingly.

[0018] While the housing liner may in principle consist solely of the aforementioned polymer-ceramic panels or multiple such panels, in one embodiment, the housing liner also includes a reinforcing plate supporting at least one polymer-ceramic panel. The reinforcing plate may be shaped (e.g., a semi-cylindrical shape as described above) before or after the polymer-ceramic panel is attached to the reinforcing plate. The reinforcing plate is suitable for use with steel, such as S235 grade structural steel or ASTM A36 structural steel. The reinforcing plate may also comprise or be made of plastics, such as fiberglass, PU, ​​or other plastic materials and composites.

[0019] In any housing liner of this invention, multiple polymer-ceramic panels may be arranged in at least one row and / or at least one column. In a preferred embodiment, multiple polymer-ceramic panels are arranged in an array of several rows and columns, such as 6 rows × 4 columns or 5 rows × 5 columns. The housing liner of this invention may also include only one row or one column of polymer-ceramic panels.

[0020] In an embodiment, the housing liner of the present invention includes at least two polymer-ceramic panels spaced apart from each other in the height direction of the panels.

[0021] Any housing liner of this invention may further include at least one mounting hole for securing a stator element (e.g., a stator ring or a segment thereof). The stator element or segment (e.g., a stator ring or a stator ring segment) may be made of, for example, polyurethane (PU), steel, or a suitable metal alloy.

[0022] In the combination of the above two aspects, at least one mounting hole is provided in the gap between the two panels.

[0023] To accommodate uneven wear along the length or height of the housing, the thickness of the first polymer-ceramic panel of the housing liner can be set to be greater than the thickness of the second polymer-ceramic panel of the housing liner. This thickness variation is caused by the different thicknesses of the elastic material layers on the panels and / or the different dimensions of the wear-resistant inserts in the thickness direction of the panels.

[0024] Alternatively or additionally, at least one polymer-ceramic panel of the liner may have raised or other thickened areas, wherein the thickness of the elastic material layer and / or the dimension of the wear-resistant insert in the panel thickness direction is greater than that of other areas of the panel. The raised or other thickened areas may be suitably positioned where the panel is configured to face the rotor disk (wherein the rotor disk is configured to rotate within the mill grinding chamber), and / or where excessive wear occurs for other reasons. For example, the raised or other thickened areas may extend along the width of the liner, and thus along the inner circumference of the housing when the liner is mounted to the housing, in order to provide improved wear resistance over the entire circumference of the housing.

[0025] The present invention also provides a stirring mill, which includes a grinding chamber and a stirring assembly arranged in the grinding chamber for rotation therein, wherein the mill further includes at least one housing liner according to the present invention, the housing liner being removably installed to the inside of the mill housing within the grinding chamber of the mill.

[0026] The housing liner can be removably mounted to the inside of the mill housing by fastening at least one polymer-ceramic panel of the liner to the inside of the mill housing. In an alternative where the housing liner also includes a reinforcing plate, the housing liner can be removably mounted to the inside of the mill housing by fastening the reinforcing plate of the liner to the inside of the mill housing. Due to the removable mounting of the housing liner, it can be replaced quite easily and quickly.

[0027] The stirred grinding mill of this invention may include multiple shell liners arranged adjacent to each other along the circumference and / or length of the mill shell.

[0028] If multiple housing liners are provided, the thickness of at least one polymer-ceramic panel in the housing liner arranged closer to the bottom of the housing or the feed end is greater than the thickness of at least one polymer-ceramic panel in the housing liner arranged closer to the top of the housing or the discharge end. This thickness variation is caused by the different thicknesses of the elastic material layers on the panels and / or the different dimensions of the wear-resistant inserts in the thickness direction of the panels.

[0029] This invention can be easily applied to various types of agitated bead mills with a fixed grinding shell and a rotating stirring assembly.

[0030] According to known types of stirred mills, the stirring assembly of the stirred mill may include a drive shaft having a plurality of rotor discs arranged along the length of the drive shaft. In this case, the mill may be, for example, a HIGmill. TM However, this invention is applicable to any type of stirred mill, including horizontal stirred mills.

[0031] An exemplary vertical mill to which this utility model applies includes a mill body, a shaft with rotor discs, a housing-mounted stator ring, a gearbox, and a drive. The grinding chamber is filled with up to 70% inert ceramic grinding media beads. The rotors agitate the material, and grinding occurs through friction between the beads. The number of rotors (grinding stages) depends on the application, i.e., it is set according to specific application requirements. The feed slurry is pumped into the bottom of the mill.

[0032] As the slurry flows upward, it passes through the free space between the rotating disk and the static counter-rotating disk lined on the wall. The number of rotating and static disks is selected based on the application. Due to the vertical arrangement of the mill, classification occurs simultaneously throughout the grinding process, with larger particles residing longer at the periphery while smaller particles move upward. This process is typically unidirectional (single-pass) and requires no external classification.

