A semi-autogenous mill hollow shaft liner bushing

Abstract

This invention provides a hollow shaft liner for a semi-autogenous grinding mill. The hollow shaft is housed within the discharge end cover of the mill, and a liner is installed on the inner wall of the shaft. The liner has an annular flared opening with a large diameter of 1900–1920 mm and a small diameter of 1730–1750 mm, with a distance of 1650–1660 mm between the two openings. A magnetic liner plate is laid on the inner wall of the liner plate, and the magnetic liner plate is bonded to the inner wall of the liner plate by bonding the N and S poles together to form an inner liner ring. Five to six inner liner rings are arranged side by side. This invention significantly extends the service life of the hollow shaft liner for the semi-autogenous grinding mill. By adsorbing magnetic materials and grinding media in the slurry through the magnetic liner plate, a dynamic protective layer is formed on the surface of the magnetic liner plate, reducing the liner wear rate by more than 70% and extending its service life.

Description

Technical Field

[0001] This utility model belongs to the field of semi-autogenous grinding mill technology, and specifically relates to a hollow shaft inner liner bushing for a semi-autogenous grinding mill. Background Technology

[0002] The semi-autogenous mill bushing in the concentrator's grinding and flotation system operates inside the discharge end cover of the semi-autogenous mill. It is bolted to the discharge end cover and the bearing housing. Its core function is to isolate the slurry from the hollow shaft, preventing direct scouring and wear of the hollow shaft by the slurry. It is a critical and easily worn component of the mill. Currently, the semi-autogenous mill bushing has the following problems: Rapid wear rate: The bushing surface has no effective protective structure and is continuously subjected to high-velocity slurry scouring and material impact during the production process, which leads to a sharp increase in wear over time and a continuous reduction in thickness, making it difficult to provide stable protection for a long period of time.

[0003] Poor maintenance effect: The existing remedial measure is to roll and paste a 12mm thick steel plate onto the bushing surface. However, due to the poor fit between the steel plate and the bushing surface, the gap is often greater than 5mm, which cannot form an effective protective layer and has a limited effect on alleviating wear.

[0004] Installation is complex: This spare part is heavy, the replacement process is cumbersome and labor-intensive, and the spare part itself is relatively expensive. The bushing is bolted to the mill body, requiring workers to enter the mill interior during installation, where the operating space is confined and the labor intensity is high. Maintenance and replacement also require significant manpower and resources; the process of disassembling and installing bolts is tedious, increasing maintenance and time costs. Furthermore, the harsh working environment inside the mill poses certain safety risks and threatens the personal safety of workers. Utility Model Content

[0005] To address the aforementioned problems, this utility model provides a hollow shaft liner for a semi-autogenous mill, which can effectively adsorb magnetic substances in the grinding media and materials while reducing wear on the hollow shaft liner.

[0006] This utility model is achieved through the following technical solution: A hollow shaft inner liner for a semi-autogenous grinding mill is disclosed. The hollow shaft is disposed within the discharge end cover of the semi-autogenous grinding mill. A liner is provided on the inner wall of the hollow shaft. The inner part of the liner is configured as an annular flared opening with a large opening diameter of 1900-1920 mm, a small opening diameter of 1730-1750 mm, and a distance of 1650-1660 mm between the large and small openings. A magnetic liner plate is laid on the inner wall of the liner plate. The magnetic liner plate is bonded to the inner wall of the liner plate by bonding the N pole and S pole to form an inner liner ring. The inner liner ring consists of 5-6 rings arranged side by side.

[0007] This invention utilizes the magnetic field generated by the magnetic liner body to effectively attract magnetic substances from the grinding media and materials, constructing a dynamic protective layer (inner liner ring) on ​​the surface of the hollow shaft inner bushing. As grinding operations continue, although this protective layer is constantly worn down, the magnetic substances from the grinding media and materials within the mill continuously replenish the surface of the inner liner ring, maintaining its integrity. Thanks to the isolation effect of the protective layer, direct contact between the grinding media / materials and the bushing body is significantly reduced; wear and impact primarily act on the protective layer (inner liner ring), thus significantly extending the service life of the bushing body. The inner liner ring is composed of multiple magnetic liners assembled magnetically. When a part is damaged, it is not necessary to disassemble the entire unit; only the damaged section of the magnetic liner needs to be replaced, greatly reducing costs.

[0008] Preferably, the magnetic liner has a length of 275–332 mm, a width of 53–55 mm, and a thickness of 3–5 mm.

[0009] The length of the magnetic liner is the same as the width of the inner liner. If the magnetic liner is too large, it will be too heavy to fit the inner surface of the bushing, while if the magnetic liner is too small, too many will be needed.

[0010] Preferably, the magnetic induction intensity on the surface of the magnetic liner is ≥600 Gauss.

[0011] If the magnetic induction intensity is too low, the magnetic liner will not be able to adhere to the inner surface of the bushing; if the magnetic induction intensity is too high, it will be difficult to remove the magnetic liner when it is replaced.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model significantly extends the service life of the hollow shaft inner liner of a semi-autogenous mill. By adsorbing magnetic materials and grinding media in the slurry through the magnetic liner, a dynamic protective layer is formed on the surface of the magnetic liner, which reduces the wear rate of the liner by more than 70% and extends its service life.

[0013] 2. This utility model has low maintenance costs. The surface of the magnetic liner layer is always in a dynamic balance of "wear-replenishment". Only the part of the magnetic liner that fails is replaced, which reduces the number of liner maintenance and liner replacement frequency and reduces the labor intensity of workers.

[0014] 3. The protective layer on the surface of the magnetic liner reduces the friction between the grinding media and materials and the liner, thereby reducing the energy consumption required for the mill to operate. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the installation structure of a semi-autogenous grinding mill.

