Method for investigating and optimizing feeding position of short-stroke spiral chute

Abstract

The invention provides a short-stroke spiral chute feeding position investigation and optimization method, which comprises the following steps of: constructing an accurate spiral chute geometric model, investigating the influence of a feeding position on a spiral chute sorting numerical test result by adopting a high-precision numerical simulation method and referring to field production materials and operation parameters, and optimizing the feeding position of the spiral chute according to the influence of the feeding position on the spiral chute sorting numerical test result. And comparing process parameters such as flow film thickness, secondary circulation, Reynolds number and particle space distribution and technical index differences such as concentrate grade, yield and recovery rate, and meanwhile, carrying out actual test verification. The limitation of research and development of traditional spiral chute equipment is broken through; a high-precision numerical model, a multi-factor investigation strategy and an actual separation verification test are integrated, and an ore feeding position optimization method is provided; aiming at the properties and working conditions of different to-be-sorted materials, theoretical and technical supports are provided for efficient optimal configuration of the feeding position of the short-stroke spiral chute, reference is provided for quality improvement and efficiency improvement of production practice, and remarkable innovativeness, practicability and application and popularization value are achieved.

Description

Technical Field

[0001] This invention belongs to the technical field of composite force field mineral processing equipment; it relates to a method for investigating and optimizing the feeding position of a short-stroke spiral chute. Background Technology

[0002] With the increasing scarcity of mineral resources and the ever-rising demands for concentrate quality, efficient and precise mineral separation has become a focal point in the mineral sorting field. Spiral sluices, as a widely used gravity separation device, occupy a crucial position in the sorting processes of non-ferrous metals, ferrous metals, and non-metallic minerals due to their advantages such as simple structure, low energy consumption, and large throughput. Their sorting principle is based on the fact that during the flow of the slurry in the spiral trough, mineral particles of different densities and sizes are subjected to the combined effects of centrifugal force, gravity, and friction, resulting in axial stratification and radial zoning.

[0003] However, existing spiral chute feeding methods are generally characterized by randomness and uniformity, with their design and layout rarely considering the diversity of minerals to be separated. From the perspective of material properties, ores come from a wide range of sources and are diverse in type, with a large density range, from approximately 4000 to 5000 kg / m³ for common iron ore. 3 Some precious metal ores have a density as high as 10,000 kg / m³ 3 The particle size distribution is extremely complex and varied, ranging from a few micrometers to several millimeters, and the shapes encompass various forms such as lumps, granules, and flakes. These inherent differences in material properties impose stringent requirements on the feed location. An improper feed location directly alters the initial flow state of the slurry upon entering the spiral chute, thus affecting the evolution and distribution of flow field characteristics such as flow regime, velocity, and secondary circulation within the chute. These changes in flow field characteristics are closely related to the stress on the particles, ultimately preventing them from settling, stratifying, and migrating along ideal paths, severely impacting separation accuracy.

[0004] On the other hand, feed parameters (such as concentration and flow rate) also have high requirements for the inlet location. Improper feed location can lead to excessively high feed concentration, increasing slurry viscosity and reducing fluidity, making it difficult for particles in the slurry flow field to spread and stratify rapidly under centrifugal force. Conversely, excessively low concentration weakens the interaction between particles, reducing throughput and separation efficiency. Simultaneously, unstable flow rate caused by an unsuitable feed location can lead to fluctuations in slurry velocity, making the residence time of mineral particles in the spiral chute uncontrollable, prolonging the longitudinal stroke required for separation, and further exacerbating the uncertainty of the separation results. Currently, scientific research and production practice mostly focus on adjusting the structural parameters of the spiral chute itself (such as pitch and cross-sectional shape) and their impact on separation, while randomly and habitually treating the feed location as a fixed constant, failing to deeply explore its profound correlation as a key factor with slurry flow characteristics, particle motion behavior, and final separation indicators. This one-sidedness will lead to the inability of a uniform feed position to achieve the best separation efficiency of the spiral chute when handling complex working conditions with different minerals under different operating conditions. It will also fail to improve product quality and efficiency, severely restricting the comprehensive utilization of mineral resources and the economic benefits of mineral processing enterprises, and making it difficult to meet the current urgent need for efficient and refined mineral processing. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention discloses a method for investigating and optimizing the feeding location of a short-stroke spiral chute, specifically including the following steps:

