Method for determining mineral particle size of mixed ball mill media

Abstract

The application discloses a kind of mineral particle size determination methods of mixed ball mill medium.The method comprises the following steps: the mineral to be ground is divided into n different particle levels, each particle level respectively uses pure steel ball, mixed ball and nano ceramic ball with same diameter as grinding medium, and single particle level grinding experiment is carried out;According to the grinding product, the corresponding sieve size values of pure steel ball, mixed ball and nano ceramic ball under different particle levels are analyzed respectively Pm ; the corresponding dimensionless parameter M value under single particle level is calculated;The dimensionless parameter M value corresponding to n different particle levels is compared, if M value is located between 0.8~1, then the particle level corresponding to the M value is the optimal mineral particle size when mixed ball is used as grinding medium.The application can scientifically determine the best mineral particle size when mixed ball is used to replace pure steel ball as grinding medium, while ensuring grinding effect and beneficiation efficiency, greatly reducing energy consumption.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, specifically to a method for determining the particle size of minerals using mixed ball milling media. Background Technology

[0002] Grinding processes can be classified by media into media grinding and medialess grinding. Media grinding includes ball milling (steel ball impact grinding), rod milling (steel rod extrusion, uniform particle size), and pebble milling (pebble media), etc.

[0003] Ball milling media mainly include pure steel balls and nano-ceramic balls. When used as grinding media, pure steel balls have a strong coarse-grain crushing ability and are suitable for various types of ores, making them the preferred media for traditional ball mills. However, they have the following disadvantages: First, they are prone to excessive wear, leading to frequent media replacements, which not only increases operating costs but also easily causes environmental pollution; second, they have a high specific gravity, resulting in excessive energy consumption; and third, they generate a lot of noise.

[0004] When nano-ceramic balls are used as grinding media, they have advantages such as low specific gravity, energy saving and consumption reduction, good wear resistance, long service life, low pollution and high efficiency. However, they are only suitable for high-precision fine grinding of metal ores, and have very strict requirements on the particle size range of minerals, and cannot be used for minerals with a wide range of particle sizes.

[0005] According to research by industry scholars, hybrid balls prepared by mixing nano-ceramics and steel, when used as grinding media, have performance between that of pure steel balls and nano-ceramic balls. They can effectively improve grinding efficiency, reduce energy consumption, and reduce noise. However, the following technical problems exist: First, the selection of mineral feed particle size relies on the subjective experience of engineers, which makes it impossible for mineral processing plants to achieve the lowest consumption reduction in actual applications. Second, when the particle size of the mineral entering the mill changes (e.g., from +0.15mm to +0.30mm). Traditional indicators, due to their dimensional dependence (unit: mm), make process data incomparable. For example, when the mineral is fed at +0.15 mm, P80 = 0.08 mm; when the mineral is fed at +0.30 mm, P80 = 0.14 mm. This makes it impossible to directly judge the grinding effect of grinding media under different feed particle sizes. Note: P80 represents the sieve particle size through which 80% of the minerals pass. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a method for determining the mineral particle size of mixed ball milling media. This method can scientifically determine the optimal mineral particle size when using mixed balls instead of pure steel balls as grinding media. It not only achieves similar grinding effects and beneficiation efficiency as when using pure steel balls as grinding media, but also avoids excessive wear, high energy consumption, and excessive noise associated with using pure steel balls as grinding media.

[0007] To achieve the above objectives, this invention designs a method for determining the particle size of minerals using mixed ball milling media, characterized by the following steps: S1) The mineral to be ground is divided into n different particle sizes. For each particle size, pure steel balls, mixed balls, and nano-ceramic balls of the same diameter are used as grinding media for single-size grinding experiments. The sieve particle sizes of pure steel balls, mixed balls, and nano-ceramic balls at different particle sizes are analyzed based on the grinding products. Pm value; S2) Calculate the dimensionless parameter M value corresponding to a single particle size, wherein the dimensionless parameter M is calculated using the following formula. In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; Pm T When nano-ceramic balls are used as grinding media, the sieve particle size that m% of the grinding product can pass through; Pm H When mixed balls are used as grinding media, the m% of the grinding product can pass through the sieve particle size; Pm G When pure steel balls are used as grinding media, the m% of the grinding product can pass through the sieve particle size; S3) Compare the dimensionless parameter M values ​​corresponding to n different particle sizes. If the M value is between 0.8 and 1, then the particle size corresponding to the M value is the optimal mineral particle size when using mixed balls as the grinding medium.