[0016] Figure 2This is a schematic diagram of the hollow shaft inner liner bushing structure.

[0017] Figure 3 This is a schematic diagram of the magnetic liner mounting structure in the embodiment.

[0018] Attached reference numerals: 1-Hollow shaft, 2-Magnetic liner, 3-Bushing, 4-Semi-autogenous mill, 5-Discharge end cover, 6-Inner liner ring. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings. In the embodiments, unless otherwise specified, the technical means used are all conventional technical means in the art. Example

[0020] A hollow shaft inner liner for a semi-autogenous mill, wherein the hollow shaft 1 is disposed inside the discharge end cover 5 of the semi-autogenous mill 4, and a bushing 3 is provided on the inner wall of the hollow shaft 1, such as... Figure 2 As shown, the bushing 3 has an annular flared opening inside. The bushing 3 body is made of ZG30CrMnSi high-strength quenched and tempered structural steel. The inner wall is machined with an annular flared opening. The diameter of the small flared opening is 1730mm, the diameter of the large flared opening is 1900mm, and the spacing is 1650mm.

[0021] The inner wall of the bushing 3 is provided with an inner liner ring 6 composed of several magnetic liner plates 2. The curvature of the magnetic liner plates 2 matches the curvature of the inner wall of the bushing 3. The magnetic liner plates 2 are attached to the inner wall of the bushing 3 after forming the inner liner ring 6 by bonding the N pole and S pole. The magnetic induction intensity of the surface of the magnetic liner plates 2 is ≥600 Gauss. The dimensions of the magnetic liner plates 2 are 275mm in length, 53mm in width, and 3mm in thickness.

[0022] Magnetic liner 2 is made of wear-resistant alloy non-magnetic steel cut into an arc shape, with the arc consistent with the inner wall of the bushing. Magnetic liner 2 is assembled inside the bushing 3, consisting of six inner liner rings 6. Figure 3 As shown. Based on the flared shape of the bushing 3, the number of inner bushings from the first ring to the sixth ring are 31.5, 33, 33.5, 34, 34.5, and 35 respectively. Except for the beginning and end, the adjacent magnetic bushings 2 are seamlessly bonded.

[0023] The specific assembly process is as follows: Step 1: Remove impurities from the inner ring of the semi-self-grinding bushing 3 to ensure the inner wall is as clean as possible. Attach the magnetic liner 2 into the bushing 3 to form the first inner liner ring 6, ensuring that the contact surface of the magnetic liner 2 coincides with the surface of the bushing 3. Attach the remaining inner liner rings 6 in the same way. Step 2: After completing the full circle of bonding, small gaps will be left in each circle. These gaps will be filled by inserting non-magnetic materials such as wood, and then filled with glue or other materials to facilitate the subsequent removal and replacement of the lining.

[0024] Step 3: Adjust the adjacent magnetic backing plates 2 to make them evenly distributed and compact, and complete the assembly.

[0025] 3. Operation and Maintenance: ① Before driving, check the adsorption force of the magnetic liner 2 to ensure that the adsorption is firm and there is no detachment.

[0026] ② After running for 3 months, check the gap of magnetic liner 2. If it exceeds 15mm, adjust it with shims.

[0027] ③ When the thickness of the protective layer (magnetic liner 2) is less than 1mm, stop the machine, clean the residual material on the surface, and replace the magnetic liner 2 at that location. Example

[0028] This embodiment is a further improvement based on Embodiment 1, as detailed below: The small flared mouth has a diameter of 1750mm, the large flared mouth has a diameter of 1920mm, the spacing is 1660mm, the magnetic liner 2 is 332mm long, 55mm wide, and 4mm thick. A total of five inner liner rings 6 are provided, and the number of magnetic liner rings 2 in each inner liner ring 6 is adjusted according to their dimensions.

[0029] The installation method in this embodiment is the same as that in Embodiment 1. Example

[0030] This embodiment is a further improvement based on Embodiment 1, as detailed below: The small flared mouth has a diameter of 1740mm, the large flared mouth has a diameter of 1910mm, the spacing is 1655mm, the magnetic liner 2 has a length of 320mm, a width of 54mm, and a thickness of 5mm. A total of unweighted inner liner rings 6 are provided, and the number of magnetic liner rings 2 in each inner liner ring 6 is adjusted according to their size.

[0031] The installation method in this embodiment is the same as that in Embodiment 1.

[0032] The above embodiments are merely exemplary embodiments of this utility model and are not intended to limit this utility model. The protection scope of this utility model is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this utility model within its substance and protection scope, and such modifications or equivalent substitutions should also be considered to fall within the protection scope of this utility model.

Claims

1. A hollow shaft inner liner for a semi-autogenous grinding mill, wherein the hollow shaft (1) is disposed inside the discharge end cover (5) of the semi-autogenous grinding mill (4), and a bushing (3) is provided on the inner wall of the hollow shaft (1), characterized in that: The bushing (3) is configured with an annular flared opening inside, with a large opening diameter of 1900-1920mm, a small opening diameter of 1730-1750mm, and a distance between the large and small openings of 1650-1660mm. The inner wall of the bushing (3) is covered with a magnetic liner (2). The magnetic liner (2) is attached to the inner wall of the bushing (3) after the N pole and S pole are bonded together to form an inner liner ring (6). The inner liner ring (6) consists of 5 to 6 rings arranged side by side.

2. The hollow shaft liner of the semi-autogenous mill according to claim 1, characterized in that: The magnetic liner (2) has a length of 275-332 mm, a width of 53-55 mm, and a thickness of 3-5 mm.

3. The hollow shaft liner of the semi-autogenous mill according to claim 1, characterized in that: The magnetic induction intensity of the surface of the magnetic liner (2) is ≥600 Gauss.

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