[0006] S1: Design the structural parameters of the spiral chute, and determine the operating parameters and property parameters of the material to be sorted for the numerical sorting test of the spiral chute;

[0007] The structural parameters of the spiral chute include outer radius, inner radius, pitch, cross-sectional geometry, and number of turns;

[0008] Furthermore, the cross-sectional geometry is any commonly used parabolic or elliptical curve;

[0009] The operating parameters include: feed solids mass concentration and feed volume flow rate;

[0010] The properties of the material to be sorted include: ore grade, particle size, density, and volume ratio of useful minerals and gangue minerals.

[0011] S2: Based on the fluid dynamics characteristics of slurry, and according to the verification and correction results of actual experiments, a high-precision numerical calculation model and solution algorithm for the flow field evolution and particle motion in the spiral chute are selected.

[0012] The numerical calculation models include turbulence models, clear water phase models, and multiphase flow models;

[0013] Furthermore, the turbulence model is the RNG k-ε turbulence model based on the Renormalization Group (RNG) theory; the clear water phase model is the VOF model; and the multiphase flow phase model is the Eulerian Multi-fluid VOF multiphase flow model.

[0014] S3: Determine the adjustment strategy for the feed position in the numerical test of spiral chute sorting. Use SolidWorks 3D modeling software to build the geometric model of the spiral chute at different feed positions, and import them into ICEM CFD software for computational domain mesh construction and independence verification.

[0015] The adjustment strategy involves setting the radial width of the feed inlet to 105mm, starting from the overlap between the inner sidewall of the feed inlet and the inner edge of the spiral chute, and moving outwards sequentially at 15mm intervals, setting different feeding position conditions to form a total of 5 feeding positions with radial positions r = 35, 50, 65, 80, and 95mm on the inner sidewall of the feed inlet. These 5 feeding position conditions are respectively denoted as IRP 1, IRP 2, IRP 3, IRP 4, and IRP 5.

[0016] The computational domain mesh is a hexahedral mesh;

[0017] The computational domain grid independence verification uses the final flow film thickness of the first loop as the evaluation criterion.

[0018] S4: Load the computational domain mesh constructed in step S3 into the computational fluid dynamics (CFD) software Ansys Fluent, set the initial conditions, boundary conditions and solution conditions, and conduct numerical experiments under different ore feeding location conditions;

[0019] The initial conditions include solver settings and gravitational acceleration settings;

[0020] Furthermore, the solver is configured with solver type, speed format, and system state;

[0021] The boundary conditions include inlet boundary conditions, wall boundary conditions, and outlet boundary conditions;

[0022] The solution conditions include the solution method, solution control, and solution accuracy.

[0023] S5: Based on the numerical test results, investigate the evolution and distribution of film thickness, fluid pattern and secondary circulation intensity in the spiral chute under different ore feeding locations;

[0024] Furthermore, the surface of the spiral chute is divided into inner edge, middle and outer edge regions from the inside to the outside, and r = 62.5, 90, 117.5, 145, 172.5 and r = 195 mm are determined as representative characteristic radial positions;

[0025] Furthermore, the radial and longitudinal evolution of the film thickness, the radial distribution of the Reynolds number at the end of the third cycle along the surface of the spiral chute, and the axial distribution of the radial velocity of the secondary circulation at the end of the third cycle along the relative water depth were investigated under different feeding conditions.

[0026] S6: Based on the results of numerical experiments, investigate the influence of different feed location conditions on the migration behavior, distribution pattern and separation effect of particles in the spiral chute, determine the regulatory role of feed location on the particle separation process and results, and determine the optimal feed location and separation stroke.

[0027] The particle separation effect is evaluated by concentrate yield, concentrate iron grade, iron recovery rate, and separation efficiency.

[0028] S7: Conduct actual separation tests of spiral chute under different feed location conditions to verify the reliability of numerical test methods and feed location optimization methods.

[0029] The equipment structure parameters, operating parameters, and material properties conditions of the actual spiral chute sorting test are consistent with those of the numerical test.