[0033] Gravity keeps the grinding media compact during operation, ensuring strong inter-bead contact and efficient, uniform energy transfer throughout the volume. The disc configuration and overall chamber geometry have been optimized for efficient energy transfer to the bead mass, internal circulation, and classification. With the grinding media evenly distributed, ore particles maintain continuous contact, significantly improving grinding efficiency. The final product is discharged from the top of the mill into the open environment.

[0034] The mill casing can be vertically flanged to divide it into two halves along the center, which can be separated by a safety barrier system (railing system). Once the interior is exposed, two skilled operators can independently replace the disc and lining sections. Disc wear is uniform along the circumference. Wear is faster at the bottom of the mill, and typically the lowest disc may need to be replaced before the entire disc assembly can be replaced. For complete replacement, a spare shaft ready for installation is an option. Wearing parts may be lined with polyurethane, hard-faced metal, or natural rubber, depending on the application.

[0035] Typical applications of this stirred mill are concentrate regrinding (e.g., magnetic separation, flotation), three-stage grinding of iron ore, fine grinding of precious metal ores, and fine grinding in hydrometallurgical processes. Both ceramic and steel balls can be used. Ceramic media are typically used for sulfide concentrate regrinding to prevent iron contamination on the surface of sulfide minerals, which would otherwise lead to a decrease in flotation recovery and grade. The mill can use a wide range of grinding media diameters, depending on the application: 0.5-1.5 mm for ultrafine grinding, 1-3 mm for fine grinding, and 3-6 mm for coarse grinding, where the grinding dimensions are defined as follows:

[0036] Coarse grinding range: F80 100-300μm, P80 50-100μm;

[0037] Fine grinding range: F80 50-100μm, P80 20-60μm;

[0038] Ultrafine grinding range: F80 < 70 μm, P80 < 20 μm.

[0039] In the existing HIGmill TM The housing liner according to this invention achieves a wear life of over 4,000 hours, which is approximately double that of a standard PU liner.

[0040] Alternatively, the stirring assembly of the mill of this invention may include an agitator screw arranged concentrically with and located within the grinding chamber for rotation therein.

[0041] The cylindrical grinding chamber can be arranged basically vertically or basically horizontally.

[0042] Embodiments of this invention can be readily applied to many different types of particulate materials, not limited to specific mineral types, but may include iron, quartz, copper, nickel, zinc, lead, gold, silver, and platinum. Other particulate materials that can be processed using embodiments of this invention include concrete, cement, recyclable materials (such as glass, ceramics, electronic devices, and metals), food, pigments, abrasives, and pharmaceutical substances. In these other applications, embodiments of this invention are used to reduce the size of particulate materials using a grinding process.

[0043] This invention provides a housing liner for a stirred mill, wherein the housing liner is configured to be removably mounted to the inside of a mill housing within the mill's grinding chamber, and wherein at least a portion of the surface of the housing liner exposed within the grinding chamber constitutes a wear surface, wherein the housing liner includes: at least one polymer-ceramic panel, the polymer-ceramic panel including an elastic material layer and a wear-resistant insert held by the elastic material layer, wherein the exposed surface of the wear-resistant insert forms a portion of the wear surface of the housing liner.

[0044] In one embodiment, the housing liner is bent into the shape of a section of a hollow cylinder.

[0045] In one embodiment, a reinforcing plate is also included to support the at least one polymer-ceramic panel.

[0046] In one embodiment, it also includes a plurality of polymer-ceramic panels arranged in at least one row and / or at least one column.

[0047] In one embodiment, at least two polymer-ceramic panels are also included, which are spaced apart from each other in the height direction of the panels.

[0048] In one embodiment, at least one mounting hole is also included for securing a stator element, such as a stator ring or a segment thereof.

[0049] In one embodiment, the panel further includes at least two polymer-ceramic panels spaced apart from each other in the height direction of the panel, wherein the at least one mounting hole is disposed in the gap between the two panels.

[0050] In one embodiment, the thickness of the first polymer-ceramic panel of the housing liner is greater than the thickness of the second polymer-ceramic panel of the housing liner. The thickness variation is caused by the different thicknesses of the elastic material layers of the panels and / or the different dimensions of the wear-resistant inserts in the thickness direction of the panels.

[0051] In one embodiment, at least one polymer-ceramic panel of the housing liner has raised or other thickened areas, wherein the thickness of the elastic material layer and / or the dimension of the wear-resistant insert in the thickness direction of the panel is greater than that of other areas of the panel.

[0052] In one embodiment, the protrusion or other thickened region is positioned where at least one polymer-ceramic panel is configured to face a rotor disk configured to rotate within the grinding chamber of the grinder.

[0053] In one embodiment, the protrusion or other thickened area extends along the width of the housing liner and thus extends along the inner periphery of the housing when the housing liner is mounted to the housing.

[0054] This utility model proposes a stirring grinder, comprising: a housing; a grinding chamber; a stirring assembly disposed within the grinding chamber for rotation therein; and at least one housing liner, the housing liner comprising at least one polymer-ceramic panel, the polymer-ceramic panel comprising an elastic material layer and a wear-resistant insert held by the elastic material layer, wherein the exposed surface of the wear-resistant insert forms part of the wear surface of the housing liner, and wherein the at least one housing liner is removably mounted to the inside of the housing within the grinding chamber.

