Composite lining plate of ore grinding and crushing equipment and preparation method of composite lining plate

Abstract

The invention relates to a composite lining plate of ore grinding and crushing equipment and a preparation method thereof, the composite lining plate comprises a plurality of lining plate bodies and metal ceramic blocks, the metal ceramic blocks are cast on the use surfaces of the lining plate bodies, and the surfaces of the metal ceramic blocks do not exceed the use surfaces of the lining plate bodies; a through hole is formed in the metal ceramic block, and when the lining plate body is cast, the lining plate body and the metal ceramic block are cast into a whole through the through hole. The surface of the metal ceramic block is not higher than the using surface of the lining plate body, and compared with a conventional lining plate, the structural design can effectively avoid the stress concentration problem caused by the surface height difference, so that the metallurgical bonding strength between the metal ceramic block and the lining plate body is greatly enhanced, and the service life of the lining plate is prolonged. When the composite lining plate bears frequent impact and friction in the ore grinding and crushing process, the composite lining plate and the composite lining plate are not prone to separation, the overall structural stability and durability of the lining plate are greatly improved, and the service life of the lining plate is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of mining machinery and equipment, and in particular to a composite lining plate of ore grinding and crushing equipment and a preparation method thereof. Background Art

[0002] In the complex and harsh working environment of ore grinding and crushing equipment, liners perform multiple critical functions. On the one hand, they are used to resist the impact and friction of the ore. When the equipment is running, the ore constantly hits and scrapes the surface of the liner. The liner's own wear-resistant properties protect the main structure of the equipment from wear and damage, thereby extending the service life of the equipment. On the other hand, the liner can optimize the material crushing effect. Its special shape and structural design can guide the ore to form a reasonable movement trajectory within the equipment, enhance the crushing and grinding efficiency, and ensure the output material has a uniform particle size. However, the hardness, particle size and abrasiveness of the ore vary significantly. When high-hardness ore continuously hits the surface of the liner, it will cause fatigue peeling of the surface material, groove wear, and even fracture cracks. The moisture content or sticky substances in the ore may aggravate the adhesive wear between the liner and the ore, resulting in thinning of the liner thickness and reduced structural strength over long-term operation.

[0003] Authorization Announcement Number: CN 107096904 A, Application Date: May 19, 2017. The invention is titled "A Method for Producing Wear-Resistant Composite Lining Plates," comprising the following steps: selecting fused zirconium corundum particles with a particle size of 2-3 mm, mixing them uniformly with 44.5 wt% water glass, and preforming them into cylindrical ceramic blocks using a mold. After forming, the blocks are dried at 250-300°C for 1-2 hours, sintered at 800-900°C for 10-15 minutes, and then cooled in the furnace. After complete cooling, the blocks are demolded and ready for use. This method effectively combines the ceramic particles with the metal matrix, cleverly utilizing the wear resistance of the ceramic, offering convenient operation, good formability, and facilitating large-scale production. Furthermore, the shape and distribution of the ceramic preform within the sand mold are rationally designed to effectively ensure the bonding of the molten metal to the ceramic block. Placing the ingate at the upper end of the preform prevents direct impact on the ceramic block while further enhancing the bonding between the metal and the preform.

[0004] The specifications for the aforementioned prior art describe a cylindrical ceramic block. When the cylinder meets the molten metal, the interface becomes a weak point in the metallurgical interface. This results in a less tight and secure bond, resulting in a low bond strength. During crusher operation, under the impact and compression of the material, these weak metallurgical interfaces are prone to cracking and separation, causing the metal-ceramic block to gradually separate from the liner, significantly shortening the service life of the composite liner. Summary of the Invention

[0005] In view of the defects of the above-mentioned prior art that the interface between the cylindrical ceramic block and the molten metal is a weak point in the metallurgical interface, the purpose of the present invention is to provide a composite lining plate for ore grinding and crushing equipment and a preparation method thereof that can effectively prevent the metal ceramic block from sliding or falling off laterally.

[0006] The technical solution provided by the present invention is:

[0007] A composite liner for ore grinding and crushing equipment, comprising a plurality of liner bodies;

[0008] It also includes a metal ceramic block, which is cast on the use surface of the liner body, and the surface of the metal ceramic block does not exceed the use surface of the liner body;

[0009] The metal ceramic block is provided with a through hole inside. When the lining plate body is cast, the lining plate body is melted into one body with the metal ceramic block through the through hole.