[0030] By employing the aforementioned technical solution, this invention discloses a method for investigating and optimizing the feed position of a short-stroke spiral chute. This method utilizes a high-precision Eulerian Multi-fluid VOF numerical model that considers the Begno shear loosening effect. Through numerical simulation, it overcomes the limitations of traditional methods relying on experience and trial-and-error experiments, accurately capturing the evolution of the slurry flow field and the migration behavior of mineral particles within the spiral chute. This invention is the first to deeply investigate the bidirectional influence mechanism of the spiral chute feed position—a key factor—on flow field evolution characteristics and particle separation behavior, providing a new theoretical basis for the optimized design of spiral chutes. Based on the patterns revealed by numerical simulation and theoretical analysis, this invention innovatively proposes optimization criteria and strategies for the spiral chute feed position for different process parameters and particle properties, enabling real-time dynamic adjustment of the feed position according to production conditions. The optimized method developed in this invention can effectively improve the sorting performance of spiral chute, shorten the longitudinal travel of mineral particle sorting, and achieve significant results in improving concentrate recovery rate, stabilizing concentrate grade, reducing tailings grade, and adapting to different ore properties. It can bring considerable economic and resource utilization benefits to mining enterprises.

[0031] The advantages of this invention lie in its provision of a method for investigating and optimizing the feed position of a short-stroke spiral chute. This numerical simulation-based optimization method reduces the blind spots and repetitiveness in the research process, significantly shortens the research cycle, and lowers equipment development costs. It clarifies the influence of the feed position on internal flow field parameters, including the evolution of flow field parameters such as flow film thickness, velocity distribution, and secondary circulation intensity, thus improving flow field stability. It also reveals the mechanism by which the feed position affects particle motion behavior, enabling flexible adjustment of the feed position according to different material characteristics. This broadens the application range of the equipment while reducing material sorting time and improving the sorting efficiency of the spiral chute. The optimization method proposed in this invention is universally applicable, not only to specific models of spiral chutes but also providing important reference value for other types and specifications of spiral chutes. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a flowchart of the method of the present invention;

[0034] Figure 2 This is a schematic diagram of the cross-sectional shape of a spiral chute.

[0035] Figure 3 Strategies for adjusting different feed positions in numerical experiments of spiral chute;

[0036] Figure 4 The radial distribution and longitudinal evolution of the downstream film thickness at different feed locations are shown in (a) at the end of circle 0.25; (b) at the end of circle 0.5; (c) at the end of circle 1; and (d) at the end of circle 3.

[0037] Figure 5 The distribution of radial velocity of the secondary circulation at the end of the third ring along the relative water depth at different feeding locations is given by: (a) r = 62.5 mm; (b) r = 90 mm; (c) r = 117.5 mm; (d) r = 145 mm; (e) r = 172.5 mm; (f) r = 195 mm.

[0038] Figure 6 The radial distribution of the Reynolds number at the end of the third cycle under different feeding positions along the trough surface;

[0039] Figure 7The distribution of hematite particles in the spiral chute at different ore feeding locations is shown in (a) IRP 1; (b) IRP 2; (c) IRP 3; (d) IRP 4; (e) IRP 5.

[0040] Figure 8 The distribution of quartz particles in the spiral chute at different feed locations is shown, where (a) IRP 1; (b) IRP 2; (c) IRP 3; (d) IRP 4; (e) IRP 5;

[0041] Figure 9 The influence of feed location on the sorting parameters at the end of the third ring includes (a) concentrate yield; (b) concentrate iron grade; (c) iron recovery rate; and (d) separation efficiency.

[0042] Figure 10 The longitudinal variation of sorting indices under different feed locations is shown, including (a) concentrate yield; (b) concentrate iron grade; (c) iron recovery rate; and (d) separation efficiency.

