A spiral chute separation performance evaluation method based on a cutting machine regulation and multi-index coupling
Patent Information
- Application Number
- CN202610119931.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2046-01-28
AI Technical Summary
Existing methods for evaluating the separation performance of spiral chute are insufficient to quantitatively measure the interrelationship between concentrate grade and recovery rate, and they neglect the dynamic impact of continuous adjustment of the cutter on separation performance, resulting in evaluation results that rely on human experience and are inaccurate.
An evaluation method based on the control of the ore cutter and the coupling of multiple indicators is adopted. Through a multi-dimensional performance index prediction model, a quantitative evaluation system is constructed by comprehensively considering concentrate grade, recovery rate and stability. Numerical simulation experiments are used to establish the relationship between the radial position of the ore cutter and the separation index, and a multi-dimensional performance index prediction model is constructed.
This enables a quantitative evaluation of the separation performance of spiral chute, reduces the impact of ore feeding conditions, ensures that the evaluation results are closely integrated with actual production needs, and provides a scientific basis for optimizing structural design and operating parameters.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of mineral processing and relates to a method for evaluating the separation performance of a spiral chute based on the control of a ore cutter and the coupling of multiple indicators. Background Technology
[0002] In the field of mineral processing, spiral sluices, as a gravity separation device that utilizes a combined force field of centrifugal inertia and gravity for separation, are widely used in the separation processes of hematite, ilmenite, cassiterite, and various non-ferrous metal minerals due to their simple structure, convenient operation, low cost, and pollution-free operation. Particle separation in spiral sluices is essentially a complex process involving the coupling of multiple factors. Its final separation performance is typically measured by several technical and economic indicators, mainly including concentrate grade, recovery rate, tailings grade, and enrichment ratio.
[0003] In the traditional evaluation method of spiral chute separation performance, multiple indicators are usually considered in conjunction with each other. Specifically, under fixed conditions, a certain parameter (such as feed concentration, feed rate or structural parameters) is systematically changed. During this process, the numerical changes of two technical indicators, concentrate grade and recovery rate, are examined and compared simultaneously to evaluate the separation performance.
[0004] As our understanding of the spiral sluice separation process deepens, researchers have begun to introduce more comprehensive evaluation indicators. For example, the separation efficiency index can simultaneously reflect the enrichment degree of the target mineral and the removal effect of gangue minerals, thus providing a useful reference for the comprehensive characterization of the separation performance of the spiral sluice.
[0005] The above methods constitute the main technical basis for evaluating the separation performance of spiral chute and guiding parameter optimization.
[0006] Existing methods for evaluating the separation performance of spiral chute separators have limitations, including: First, in the correlation analysis of separation indicators, there is a certain constraint relationship between separation indicators such as concentrate grade and recovery rate, exhibiting a typical inverse relationship. Specifically, to improve concentrate grade, the cutter often needs to be adjusted inward, but this usually results in a loss of recovery rate; conversely, pursuing a high recovery rate may lead to a decrease in concentrate grade. This mutual constraint between indicators makes the judgment of separation performance often rely on human experience, making it difficult to form quantifiable criteria.
[0007] Secondly, although composite indicators such as separation efficiency make up for the above deficiencies to some extent, these indicators are easily affected by the grade of the feed.
[0008] Finally, it should be noted that the optimal results obtained using existing evaluation methods often only consider the influence of the local cutter position, neglecting the dynamic changes in separation performance caused by continuous adjustment of the cutter, and thus failing to accurately characterize the spiral chute separation process. Excellent separation conditions should not only perform exceptionally well at a specific radial position of the cutter, but also maintain stable and efficient separation performance within an adjustment range. Summary of the Invention
[0009] To address the aforementioned problems, the technical solution adopted in this invention is: a method for evaluating the separation performance of a spiral chute based on the coupling of ore cutter control and multiple indicators, characterized by comprising the following steps:
[0010] Obtain the structural parameters, feeding conditions, and operating parameters of the target spiral chute; When the position of the cutter changes continuously within the same cross section, the parabolic exponents of multiple target spiral chutes are different. Under the condition that other structural parameters, feeding conditions and operating parameters are the same, the multidimensional performance indexes of multiple target spiral chutes are compared based on the multidimensional performance index prediction model. When the multidimensional performance index value of the target spiral chutes is the largest, it is judged that the spiral chutes have the best separation performance. When the position of the cutter changes continuously within the same cross section, for the same target spiral chute, under the conditions that any one of the operating parameters is different while the other operating parameters, structural parameters, and feeding conditions are the same, or under the conditions that any one of the other feeding conditions is different while the other feeding conditions, structural parameters, and operating parameters are the same, based on the multidimensional performance index prediction model, multiple multidimensional performance indices are compared. When the multidimensional performance index value of the target spiral chute is the largest under the same conditions, it is judged that the spiral chute has the best separation performance.