[0010] Furthermore, the metal ceramic block has no less than two through holes, and the through holes are circular or square.

[0011] Furthermore, the metal ceramic blocks are evenly distributed with gaps on the use surface of the liner body; and the net distance between two adjacent metal ceramic blocks is not less than 12 mm.

[0012] Furthermore, the metal ceramic block includes a single-row metal ceramic block and a multi-row metal ceramic block;

[0013] The through holes of the single-row metal ceramic block are arranged in a straight line, and the through holes of the multi-row metal ceramic block are arranged in an array.

[0014] Furthermore, a single metal ceramic block is placed horizontally or vertically on the use surface of the liner body.

[0015] Furthermore, for a single metal ceramic block, the net distance from the edge of the through hole to the edge of the metal ceramic block is A, and A is ≥ 10 mm.

[0016] Furthermore, when the through hole is circular, its diameter is B, and the range of B is 18 mm to 23 mm;

[0017] When the through hole is square, the side length is C, and the range of C is 20 mm to 25 mm.

[0018] Furthermore, when the through holes are circular, the net distance between adjacent through holes is D, and B / 2≤D≤B;

[0019] When the through holes are square, the net distance between adjacent through holes is E, and C / 2≤E≤C.

[0020] A method for preparing a composite liner for ore grinding and crushing equipment comprises the following steps:

[0021] S1: a prefabricated metal ceramic block with through holes;

[0022] S2: Make a foam white mold of the liner body, reserve a fitting portion on its use surface to match the metal ceramic block; place the metal ceramic block into the fitting portion;

[0023] S3: Evenly cover the surface of the foam white mold embedded with metal ceramic blocks with refractory coating and dry it in the sun to form an effective barrier layer;

[0024] S4: placing the foam white mold coated with refractory coating in a sand box and filling it with molding sand;

[0025] S5: Vacuum the air under negative pressure to compact the molding sand to fix the foam white mold and metal ceramic blocks;

[0026] S6: injecting the liner body metal liquid through the gate into the sand box, causing the foam white mold to vaporize and disappear due to heat, and the metal liquid fills the original foam model space and fills the through holes of the metal ceramic block, and generates an interface metallurgical bonding reaction with the metal ceramic block; the metal liquid is cast using a bottom pouring system;

[0027] S7: After the molten metal cools and solidifies, the blank workpiece is taken out and processed and heat treated in sequence to obtain the final product.

[0028] Furthermore, in step S1, positioning pieces are connected to the outer surface of the metal ceramic block, and each metal ceramic block is simultaneously connected to no less than three positioning pieces.

[0029] Furthermore, in step S4, the positioning piece is inserted obliquely downward into the molding sand to fix the metal ceramic block.

[0030] Furthermore, the positioning piece is a steel nail, and is connected to the metal ceramic block by welding.

[0031] Furthermore, in step S6, the furnace tapping temperature of the molten metal of the liner body is greater than 1500°C, and the pouring temperature is greater than 1480°C.

[0032] Furthermore, in step S7, the processing includes cutting the positioning parts; the heat treatment includes heating the finished product to 300-400°C, heating it to 1000-1050°C at a rate of 50-80°C per hour, keeping it warm for 2-3 hours, and then cooling it to room temperature with the furnace.

[0033] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0034] (1) The surface of the metal ceramic block of the present invention is not higher than the use surface of the liner body. Compared with conventional liners, this structural design can effectively avoid the stress concentration problem caused by the surface height difference, thereby greatly enhancing the metallurgical bonding strength between the metal ceramic block and the liner body. When the composite liner is subjected to frequent impact and friction during ore grinding and crushing, the two are not easily separated, which greatly improves the overall structural stability and durability of the liner and extends the service life of the liner.

[0035] (2) The present invention provides through holes within the metal ceramic block. These holes allow molten metal to penetrate the block during casting, forming a "metal anchor" structure after cooling and solidification. This provides the metal ceramic block with a pull-out resistance perpendicular to the interface, effectively preventing the metal ceramic block from sliding or falling off laterally under impact loads. When dealing with high-impact conditions such as ore crushing, the metal ceramic block can consistently and stably demonstrate its high hardness and high wear resistance, maintaining the wear resistance of the liner surface, effectively reducing equipment maintenance frequency, and lowering operating costs.