[0043] Figure 11 This is a schematic diagram of a spiral chute sorting experimental system;

[0044] Figure 12 To verify the effect of the feed location on the sorting index at the end of the third ring in the actual test, including (a) concentrate yield; (b) concentrate iron grade; and (c) iron recovery rate. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] like Figure 1 The method for investigating and optimizing the feed location of a short-stroke spiral chute, as shown, specifically includes the following steps:

[0047] S1. Design the structural parameters of the spiral chute, and determine the operating parameters and property parameters of the material to be sorted for the numerical sorting test of the spiral chute;

[0048] S2, based on the fluid dynamics characteristics of slurry, and according to the verification and correction results of actual experiments, selects a high-precision numerical calculation model and solution algorithm for the flow field evolution and particle motion in the spiral chute;

[0049] S3, determine the adjustment strategy of the feed position in the numerical test of spiral chute separation, use SolidWorks 3D modeling software to build the geometric model of spiral chute at different feed positions, and import them into ICEM CFD software for computational domain mesh construction and independence verification.

[0050] S4. Load the computational domain mesh constructed in step S3 into the computational fluid dynamics (CFD) software Ansys Fluent, set the initial conditions, boundary conditions and solution conditions, and conduct numerical experiments under different ore feeding location conditions.

[0051] S5. Based on the numerical test results, the evolution and distribution of the film thickness, fluid pattern and secondary circulation intensity in the spiral chute under different ore feeding locations were investigated.

[0052] S6. Based on the numerical test results, investigate the influence of different feed location conditions on the migration behavior, distribution pattern and separation effect of particles in the spiral chute, determine the regulatory role of feed location on the particle separation process and results, and determine the optimal feed location and separation stroke.

[0053] S7. Conduct actual separation tests of spiral chute under different feed positions to verify the reliability of numerical test methods and feed position optimization methods.

[0054] The structural parameters of the spiral chute include outer radius, inner radius, pitch, cross-sectional geometric parameters, and number of turns;

[0055] Furthermore, the cross-sectional geometry is any commonly used parabolic or elliptical curve;

[0056] The operating parameters include: feed solids mass concentration and feed volume flow rate;

[0057] The property parameters of the material to be sorted include: ore grade, particle size, density and volume ratio of useful minerals and gangue minerals;

[0058] The numerical calculation models include turbulence models, clear water phase models, and multiphase flow models;

[0059] Furthermore, the turbulence model is the RNG k-ε turbulence model based on the Renormalization Group (RNG) theory; the clear water phase model is the VOF model; and the multiphase flow phase model is the Eulerian Multi-fluid VOF multiphase flow model.

[0060] The adjustment strategy involves setting the radial width of the feed inlet to 105mm, starting from the overlap between the inner sidewall of the feed inlet and the inner edge of the spiral chute, and moving outwards sequentially at 15mm intervals, setting different feed position conditions to form five feed positions with radial positions r = 35, 50, 65, 80, and 95mm on the inner sidewall of the feed inlet. These five feed position conditions are respectively denoted as IRP 1, IRP 2, IRP 3, IRP 4, and IRP 5.

[0061] The computational domain mesh is a hexahedral mesh;

[0062] The computational domain grid independence verification uses the final flow film thickness of the first loop as the evaluation criterion.

[0063] The initial conditions include solver settings and gravitational acceleration settings;

[0064] Furthermore, the solver is configured with solver type, speed format, and system state;

[0065] The boundary conditions include inlet boundary conditions, wall boundary conditions, and outlet boundary conditions;

[0066] The solution conditions include the solution method, solution control, and solution accuracy;

[0067] Furthermore, the surface of the spiral chute is divided into inner edge, middle and outer edge regions from the inside to the outside, and r = 62.5, 90, 117.5, 145, 172.5 and r = 195 mm are determined as representative characteristic radial positions;

[0068] Furthermore, the radial and longitudinal evolution of the film thickness, the radial distribution of the Reynolds number at the end of the third cycle along the surface of the spiral chute, and the axial distribution of the radial velocity of the secondary circulation at the end of the third cycle along the relative water depth were investigated under different feeding conditions.

[0069] The particle separation effect is evaluated by concentrate yield, concentrate iron grade, iron recovery rate, and separation efficiency.

[0070] The equipment structure parameters, operating parameters, and material properties conditions of the actual spiral chute sorting test are consistent with those of the numerical simulation test.

