Design method for equal-life lining plate of semi-autogenous mill barrel

Abstract

The invention discloses a semi-autogenous mill barrel equal-life lining plate design method which comprises the following steps: carrying out a mechanical property test and a crushing experiment on ores, steel balls and lining plates to obtain corresponding mechanical property and crushing characteristic parameters; the method comprises the following steps of: establishing an ore crushing model and a medium particle model by using a Tavaries crushing model on the basis of a discrete element method; the method comprises the following steps: establishing a three-dimensional model of the semi-autogenous mill by using SOLIDWORKS software, and carrying out regional division on a barrel lining plate of the semi-autogenous mill in the axial direction and the radial direction; abrasion volume quantities of different areas in the axial direction and the radial direction are obtained through an Archard abrasion model, the lining plate volumes of all the areas are redistributed based on the simulated abrasion volume quantities, and the equal-service-life lining plate is designed. By the adoption of the design method for the service-life lining plate of the semi-autogenous mill barrel, the axial abrasion non-uniform degree of the lining plate of the semi-autogenous mill is reduced, the overall service life of the lining plate is prolonged, the steel utilization rate of the lining plate is increased, the working efficiency of the semi-autogenous mill is improved, and the mineral separation cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing engineering, in particular to a design method for a semi-autogenous mill barrel isochronous liner. Background Art

[0002] The lining of the SAG mill plays the role of lifting materials and grinding media and protecting the cylinder of the SAG mill from the impact of materials and grinding media. When the SAG mill is working, its lining is subject to wear and impact from materials and grinding media. It is necessary to stop the mill regularly for inspection and replacement of the lining to avoid wear through. The replacement of the lining of the SAG mill and the unplanned shutdown of the SAG mill have a great impact on the production efficiency of the ore dressing plant. Prolonging the life of the lining is of great significance to improving the efficiency of the ore dressing plant.

[0003] In the prior art, mineral processing workers mainly use wear-resistant materials and select reasonable liner structure parameters to improve the liner life. These two methods improve the liner life to a certain extent. However, in the actual operation of the semi-autogenous mill, due to the existence of the end liners at both ends of the feed and discharge, the material and the grinding medium are unevenly distributed along the axial direction of the cylinder liner, resulting in different wear effects of the material and the grinding medium on the cylinder liner, causing uneven wear of the liner along the axial direction, and ultimately causing the liner to fail due to local excessive wear. Summary of the invention

[0004] The purpose of the present invention is to provide a method for designing a semi-autogenous mill barrel liner with equal life, reduce the uneven degree of axial wear of the semi-autogenous mill liner, extend the overall life of the liner without significantly increasing the mass of the liner, improve the utilization rate of the liner steel, improve the ore dressing operation efficiency, and reduce the ore dressing cost.

[0005] To achieve the above object, the present invention provides a method for designing a liner with an equal life span of a semi-autogenous mill cylinder, comprising the following steps:

[0006] S1. Obtain the mechanical properties of ore, liner and steel ball through uniaxial compression test, drainage method and strain test system, where the mechanical properties include elastic modulus, shear modulus, density and Poisson's ratio;

[0007] S2. Use a falling weight crushing device to perform a single particle crushing experiment on the ore to obtain crushing characteristic parameters, wherein the crushing characteristic parameters include damage accumulation constant, fitting parameters, fracture energy standard deviation, minimum crushing size, minimum collision energy, and tangential energy ratio;

[0008] S3. Obtain the contact coefficient by using the inclined plate method test, the cylinder lifting test and the rockfall impact test, wherein the contact coefficient includes the static friction coefficient, the rolling friction coefficient and the restitution coefficient;

[0009] S4. Use SOLIDWORKS software to build a three-dimensional solid model of the semi-autogenous mill and divide the cylinder liner into regions along the axial direction;

[0010] S5, dividing each regional liner into regions according to the radial direction, and establishing a discrete element simulation model;

[0011] S6. Determine the normal operating status and parameters of the SAG mill;