[0036] (3) The metal ceramic block of the present invention has no less than two through holes. On the one hand, the multiple through holes significantly increase the contact and bonding area between the molten metal and the metal ceramic block, further strengthening the metallurgical bonding between the two, making the structure of the composite lining plate more dense and stable at the microscopic level, and improving the overall mechanical properties. On the other hand, the diversified through hole arrangement method derives single-row metal ceramic blocks and multi-row metal ceramic blocks. Users can flexibly select the appropriate type of metal ceramic block according to actual working conditions such as different ore characteristics, working parameters of grinding and crushing equipment, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is an overall structural diagram of a composite liner in one embodiment of the present application;

[0038] Figure 2 This is a distribution diagram of metal ceramic blocks in one embodiment of the present application;

[0039] Figure 3 This is a schematic diagram of the structure of single-row metal ceramic blocks and multi-row metal ceramic blocks uniformly distributed on a composite liner in one embodiment of the present application;

[0040] Figure 4 This is a three-dimensional structural diagram of a single-row metal ceramic block with circular through holes in an embodiment of the present application;

[0041] Figure 5 This is a front view of a single-row metal ceramic block with circular through holes in one embodiment of the present application;

[0042] Figure 6 This is a three-dimensional structural diagram of a single-row metal ceramic block with square through holes in an embodiment of the present application;

[0043] Figure 7 This is a front view of a single-row metal ceramic block with square through holes in one embodiment of the present application;

[0044] Figure 8 This is a three-dimensional structural diagram of a multi-row metal ceramic block with circular through holes in one embodiment of the present application;

[0045] Figure 9 This is a front view of a multi-row metal ceramic block with circular through holes in one embodiment of the present application;

[0046] Figure 10 This is a three-dimensional structural diagram of a multi-row metal ceramic block with regular hexagonal through holes in one embodiment of the present application.

[0047] Explanation of the numbers in the schematic diagram:

[0048] Liner body 1;

[0049] Metal ceramic block 2, single-row metal ceramic block 21, and multi-row metal ceramic block 22. DETAILED DESCRIPTION

[0050] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0051] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the present invention and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the present invention without substantially changing the technical content.

[0052] The linings of ore grinding and crushing equipment face multiple failure risks such as high wear, high impact, and high corrosion due to their extremely harsh working environment.

[0053] In equipment like ball mills and crushers, high-frequency collisions and friction between ore and steel balls, and between ore and ore, can cause gouging and sliding wear on the liner surface. For example, hard ores like iron ore and gold ore have a Mohs hardness of 6-7, equivalent to the abrasive strength of quartz sand. Continuous friction can cause the liner surface to gradually thin and groove.

[0054] When mineral powder or mud flows at high speed in the equipment, the sharp particles in it will cause erosion and wear on the liner, similar to the "sandpaper polishing" effect.

[0055] When crushing equipment (such as jaw crushers and cone crushers) processes large-particle ore, the liners must withstand the transient impact loads caused by the falling or squeezing of the ore, which can cause surface cracks, localized dents, or even breakage. When a semi-autogenous grinding mill or ball mill rotates, the liners rotate with the drum, lifting the steel balls and ore to a certain height before dropping them. Repeated bending and shear stresses on the liners can easily lead to fatigue wear.

[0056] Example 1

[0057] The present application discloses a composite liner for ore grinding and crushing equipment, comprising a liner body 1 and a metal ceramic block 2. The metal ceramic block 2 is melt-cast on the use surface of the liner body 1, and the surface of the metal ceramic block 2 does not exceed the use surface of the liner body 1. The advantage of this design is that it avoids the stress concentration phenomenon caused by the metal ceramic block 2 protruding from the use surface. Stress concentration can easily lead to cracks at the joints between the metal ceramic block 2 and the liner body 1, thereby causing the metal ceramic block 2 to loosen or even fall off. The composite liner of the present application is designed to be flush with the liner body 1, so that the stress can be evenly dispersed along the surface of the liner, effectively enhancing the metallurgical bonding strength between the metal ceramic block 2 and the liner body 1, and ensuring the structural stability of the composite liner under long-term high-load working conditions.