[0011] Furthermore, the calculation formula for the multidimensional performance index prediction model is as follows:
[0012] In the above formula, PI is the multidimensional performance index; A is the grade efficiency factor; B is the recovery efficiency factor; S is the stability coefficient; λ and μ are the weighting coefficients of the grade efficiency factor and the recovery efficiency factor, respectively, and satisfy λ+μ=1.
[0013] Furthermore: the grade efficiency factor A represents the actual grade output relative to the theoretical optimal value within the range of producing qualified concentrate. The formula for calculating the degree of achievement of the grade efficiency factor A is as follows: A=G eff / (100% × W) eff ) Among them: G eff W is the integral area of the grade-cutter radial position curve within the effective separation interval.eff To effectively separate the total width of the interval.
[0014] Furthermore: the integral formula for the integral area of the grade-cutter radial position curve within the effective separation interval is:
[0015] in: The effective grade threshold; For effective separation intervals; This is a distribution curve showing the change in concentrate grade with the radial position of the cutter.
[0016] Furthermore: the recovery efficiency factor B characterizes the degree to which the recovery rate is achieved relative to the theoretical maximum value within the range of qualified concentrate output; the calculation formula for the recovery efficiency factor B is as follows: B=R eff / (100% × W) eff ) In the above formula, R eff W is the integral area of the recovery rate-cutter radial position curve within the effective separation range. eff To effectively separate the total width of the interval.
[0017] Furthermore: the integral formula for the integral area of the recovery rate-cutter radial position curve within the effective separation interval is:
[0018] Wherein: the effective grade threshold is βmin, and the effective separation interval is... , The curve represents the distribution of recovery rate as a function of the radial position of the cutter.
[0019] Furthermore: the stability coefficient S quantifies the smoothness of the separation process, and the formula for calculating the stability coefficient S is as follows: S = 1 / (1 + k × CV) Wherein, CV is the coefficient of variation of all grade measurements within the effective separation interval, and its expression is as follows: CV=σG / μG In the above formula, k is the grade fluctuation penalty weighting coefficient; σG is the standard deviation of grade within the effective separation interval; and μG is the average grade within the effective separation interval.
[0020] Furthermore: the effective separation interval is based on a set effective grade threshold. From all radial position control points of the ore cutter, all measurement points with grade values not lower than the threshold are selected. The effective grade threshold is the lowest concentrate grade value.
[0021] Furthermore, the construction process of the multidimensional performance index prediction model includes: Based on the structural parameters, feeding conditions, and operating parameters of the target spiral chute; A numerical simulation model consistent with the physical processes of slurry movement and separation was constructed and run to conduct numerical simulation experiments on the movement and separation behavior of slurry in a spiral chute. Based on the results of numerical simulation experiments, data on the distribution of particles at the end of the third cycle of the spiral chute were extracted. Based on this, the concentrate grade and recovery rate corresponding to different radial positions of the cutter were calculated. A deterministic correspondence between the radial position of the cutter and each separation index was established to construct a multidimensional performance index prediction model.
[0022] Furthermore, the structural parameters of the target spiral chute include outer radius R, inner radius r, pitch P, downward angle γ, and number of turns N; Ore feeding conditions include mineral type, grade of valuable elements, particle size and density; Operating parameters include solid mass concentration and inlet volumetric flow rate.