[0055] In one embodiment, the housing liner is removably mounted to the inside of the housing of the grinder by fastening an elastic material layer of at least one polymer-ceramic panel of the housing liner to the inside of the housing.

[0056] In one embodiment, the housing liner further includes a reinforcing plate, and the housing liner is removably mounted to the inside of the housing of the grinder by fastening the reinforcing plate of the liner to the inside of the housing of the grinder.

[0057] In one embodiment, a plurality of housing liners are included, wherein the thickness of at least one polymer-ceramic panel of the housing liner arranged closer to the bottom or feed end of the housing is greater than the thickness of at least one polymer-ceramic panel of the housing liner arranged closer to the top or discharge end of the housing, the thickness variation being caused by the panels having elastic material layers of different thicknesses and / or the wear-resistant inserts having different dimensions in the thickness direction of the panels.

[0058] In one embodiment, the stirring assembly includes: a drive shaft having a plurality of rotor disks arranged along the length of the drive shaft, or a stirrer screw arranged concentrically with and located within the grinding chamber for rotation therein.

[0059] In one embodiment, the grinding chamber is arranged substantially vertically or substantially horizontally. Attached Figure Description

[0060] In the following description, the present invention will be described in more detail by way of exemplary embodiments and with reference to the accompanying drawings, wherein:

[0061] Figure 1 This is a perspective view of an exemplary grinding machine that includes grinding elements according to embodiments of the present invention;

[0062] Figure 2 yes Figure 1 A side view of the grinding machine;

[0063] Figure 3 yes Figure 1 A front view of the grinding machine;

[0064] Figure 4 yes Figure 1 A schematic longitudinal cross-sectional view of an exemplary mill body used in a grinding mill;

[0065] Figure 5 This is a perspective view of an exemplary toothed rotor disk;

[0066] Figure 6 It is a schematic exploded view of a grinding machine including the housing liner;

[0067] Figure 7a This is a perspective view of an embodiment of the shell liner of this utility model in a bent state;

[0068] Figure 7b yes Figure 7a A front view of the shell lining;

[0069] Figure 7c yes Figure 7b Cross-sectional view along the CC line;

[0070] Figure 7d yes Figure 7b Cross-sectional view along the DD line;

[0071] Figure 7e Show Figure 7d Details listed separately;

[0072] Figure 7f Show Figure 7b Details listed separately;

[0073] Figure 8 The housing liner of this invention, in which the stator ring section is installed, is shown.

[0074] Figure 9a The shell liner of this utility model is shown in a flattened state;

[0075] Figure 9b yes Figure 9a Cross-sectional view along line BB;

[0076] Figure 9c yes Figure 9a Side view of the shell lining;

[0077] Figure 10a yes Figures 9a-9c A front view of a polymer-ceramic panel in the shell lining;

[0078] Figure 10b yes Figure 10a Cross-sectional view along line BB;

[0079] Figure 11 It corresponds to Figure 4 The view shows a significant wear area on the inner circumference of the housing; and

[0080] Figure 12 This is a side view of a housing liner according to a modified embodiment of the present invention, wherein some of the polymer-ceramic panels have protrusions in areas of significant wear. Detailed Implementation

[0081] In the following description, an embodiment of the housing liner for a stirred bead grinding mill will be used as an example. In the various figures, the same reference numerals denote the same or corresponding parts.

[0082] Figures 1 to 3 An exemplary agitated bead mill 1 for grinding slurries containing particulate materials is shown. This mill 1 includes a mill body 2 and a drive mechanism 4 for rotating a drive shaft 11 of the mill body 2 about a longitudinal axis 6, thereby providing agitation to the slurry in the mill body 2. The mill body 2 and the drive mechanism 4 are respectively mounted on a frame structure, such as a base frame 3 and a drive frame 5. The mill body 2 includes a mounting assembly 9 for assembling the mill body to the base frame 3 and operatively aligning the mill body with the drive mechanism 4.

[0083] This grinding mill can be any type of stirred mill, such as a fine mill type known as a high-intensity mill. In a stirred mill, the rotational motion of the drive shaft within the mill body causes the grinding media to move in a manner described in more detail below (see reference). Figure 4 The slurry particles are intensely ground.

[0084] Grinding mills, in order to achieve fine grinding, may have relatively high power consumption, for example, in the range of 5 kWhr / t to 100 kWhr / t (kilowatt-hours per ton). The power intensity of a grinding mill (kW / m²) 3 It could also be relatively high, for example, as high as 100-300 kW / m 3 Or higher.

[0085] To operate this grinding mill, a feed slurry containing, for example, mineral particles is fed into the mill body 2 through a bottom inlet 7, which in this example is shown as a center inlet (see...). Figure 2 The mill body 2 may be partially filled (e.g., about 2 / 3 filled) with grinding media, such as beads. The grinding media may also initially pass through outlet 8 (see [link to relevant documentation]) before the addition of feed slurry (e.g., particulate material and slurry liquid) and before the mill 1 is put into operation. Figure 3 It can be added to the mill body 2 through a separate inlet at the top of the mill.