[0058] Another solution is that the surface of the metal ceramic block 2 is slightly lower than the use surface of the liner body 1 by 0.5 to 3 mm, which can form a unique wear protection mechanism. After the liner body 1 is worn to a certain extent, the metal ceramic block 2 is gradually exposed and bears the main wear load (similar to the "gradient wear" mechanism), forming a natural "hard support layer".

[0059] The metal ceramic blocks 2 are evenly spaced across the working surface of the liner body 1. These evenly distributed metal ceramic blocks 2 act as "rigid fulcrums" embedded within the liner body 1. Through holes are provided within the metal ceramic blocks 2. During casting of the liner body 1, these holes allow molten metal to penetrate the interior of the metal ceramic blocks 2. After cooling and solidification, a "metal anchor" structure is formed, providing the metal ceramic blocks 2 with pull-out resistance perpendicular to the interface, effectively preventing lateral slippage or dislodging of the metal ceramic blocks 2 under impact loads. Preferably, the metal ceramic blocks are distributed in an array, staggered, or gradient pattern on the working surface of the liner body 1.

[0060] The net distance between two adjacent metal ceramic blocks 2 is not less than 12 mm, and the preferred spacing range is 12 mm to 20 mm. During pouring, this spacing allows the molten metal to flow more freely between the metal ceramic blocks, fully filling the bonding area between the liner body 1 and the metal ceramic block 2, and avoiding the situation where the molten metal is difficult to fully penetrate due to the small spacing, resulting in loose filling and loose bonding.

[0061] In terms of structural stability, this spacing arrangement creates a scientific "spaced support" layout for the metal ceramic blocks on the liner. When the composite liner is subjected to material compression and friction, each metal ceramic block 2 can distribute the load and evenly transmit the stress to the liner body 1 through the surrounding metal layer, avoiding stress concentration in a single area.

[0062] To ensure the structural strength of the metal ceramic block 2, for each metal ceramic block 2, the net distance from the edge of the through hole to the edge of the metal ceramic block 2 is A, A ≥ 10mm, forming an annular protective layer with a width of not less than 10mm. To ensure the bonding stability between the metal ceramic block 2 and the liner body 1, the metal ceramic block 2 preferably adopts a porous structure with at least two through holes. This structure significantly increases the contact area with the molten metal of the liner body 1 and strengthens the metallurgical bonding effect at the interface.

[0063] The through holes are preferably circular or square. When the through holes are circular, the diameter B ranges from 18 mm to 23 mm, and the clearance between adjacent through holes is D, where B / 2 ≤ D ≤ B. When the through holes are square, the side length C ranges from 20 mm to 25 mm, and the clearance between adjacent through holes is E, where C / 2 ≤ E ≤ C. It is worth noting that the clearance here refers to the vertical distance between the edges of adjacent through holes.

[0064] In addition, the through holes can also be regular polygons other than squares, such as regular hexagons. In this case, the diameter of the through hole circumscribed circle is 20 mm to 25 mm, and the net distance between adjacent through holes is not less than the radius of the through hole circumscribed circle and not greater than the diameter of the through hole circumscribed circle.

[0065] The net distance between adjacent through holes can ensure the structural strength of the metal ceramic block 2. The diameter requirement of the through hole ensures that the metal liquid of the liner body 1 is fully filled in the through hole, forming an evenly distributed "metal anchor" reinforcement structure, enhancing the mechanical interlocking performance of the metal ceramic block 2 and the liner body 1, and ultimately achieving an improvement in the overall wear resistance and impact resistance of the composite liner.

[0066] In addition, according to the requirements of different ore grinding and crushing equipment, the thickness of the metal ceramic block 2 is 10 mm to 70 mm.

[0067] The metal ceramic blocks 2 are classified according to the through hole type, including a single-row metal ceramic block 21 and a multi-row metal ceramic block 22. The through holes of the single-row metal ceramic block 21 are arranged in a straight line, while the through holes of the multi-row metal ceramic block 22 are arranged in an array.

[0068] According to the type of ore grinding and crushing equipment and the actual working conditions, single-row metal ceramic blocks 21, multi-row metal ceramic blocks 22, or a mixed layout of the two can be flexibly selected, and a single metal ceramic block 2 can be arranged horizontally or vertically on the liner body 1.

[0069] For example, when the arrangement is limited by space, a single row of metal ceramic blocks 21 is selected and placed vertically, which can not only ensure the wear resistance of the key area of ​​the working surface, but also avoid the problems of insufficient casting space and reduced bonding strength.

