A semi-autogenous mill discharge chute liner capable of effectively prolonging service life

Abstract

The application discloses a semi-autogenous mill discharge chute lining plate capable of effectively prolonging service life, which comprises a bottom plate, a spacing plate, an arc-shaped end head plate and wear-resistant bosses, the spacing plate is arranged above the middle part of the bottom plate, the arc-shaped end head plate is arranged above the large end of the bottom plate, the wear-resistant bosses are symmetrically arranged on the inner side of the arc-shaped end head plate with the spacing plate as the center, the two edges of the bottom plate are respectively narrowed by 10mm, and the radius of the small head arc edge is increased by 5mm, the spacing plate is in the shape of trapezoid, and the material of the discharge chute lining plate is high manganese steel, and the contents of C, Cr and Mn are increased. The contents of C, Cr and Mn are increased to increase the wear resistance of the material, the wear-resistant bosses are arranged at the position of the inner side of the arc-shaped end head plate which is most seriously impacted, so that the whole discharge chute lining plate can be uniformly worn to prolong the service life, and the gap between the edges of every two lining plates is 20mm in nominal size, so that the interference phenomenon is avoided during the installation of the lining plate, and the replacement time of the lining plate is shortened.

Description

Technical Field

[0001] This invention belongs to the field of mining equipment technology, and further to the field of grinding equipment technology. Specifically, it relates to a semi-autogenous mill discharge trough liner that is simple in structure, easy to install, reliable in operation, and can effectively extend its service life. Background Technology

[0002] A semi-autogenous grinding mill (SAG) consists of a rotating body containing a certain amount of grinding media (steel balls, typically 8%–12% filling rate). Under the influence of centrifugal force and friction, the grinding media and ore are lifted to a certain height as the mill rotates, and then thrown down at a certain linear velocity, undergoing free fall. Iron ore is continuously fed into the mill through a feed trolley accompanied by water flow. It is ground through continuous and intense impacts between the ore and steel balls, as well as between the steel balls and the mill liner, achieving the grinding purpose. The ground, qualified material is then discharged from the mill by the force of the water flow, entering the next process stage. The SAG is a crucial piece of equipment in mineral processing, primarily responsible for the primary crushing of large pieces of raw ore. It is the leading piece of equipment in the process; if the SAG stops operating, it will affect subsequent mineral processing steps, thus impacting the entire mineral processing production line.

[0003] The semi-autogenous grinding mill consists of a main motor, pneumatic clutch, gear transmission unit, slow-disc device, bearing unit, and rotating body unit. The rotating body unit is the main component of the semi-autogenous grinding mill, comprising end caps at both ends and a cylinder. The rotating body is internally lined with liners secured with special bolts. Rubber gaskets are installed between the liners and the cylinder and end caps to cushion the impact of steel balls on the cylinder and to help the liners fit tightly against the inner wall of the cylinder. Rubber sealing gaskets and special metal gaskets are placed under the nuts on the outside of the cylinder to prevent slurry leakage.

[0004] Liners are key consumable parts of semi-autogenous grinding mills, made of high-manganese steel. They protect the mill cylinder and end caps from direct impact and friction from the grinding media and materials. Different liner designs can also be used to adjust the movement of the grinding media, enhancing their crushing effect on the material. This helps improve the mill's grinding efficiency, increase output, and reduce metal consumption. The service life of the liners directly affects the mill's operating rate. In existing semi-autogenous grinding mills, the discharge chute liner is installed below the discharge end grid plate. During operation, the steel balls and slurry behind the discharge end grid plate, under centrifugal force, continuously scour the end of the discharge chute liner, causing severe wear on the impacted areas and even wearing through the liner. This reduces the overall service life of the discharge chute liner; currently, the average service life is only about 5 months. Furthermore, the current discharge chute liner structure is inconvenient for installation. While the nominal gap between the edges of every two liners is 10mm, manufacturing errors result in gaps that are too small, even causing interference. This leads to excessively long liner replacement times; for example, replacing a set of Φ8.53×4.27 m semi-autogenous mill discharge chute liners requires 40 hours, resulting in significant downtime and production disruptions. Therefore, developing a semi-autogenous mill discharge chute liner with a simple structure, easy installation, reliable operation, and effectively extended service life is crucial to solving this problem. Summary of the Invention

[0005] The purpose of this invention is to provide a semi-autogenous mill discharge trough liner that is simple in structure, easy to install, reliable in operation, and can effectively extend its service life.