[0012] S7. Perform particle size screening on the feed to the semi-autogenous mill to determine the particle size distribution of the feed ore medium;

[0013] S8, input the mechanical properties, crushing characteristic parameters and contact parameters of the ore, steel ball and liner obtained in S1, S2 and S3 into the discrete element software, use the Tavares crushing model to establish the ore crushing model, medium particle model and discrete element contact model, and import the discrete element simulation model into the discrete element software;

[0014] S9. Based on the discrete element method, using the Archard wear model, discrete element simulation is performed to obtain the axial wear volume of the liner according to the divided axial direction area; according to the divided radial direction area, the radial area wear volume of the liner in different axial areas is obtained;

[0015] S10, reallocating the axial volume of the liner according to the obtained axial wear volume;

[0016] S11, reallocating the liner volume in each radial area according to the liner wear volume in the radial area and the liner volume in each area after reallocation;

[0017] S12. Design lining plates with equal service life according to the lining plate volumes in different areas.

[0018] Preferably, in S4, the three-dimensional solid model of the entire semi-autogenous mill includes: a feed trolley, a guide trough, a feed end cover, a cylinder liner, a discharge cover end, and a lifter. The feed trolley is used to simulate the feeding process of the semi-autogenous mill, the feed end cover is used to simulate the feeding process of the semi-autogenous mill, the cylinder liner is used to simulate the ore crushing process of the semi-autogenous mill, and the discharge end cover and the lifter are used to simulate the discharging process of the semi-autogenous mill.

[0019] Preferably, in S6, the normal operating status and parameters of the SAG mill include: SAG mill speed, comprehensive filling rate, ore filling rate, and steel ball filling rate.

[0020] Preferably, in S7, the feed to the semi-autogenous mill is subjected to particle size screening, different particle size names are defined according to the size of the ore medium of the feed, and the yield and cumulative yield of different particle sizes are obtained.

[0021] Preferably, in S8, the discrete element software is EDEM software, and the rotation speed, comprehensive filling rate, ore filling rate, and steel ball filling rate are set according to the operating status and parameters of the semi-autogenous mill; the feed rate and feed particle size are set according to the ore particle size distribution.

[0022] Preferably, in S9, the wear volume calculation formula in the Archard wear model is:

[0023] Q=WF n S

[0024] Where Q is the volume wear, W is the wear constant, and F n is the normal force and S is the tangential displacement.

[0025] Preferably, in S10, the volume of the liner in the axial direction is redistributed, and the distribution formula is as follows:

[0026]

[0027] Where n is the number of axial division areas, V i V is the volume of each liner after redistribution. initial is the total volume of the initial liner, C is the mass ratio of the redesigned liner to the initial liner, where V i Satisfy the following formula:

[0028]

[0029] Among them, l i is the length of region i, Q i is the axial volume wear of region i.

[0030] Preferably, in S11, the liner volume of each radial region is redistributed, and the distribution formula is as follows:

[0031]

[0032] Where t is the number of radially divided regions, V s is the volume of the Sth axial region, is the volume of the i-th radial region of the S-th axial region after redistribution, where Satisfy the following formula:

[0033]

[0034] in, is the wear volume of the i-th radial region of the S-th axial region.

[0035] Therefore, the present invention adopts the above-mentioned semi-autogenous mill barrel isochronous liner design method, and the beneficial effects are as follows:

[0036] (1) The present invention prolongs the overall service life of the liner without significantly increasing the mass of the liner.