[0070] When the arrangement space is not restricted, multiple rows of metal ceramic blocks 22 can be selected and placed horizontally, and their array-type through-hole structure can be used to enhance the overall wear resistance and impact resistance; multiple rows of single-row metal ceramic blocks 21 can also be used and placed vertically, while ensuring the casting quality, the wear-resistant coverage area is expanded to meet the use requirements of the liner body 1 under high-intensity grinding conditions.

[0071] From the perspective of reducing the weight of the liner, the metal ceramic block 2 is composed of a composite of a metal phase and a ceramic phase. Compared with traditional single metal materials, its density is lower, which can effectively reduce the weight of the liner. In addition, due to the excellent wear resistance of the metal ceramic block 2, the degree of wear of the liner is reduced during use, reducing the need to thicken the liner due to excessive wear. In order to ensure the service life, traditional liners often need to increase the thickness, resulting in a significant increase in weight. However, due to the characteristics of the metal ceramic block 2, the composite liner does not need to be excessively thickened, thereby effectively controlling the overall quality. The lightweight composite liner can not only reduce the energy consumption of ore grinding and crushing equipment during operation, reduce the mechanical loss of the equipment due to weight, but also reduce the manpower and material costs during equipment installation and maintenance.

[0072] Example 2

[0073] This embodiment describes a method for preparing a composite liner based on embodiment 1.

[0074] S1: a prefabricated metal ceramic block 2 with a through hole;

[0075] S2: Make a foam white mold of the liner body 1, and reserve a fitting portion on its use surface to match the metal ceramic block 2. Place the metal ceramic block 2 into the fitting portion;

[0076] S3: evenly cover the surface of the foam white mold embedded with the metal ceramic block 2 with the refractory coating and dry it to form an effective barrier layer;

[0077] S4: placing the foam white mold coated with refractory coating in a sand box and filling it with molding sand;

[0078] S5: Vacuuming with negative pressure to compact the molding sand to fix the foam white mold and the metal ceramic block 2;

[0079] S6: The molten metal of the liner body 1 is injected into the sand box through the gate, so that the foam white mold is vaporized and disappears due to heat, and the molten metal fills the original foam model space and undergoes an interface metallurgical bonding reaction with the metal ceramic block 2; a bottom pouring system is used for the molten metal casting.

[0080] S7: After the molten metal cools and solidifies, the blank workpiece is taken out and processed and heat treated in sequence to obtain the final product.

[0081] The preparation process of the metal ceramic block 2 in step S1 is carried out as follows:

[0082] Raw material selection and proportioning: A high-temperature-resistant casting inorganic binder, FeCrC self-fluxing alloy powder, and ceramic particles are precisely mixed in a mass ratio of 0.4:3:7 to 0.5:4:8. The ceramic particles are selected from 10-20 mesh zirconium corundum, black corundum, silicon carbide, or boron carbide. These particles are hard and wear-resistant, significantly enhancing the liner's wear resistance. The binder, a compound of high-temperature-resistant inorganic mineral powder and inorganic resin, exhibits excellent high-temperature bonding properties, capable of withstanding the intense impact of molten metal at temperatures exceeding 1400°C, ensuring the liner's structural stability under high-temperature conditions. The FeCrC alloy powder particle size is controlled between 0.5 and 30 μm, and its addition level is 25% to 35% of the ceramic particle mass. The FeCrC alloy powder exhibits excellent self-fluxing properties, forming a strong metallurgical bond with the ceramic particles and binder at high temperatures, enhancing the overall strength of the composite liner.

[0083] Mixing Process: The above raw materials are placed in a blender and thoroughly mixed using mechanical stirring. During the mixing process, the stirring speed and duration are controlled to ensure that the FeCrC alloy powder adheres evenly to the surface of the ceramic particles, forming metal-ceramic hybrid particles coated with a binder. This mixing process ensures full contact and uniform dispersion of the raw materials, laying the foundation for the subsequent casting process and ensuring uniform and stable performance across all parts of the composite liner.

[0084] Molding Process: A foaming mold is used as the molding medium, and the mold cavity is quantitatively filled with uniformly mixed metal-ceramic particles. Mechanical compaction and vibration are used in synergy. During the compaction process, hydraulic pressure is applied to achieve initial densification of the material. Simultaneously, a vibration device is activated, using vibration energy to promote the mutual filling and sliding of material particles, expelling internal air and eliminating voids, achieving a high degree of material density. After compaction and vibration, the mold is left to rest, allowing the material to further shape naturally and form a stable green body structure, providing a good foundation for subsequent drying processes.