[0023] This invention provides a method for evaluating the separation performance of spiral chute based on the coupling of ore cutter control and multiple indicators. This comprehensive evaluation method can quantify and integrate the continuous sliding characteristics and robustness requirements of the ore cutter, while effectively measuring the equipment's separation capacity and avoiding interference from feed conditions, and is of crucial significance. This method aims to transform multiple mutually restrictive single indicators into a series of comparable, robust, multidimensional correlated indicators, thereby providing a scientific basis for evaluating the separation performance of spiral chute.
[0024] By constructing a multi-dimensional performance evaluation system, the trade-off between "grade" and "recovery rate" is effectively resolved. Secondly, this method uses the characteristics of the final concentrate product as the evaluation benchmark, ensuring it is unaffected by fluctuations in the original feed grade and significantly improving the horizontal comparability of data from different feed conditions, separation processes, and production periods. Furthermore, by introducing the concept of an effective grade threshold, the evaluation scope is limited to the concentrate interception range that meets product quality requirements, ensuring close alignment with actual production needs. Simultaneously, a radial control strategy for the interceptor is adopted to systematically examine the performance characteristics within the effective separation range, accurately selecting suitable operating parameter ranges that maintain robust and excellent performance. In summary, the evaluation method established in this invention, through the coupling of interceptor control and multiple indicators, achieves a quantitative evaluation of the separation performance of spiral chutes, providing a scientific basis for the structural design or determination of operating parameters of spiral chutes.
[0025] A method for evaluating the separation performance of spiral chute based on the control of ore cutter and the coupling of multiple indicators is established to quantify and screen the separation performance under different conditions. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a flowchart of the method; Figure 2 These are effective integral area diagrams for grade; where (a) is the effective integral area diagram for grade I; (b) is the effective integral area diagram for grade II; (c) is the effective integral area diagram for grade III; (d) is the effective integral area diagram for grade IV; and (e) is the effective integral area diagram for grade V. Figure 3 These are effective integral area plots of recovery rates; where (a) is the effective integral area plot of recovery rate for sequence number I; (b) is the effective integral area plot of recovery rate for sequence number II; (c) is the effective integral area plot of recovery rate for sequence number III; (d) is the effective integral area plot of recovery rate for sequence number IV; and (e) is the effective integral area plot of recovery rate for sequence number V. Detailed Implementation
[0028] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] A method for evaluating the separation performance of a spiral chute based on the coupling of ore cutter control and multiple indicators includes the following steps: S1: Obtain the structural parameters, feeding conditions, and operating parameters of the target spiral chute; S2: When the position of the cutter changes continuously within the same cross section, the parabolic exponents of multiple target spiral chutes are different. Under the condition that other structural parameters, feeding conditions and operating parameters are the same, the multidimensional performance indexes of multiple target spiral chutes are compared based on the multidimensional performance index prediction model. When the multidimensional performance index value of the target spiral chutes is the largest, it is judged that the spiral chutes have the best separation performance. The cross-sectional curve function is composed of the downslope angle and the parabolic exponent from the structural parameters. S3: When the position of the cutter changes continuously within the same cross section, for the same target spiral chute, under the condition that any one of the operating parameters is different while the other operating parameters, structural parameters, and feeding conditions are the same, or under the condition that any one of the other feeding conditions is different while the other feeding conditions, structural parameters, and operating conditions are the same, based on the multidimensional performance index prediction model, multiple multidimensional performance indices are compared. When the multidimensional performance index value of the target spiral chute is the largest under the same conditions, it is judged that the spiral chute has the best separation performance.
[0031] After step S1 is executed, steps S2 and S3 are executed in parallel. Furthermore, the calculation formula for the multidimensional performance index prediction model is as follows:
[0032] In the above formula, PI is the multidimensional performance index; A is the grade efficiency factor; B is the recovery efficiency factor; S is the stability coefficient; λ and μ are the weighting coefficients of the grade efficiency factor and the recovery efficiency factor, respectively, and satisfy λ+μ=1.