[0071] Example 1: A method for investigating and optimizing the feed location of a short-stroke spiral chute, comprising the following steps:

[0072] S1. Design the structural parameters of the spiral chute, and determine the operating parameters and property parameters of the material to be sorted for the numerical sorting test of the spiral chute;

[0073] The structural parameters of the spiral chute include outer radius R, inner radius r, pitch P, cross-sectional geometry, and number of turns N;

[0074] Furthermore, the outer radius R = 200 mm, the inner radius r = 35 mm, the pitch P = 240 mm, and the number of turns N = 3.25;

[0075] Furthermore, the cross-sectional geometry is a cubic parabolic curve, and its functional expression is |x|=0.0038|y|. 3 A schematic diagram of the cross-sectional shape of the spiral chute is shown below. Figure 2 As shown;

[0076] The operating parameters include: a solid mass concentration of 20% in the feed and a feed volumetric flow rate of 12 L / min.

[0077] The properties of the material to be sorted include: a feed grade of 45.59%, particle sizes of the valuable mineral hematite and the gangue mineral quartz of 90 μm and 38 μm, respectively, and densities of 4950 kg / m³. 3 and 2650kg / m 3 The volume ratio is 1:1.

[0078] S2, based on the fluid dynamics characteristics of slurry, and verified and corrected by actual experiments, selects a high-precision numerical calculation model and solution algorithm for the flow field evolution and particle motion in the spiral chute;

[0079] The numerical calculation models include turbulence models, clear water phase models, and multiphase flow models;

[0080] Furthermore, the turbulence model is the RNG k-ε turbulence model based on the Renormalization Group (RNG) theory; the clear water phase model is the VOF model; and the multiphase flow phase model is the Eulerian Multi-fluid VOF multiphase flow model.

[0081] S3, determine the adjustment strategy of the feed position in the numerical test of spiral chute separation, use SolidWorks 3D modeling software to build the geometric model of spiral chute at different feed positions, and import them into ICEM CFD software for computational domain mesh construction and independence verification.

[0082] The adjustment strategy involves setting the radial width of the feed inlet to 105mm, starting from the overlap between the inner sidewall of the feed inlet and the inner edge of the spiral chute, and moving outwards sequentially at 15mm intervals, setting different feeding position conditions to form a total of 5 feeding positions with radial positions r = 35, 50, 65, 80, and 95mm on the inner sidewall of the feed inlet. These 5 feeding position conditions are respectively denoted as IRP 1, IRP 2, IRP 3, IRP 4, and IRP 5.

[0083] The computational domain mesh is a hexahedral mesh;

[0084] The computational domain grid independence verification uses the final flow film thickness of the first loop as the evaluation criterion.

[0085] S4. Load the computational domain mesh constructed in step S3 into the computational fluid dynamics (CFD) software Ansys Fluent, set the initial conditions, boundary conditions and solution conditions, and conduct numerical experiments under different ore feeding location conditions.

[0086] The initial conditions include solver settings and gravitational acceleration, using a pressure-based unsteady-state solution method, with gravitational acceleration set to 9.8 m / s². 2 ;

[0087] The boundary conditions include inlet boundary conditions, wall boundary conditions, and outlet boundary conditions. The inlet boundary is set as a velocity inlet, the outlet boundary is set as a pressure outlet, and the upper and lower surfaces are set as a free-slip wall and a non-slip wall, respectively.

[0088] The solution conditions include the solution method, solution control, and solution accuracy. In numerical simulations of gas-liquid two-phase flow, the SIMPLE algorithm is used for the coupled solution of the pressure and velocity fields; in numerical simulations of gas-liquid-solid multiphase flow, the Phase Coupled SIMPLE algorithm is used for the coupled solution of the pressure and velocity fields, and second-order accuracy schemes are used for the spatial discretization of other convection terms; the relative residuals of all terms in the differential control equations are limited to 10. -4 The following steps are taken to ensure the accuracy of the solution.

[0089] S5. Based on the numerical test results, the evolution and distribution of the film thickness, fluid pattern and secondary circulation intensity in the spiral chute under different ore feeding locations were investigated.