[0085] Drying process: The shaped green body is transferred to a drying device with temperature control function. A step-by-step heating strategy is adopted, and the temperature is gradually heated to 200-250°C at a heating rate of 80-150°C / h. This heating rate can effectively avoid the large temperature difference between the inside and outside of the green body caused by too fast heating, which will cause thermal stress and cause defects such as cracking and deformation. After reaching the target temperature, insulation treatment is carried out to fully evaporate the moisture inside the green body and promote the initial solidification of the binder. After the insulation is completed, the heating system is turned off and the green body is allowed to slowly cool to room temperature with the furnace. During this process, a series of physical and chemical reactions occur inside the green body, and eventually a metal ceramic block 2 with a porous structure is formed.

[0086] This structure not only gives the metal ceramic block 2 the characteristics of lightness and high strength, but also reduces the overall weight of the composite liner and improves the comprehensive performance of the liner.

[0087] It is worth noting that after each metal ceramic block 2 is formed, it is welded with no less than three positioning pieces, and the positioning pieces are preferably steel nails. During the molding sand landfill process of step S4, the metal ceramic block 2 with the positioning piece is inserted into the molding sand of the sand box, the insertion depth is not less than 80 mm, and the positioning piece is inserted into the molding sand obliquely downward, with an inclination angle of 30° to 60°. The molding sand is compacted by negative pressure evacuation (step S5), and the molding sand particles tightly wrap the positioning piece to form a mechanical embedding force, which is equivalent to the anchoring effect of "concrete steel bars".

[0088] At the same time, when the molten metal of the liner body 1 is being poured, the metal ceramic block 2 may tend to float upward due to the density difference with the molten metal. The positioning member, through the dual effects of gravity and friction in the insertion direction, simultaneously controls the insertion depth and direction, providing a downward anchoring force for the metal ceramic block 2 and the foam white mold, counteracting the upward floating tendency of the metal ceramic block 2. This effectively resists the impact force and buoyancy during the casting of the liner body 1.

[0089] In step S2, EPS foam is preferably used and cut and shaped to create a foam blank mold for the liner body 1. A mating portion precisely matching the shape and size of the metal ceramic block 2 is milled or engraved on the working surface of the foam blank mold. The prefabricated metal ceramic block 2 is placed into the mating portion and temporarily secured using hot melt adhesive or a specialized foam adhesive.

[0090] In step S3, the foam white mold is subjected to at least three dipping processes. After each dipping, it is placed in a constant temperature dry environment for sufficient drying to make the coating thickness uniform and dense, forming an effective barrier layer. This process can effectively resist the thermal shock of the metal liquid, reduce the thermal decomposition rate of the foam white mold during the pouring process, and significantly improve the molding accuracy and surface quality of the casting.

[0091] In steps S4 and S5, a bottom pouring system is used, and the specific process is: laying bottom sand → placing foam white mold → filling molding sand (filling to 90% height for the first time) → vibration compaction → starting the negative pressure system to evacuate air → covering with sealing film → adding floating sand.

[0092] The negative pressure technology not only improves the compactness of the molding sand, but also realizes the mechanical anchoring of the metal ceramic block 2 and the foam white mold through the positioning parts, thereby enhancing the composite effect.

[0093] Among them, the bottom pouring system is adopted for casting the molten metal. The molten metal is smoothly injected from the bottom gate of the sand mold. Through the "bottom-up" filling method, it has the following advantages.

[0094] Firstly, the splashing and oxidation of the molten metal are suppressed. The molten metal rises slowly along the bottom of the sand mold, avoiding the splashing and turbulence caused by the high-speed impact of the molten metal on the liner body 1 in top pouring, reducing the contact area between the molten metal of the liner body 1 and the air, thereby significantly suppressing the oxidation slag defect.

[0095] Secondly, the gas exhaust path is optimized so that the air in the cavity can be naturally discharged along the rising direction of the molten metal. Combined with the sealing film covering the top, a "one-way exhaust channel" is formed to prevent gas from being trapped and forming pores.