[0037] (2) The present invention improves the utilization rate of lining steel, improves the efficiency of mineral processing operations, and reduces mineral processing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the working process of an embodiment of a method for designing a liner of a semi-autogenous mill cylinder with equal life span according to the present invention;

[0039] Figure 2 It is a schematic diagram of a three-dimensional solid model of a semi-autogenous mill according to an embodiment of a method for designing a liner of a semi-autogenous mill cylinder of the present invention;

[0040] Figure 3 It is a schematic diagram of an initial cylinder liner model of an embodiment of a method for designing a cylinder liner of a semi-autogenous mill of the present invention;

[0041] Figure 4 It is a schematic diagram of the regional division of a cylinder liner model along the axial direction of an embodiment of a method for designing a cylinder liner of a semi-autogenous mill of the present invention;

[0042] Figure 5 It is a schematic diagram of the division of regions in the radial direction of a cylinder liner model of an embodiment of a method for designing a cylinder liner of a semi-autogenous mill of the present invention;

[0043] Figure 6 It is a schematic diagram of the axial wear volume of the liner of an embodiment of a method for designing a liner of equal life of a semi-autogenous mill cylinder according to the present invention;

[0044] Figure 7 is the wear volume of liners in different radial regions of each axial region of an embodiment of a semi-autogenous mill barrel equal life liner design method of the present invention;

[0045] Figure 8 The invention discloses an equal life liner model designed in an embodiment of a method for designing equal life liners for a semi-autogenous mill cylinder.

[0046] Reference numerals

[0047] 1. Feed trolley; 2. Material guide chute; 3. Feed end cover; 4. Cylinder lining; 5. Discharge end cover; 6. Lifter. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0049] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0050] Embodiment 1

[0051] like Figure 1 As shown, a method for designing a liner with equal life span for a semi-autogenous mill cylinder specifically comprises the following steps:

[0052] S1. Use an electro-hydraulic servo universal testing machine to perform uniaxial compression tests on ore, liner and steel ball to obtain elastic modulus and shear modulus; use the drainage method to measure the density of ore, liner and steel ball; use a strain test system to measure the Poisson's ratio of ore, liner and steel ball.

[0053] S2. Use falling weight crushing equipment to carry out single particle crushing test on the ore and measure the ore crushing characteristic parameters.

[0054] S3. Use the inclined plate method test and the cylinder lifting test to measure the static friction coefficient and the rolling friction coefficient; use the rockfall impact test to measure the restitution coefficient.

[0055] According to the obtained ore mechanical property parameters, crushing characteristic parameters, mechanical parameters of steel balls and liner plates, and contact parameters, as shown in Tables 1 and 2, the ore crushing model, medium particle model, and discrete element contact model are established.

[0056] Table 1 Mechanical properties and contact parameters of ore, steel ball and liner

[0057] parameter Numeric unit Ball density 7800 <![CDATA[kg / m 3 ]]> Steel ball shear modulus 7.00e+10 Pa Poisson's ratio of steel ball 0.28 - Ore density 3400 <![CDATA[kg / m 3 ]]> Ore shear modulus 2.00e+10 Pa Poisson's ratio of ore 0.23 - Steel ball and steel ball restitution coefficient 0.70 - Static friction coefficient between steel balls 0.20 - Rolling friction coefficient between steel balls 0.01 - Recovery coefficient of steel ball and ore 0.41 - Static friction coefficient between steel ball and ore 0.50 - Rolling friction coefficient between steel ball and ore 0.20 - Ore and Ore Recovery Factor 0.30 - Static friction coefficient between ore and ore 0.60 - Coefficient of rolling friction between ore and ore 0.15 -

[0058] Table 2 Ore crushing characteristic parameters

[0059]

[0060]

[0061] S4, such as Figure 2-Figure 5 As shown, a three-dimensional solid model of the semi-autogenous mill is established, and the liner is divided into multiple areas along the axial direction. In this embodiment, the liner is divided into three areas along the axial direction, named Z01, Z02, and Z03.

[0062] S5. Divide each area liner into regions according to the radial direction. In this embodiment, the liner is radially divided into three regions, named R01, R02, and R03. The arrow indicates the rotation direction of the cylinder liner.

[0063] A discrete element simulation model was established, in which the feed trolley 1 and the guide chute 2 were used to simulate the process of ore transportation to the semi-autogenous mill, the feed end cover 3 was used to simulate the feeding process of the semi-autogenous mill, the cylinder liner 4 was used to simulate the ore crushing process of the semi-autogenous mill, and the discharge end cover 5 and the lifter 6 were used to simulate the discharge process of the semi-autogenous mill.