[0086] During operation, the drive shaft 11 inside the mill body 2 is driven by the drive mechanism 4 to rotate around the axis 6, thereby rotating or agitating the feed slurry and grinding media. This provides relative motion between the grinding media and the slurry of particulate material at the desired speed within the grinding chamber 15 inside the mill body 2, causing the feed slurry particles to be crushed or ground by the grinding media and crushed or ground between the grinding media, thus achieving pulverization through friction between the grinding media. The ground product is then discharged through the top outlet 8.

[0087] Abrasive media typically include ceramic or steel balls with diameters ranging from 0.5 mm to 50 mm. The size of the abrasive media can vary depending on the requirements.

[0088] Figure 4 Is with Figure 1-3 The diagram shows a schematic cross-sectional view of a stirred bead mill operating on the same principle. In the exemplary embodiment shown, the mill body 2 has a fixed grinding shell or cylinder 18, which is vertically arranged within the mill and has the aforementioned bottom inlet 7 and top outlet 8. In other embodiments, the inlet 7 and outlet 8 may be located outside the bottom and top of the shell, respectively.

[0089] A generally cylindrical tube or shell 18 defines the internal cavity or grinding chamber 15. The term "cylindrical" as used herein should be understood broadly to refer to any cylindrical structure having a circular cross-section, and although the mill body 2 is generally cylindrical in the exemplary embodiment shown, it should be understood that in other embodiments the mill body or shell 18 may have other cross-sectional shapes, such as rectangular, square, elliptical or quasi-elliptical, or any other regular or irregular polygonal shape (such as hexagonal), to define the grinding chamber 15.

[0090] The rotary stirring assembly 10 is positioned within the housing 18. The stirring assembly 10 includes the aforementioned drive shaft 11, and a plurality of grinding rotor discs 12 are mounted to the drive shaft 11. The rotor discs 12 will be described in more detail below (see reference). Figure 5 The drive shaft 11 may be coaxial with the mill body 2 or its housing 18 (as shown in the exemplary embodiment). The drive shaft 11 may be parallel to the longitudinal axis 6 of the mill body 2 (as shown in the exemplary embodiment), or the drive shaft may be inclined or at an angle relative to the axis of the mill body.

[0091] In the illustrated embodiment, the rotor disks 12 are arranged at regular intervals along the longitudinal axis of the drive shaft 11 and are coaxial with the axis of the drive shaft 11.

[0092] On the inner circumferential surface 13 of the fixed grinding housing 18, a plurality of stator elements (such as stator rings 14) are arranged to protrude into the grinding cavity 15. Viewed from the height direction of the housing 18 (i.e., along axis 6), each stator ring 14 is located between two rotor disks 12. The stator rings 14 thus subdivide the grinding cavity 15 into compartments 17 interconnected by channels between the stator rings 14 and the drive shaft 11, the channels being defined by a central opening 16 within the stator rings. Depending on the application, any number of sets of (rotating) rotor disks 12 and (fixed) stator rings 14 can be present. For example, up to dozens of sets are possible, but typically 5-20 sets are used.

[0093] Stator rings or stator ring sections may be made of polymers such as polyurethane (PU), rubber, polymer blends, or steel or suitable metal alloys. Depending on the application, stator elements other than rings may be used, such as baffles, ribs, grooves, and / or lifters.

[0094] During operation, the drive mechanism 4 rotates the drive shaft 11 of the stirring assembly 10, causing the rotor disk 12 to rotate, thereby applying rotational motion to the slurry of grinding media and particulate material at the desired speed within the grinding chamber 15 of the mill body 2. This rotational motion causes the feed slurry particles to be ground by the harder grinding media and ground between the harder grinding media, thereby releasing valuable mineral particles and reducing their size for subsequent downstream processing after discharge through the outlet 8. The slurry flows upward through the grinding chamber 15, from the bottom to the top of the housing 18 through the various compartments 17.

[0095] Each compartment 17 can be considered a grading stage, in which coarser particles move toward the inner wall of the shell 18, while finer particles move upward through the channel 16 more quickly. Due to the vertical arrangement of the mill 1, grading occurs simultaneously throughout the grinding process, with larger particles remaining at the periphery for a longer time, while smaller particles move upward.

[0096] In other words, in an exemplary vertical stirred bead mill, the feed slurry is fed from below, and particles (e.g., ore particles) are gradually ground into smaller particles by moving grinding media beads before exiting from the top of the mill. The grinding media beads are significantly larger than the ore particles (e.g., tens of times larger), which is necessary for grinding and also helps retain the grinding media beads within the mill because their settling velocity is faster than the upward flow velocity of the feed slurry. However, the mill can be sized so that the grinding media beads are partially fluidized by the upward flow of the feed slurry. The electrical power consumption of the drive shaft is sensitive to the feed flow rate; that is, at higher flow rates, the grinding media beads are slightly lifted, resulting in less resistance to the rotor disc. In a horizontal stirred bead mill, a centrifugal separator can be installed at the end of the mill to retain the beads and coarser particles within the mill.