[0033] Furthermore: The grade efficiency factor A represents the actual grade output relative to the theoretical optimal value within the range of producing qualified concentrate. The formula for calculating the degree of achievement of the grade efficiency factor A is as follows: A=G eff / (100% × W) eff ) Among them: G eff W is the integral area of the grade-cutter radial position curve within the effective separation interval. eff To effectively separate the total width of the interval.
[0034] The radial position of the cutter is the distance between the cutter baffle and the inner radius of the spiral groove. Grade refers to the percentage content of useful mineral components in the concentrate product. The higher the grade, the purer the product, and the higher its value. Grade - Radial position of the cutter: This refers to the fact that by adjusting the radial position of the cutter at the bottom of the spiral chute, the width of the collected ore band can be directly changed. Adjusting it inward will only collect the innermost high-purity heavy minerals, resulting in a high grade but a small quantity. Adjusting it outward will collect a wider ore band, recovering more heavy minerals, but also introducing more impurities, leading to a decrease in grade.
[0035] Grade-cutter radial position curve: This refers to the curve formed by gradually moving the cutter from the innermost edge of the spiral groove to the outermost edge, and obtaining the concentrate grade at each fixed position. The corresponding concentrate grade and the radial position of the cutter are then plotted on a coordinate graph, which can intuitively show the changing pattern of the two.
[0036] The integral formula for the integral area of the grade-cutter radial position curve within the effective separation interval is:
[0037] in: The effective grade threshold; For effective separation intervals; The curve formed by grade and radial position of the cutter; Furthermore: the recovery efficiency factor B characterizes the degree to which the recovery rate is achieved relative to the theoretical maximum value within the range of qualified concentrate output; the calculation formula for the recovery efficiency factor B is as follows: B=R eff / (100% × W) eff ) In the above formula, R eff W is the integral area of the recovery rate-cutter radial position curve within the effective separation range. eff To effectively separate the total width of the interval.
[0038] Recovery rate is a measure of the efficiency of a sorting process in extracting valuable minerals from the ore in terms of quantity. The formula for calculating the recovery rate is: Recovery rate = (Total weight of useful minerals in the concentrate / Total weight of useful minerals in the raw ore) × 100% By adjusting the cutter further outward, the width of the cut-off ore flow increases, and the total amount of useful minerals entering the concentrate product also increases, thus increasing the recovery rate (amount of useful minerals in the concentrate / amount of useful minerals in the raw ore). Recovery rate-cutter radial position curve: This refers to the curve formed by gradually moving the cutter from the innermost edge of the spiral groove to the outermost edge, and obtaining the recovery rate at each fixed position. The corresponding recovery rate and the radial position of the cutter are then plotted on a coordinate graph, creating a curve that visually shows the changing pattern of the two.
[0039] The integral formula for the area of the recovery rate-cutter radial position curve within the effective separation interval is:
[0040] The effective grade threshold is β min The effective separation interval is , : The curve formed by the recovery rate and the radial position of the cutter; Furthermore: the stability coefficient S quantifies the smoothness of the separation process, and the formula for calculating the stability coefficient S is as follows: S = 1 / (1 + k × CV) Wherein, CV is the coefficient of variation of all grade measurements within the effective separation interval, and its expression is as follows: CV=σG / μG In the above formula, k is the grade fluctuation penalty weighting coefficient; σG is the standard deviation of grade within the effective separation interval; and μG is the average grade within the effective separation interval.
[0041] Furthermore: the effective separation interval is based on a set effective grade threshold, and all measurement points with grade values not lower than the threshold are selected from all radial position control points of the ore cutter.
[0042] Furthermore: the effective grade threshold is the minimum concentrate grade value.
[0043] Furthermore, the construction process of the multidimensional performance index prediction model includes: Based on the structural parameters, feeding conditions, and operating parameters of the target spiral chute; A numerical simulation model consistent with the physical processes of slurry movement and separation was constructed and run to conduct numerical simulation experiments on the movement and separation behavior of slurry in a spiral chute. Based on the results of numerical simulation experiments, data on the distribution of particles at the end of the third cycle of the spiral chute were extracted. Based on this, the concentrate grade and recovery rate corresponding to different radial positions of the cutter were calculated. A deterministic correspondence between the radial position of the cutter and each separation index was established to construct a multidimensional performance index prediction model.