[0006] The objective of this invention is achieved as follows: the unloading trough liner includes a bottom plate, a partition plate, an arc-shaped end plate, and wear-resistant bosses. The partition plate is disposed above the middle part of the bottom plate; the arc-shaped end plate is disposed above the large end of the bottom plate; one wear-resistant boss is symmetrically disposed on each side of the arc-shaped end plate with the partition plate as the center; the fan-shaped sides of the bottom plate are narrowed by 10mm, and the radius of the arc edge of the small end is increased by 5mm; the partition plate is trapezoidal; the unloading trough liner is made of high manganese steel, with increased C, Cr, and Mn content.

[0007] This invention improves the weight fraction of each component in the unloading trough liner by increasing the content of C, Cr, and Mn, thereby achieving better mechanical properties and increasing the material's wear resistance. Wear-resistant bosses are set on the inner side of the arc-shaped end plate at the location most severely impacted, allowing the entire unloading trough liner to wear evenly and extend its service life. The fan-shaped sides of the bottom plate are narrowed by 10mm each, and the radius of the small end arc edge is increased by 5mm, so that the nominal gap between the edges of every two liners is 20mm, to compensate for manufacturing errors, avoid interference during liner installation, shorten liner replacement time, and thus reduce downtime for maintenance.

[0008] The service life of the unloading chute liner of this invention is extended from approximately 5 months to 9 months, an increase of 4 months. Replacing a set of Φ8.53×4.27 m semi-autogenous mill unloading chute liners is now reduced from 40 hours to 20 hours, saving 20 hours of maintenance time.

[0009] This invention has a simple structure, is easy to install, and is reliable in operation, effectively extending the service life of the unloading trough liner. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0011] Figure 2 for Figure 1 AA sectional view;

[0012] Figure 3 for Figure 1 BB sectional view diagram;

[0013] Figure 4 This is a schematic diagram of the casting process of the present invention;

[0014] Figure 5 This is a schematic diagram of the working state of the present invention.

[0015] In the figure: 1-Unloading chute liner, 101-Bottom plate, 102-Spare plate, 103-Arc-shaped end plate, 104-Wear-resistant boss, 2-Casting gate, 3-Feeding riser, 4-End cover, 5-Discharge end grid plate, 6-Cylinder body, 7-Cylinder body liner, 8-Feeding end liner. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings, but this does not limit the present invention in any way. Any modifications made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0017] like Figures 1-5 As shown, the unloading trough liner 1 of the present invention includes a base plate 101, a partition plate 102, an arc-shaped end plate 103, and wear-resistant bosses 104. The partition plate 102 is arranged above the middle part of the base plate 101; the arc-shaped end plate 103 is arranged above the large end of the base plate 101; one wear-resistant boss 104 is symmetrically arranged on the inner side of the arc-shaped end plate 103 with the partition plate 102 as the center; the two fan-shaped sides of the base plate 101 are narrowed by 10mm respectively, and the radius of the arc edge of the small end is increased by 5mm; the partition plate 102 is trapezoidal; the material of the unloading trough liner 1 is high manganese steel, and the content of C, Cr and Mn is increased.

[0018] The nominal gap between the edges of every two unloading chute liners 1 is 20mm during installation.

[0019] The weight fractions of each component in the unloading trough liner 1 are as follows: C: 1.0%~1.3%; Si: ≤1%; Mn: 11%~14%; Cr: ≤1%; Mo: ≤0.5%; S ≤0.05%; P ≤0.05%.

[0020] The mechanical performance parameters of the unloading trough liner 1 are: HB=190~220; aK≥80J / cm², without gaps.