[0096] Finally, the structure of the metal ceramic block 2 is protected, and the smooth flow of molten metal reduces the scouring force on the foam white mold and the metal ceramic block 2, which is especially suitable for the composite casting of the honeycomb metal ceramic block 2, preventing the molten metal in the through hole from generating turbulence due to severe impact, and ensuring the uniform molding of the "metal anchor" structure.

[0097] In the step-by-step filling process of molding sand, the first filling to 90% of the sand box height creates key conditions for subsequent processes:

[0098] First, ensure a 10% filling margin to provide a buffer space for the vibration compaction process, so that the molding sand particles can fully move and fit together during the vibration process, avoiding voids or uneven compaction inside the molding sand due to one-time filling.

[0099] Secondly, the negative pressure system activated after step-by-step filling can avoid uneven local pressure when the film is covered due to overfilling of the molding sand, ensuring that the sealing film fits tightly to the molding sand surface. At the same time, the 90% filling height makes it easier to expel air from the molding sand.

[0100] Finally, the reserved 10% space is used to add floating sand, forming a uniform buffer layer. The floating sand layer absorbs high-temperature radiant heat during molten metal pouring, reducing the temperature gradient on the sand mold surface and slowing thermal expansion of the sand mold surface.

[0101] Through the synergistic effect of bottom pouring and step-by-step filling, the scrap rate of composite liner casting is reduced, and the casting quality and production efficiency are significantly improved.

[0102] In step S6, the high manganese steel, ultra-high manganese steel or chromium-molybdenum alloy raw material is melted to a furnace temperature greater than 1500°C, and the pouring temperature is controlled to be greater than 1480°C to ensure that the molten metal of the liner body 1 has good fluidity, fully infiltrates with the metal ceramic block at high temperature and undergoes an interfacial metallurgical reaction.

[0103] In step S7 , during the processing of the blank workpiece after cooling and solidification, the positioning piece is preferably removed by laser cutting technology to ensure that thermal damage to the liner body 1 and the metal ceramic block 2 is avoided while cutting off the positioning piece.

[0104] Then enter the surface machining stage, the lining body 1 is ground on its use surface, and the surface of the metal ceramic block 2 is polished by a grinding process to make the surface hardness of the metal ceramic block 2 uniform, creating good surface conditions for subsequent heat treatment.

[0105] The heat treatment process uses a staged heating process. First, the finished product is heated to 300-400℃. After preheating, the workpiece is heated to 1000-1050℃ at a rate of 50-80℃ per hour. This stage can greatly reduce the thermal stress of the liner during the subsequent heating process. The composite liner is composed of a liner body 1 and a metal ceramic block 2. There is a difference in the thermal expansion coefficients of the two materials. If the temperature is directly increased rapidly, the rapid temperature change will generate large thermal stress inside the material, which may cause cracks in the joint between the metal ceramic block 2 and the liner body 1, or even cause the metal ceramic block 2 to fall off. By preheating to 300-400℃, the entire liner is heated slowly and evenly, so that thermal expansion proceeds synchronously, effectively avoiding structural damage caused by concentrated thermal stress and laying a good foundation for subsequent heat treatment.

[0106] After preheating is completed, the workpiece is heated to 1000-1050°C at a rate of 50-80°C per hour. This heating rate ensures that the lining material undergoes sufficient structural transformation at high temperatures while preventing the adverse effects of excessively rapid heating. Metal materials undergo structural transformations such as austenitization at high temperatures, allowing the lining body 1 to acquire good toughness and strength. For the metal ceramic block 2, slow heating can prevent the separation of the ceramic and metal phases due to sudden temperature changes, maintaining the structural stability and wear resistance of the ceramic block. If the heating rate is too rapid, on the one hand, it may lead to incomplete structural transformation within the material, affecting the final performance of the lining; on the other hand, the thermal shock caused by rapid heating will damage the lining structure and reduce its service life.

[0107] The heat treatment is carried out for 2 to 3 hours. After the heat treatment, the heat treatment is followed by cooling at a rate of 10 to 20°C / h, which allows the austenite to slowly transform into a uniform and fine structure of pearlite and ferrite. The composite lining after the heat treatment has excellent wear resistance and impact resistance.