[0044] At the end of the third cycle of the spiral slurry, heavy minerals and light minerals have formed a stable and clear separation zone along the width of the slurry (heavy minerals are enriched on the inner edge and light minerals are enriched on the outer edge). At this point, the grade and recovery rate reach a dynamic equilibrium and will not change significantly with the number of cycles.
[0045] Numerical calculation models include turbulence models, clear water phase models, and multiphase flow models; Furthermore, the turbulence model is the RNG k-ε turbulence model based on the Renormalization Group (RNG) theory. The differential transport equations for turbulent kinetic energy and turbulent dissipation rate of the RNG k-ε turbulence model are shown in equations (1) and (2). The clear water phase model is the VOF model. The governing equations for the VOF multiphase flow model are shown in equations (3) and (4). The multiphase flow phase model is the Eulerian Multi-fluid VOF multiphase flow model considering the Bagnold effect. (1) (2) In the formula, G k This represents the turbulent kinetic energy generation term; Effective viscosity (the sum of molecular viscosity and turbulent viscosity, kg / (m·s)); This is an additional term in the equation for the turbulent kinetic energy dissipation rate. k The turbulent kinetic energy is expressed in J / kg. The turbulent kinetic energy dissipation rate is expressed in W / kg. , These are the coefficients in the model.
[0046] (3) (4) In the formula, For the volume fraction of a certain phase, when q When = 1, it is the aqueous phase; when q =2 indicates the gas phase, % t For time, s; (or () represents the coordinate components; (or ) is the speed at i (or j The component in the direction of ) m / s; The acceleration due to gravity is m / s². 2 ; and These are the average density and viscosity of the fluid, respectively, in kg / m³. 3 , kg / (m·s).
[0047] Furthermore, a stable gas-liquid two-phase flow field was obtained by employing the RNG k-ε turbulence model and the VOF multiphase flow model; Furthermore, a particulate phase was added to the stable gas-liquid two-phase flow field, and the gas-liquid-solid multiphase flow field was investigated using the RNG k-ε turbulence model and the Eulerian Multi-fluid VOF multiphase flow model. Furthermore, the process of calculating the concentrate grade and recovery rate corresponding to different radial positions of the ore cutter is as follows: The radial position L of the cutter is a radial dividing point. The radial position L of the cutter can slide from the inner radius r to the outer radius R, i.e., r ≤ L ≤ R. All particles that satisfy r ≤ L are screened out. This set of particles represents the concentrate obtained at this cutter position.
[0048]
[0049] Example 1: A method for evaluating the separation performance of a spiral chute based on the coupling of ore cutter control and multiple indicators, the process of which is as follows: Figure 1 As shown, it includes the following steps: S1. Determine the structural parameters and feeding conditions of multiple target spiral chutes, and design the condition parameters to be evaluated; The structural parameters of the target spiral chute include outer radius R, inner radius r, pitch P, downward angle γ, and number of turns N; Furthermore, the outer radius R = 150 mm, the inner radius r = 30 mm, the pitch P = 240 mm, the undercut angle γ = 9°, and the number of turns N = 3; The target spiral chute feeding conditions include mineral type, valuable element grade, particle size, and density; The operating parameters include solid mass concentration and inlet volumetric flow rate; The trial conditions for this method are: when the position of the cutter changes continuously within the same cross section, the cross-sectional curve functions of multiple target spiral chutes are different, while other structural parameters, feeding conditions and operating parameters are the same; Furthermore, the minerals are hematite (a valuable mineral) and quartz (a gangue mineral), the iron grade of the feed is 45.59%, the particle sizes of hematite and quartz are set to 90 μm and 38 μm, respectively, the densities of hematite and quartz are set to 4950 kg / m3 and 2650 kg / m3, respectively, the solid mass concentration is 20%, and the inlet volumetric flow rate is 12 L / min. The conditional parameter to be evaluated is the cross-sectional curve function, which is shown in Table 1.