[0021] The unloading trough liner 1 is manufactured using resin sand casting process. The inner casting channel is circular in shape and is equipped with a casting port 2 and a feeding riser 3. Molten steel is fed in through one channel and is located at the center of the cross section of the arc-shaped end plate 103.

[0022] The casting of the unloading trough liner 1 is austenitized at 1080℃, water-quenched to room temperature, tempered at 450℃, and naturally cooled to room temperature, with the temperature change controlled within ±20℃.

[0023] The bottom width of the partition plate 102 is 1 / 3 of the width of the base plate 101.

[0024] The angle between the hypotenuse of the partition plate 102 and the normal to the center line of the base plate 101 is 1.5° to 2.0°.

[0025] The wear-resistant boss 104 is located at the position of the arc-shaped end plate 103 where the impact is most severe.

[0026] The wear-resistant boss 104 has dimensions of 100×100×20mm.

[0027] Working principle and process of this invention:

[0028] This invention improves the weight fraction of each component in the unloading trough liner 1 by increasing the content of C, Cr, and Mn, thereby obtaining better mechanical properties and increasing the wear resistance of the material. Wear-resistant bosses 104 are set on the inner side of the arc-shaped end plate 103 at the position where the impact is most severe, so that the entire unloading trough liner 1 can wear evenly, thus extending its service life. The fan-shaped sides of the bottom plate 101 are narrowed by 10mm and the radius of the small end arc edge is increased by 5mm, so that the nominal gap between the edges of every two unloading trough liners 1 is 20mm, in order to compensate for manufacturing errors, avoid interference when installing the unloading trough liner 1, shorten the time for replacing the unloading trough liner 1, and thus reduce downtime for maintenance.

Claims

1. A semi-autogenous mill discharge chute liner capable of effectively prolonging the service life, wherein the discharge chute liner (1) comprises a bottom plate (101), a partition plate (102), an arc-shaped end head plate (103) and a wear-resistant boss (104), and is characterized in that: A partition plate (102) is provided above the middle part of the base plate (101); an arc-shaped end plate (103) is provided above the large end of the base plate (101); a wear-resistant boss (104) is symmetrically provided on the inner side of the arc-shaped end plate (103) with the partition plate (102) as the center; the two sides of the fan-shaped base plate (101) are narrowed by 10mm respectively, and the radius of the small end arc edge is increased by 5mm; the partition plate (102) is trapezoidal; the material of the unloading trough liner (1) is high manganese steel, and the content of C, Cr and Mn is increased.

2. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The nominal gap between the edges of every two unloading trough liners (1) is 20mm during installation.

3. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The weight fractions of each component in the unloading trough liner (1) are as follows: C: 1.0%~1.3%; Si: ≤1%; Mn: 11%~14%; Cr: ≤1%; Mo: ≤0.5%; S≤0.05%; P≤0.05%.

4. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The mechanical performance index range of the unloading trough liner (1) is: HB=190~220; aK≥80J / cm², no gaps.

5. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The unloading trough liner (1) is manufactured using resin sand casting process. The inner casting channel is circular in shape and is equipped with a casting port (2) and a feeding riser (3). Molten steel enters through one channel and is located at the center of the cross section of the arc-shaped end plate (103).

6. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The casting of the unloading trough liner (1) is austenitized at 1080℃, water-quenched to room temperature, tempered at 450℃, and naturally cooled to room temperature, with the temperature change controlled within ±20℃.

7. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The bottom width of the partition plate (102) is 1 / 3 of the width of the base plate (101).

8. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The angle between the hypotenuse of the partition plate (102) and the normal to the center line of the base plate (101) is 1.5° to 2.0°.

9. The semi-autogenous mill discharge chute liner according to claim 1, which can effectively extend service life, is characterized in that: The wear-resistant boss (104) is located at the position where the arc-shaped end plate (103) is most severely impacted.

10. The semi-autogenous mill discharge chute liner according to claim 1, characterized in that: The wear-resistant boss (104) has dimensions of 100×100×20mm.

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