[0008] Furthermore, in S1), n ​​is greater than or equal to 5.

[0009] Furthermore, in S1), the mass ratio of pure steel to nano-ceramics in the mixed sphere is 1:1.

[0010] Further, in S2), the... m The value is 80, and the formula for the dimensionless parameter M is: In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; P80 T When nano-ceramic balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm. P80 H When mixed balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through, in mm; P80 G When pure steel balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm.

[0011] Furthermore, in S3), pure steel balls and mixed balls were used as grinding media to conduct mixed particle size grinding experiments to verify the optimal mineral particle size.

[0012] Furthermore, the determination method also includes step S4), using pure steel balls and mixed balls as grinding media respectively, using minerals of the optimal mineral particle size as raw materials, grinding, and then performing weak magnetic separation experiments on the grinding products to calculate the beneficiation efficiency values ​​when using pure steel balls and mixed balls as grinding media respectively.

[0013] Furthermore, in S4), the magnetic field strength of the weak magnetic separation experiment is 1000-2000 Gs.

[0014] The advantages of this invention are: This invention establishes a dimensionless parameter M that spans particle sizes, accurately locates the performance coordinates of the mixed ball media between ceramic balls and pure steel balls, achieves data comparability under different infeed particle sizes, and thus enables the determination of the optimal mineral particle size when using mixed balls as the grinding media. This invention first separates the mineral to be ground into several different particle sizes, and then analyzes the sieve particle size corresponding to pure steel balls, mixed balls, and nano-ceramic balls at different particle sizes. Pm The value is then calculated, and the dimensionless parameter M value corresponding to a single particle size is obtained. The particle size corresponding to the M value between 0.8 and 1 is taken as the optimal mineral particle size when using mixed balls as the grinding medium. The optimal mineral particle size is verified by using pure steel balls and mixed balls as grinding media respectively and by conducting mixed particle size grinding experiments. The mineral particle size determination method of the mixed ball milling media of the present invention can scientifically determine the optimal mineral particle size when using mixed balls instead of pure steel balls as grinding media. It not only has similar grinding effect and mineral processing efficiency as when using pure steel balls as grinding media, but also avoids excessive wear, high energy consumption and high noise when using pure steel balls as grinding media. Attached Figure Description

[0015] Figure 1 This is a flowchart of the mineral particle size determination method using mixed ball milling media according to the present invention; Figure 2 For grinding products of different grinding media with a single feed size P80 and MThe impact of the value; Figure 3 To mix into the grinding mill stage for grinding products P80 The impact; Figure 4 The impact of mixing into the grinding mill stage on grinding efficiency. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 1 As shown, a method for determining the mineral particle size using mixed ball milling media is characterized by comprising the following steps: S1) The mineral to be ground is divided into n different particle sizes. For each particle size, pure steel balls, mixed balls, and nano-ceramic balls of the same diameter are used as grinding media for single-size grinding experiments. The sieve particle sizes of pure steel balls, mixed balls, and nano-ceramic balls at different particle sizes are analyzed based on the grinding products. Pm value.

[0018] Preferably, n is greater than or equal to 5.

[0019] Specifically, the mass ratio of pure steel to nano-ceramics in the hybrid sphere is 1:1.

[0020] In this embodiment, the minerals finely ground by the process are divided into 6 particle sizes, namely -3+2mm, -2+1mm, -1+0.6mm, -0.6+0.3mm, -0.3+0.15mm, and -0.15+0.074mm.

[0021] S2) Calculate the dimensionless parameter M value corresponding to a single particle size, wherein the dimensionless parameter M is calculated using the following formula. In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; Pm T When nano-ceramic balls are used as grinding media, the sieve particle size that m% of the grinding product can pass through; Pm H When mixed balls are used as grinding media, the m% of the grinding product can pass through the sieve particle size; Pm G When pure steel balls are used as grinding media, the m% of the grinding product can pass through the sieve.

[0022] Preferably, them The value is 80, and the formula for the dimensionless parameter M is: In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; P80 T When nano-ceramic balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm. P80 H When mixed balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through, in mm; P80 G When pure steel balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm.