[0097] Figure 5 An example of a rotor disk 12 is shown. In an exemplary embodiment, the rotor disk 12 includes a flat disk body 20 connected to a mounting ring 21 via arms 22 (generally referred to as spokes) for mounting the rotor disk 12 to a drive shaft 11 of a stirring assembly 10. The exemplary embodiment of the rotor disk 12 also includes toothed blocks 25 in the form of block-like elements, which are integrally formed with the disk body 20 and arranged such that opposite sides and one end of the blocks protrude outward from the flat surface and outer edge of the disk body 20. Thus, each block 25 extends substantially orthogonal to the opposite flat surface through its opposite side and extends radially outward from its end through its outer edge. The toothed blocks 25 may take any number of forms to form an area around each rotor disk 12. Examples of other forms or shapes of protective elements are disclosed in WO2017 / 017315A1.

[0098] In stirred media mills, shear forces are significant, and in fact, wear is unavoidable even in well-designed and manufactured equipment. Accelerated wear of mill components results in a very short service life, necessitating replacement more frequently than expected. Replacement of mill components leads to downtime, reduces mill efficiency, and increases maintenance costs.

[0099] To protect the inner circumferential surface of the mill housing 18 from wear, a housing liner is typically used, which is installed on the inner circumferential surface and replaced when wear becomes significant. Figure 6 This housing liner (schematically shown as 30) is illustrated as being installed within the housing 18 of the grinding mill body 2. In the illustrated example, the housing 18 is divided into two halves 18a, 18b axially (e.g., vertically in a vertical mill, horizontally in a horizontal mill); it may also be divided into three or more separable sections. The two halves or other sections of the housing 18 may be flanged together axially (vertically) so that they can be separated. For example, the two halves of the grinding mill body 2 may be hinged together so that the housing halves can swing apart after the flange bolts, etc., are removed.

[0100] After opening the housing 18, the housing liner 30 can be installed or secured to the inside of the housing halves 18a, 18b, or other sections. If necessary, the rotor disc 12 can also be easily replaced at this time.

[0101] In the example shown, ten semi-cylindrical housing liners 30 are arranged within each half 18a, 18b of the housing 18. The housing liners 30 can be arranged to fit tightly or loosely against the inner surface of the housing 18 to prevent wear on the housing 18. The housing liners 30 can be connected to the housing segments 18a, 18b via suitable connecting devices. The housing liners 30 can also be embedded units. Any housing liner 30 can be replaced individually or all at once within the entire housing.

[0102] The worn housing liner 30 can be easily replaced by reversing the steps: separate the mill body 2 into half, replace the worn housing liner 30, and then reassemble the mill body.

[0103] In conventional stirred mills, the shell liner 30 is made of, for example, polyurethane. Polyurethane wears down, especially in the area near the bottom of the shell 18 where abrasive forces are most pronounced, with the area of ​​the liner directly facing the rotor disk experiencing the most significant wear. Failure to replace the PU liner before exposing the mill shell will result in damage to the mill shell.

[0104] The housing liner according to this invention has improved wear life. According to this invention, the housing liner includes a layer of elastic material in which wear-resistant components are embedded at least in the surface region forming the wear surface. The exposed surface of each wear-resistant component forms part of the wear surface of the housing liner. The remaining portion of each wear-resistant component is immersed in the elastic material layer.

[0105] The elastic material layer can be a polymer layer, and the wear-resistant component can be a ceramic insert. One possible implementation is a layer made of polymer-ceramic composite material. Therefore, the wear surface of the housing liner will also be referred to as the "polymer-ceramic layer" below.

[0106] Figure 7a This is a perspective view of one embodiment of the housing liner 30 according to the present invention. The housing liner 30 of this embodiment mainly consists of three components: a plurality of polymer-ceramic panels 40, a reinforcing plate 50, for example made of steel, and a vulcanized rubber layer 60 supporting the polymer-ceramic panels 40 to the reinforcing plate 50. The reinforcing plate 50 supporting the polymer-ceramic panels 40 is bent into a curved shape complementary to the shape of the halves 18a, 18b of the housing 18.

[0107] exist Figure 7a In one embodiment, the housing liner 30 comprises a total of 24 polymer-ceramic panels 40 arranged in four rows and six columns.

[0108] Between the top first and second rows of panels 40, and between the second and third rows, the panels 40 are spaced apart to provide space for attaching the stator ring 14 or its segments, respectively. Figure 8 As illustrated schematically, a bolt hole connection device 55 is provided for this purpose. Thus, the exemplary housing liner 30 provides space for two stator rings 14 in the axial direction. The housing liner of this invention may also have only two rows of polymer-ceramic panels spaced apart to provide space for attaching one stator ring 14 or a segment thereof, or there may be more than two intervals between the rows of polymer-ceramic panels in the height direction of the housing liner 30. The housing liner 30 of this invention may also include only one row of polymer-ceramic panels 40, in which case the stator ring 14 or a segment may be mounted, for example, in the axial direction of the housing 18 to the housing 18 between the two housing liners 30.