[0050] Table 1 Cross-sectional curve functions
[0051] S2. Based on the determined target spiral chute structural parameters and feeding conditions, construct a numerical calculation model that conforms to the physical processes of slurry movement and separation behavior, and conduct numerical simulation experiments on the movement and separation behavior of particles in the spiral chute. The numerical simulation experiment includes solving the gas-liquid two-phase flow field, and then introducing a particulate phase to simulate the gas-liquid-solid three-phase flow.
[0052] S3. Based on the numerical simulation results, the distribution data of particles at the end of the third turn of the spiral chute is extracted, and the concentrate grade and recovery rate corresponding to different radial positions of the cutter are calculated accordingly. A deterministic correspondence between the radial position of the cutter and each separation index is established, providing basic data for the subsequent construction of a multidimensional performance index prediction model. The calculation formula for the multidimensional performance index prediction model is as follows: PI = (A^λ·B^μ)·S In the above formula, PI is the multidimensional performance index; A is the grade efficiency factor; B is the recovery efficiency factor; S is the stability coefficient; λ and μ are the weighting coefficients of the grade efficiency factor and the recovery efficiency factor, respectively, and satisfy λ+μ=1.
[0053] Furthermore, in this embodiment, λ=0.5 and μ=0.5 are set to indicate that grade and recovery rate are equally important in the comprehensive evaluation; Furthermore, the grade efficiency factor A characterizes the degree to which the actual grade output is achieved relative to the theoretical optimal value within the range where qualified concentrate can be produced, and its calculation formula is as follows: A = Geff / (100% × Weff) In the above formula, Geff is the integral area of the grade-cutter radial position curve within the effective separation interval; Weff is the total width of the effective separation interval.
[0054] Furthermore, the recovery efficiency factor B characterizes the degree to which the recovery rate is achieved relative to the theoretical maximum value within the range of qualified concentrate output, and its calculation formula is as follows: B = Reff / (100% × Weff) In the above formula, Reff is the integral area of the recovery rate-cutter radial position curve within the effective separation interval; Weff is the total width of the effective separation interval.
[0055] Furthermore, the effective separation interval is based on a set effective grade threshold. From all radial position control points of the ore cutter, measurement points with grade values not lower than the threshold are selected. The continuous or discontinuous radial position ranges formed by these points are uniformly defined as the effective separation interval, and its total width is denoted as Weff. Furthermore, the effective grade threshold is the minimum concentrate grade value that meets the quality specifications of the product plan; Furthermore, in this embodiment, the effective grade threshold is set to 63%. Based on this threshold, the effective integral area of grade and the effective integral area of recovery rate under each cross-sectional curve function are obtained, and the results are as follows: Figure 2 and Figure 3 As shown.
[0056] Figure 2 These are effective integral area diagrams for grade; where (a) is the effective integral area diagram for grade I; (b) is the effective integral area diagram for grade II; (c) is the effective integral area diagram for grade III; (d) is the effective integral area diagram for grade IV; and (e) is the effective integral area diagram for grade V. Figure 3 These are effective integral area plots of recovery rates; where (a) is the effective integral area plot of recovery rate for sequence number I; (b) is the effective integral area plot of recovery rate for sequence number II; (c) is the effective integral area plot of recovery rate for sequence number III; (d) is the effective integral area plot of recovery rate for sequence number IV; and (e) is the effective integral area plot of recovery rate for sequence number V.
[0057] The values of grade efficiency factor A and recovery efficiency factor B under the curve function of each cross section, calculated based on the integral area, are detailed in Table 2.
[0058] Table 2. Grade efficiency factor A and recovery efficiency factor B corresponding to different cross-sectional curve functions.
[0059] Furthermore, the stability coefficient S quantifies the smoothness of the separation process, enabling the model to pursue not only high average performance but also low performance fluctuations. The closer its value is to 1, the more stable the separation process. Its calculation formula is as follows: S = 1 / (1 + k × CV) Wherein, CV is the coefficient of variation of all grade measurements within the effective separation interval, and its expression is as follows: CV=σ G / μ G In the above formula, k is the weighting coefficient for grade fluctuation penalty; σ G To effectively separate the standard deviation of grades within the interval; μ G The average grade within the effective separation range.