[0090] Furthermore, the surface of the spiral chute is divided into inner edge, middle and outer edge regions from the inside to the outside, and r = 62.5, 90, 117.5, 145, 172.5 and r = 195 mm are determined as representative characteristic radial positions;

[0091] Furthermore, the distribution characteristics of the flow film thickness, secondary circulation intensity, and Reynolds number during the steady-state phase (end of the 3rd cycle) were examined under different flow cycles when adjusting the feed position. Figures 4-6As shown, it can be observed that adjusting the feed position significantly affects the evolution of fluid morphology and the intensity of secondary circulation, with a highly consistent pattern. When the feed inlet is in the center, the radial distribution of the fluid film transitions most smoothly, with the largest film thickness within the range of r = 140–190 mm, and the fewest flow cycles required for its spread and evolution to a stable state. The circulation intensity is greatest in the inner and outer edge regions and in the outer circulation region of the middle region. Sufficient exchange of secondary circulation is beneficial for promoting selective migration and distribution of particles, shortening the separation path. The Reynolds number increases from the inside to the outside of the tank surface, and the fluid in the tank gradually transitions from laminar flow to turbulent flow, with laminar flow having the widest distribution range, followed by transitional flow and turbulent flow. When the inlet is in the middle of the tank surface, the flow pattern develops quickly and stably; when the inlet is further inside or outside, the flow pattern evolution exhibits different degrees of fluctuation.

[0092] S6. Based on the numerical test results, investigate the influence of different feed location conditions on the migration behavior, distribution pattern and separation effect of particles in the spiral chute, determine the regulatory role of feed location on the particle separation process and results, and determine the optimal feed location and separation stroke.

[0093] Furthermore, the influence of the feed location on particle migration behavior and distribution patterns was examined, such as... Figure 7 and Figure 8 As shown in the diagram, the experimental results indicate that as the fluid spreads radially and the longitudinal travel lengthens, hematite particles initially move outwards, then migrate inwards and accumulate in the inner half of the tank. Quartz particles migrate rapidly outwards in the first half of the tank and then maintain stable motion with the fluid. The separation process of the two types of particles mainly occurs in the inner and middle regions, while the turbulent flow with higher velocity in the outer region is not conducive to radial separation. Adjusting the feed position outwards promotes the inward migration and accumulation of hematite, but at the same time severely restricts the outward migration of quartz, leading to an increase in the mismatch between the two types of particles in the middle region, hindering the selective separation of hematite and quartz particles, and prolonging the effective longitudinal travel length for separation.

[0094] Furthermore, the influence of the feed location on the separation performance of the spiral chute was examined, such as... Figure 9 and Figure 10As shown in the figure. The experimental results show that, under any feed position condition, as the cutter position moves outward, the concentrate yield first increases, then remains stable, and then increases rapidly. The concentrate iron grade gradually decreases, and the iron recovery rate increases rapidly and then remains constant. The separation efficiency of hematite and quartz generally shows a peak-shaped distribution that first increases and then decreases. When the feed position is in the middle (IRP 3), the maximum separation efficiency of 85.83% is achieved at the cutter position r = 110 mm. At this time, the concentrate iron grade is 65.12%, which is higher than the technical indicators obtained under other feed positions. This is because the middle and outer feed positions can promote the inward migration of hematite to form a high enrichment. With the extension of the longitudinal fluid travel, the concentrate yield, concentrate iron grade, iron recovery rate, and separation efficiency under each feed position condition generally show an increasing trend. In contrast, the middle feed position (IRP 3) maintains a high level of concentrate iron grade, iron recovery rate, and separation efficiency at any number of flow cycles, that is, the longitudinal travel required to achieve the same and optimal separation indicators is the shortest.

[0095] S7. Conduct actual separation tests of spiral chute under different feed positions to verify the reliability of numerical test methods and feed position optimization methods.

[0096] The actual sorting test system of the spiral chute is as follows: Figure 11 As shown, the equipment structural parameters, operating parameters, and material properties are consistent with those of the numerical experiment. Specifically, the radial position of the cutter is based on the radial position r = 110 mm corresponding to the highest grade and separation efficiency achieved when the feed position is IRP 3 in S6.

[0097] Furthermore, actual separation tests were conducted using spiral chute under different ore feeding locations, and the results are as follows: Figure 12 As shown. The experimental results show that hematite and quartz particles form a selective distribution under the action of secondary circulation separation. When the feed position is in the middle, the separation technical indicators of 65.54% concentrate grade, 1.09% tailings grade and 98.57% recovery rate can be obtained within 3 short cycles, which is significantly better than other feed positions.