[0023] To quantitatively evaluate the grinding effect of the hybrid balls relative to ceramic balls and steel balls, a method was introduced... The value is used as a standard of measurement. The setting of the dimensionless parameter M has a clear physical meaning, when the spheres are mixed... P80 H With ceramic balls P80 T Maintaining normalcy (i.e.) P80 H = P80 T Then the dimensionless parameter M=0; when the mixed balls achieve the grinding effect of pure steel balls (i.e. P80 G = P80 H If the performance of the hybrid sphere is between the two values, then the dimensionless parameter M = 1. In actual working conditions, when the performance of the hybrid sphere is between the two values, the value of M is calculated as a dimensionless value between 0 and 1.

[0024] S3) Compare the dimensionless parameter M values ​​corresponding to n different particle sizes. If the M value is between 0.8 and 1, then the particle size corresponding to the M value is the optimal mineral particle size when using mixed balls as the grinding medium.

[0025] The particle size corresponding to the M value between 0.8 and 1 is selected as the optimal mineral particle size when using mixed balls as the grinding medium, and the following analysis explains this.

[0026] The above six particle size minerals were milled using pure steel balls, mixed balls, and nano-ceramic balls of the same diameter, respectively, and the results showed that six... P80 G Value, 6 P80 H Value, 6P80 T The values ​​were calculated, and six values ​​corresponding to different particle sizes were determined. M Values. Draw 6 values ​​respectively. P80 G Value, 6 P80 H Value, 6 P80 T The values ​​were fitted to the particle distribution curve, and six values ​​were plotted on the particle distribution curve graph. M A dimensionless percentage curve of parameters composed of values, such as Figure 2 As shown.

[0027] from Figure 2 As can be seen, when the particle size of the feed material decreases from -0.6 + 0.3 mm to -0.15 + 0.074 mm, the particle size distribution curves of the mixed balls and the pure steel balls almost overlap, indicating that when the mixed balls and the pure steel balls are used as grinding media, they have similar grinding effects on feed minerals with particle sizes of -0.6 + 0.3 mm, -0.3 + 0.15 mm, and -0.15 + 0.074 mm.

[0028] In the single-size grinding experiment, the dimensionless parameter M corresponding to the -0.6 +0.3 mm particle size material is between 0.8 and 1. Therefore, in this embodiment, the -0.6 +0.3 mm particle size is selected as the optimal mineral particle size when using mixed balls as the grinding medium.

[0029] Preferably, pure steel balls and mixed balls are used as grinding media to conduct mixed particle size grinding experiments to verify the optimal mineral particle size.

[0030] Based on the analysis of single-size grinding experiments, for materials in the -0.6 to +0.3 mm size range, ceramic balls exhibit significantly inferior grinding performance compared to mixed balls and pure steel balls. Therefore, the mixed-size grinding experiments only used mixed balls and pure steel balls as grinding media to analyze the impact of the mixed feed size on the P80 of the grinding product. Figure 3 As shown; simultaneously, the impact of mixing into the grinding mill stage on grinding efficiency is analyzed, such as... Figure 4 As shown.

[0031] Figure 3 In this process, the six particle sizes of -3+2mm, -2+1mm, -1+0.6mm, -0.6+0.3mm, -0.3+0.15mm, and -0.15+0.074mm are mixed to obtain four mixed particle sizes of -0.6+0.074mm, -1+0.074mm, -2+0.074mm, and -3+0.074mm, respectively. These mixed particle sizes are then ground using mixed balls and pure steel balls as grinding media. Simultaneously, grinding of the raw ore without grinding media is also performed.

[0032] from Figure 3 As can be seen, compared with pure steel balls, the grinding effect of mixed balls is more sensitive to changes in feed particle size. During the process of decreasing the feed material particle size from -3 + 0.074 mm to -1 + 0.074 mm, the grinding effect of mixed balls was significantly worse than that of steel balls.

[0033] from Figure 4 As can be seen, when the particle size of the feed material further decreases from -1 + 0.074 mm to -0.6 + 0.074 mm, the grinding efficiency of the mixed ball mill product with a particle size of -0.074 mm increases from 15.74% to 53.47%, while that of pure steel balls is 58.79%; the proportion of newly generated -0.074 mm particles increases from 14.54% to 39.01%, while that of pure steel balls is 43.66%; and the proportion of newly generated -0.019 mm particles increases from 4.97% to 15.3%, while that of pure steel balls is 17.97%. This indicates that when the particle size of the feed material is -0.6 + 0.074 mm, the grinding effect of the mixed balls is significantly improved to be similar to that of pure steel balls.

[0034] Therefore, the mixed-size grinding experiment concludes that the selection of -0.6 to +0.3 mm particle size as the optimal mineral particle size when using mixed balls as the grinding medium in this embodiment is correct.