[0060] Furthermore, in this embodiment, the grade fluctuation penalty weighting coefficient k is set to 2. Based on the grade data within the effective separation interval, the standard deviation σ of the grade under each cross-sectional curve function is calculated. G Average value μG The resulting coefficient of variation (CV) was calculated, and the stability coefficient (S) was finally determined. All numerical results are summarized in Table 3.
[0061] Table 3. Stability-related parameters of curve functions at different cross-sections
[0062] S4. For target spiral chutes under different conditions, multidimensional performance indicators are calculated based on the multidimensional performance index prediction model to determine the optimal condition parameters. Furthermore, based on the multidimensional performance index prediction model, the PI values under each cross-sectional curve function are calculated and compared. The cross-sectional curve function corresponding to the largest PI value is the optimal one. The comparison results are shown in Table 4.
[0063] Table 4. Stability-related parameters of curve functions at different cross-sections
[0064] S5: Compare the multidimensional performance index values of the target spiral chute under different conditions. When the multidimensional performance index value of the target spiral chute is the largest, it is determined that the spiral chute has the best separation performance. As shown in Table 4, the multidimensional performance index PI value is the largest when the serial number is IV, which indicates that the spiral chute under this condition is more conducive to the separation of hematite and quartz.
[0065] Example 2: S1: Obtain the structural parameters, feeding conditions, and operating parameters of the target spiral chute; when the position of the cutter changes continuously within the same cross section, the trial conditions of this application are: for the same target spiral chute, the same operating parameter, different values, other operating parameters are the same, and the structural parameters and feeding conditions are the same; that is, the solid mass concentration or inlet volumetric flow rate is under different value changes; S2: Construct and run a numerical calculation model that conforms to the physical process of slurry movement and separation behavior, and conduct numerical simulation experiments on the movement and separation behavior of slurry in the spiral chute; S3: Based on the results of numerical simulation experiments, data on the distribution of particles at the end of the third cycle of the spiral chute are extracted, and the concentrate grade and recovery rate corresponding to different radial positions of the cutter are calculated accordingly. A deterministic correspondence between the radial position of the cutter and various separation indicators is established to construct a multidimensional performance index prediction model. S4: Based on the multidimensional performance index prediction model, calculate the multidimensional performance index of the same target spiral chute under the same operating parameters and different values; S5: Compare the multi-dimensional performance indicators of the same target spiral chute under the same operating parameters and different values. When the multi-dimensional performance indicator value of the target spiral chute is the largest, it is determined that the spiral chute has the best separation performance.
[0066] Example 3: S1: Obtain the structural parameters, feeding conditions, and operating parameters of the target spiral chute; when the position of the cutter changes continuously within the same cross section, the trial conditions of this application are: for the same target spiral chute, under the same feeding conditions but different values, other feeding conditions are the same, and the structural parameters and operating parameters are the same; that is, under the change of any one of the following: mineral type, valuable element grade, particle size, and density; S2: Construct and run a numerical calculation model that conforms to the physical process of slurry movement and separation behavior, and conduct numerical simulation experiments on the movement and separation behavior of slurry in the spiral chute; S3: Based on the results of numerical simulation experiments, data on the distribution of particles at the end of the third cycle of the spiral chute are extracted, and the concentrate grade and recovery rate corresponding to different radial positions of the cutter are calculated accordingly. A deterministic correspondence between the radial position of the cutter and various separation indicators is established to construct a multidimensional performance index prediction model. S4: Based on the multidimensional performance index prediction model, calculate the multidimensional performance index of the same target spiral chute under the same operating parameters and different values; S5: Compare the multi-dimensional performance indicators of the same target spiral chute under the same feeding conditions and different values. When the multi-dimensional performance indicator value of the target spiral chute is the largest, it is judged that the spiral chute has the best separation performance.