[0109] Figures 7b-7f yes Figure 7a Further view of the housing liner 30: Figure 7b It is a front view. Figure 7c yes Figure 7b Cross-sectional view along the CC line. Figure 7d yes Figure 7b Cross-sectional view along the DD line. Figure 7e and Figure 7f Show each Figure 7d and Figure 7b Details listed separately.

[0110] As can be seen from these figures, polymer-ceramic panels of different sizes are combined in the housing liner 30 of this embodiment: in this embodiment, the polymer-ceramic panels are arranged in a total of six columns and four rows. The dimensions of the panels in the width direction (i.e., along the circumference of the circular or curved housing liner 30) are largest for the outermost row of panels 40a and smallest for the two central rows of panels 40c of the housing liner 30.

[0111] In addition, each polymer-ceramic panel 40a-c has a curved profile adapted to the curved shape of the reinforcing plate 50 supporting the panel 40.

[0112] Regarding the appropriate dimensions of the various components of the housing liner 30, the thickness of the polymer-ceramic panel 40 can be, for example, 30 mm, the thickness of the reinforcing plate 32 can be, for example, 10 mm, and the thickness of the intermediate rubber layer 60 can be, for example, 5 mm. Suitable thickness ranges are: panel 40 20-100 mm, reinforcing plate 32 5-15 mm, and intermediate rubber layer 60 2-20 mm.

[0113] Figures 7a-7fThe shell liner 30 is in the shape of a semi-hollow cylinder, such that the corresponding liners placed at the same height in each shell half 18a, 18b (within) Figure 6 (In a manner generally shown) they will be assembled into a hollow cylinder to protect the entire inner circumference of the housing 18. Similarly, three 120-degree housing liners or four 90-degree housing liners may be placed within the housing 18 to assemble into a hollow cylinder. In embodiments, the housing liners 30 may also be independent elements adapted to be loosely mounted within the grinding housing 18.

[0114] In an embodiment, the height of the housing liner (corresponding to the axial length in the liner-installed state) is approximately equal to or a multiple of the distance between the rotor disks 12 axially spaced from the central stirring shaft 11.

[0115] In one embodiment, the housing liner 30 is sized to stack axially with one or more other housing liners 30 within the cylindrical grinding housing 18 to cover substantially the entire axial length of the inner side of the housing 18.

[0116] Figures 9a-9c The housing liner 30 of this invention is shown in a flattened state, which is consistent with the reference liner. Figures 7a-7f The shell liner 30 described above is the same as or similar to that described above. Figures 9a-9c These are the front views of the shell liner 30, Figure 9a Detailed cross-sectional view and side view along the BB line. Except for the last row at the bottom and the last column on the right side of the figure, which use panels 40", 40'" and 40"" (located in the lower right corner), the entire liner 30 uses polymer-ceramic panels 40' of the same size.

[0117] Figure 10a This is a front view of a single polymer-ceramic panel 40', specifically... Figures 9a-9c The dimensions and shapes used in the embodiments (except for the bottom row and outermost column panels, panels 40", 40'" and 40" are used as described above). Figure 10b yes Figure 10a Cross-sectional view along line BB.

[0118] In any embodiment of the present invention, the material of the elastic material layer 42 may be a polymer material, particularly an elastomer material, such as rubber, isoprene, polybutadiene, butadiene, nitrile, ethylene, propylene, chloroprene rubber or silicone rubber, or a mixture thereof, including fillers or auxiliary materials and impurities comprising up to 30% by volume.

[0119] Insert 44 can be a metal or ceramic insert, or made of a metal-ceramic composite. If metallic, they can be iron-based metals, including 10-50% by volume metal carbides or oxides. If ceramic, they can consist of carbides or oxides of metallic elements (e.g., aluminum, titanium, tantalum, tungsten, chromium, or zirconium), or mixtures thereof. If cermet, they can include carbides or oxides of metallic elements (e.g., aluminum, titanium, tantalum, tungsten, chromium, or zirconium), or mixtures thereof, and a metallic binder, which is a pure metal or metal alloy and has cobalt, nickel, or iron as the main component of the binder.

[0120] As shown in the various figures, especially Figure 10a and 10b The polymer-ceramic panel 40 of this invention includes a polymer layer 42 with embedded ceramic inserts 44, thereby forming a wear surface. In the installed state including the liner 30 of the panel 40, the wear surface will face the inside of the grinding chamber 15 to be exposed to the material passing through the chamber 15.

[0121] Each wear-resistant insert 44 has an exposed surface that forms part of the wear surface of the polymer-ceramic panel 40, and thus part of the wear surface of the housing liner 30. The remainder of each insert 44 is immersed in the polymer material 42 of the panel 40. Figure 10b As shown, insert 44 protrudes slightly from polymer material 42, for example, about 2.5 mm.