[0108] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A composite liner for ore grinding and crushing equipment, comprising a plurality of liner bodies (1); characterized in that: It also includes a metal ceramic block (2), the metal ceramic block (2) is melt-cast on the use surface of the liner body (1), and the surface of the metal ceramic block (2) does not exceed the use surface of the liner body (1); A through hole is provided inside the metal ceramic block (2). When the lining plate body (1) is cast, the lining plate body (1) is melted and cast into one piece with the metal ceramic block (2) through the through hole.

2. The composite liner for ore grinding and crushing equipment according to claim 1, characterized in that: The metal ceramic block (2) has no less than two through holes, and the through holes are circular or square.

3. The composite liner for ore grinding and crushing equipment according to claim 2, characterized in that: The metal ceramic blocks (2) are evenly distributed on the use surface of the lining plate body (1) with gaps; the net distance between two adjacent metal ceramic blocks (2) is not less than 12 mm.

4. The composite liner for ore grinding and crushing equipment according to claim 2, characterized in that: The metal ceramic blocks (2) include single-row metal ceramic blocks (21) and multi-row metal ceramic blocks (22); The through holes of the single-row metal ceramic block (21) are arranged in a straight line, and the through holes of the multi-row metal ceramic block (22) are arranged in an array.

5. The composite liner for ore grinding and crushing equipment according to claim 4, characterized in that: The single metal ceramic block (2) is placed horizontally or vertically on the use surface of the lining plate body (1).

6. The composite liner for ore grinding and crushing equipment according to claim 1, characterized in that: For a single metal ceramic block (2), the net distance from the edge of the through hole to the edge of the metal ceramic block (2) is A, and A is ≥ 10 mm.

7. The composite liner for ore grinding and crushing equipment according to claim 2, characterized in that: When the through hole is circular, its diameter is B, and the range of B is 18mm to 23mm; When the through hole is square, the side length is C, and the range of C is 20 mm to 25 mm.

8. The composite liner for ore grinding and crushing equipment according to claim 7, characterized in that: When the through holes are circular, the net distance between adjacent through holes is D, B / 2≤D≤B; When the through holes are square, the net distance between adjacent through holes is E, and C / 2≤E≤C.

9. A method for preparing a composite liner for ore grinding and crushing equipment, characterized by: The following steps are included: S1: a prefabricated metal ceramic block with through holes; S2: Make a foam white mold of the liner body, reserve a fitting portion on its use surface to match the metal ceramic block; place the metal ceramic block into the fitting portion; S3: Evenly cover the surface of the foam white mold embedded with metal ceramic blocks with refractory coating and dry it in the sun to form an effective barrier layer; S4: placing the foam white mold coated with refractory coating in a sand box and filling it with molding sand; S5: Vacuum the air under negative pressure to compact the molding sand to fix the foam white mold and metal ceramic blocks; S6: injecting the liner body metal liquid through the gate into the sand box, causing the foam white mold to vaporize and disappear due to heat, and the metal liquid fills the original foam model space and fills the through holes of the metal ceramic block, and generates an interface metallurgical bonding reaction with the metal ceramic block; the metal liquid is cast using a bottom pouring system; S7: After the molten metal cools and solidifies, the blank workpiece is taken out and processed and heat treated in sequence to obtain the final product.

10. The method for preparing a composite liner for ore grinding and crushing equipment according to claim 9, characterized in that: In step S1 , positioning pieces are connected to the outer surface of the metal ceramic block, and each metal ceramic block is simultaneously connected to no less than three positioning pieces.

11. The method for preparing a composite liner for ore grinding and crushing equipment according to claim 10, characterized in that: In step S4, the positioning piece is inserted into the molding sand at an angle downward to fix the metal ceramic block.

12. The method for preparing a composite liner for ore grinding and crushing equipment according to claim 10, characterized in that: The positioning piece is a steel nail, and is connected to the metal ceramic block by welding.

13. The method for preparing a composite liner for ore grinding and crushing equipment according to claim 10, characterized in that: In step S6, the furnace temperature of the molten metal of the liner body is greater than 1500°C, and the pouring temperature is greater than 1480°C.

14. The method for preparing a composite liner for ore grinding and crushing equipment according to claim 13, characterized in that: In step S7, the processing includes cutting the positioning piece; the heat treatment includes heating the finished product to 300-400°C, heating it to 1000-1050°C at a rate of 50-80°C per hour, keeping it warm for 2-3 hours, and then cooling it to room temperature with the furnace.

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