[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for evaluating the separation performance of a spiral chute based on the coupling of ore cutter control and multiple indicators, characterized in that: Includes the following steps: Obtain the structural parameters, feeding conditions, and operating parameters of the target spiral chute; When the position of the cutter changes continuously within the same cross section, the parabolic exponents of multiple target spiral chutes are different. Under the condition that other structural parameters, feeding conditions and operating parameters are the same, the multidimensional performance indexes of multiple target spiral chutes are compared based on the multidimensional performance index prediction model. When the multidimensional performance index value of the target spiral chutes is the largest, it is judged that the spiral chutes have the best separation performance. When the position of the cutter changes continuously within the same cross section, for the same target spiral chute, under the condition that any one of the operating parameters is different while the other operating parameters, structural parameters, and feeding conditions are the same, or under the condition that any one of the other feeding conditions is different while the other feeding conditions, structural parameters, and operating conditions are the same, based on the multidimensional performance index prediction model, multiple multidimensional performance indices are compared. When the multidimensional performance index value of the target spiral chute is the largest under the same conditions, it is judged that the spiral chute has the best separation performance. The construction process of the multidimensional performance index prediction model includes: Based on the structural parameters, feeding conditions, and operating parameters of the target spiral chute; A numerical simulation model consistent with the physical processes of slurry movement and separation was constructed and run to conduct numerical simulation experiments on the movement and separation behavior of slurry in a spiral chute. Based on the results of numerical simulation experiments, data on the distribution of particles at the end of the third cycle of the spiral chute were extracted, and the concentrate grade and recovery rate corresponding to different radial positions of the cutter were calculated accordingly. A deterministic correspondence between the radial position of the cutter and each separation index was established to construct a multidimensional performance index prediction model. The calculation formula for the multidimensional performance index prediction model is as follows: In the above formula, PI is the multidimensional performance index; A is the grade efficiency factor; B is the recovery efficiency factor; S is the stability coefficient; λ and μ are the weighting coefficients of the grade efficiency factor and the recovery efficiency factor, respectively, and satisfy λ+μ=1; Numerical calculation models include turbulence models, clear water phase models, and multiphase flow models; The grade efficiency factor A represents the actual grade output relative to the theoretical optimal value within the range of producing qualified concentrate. The formula for calculating the degree of achievement of the grade efficiency factor A is as follows: A = Geff / (100% × Weff) Where: Geff is the integral area of the grade-cutter radial position curve within the effective separation interval; Weeff is the total width of the effective separation interval; The integral formula for the integral area of the grade-cutter radial position curve within the effective separation interval is: in: The effective grade threshold; For effective separation intervals; This is a distribution curve of concentrate grade as a function of the radial position of the cutter; Grade-cutter radial position: refers to the radial position of the cutter at the bottom of the spiral chute, adjusted by the cuttingter's position. The recovery efficiency factor B characterizes the degree to which the recovery rate is achieved relative to the theoretical maximum value within the range of qualified concentrate output; the calculation formula for the recovery efficiency factor B is as follows: B = Reff / (100% × Weff) In the above formula, Reff is the integral area of the recovery rate-cutter radial position curve within the effective separation interval; Weff is the total width of the effective separation interval. The integral formula for the integral area of the recovery rate-cutter radial position curve within the effective separation interval is: Wherein: the effective grade threshold is βmin, and the effective separation interval is... , The curve showing the distribution of recovery rate as a function of the radial position of the cutter; The stability coefficient S quantifies the smoothness of the separation process, and the formula for calculating the stability coefficient S is as follows: S = 1 / (1 + k × CV) Wherein, CV is the coefficient of variation of all grade measurements within the effective separation interval, and its expression is as follows: CV=σG / μG In the above formula, k is the grade fluctuation penalty weighting coefficient; σG is the standard deviation of grade within the effective separation interval; μG is the average grade within the effective separation interval; The effective separation range is based on a set effective grade threshold, from which all measurement points with grade values not lower than the threshold are selected from all radial position control points of the ore cutter; The effective grade threshold is the minimum concentrate grade value.
2. The method for evaluating the separation performance of a spiral chute based on the control of a cutter and the coupling of multiple indicators as described in claim 1, characterized in that: The target spiral chute structural parameters include outer radius R, inner radius r, pitch P, downward angle γ, and number of turns N; Ore feeding conditions include mineral type, grade of valuable elements, particle size and density; Operating parameters include solid mass concentration and inlet volumetric flow rate.