[0122] On the side opposite to the ceramic insert 44, the polymer layer 42 of the panel 40 will be supported by the reinforcing plate 50, for example... Figures 7a-7b As shown, it is adhered to the reinforcing plate 50 through the vulcanized rubber layer 60.

[0123] The combination of wear-resistant components (e.g., ceramic element 44) and elastic layers (e.g., polymer layer 42) is advantageous because ceramics are primarily suited for compensating for sliding or abrasive wear, while polymers are primarily suited for compensating for impact wear. Therefore, the housing liner 30 of this invention provides a longer wear life than conventional liner types (e.g., PU liner). The reduction in wear will also reduce downtime required to replace worn components.

[0124] In summary, the relative proportions of the elastic material 42 and the wear-resistant insert 44 depend on the wear conditions and the attachment location and manner of the housing liner within the mill. According to one embodiment, the wear-resistant insert 44 may be arranged and distributed around the elastic material layer 42 such that the exposed surface of at least one region of the housing liner 30 is primarily composed of the wear-resistant element 44.

[0125] In the illustrated embodiment, ceramic inserts 44 are distributed across the entire surface of the polymer-ceramic panel 40. The inserts 44 are arranged in columns along the width direction of each panel 40, with one column of inserts 44 offset relative to the adjacent column of inserts 44 by the radius of one insert 44, thereby covering the panel 40 with inserts 44 to the best possible extent.

[0126] The wear-resistant insert 44 can also be attached to the elastic material layer 42 by vulcanization, for example by vulcanizing the ceramic insert 44 into the polymer-based material layer 42. Alternatively or additionally, the wear-resistant insert 44 can be mechanically held within the elastic material layer 42 by press fitting and / or form fitting.

[0127] There are several different possibilities for fixing the housing liner 30 of this invention to the housing 18 of the mill 1.

[0128] On one hand, the housing liner 30 can be removably secured within the housing 18 by securing the polymer-ceramic panel 40 itself within the housing 18. The resilient material layer 42 of the panel 40 can be removably secured to the housing 18 by any removable fastening means known in the art, such as by screws or bolts, by clamping or similar methods.

[0129] On the other hand, as shown in the above embodiments, the housing liner 30 may further include a reinforcing plate 50, in which case the housing liner 30 is suitably removably mounted within the housing 18 by securing the reinforcing plate 50 within the housing 18. The reinforcing plate 50 may then be secured to the housing 18 by any removable fastening means known in the art, such as by screws or bolts, by clamping or similar methods, or simply by sitting on a support structure (i.e., a form-fitting manner).

[0130] According to this invention, at least a portion of the exposed surface of the housing liner 30 constitutes a wear surface. The exposed surface is the surface of the housing liner 30 exposed within the grinding chamber 15, thus exposed to contact with material passing through the mill. The exposed surface of the wear-resistant insert 44 forms part of the wear surface of the housing liner 30. However, areas of the housing liner 30 outside this wear surface may not have any wear-resistant insert 44.

[0131] Uneven wear of the lining was observed in a stirred mill, with the lining in the lower compartment (feed end) wearing faster than that in the upper compartment (discharge end). One reason for this uneven wear may be that the grinding media beads are only partially fluidized, meaning that only a portion of their weight is supported by the upward flow of the feed slurry. The remaining weight falls downward through the packed bed of grinding media beads, resulting in the highest gravity at the bottom of the mill. This increases the forces acting on the mill casing, thus leading to a higher wear rate at the bottom of the mill.

[0132] Another reason for uneven wear may be that coarse feed particles are introduced into the bottom of the mill, which may also increase the wear rate at the bottom of the mill.

[0133] In the event of uneven wear of the housing liner 30, a single worn housing liner 30 can be replaced while the other liners remain unchanged, which reduces maintenance work and costs as well as spare parts costs.

[0134] Although not explicitly shown, the housing liner 30 of this invention may have further novel constructions to compensate for uneven wear. Indeed, uneven wear can also occur on a single liner, or even on a single polymer-ceramic panel of the liner according to this invention, because the areas of the liner 30 and panel 40 directly facing the rotor disk 12 during mill 1 operation suffer significantly stronger abrasive wear and therefore wear faster than other areas of the panel 40 or liner 30. To compensate for this phenomenon, the housing liner 30 of this invention may have raised or thickened areas, wherein the thickness of the polymer layer 42 and / or the dimension of the wear-resistant insert 44 in the thickness direction of the panel 40 is larger than that of other areas of the panel 40.

[0135] Figure 11 Corresponding to Figure 4 And schematically indicate the area 70 within the housing 18, where the corresponding raised or thickened areas of the housing liner 30 will be appropriately arranged.

[0136] Figure 12 Corresponding to Figure 9b And schematically indicates the raised protrusion 80 formed on the panel 40 of the housing liner 30. The protrusion 80 may extend only slightly from the panel 40 (e.g., corresponding to about 10% of the thickness of the panel 40), but may also extend significantly (e.g., corresponding to about 50% to 100% or more of the thickness of the panel 40).