[0098] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for investigating and optimizing the feeding position of a short-stroke spiral chute, characterized in that... include: S1: Design the structural parameters of the spiral chute, and determine the operating parameters and property parameters of the material to be sorted for the numerical sorting test of the spiral chute; S2: Based on the fluid dynamics characteristics of slurry, and according to the verification and correction results of actual experiments, a high-precision numerical calculation model and solution algorithm for the flow field evolution and particle motion in the spiral chute are selected. S3: Determine the adjustment strategy for the feed position in the numerical test of spiral chute sorting. Use 3D modeling software to establish the geometric model of the spiral chute at different feed positions, and import them into ICEM CFD software to construct the computational domain mesh and verify the independence. S4: Load the computational domain mesh into the computational fluid dynamics software Ansys Fluent, set the initial conditions, boundary conditions and solution conditions, and conduct numerical experiments under different ore feeding conditions; S5: Based on the numerical test results, investigate the evolution and distribution of film thickness, fluid pattern and secondary circulation intensity in the spiral chute under different ore feeding conditions; S6: Based on the numerical test results, investigate the influence of different feed location conditions on particle migration behavior, particle distribution pattern and particle separation effect in the spiral chute, determine the regulatory role of feed location on particle separation process and results, and determine the optimal feed location and separation stroke. S7: Conduct actual separation tests of spiral chute under different feed positions to verify the reliability of numerical test methods and feed position optimization methods.

2. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The structural parameters of the spiral chute include outer radius, inner radius, pitch, cross-sectional geometric parameters, and number of turns, wherein the cross-sectional geometry is any commonly used parabolic or elliptical curve; The operating parameters for the numerical test of spiral chute separation include: feed solids concentration and feed volumetric flow rate; The property parameters of the materials to be sorted include the grade of the feed, the particle size, density and volume ratio of the useful minerals and gangue minerals.

3. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The numerical calculation models include turbulence models, clear water phase models, and multiphase flow models; The turbulence model is the RNG k-ε turbulence model based on the renormalization group theory; the clear water phase model is the VOF model; and the multiphase flow phase model is the Euler volumetric multiphase flow model.

4. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The strategy for adjusting the feed position in the numerical test of spiral chute separation is as follows: the radial width of the feed inlet is set to 105 mm. Starting from the overlap between the inner sidewall of the feed inlet and the inner edge of the spiral chute, the feed position is moved outwards at intervals of 15 mm. Different feed position conditions are set, resulting in five feed positions with radial positions r = 35, 50, 65, 80, and 95 mm on the inner sidewall of the feed inlet. These five feed position conditions are recorded as IRP 1, IRP 2, IRP 3, IRP 4, and IRP 5, respectively. The computational domain mesh is a hexahedral mesh; The computational domain grid independence verification uses the final flow film thickness of the first loop as the evaluation criterion.

5. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The computational domain mesh is loaded into the computational fluid dynamics software Ansys Fluent. The initial conditions set include solver settings and gravity acceleration settings. The solver is set to solver type, velocity format and system state. The boundary conditions include inlet boundary conditions, wall boundary conditions and outlet boundary conditions. The solution conditions include solution method, solution control and solution accuracy.

6. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The following method was used to investigate the evolution and distribution of film thickness, fluid pattern, and secondary circulation intensity in a spiral chute under different feeding conditions: The surface of the spiral chute was divided into inner, middle, and outer edge regions from the inside out, and r = 62.5, 90, 117.5, 145, 172.5, and r = 195 mm were determined as representative radial locations. The radial and longitudinal evolution of film thickness, the radial distribution of Reynolds number at the end of the third cycle along the surface of the spiral chute, and the axial distribution of the radial velocity of the secondary circulation at the end of the third cycle along the relative water depth were investigated under different feeding conditions.

7. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The particle separation effect is judged by using concentrate yield, concentrate iron grade, iron recovery rate and separation efficiency.

8. The method for investigating and optimizing the feeding position of a short-stroke spiral chute according to claim 1, characterized in that: The equipment structure parameters, operating parameters, and material properties conditions of the actual spiral chute sorting test are consistent with those of the numerical simulation test.

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