[0035] The mineral particle size determination method of the mixed ball milling media of the present invention further includes step S4), using pure steel balls and mixed balls as grinding media respectively, using minerals with the optimal mineral particle size as raw materials, grinding, and then performing weak magnetic separation experiments on the grinding products to calculate the beneficiation efficiency values ​​when using pure steel balls and mixed balls as grinding media respectively.

[0036] Preferably, the magnetic field strength of the weak magnetic separation experiment is 1000-2000 Gs.

[0037] In this embodiment, pure steel balls and mixed balls were used as grinding media, and magnetic separation verification experiments were conducted under the same conditions using minerals with a particle size of -0.6 to +0.3 mm as raw materials. The effects of pure steel balls and mixed balls on the magnetic separation performance of the grinding products at the -0.6 to +0.3 mm feed particle size are shown in Table 1.

[0038] Table 1. Effects of steel balls and mixed balls at different feed sizes on the magnetic separation performance of grinding products. Table 1 shows that after one magnetic separation, the concentrate grade of the pure steel ball mill product is 64.47%, the recovery rate is 88.88%, and the beneficiation efficiency is 67.46%. After one magnetic separation, the concentrate grade of the mixed ball mill product is 64.89%, the recovery rate is 88.11%, and the beneficiation efficiency is 68.00%. Therefore, at an infeed particle size of -0.6 to +0.3 mm, the beneficiation efficiency using mixed balls as the grinding media is similar to that using pure steel balls. In other words, at an infeed particle size of -0.6 to +0.3 mm, the grinding effect and beneficiation efficiency of using mixed balls as the grinding media are similar to those of using pure steel balls, and it avoids the excessive wear, high energy consumption, and excessive noise associated with using pure steel balls.

[0039] Therefore, in this embodiment, the optimal mineral particle size when using mixed balls instead of pure steel balls as the grinding media is -0.6 to +0.3 mm.

[0040] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for determining the mineral particle size distribution using mixed ball milling media, characterized in that, Includes the following steps: S1) The mineral to be ground is divided into n different particle sizes. For each particle size, pure steel balls, mixed balls, and nano-ceramic balls of the same diameter are used as grinding media for single-size grinding experiments. The sieve particle sizes of pure steel balls, mixed balls, and nano-ceramic balls at different particle sizes are analyzed based on the grinding products. Pm value; S2) Calculate the dimensionless parameter M value corresponding to a single particle size, wherein the dimensionless parameter M is calculated using the following formula. In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; Pm T When nano-ceramic balls are used as grinding media, the sieve particle size that m% of the grinding product can pass through; Pm H When mixed balls are used as grinding media, the m% of the grinding product can pass through the sieve particle size; Pm G When pure steel balls are used as grinding media, the m% of the grinding product can pass through the sieve particle size. S3) Compare the dimensionless parameter M values ​​corresponding to n different particle sizes. If the M value is between 0.8 and 1, then the particle size corresponding to the M value is the optimal mineral particle size when using mixed balls as the grinding medium.

2. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 1, characterized in that: In S1), n ​​is greater than or equal to 5.

3. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 2, characterized in that: In S1), the mass ratio of pure steel to nano-ceramics in the mixed sphere is 1:

1.

4. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 1, characterized in that: In S2), the m The value is 80, and the formula for the dimensionless parameter M is: In the formula, M The parameter is dimensionless and represents the grinding effect of the mixed balls relative to pure steel balls and nano-ceramic balls, ranging from 0 to 1; P80 T When nano-ceramic balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm. P80 H When mixed balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through, in mm; P80 G When pure steel balls are used as grinding media, the sieve particle size that 80% of the grinding product can pass through is measured in mm.

5. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 1, characterized in that: In S3), pure steel balls and mixed balls were used as grinding media to conduct mixed particle size grinding experiments to verify the optimal mineral particle size.

6. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 5, characterized in that: The determination method further includes step S4), using pure steel balls and mixed balls as grinding media respectively, using minerals of the optimal mineral particle size as raw materials, grinding, and then performing weak magnetic separation experiments on the grinding products to calculate the beneficiation efficiency values ​​when using pure steel balls and mixed balls as grinding media respectively.

7. The method for determining the mineral particle size distribution of mixed ball milling media according to claim 6, characterized in that: In S4), the magnetic field strength of the weak magnetic separation experiment is 1000-2000 Gs.

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