[0137] Although the present invention has been described with reference to specific examples, those skilled in the art will understand that the present invention may be implemented in many other forms.

[0138] For example, although the housing liner 30 shown herein has a hollow semi-cylindrical shape, the housing liner 30 of this invention may have other cylindrical segment shapes, such as a hollow 1 / 3 cylinder (120-degree segment of the cylinder) or a hollow 1 / 4 cylinder (90-degree segment of the cylinder). The housing liner may also have a hollow full-cylindrical shape; in this case, the radius of the central opening 16 of the grinding element 80 must be larger than the outer radius of the rotor disk 12 to allow the drive shaft 11 and the rotor disk 12 to pass through the opening 16 during installation.

Claims

1. A housing liner for a stirred mill, characterized in that, The housing liner is configured to be removably mounted to the inside of the grinding mill housing within the grinding chamber of the grinding mill. Furthermore, wherein at least a portion of the surface of the housing liner exposed within the grinding chamber constitutes a wear surface, wherein the housing liner comprises: At least one polymer-ceramic panel, the polymer-ceramic panel comprising an elastic material layer and a wear-resistant insert held by the elastic material layer, wherein the exposed surface of the wear-resistant insert forms part of the wear surface of the housing liner.

2. The shell liner according to claim 1, characterized in that, The shell lining is bent into the shape of a section of a hollow cylinder.

3. The shell liner according to claim 1, characterized in that, It also includes a reinforcing plate that supports the at least one polymer-ceramic panel.

4. The shell liner according to claim 1, characterized in that, It also includes multiple polymer-ceramic panels arranged in at least one row and / or at least one column.

5. The shell liner according to claim 1, characterized in that, It also includes at least two polymer-ceramic panels spaced apart from each other in the height direction of the panels.

6. The shell liner according to claim 1, characterized in that, It also includes at least one mounting hole for securing stator elements, such as stator rings or sections thereof.

7. The shell liner according to claim 6, characterized in that, It also includes at least two polymer-ceramic panels spaced apart from each other in the height direction of the panel, wherein the at least one mounting hole is provided in the gap between the two panels.

8. The shell liner according to claim 1, characterized in that, The thickness of the first polymer-ceramic panel of the housing lining is greater than the thickness of the second polymer-ceramic panel of the housing lining. The thickness variation is caused by the different thicknesses of the elastic material layers of the panel and / or the different dimensions of the wear-resistant inserts in the thickness direction of the panel.

9. The shell liner according to claim 1, characterized in that, At least one polymer-ceramic panel of the housing lining has a raised or other thickened area, wherein the thickness of the elastic material layer and / or the dimension of the wear-resistant insert in the thickness direction of the panel is greater than that of other areas of the panel.

10. The shell liner according to claim 9, characterized in that, The protrusion or other thickened area is positioned where at least one polymer-ceramic panel is configured to face the rotor disk, which is configured to rotate within the grinding chamber of the grinder.

11. The shell liner according to claim 9, characterized in that, The protrusion or other thickened area extends along the width of the housing liner and thus extends along the inner periphery of the housing when the housing liner is mounted to the housing.

12. A stirring-type grinding mill, characterized in that, include: case; Grinding chamber; A stirring assembly arranged within the grinding chamber to rotate therein; as well as At least one housing liner, the housing liner comprising at least one polymer-ceramic panel, the polymer-ceramic panel comprising an elastic material layer and a wear-resistant insert held by the elastic material layer, wherein the exposed surface of the wear-resistant insert forms part of the wear surface of the housing liner. The at least one housing liner is removably installed to the inside of the housing within the grinding chamber.

13. The stirred grinding mill according to claim 12, characterized in that, The housing liner is removably mounted to the inside of the housing of the grinder by fastening an elastic material layer of at least one polymer-ceramic panel of the housing liner to the inside of the housing.

14. The stirred grinding mill according to claim 12, characterized in that, The housing liner also includes a reinforcing plate, and the housing liner is removably mounted to the inside of the housing of the grinder by fastening the reinforcing plate of the liner to the inside of the housing of the grinder.

15. The stirred grinding mill according to claim 12, characterized in that, The device includes multiple housing liners, wherein the thickness of at least one polymer-ceramic panel in the housing liner located closer to the bottom or feed end of the housing is greater than the thickness of at least one polymer-ceramic panel in the housing liner located closer to the top or discharge end of the housing. The thickness variation is caused by the panels having elastic material layers of different thicknesses and / or the wear-resistant inserts having different dimensions in the thickness direction of the panels.

16. The stirred grinding mill according to claim 12, characterized in that, The stirring assembly includes: A drive shaft having a plurality of rotor disks arranged along the length of the drive shaft, or A stirrer screw is arranged concentrically with the grinding chamber and located within the grinding chamber to rotate therein.

17. The stirred grinding mill according to claim 12, characterized in that, The grinding chambers are arranged either vertically or horizontally.

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