[0064] S6. Determine that when the SAG mill is operating normally, the speed is 75% of the critical speed, the comprehensive filling rate is 28%, of which steel balls are 11% and ore is 17%, and the maximum diameter of the steel balls is 120mm.

[0065] S7. Perform particle size screening on the feed to the SAG mill to determine the particle size distribution of the ore medium, as shown in Table 3.

[0066] Table 3 SAG mill feed size

[0067] Particle size name / mm Yield Cumulative yield +150 9.79％ - -150+50 14.87％ 24.66％ -50+20 26.61％ 51.27％ -20 48.73％ 100％

[0068] S8, input the mechanical parameters and contact parameters obtained in S1 and S3 into EDEM software, and use the Tavares crushing model to input relevant crushing characteristic parameters into it;

[0069] Import the 3D solid simulation model of the SAG mill in S4 into the EDEM software;

[0070] According to the parameters of the SAG mill in S6 during normal operation, corresponding initial particles are arranged inside the SAG mill, and the rotation speeds of the feed end 3, the cylinder liner 4, the discharge end cover 5 and the lifter 6 are set;

[0071] A pellet factory is set in the feed trolley to generate pellets at a rate of 150 kg / s according to the particle size distribution in S7, so that the pellets enter the semi-autogenous mill through the feed trolley 1, the guide trough 2, and the material end cover 3 after being generated;

[0072] The Archard wear model was used, and the wear constant W was set to 1.0×10 -10 , and perform simulation.

[0073] S9. After the simulation is completed, the wear volume of different areas in the axial direction and radial direction of the semi-autogenous mill is obtained according to the areas divided by S4 and S5, such as Figure 5 As shown, the wear volume increases gradually from S01 to S03, so the liner volume should increase gradually from S01 to S03.

[0074] like Figure 6-Figure 7 As shown, the wear of Z02 and Z03 areas in S01 to S03 regions increases successively, and the wear of Z01 area in S02 and S03 regions is similar, but both are greater than that in S01 area. Moreover, the wear shows a trend that Z03 area is greater than Z02 area, and Z02 area is greater than Z01 area.

[0075] S10, according to the axial wear volume obtained in S9, redistribute the axial volume of the liner, and the distribution formula is as follows;

[0076]

[0077] Where n is the number of axial division areas, V i V is the volume of each liner after redistribution. initial =0.4120m 3 , C is the mass ratio of the redesigned liner to the initial liner, which is 1 here, where V i Satisfy the following formula:

[0078]

[0079] Among them, l i is the length of region i, Q i is the axial volume wear of region i, l i The mass distribution of each axial region can be calculated as follows: V1 = 0.0992m 3 , V2=0.1479m 3 , V3=0.1649m 3 .

[0080] S11. Redistribute the liner volume of each radial area according to the liner wear volume of the radial area in S9 and the liner volume of each area after redistribution in S10. The distribution formula is as follows:

[0081]

[0082] Where t is the number of radially divided regions; V s is the area of ​​the Sth axial region; is the area of ​​the i-th radial region of the S-th axial region after redistribution, where Satisfy the following formula:

[0083]

[0084] Among them, Q i s is the wear volume of the i-th radial region of the S-th axial region.

[0085] The volume of different radial regions in each axial region can be obtained by calculation:

[0086]

[0087]

[0088] S12, such as Figure 8 As shown in the figure, reasonable linings with equal service life are designed according to the lining volumes in different areas of S10 and S11.

[0089] Therefore, the present invention adopts the above-mentioned semi-autogenous mill barrel equal life liner design method to obtain the wear of the liner in different areas along the axial direction, and redesign the liner according to the wear conditions, thereby reducing the uneven axial wear without significantly increasing the mass of the liner, extending the service life of the liner, improving the utilization rate of the liner steel, and effectively reducing the production cost of the ore dressing plant.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for designing a liner with equal life span for a semi-autogenous mill cylinder, characterized in that: The following steps are involved: S1. Obtain the mechanical properties of ore, liner and steel ball through uniaxial compression test, drainage method and strain test system, where the mechanical properties include elastic modulus, shear modulus, density and Poisson's ratio; S2. Use a falling weight crushing device to perform a single particle crushing experiment on the ore to obtain crushing characteristic parameters, wherein the crushing characteristic parameters include damage accumulation constant, fitting parameters, fracture energy standard deviation, minimum crushing size, minimum collision energy, and tangential energy ratio; S3. Obtain the contact coefficient by using the inclined plate method test, the cylinder lifting test and the rockfall impact test, wherein the contact coefficient includes the static friction coefficient, the rolling friction coefficient and the restitution coefficient; S4. Use SOLIDWORKS software to build a three-dimensional solid model of the semi-autogenous mill and divide the cylinder liner into regions along the axial direction; S5, dividing each regional liner into regions according to the radial direction, and establishing a discrete element simulation model; S6. Determine the normal operating status and parameters of the SAG mill; S7. Perform particle size screening on the feed to the semi-autogenous mill to determine the particle size distribution of the feed ore medium; S8, input the mechanical properties, crushing characteristic parameters and contact parameters of the ore, steel ball and liner obtained in S1, S2 and S3 into the discrete element software, use the Tavares crushing model to establish the ore crushing model, medium particle model and discrete element contact model, and import the discrete element simulation model into the discrete element software; S9. Based on the discrete element method, using the Archard wear model, discrete element simulation is performed to obtain the axial wear volume of the liner according to the divided axial direction area; according to the divided radial direction area, the radial area wear volume of the liner in different axial areas is obtained; S10, reallocating the axial volume of the liner according to the obtained axial wear volume; S11, reallocating the liner volume of each radial area according to the liner wear volume of the radial area and the liner volume of each area after reallocation; S12. Design lining plates with equal service life according to the lining plate volumes in different areas.

2. A method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: In S4, the three-dimensional solid model of the whole SAG mill includes: a feed trolley, a guide chute, a feed end cover, a cylinder liner, a discharge cover, and a lifter. The feed trolley is used to simulate the feeding process of the SAG mill, the feed end cover is used to simulate the feeding process of the SAG mill, the cylinder liner is used to simulate the ore crushing process of the SAG mill, and the discharge end cover and lifter are used to simulate the discharging process of the SAG mill.

3. A method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: In S6, the normal operating status and parameters of the SAG mill include: SAG mill speed, comprehensive filling rate, ore filling rate, and steel ball filling rate.

4. A method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: In S7, the feed to the semi-autogenous mill is subjected to particle size screening, and different particle size names are defined according to the ore medium size of the feed, and the yield and cumulative yield of different particle sizes are obtained.

5. The method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 3 is characterized in that: In S8, the discrete element software is EDEM software. According to the operating status and parameters of the semi-autogenous mill, the rotation rate, comprehensive filling rate, ore filling rate and steel ball filling rate are set; according to the ore particle size distribution, the feed rate and feed particle size are set.

6. A method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: In S9, the wear volume calculation formula in the Archard wear model is: Q=WF n S Where Q is the volume wear, W is the wear constant, and F n is the normal force and S is the tangential displacement.

7. A method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: exist In S10, the volume in the axial direction of the liner is redistributed, and the distribution formula is as follows; Where n is the number of axial division areas, V i V is the volume of each liner after redistribution. initial is the total volume of the initial liner, C is the mass ratio of the redesigned liner to the initial liner, where V i Satisfy the following formula: Among them, l i is the length of region i, Q i is the axial volume wear of region i.

8. The method for designing a liner with equal life span for a semi-autogenous mill cylinder according to claim 1, characterized in that: In S11, the liner volume in each radial area is allocated according to the following formula: Where t is the number of radially divided regions, V s is the volume of the Sth axial region, is the volume of the i-th radial region of the S-th axial region after redistribution, where Satisfy the following formula: in, is the wear volume of the i-th radial region of the S-th axial region.

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