CN-121980726-A - Ore grinding medium type selection method based on capture area evaluation

CN121980726ACN 121980726 ACN121980726 ACN 121980726ACN-121980726-A

Abstract

The invention relates to a grinding medium type selection method based on capture area evaluation, and belongs to the field of grinding in mineral separation. According to the mass of the grinding medium of the target mill, the distance from the center of the medium to the mill and the rotating speed of the mill per minute, theoretical kinetic energy of the grinding medium during throwing in the mill is calculated, laboratory simulated impact is constructed, the capturing area is quantized, a pressure testing machine is used for acting on the medium according to the theoretical kinetic energy A, impact on a standardized ore material layer is simulated, the capturing area is quantized through an image processing technology, capturing area data of various mediums under different energies are obtained through step energy measurement, and a medium with better capturing area is selected as the optimal grinding medium through comparison. The invention realizes quantitative measurement of the 'capture area' of the grinding medium, solves the problems of blindness, high cost and long period of the traditional grinding test, and realizes quick, low-consumption and accurate medium type selection.

Inventors

XU JILONG
GAN MAOWU
ZHANG ZUGANG
SUN BOYUAN
XIAO QINGFEI
ZHANG DENGFENG
HUANG YUXUAN

Assignees

南京宝地梅山产城发展有限公司

Dates

Publication Date: 20260505
Application Date: 20251120

Claims (7)

1. The grinding medium model selection method based on the capture area evaluation is characterized by comprising the following steps of: S1, determining a target working condition and theoretical kinetic energy of a medium, namely calculating the theoretical kinetic energy A of the medium when the medium is thrown in a grinding machine based on the operation parameters of a target grinding machine and the physical properties of the grinding medium to be evaluated; S2, constructing a laboratory to simulate impact and quantify the capture area, namely using theoretical kinetic energy A as an energy reference, using a pressure testing machine to apply work to a medium, simulating impact of the medium on a standardized ore material layer, and quantifying the capture area of the impact through an image processing technology; S3, establishing performance data and a model selection decision, namely acquiring capture area data of various media under different energies through step energy test, predicting grinding efficiency of each medium in the mill based on the capture area data, and selecting a medium with better grinding efficiency as an optimal grinding medium for the target mill by comparing the data with a prediction result.
2. The grinding medium type selection method based on the capture area evaluation according to claim 1, wherein in step S1, the theoretical kinetic energy a is calculated by the following formula: wherein: m mass of grinding medium, kg; g is gravity acceleration, N.kg -1 ; R is the distance from the center of the medium to the center of the mill to the mill, and m; n is the rotating speed of the mill per minute, and r.min -1 .
3. The grinding medium type selection method based on the capture area evaluation according to claim 1, wherein step S2 specifically includes: s2.1, preparing a standardized ore material layer, namely uniformly spreading ore particles with fixed quality and size fraction into a material layer with consistent thickness, S2.2, configuring a capture area recording unit, namely arranging a copying paper and a substrate for recording contact marks below the material layer, so that the medium can form the mark marks corresponding to the ore contact areas on the substrate after being impacted, S2.3, energy equivalent simulation impact, namely setting the work of the pressure testing machine on the medium to be equal to the theoretical kinetic energy A, S2.4, performing impact and image acquisition, namely enabling the medium to impact the material layer under set work to obtain a capturing area imprinting image, S2.5, digital processing and area calculation, namely scanning or shooting the indentation marks to obtain digital images, and then carrying out pixel statistics on the digital images by using image processing software to calculate a capturing area value.
4. The method for selecting a grinding medium based on measurement of a capture area according to claim 3, wherein in step S2.3, the work performed on the medium by the pressure tester is set to be equal to the theoretical kinetic energy a, so as to realize equivalent simulation of the impact energy of a laboratory and the throwing kinetic energy of a mill.
5. The method for selecting a grinding medium based on measurement of a capturing area according to claim 1, wherein in step S3, the step energy measurement means that a theoretical kinetic energy a is taken as a highest reference, a plurality of energy levels are set in a decreasing manner according to a preset ratio, and the capturing area under each energy level is measured respectively.
6. The method for selecting the grinding medium based on the measurement of the capture area according to claim 1, wherein the grinding medium is made of low/high chromium alloy, cast iron or ceramic, and is spherical, rod-shaped or polyhedral.
7. The grinding medium model selection method based on the capture area evaluation according to claim 1, wherein S3, establishing performance data and model selection decisions is as follows, S3.1, step energy test, namely changing the set work of the pressure testing machine, taking the kinetic energy A as a reference, decreasing according to a preset proportion, repeating the step S2 to obtain a series of capture areas S i under different energies A i , thereby constructing the 'energy-capture area' relationship of the medium, S3.2. Performance comparison, for a plurality of media to be selected, executing steps S1 to S3.1 under the same test conditions to obtain respective 'energy-capture area' data, S3.3, selecting an optimal medium, namely selecting a medium with stable capturing area and larger value in a target energy interval as an optimal ore grinding medium for the target mill by comparing capturing areas of the mediums under the same energy level.

Description

Ore grinding medium type selection method based on capture area evaluation Technical Field The invention relates to a grinding medium type selection method based on capture area evaluation, and belongs to the field of grinding in mineral separation. Background The mineral deposit causes are complex, and the ores have remarkable differences in structure, embedding characteristics, mechanical properties and the like, which puts forward extremely high requirements on the key link of mineral dressing resource utilization. The core task of the ore grinding operation in the ore dressing flow, which is used as a pre-process of the continuous crushing and the sorting, is to reduce the granularity of the ore through the action of mechanical force, and finally realize the full 'monomer dissociation' of the useful mineral and gangue mineral. The quality of the ground mineral product directly determines the final index of the subsequent sorting process. Therefore, the improvement of the grinding efficiency is a core subject of cost reduction and efficiency improvement in the field of mineral separation. The grinding medium is used as a direct carrier for energy transmission, and the physical properties and the kinematic parameters of the grinding medium have decisive influence on the working performance of the mill. The grinding efficiency depends on the efficiency of the interaction between the medium and the ore particles. One of the key microscopic mechanisms is the "capture area" which is the actual effective contact area of the grinding media with the ore particle population at the moment of impact or spalling. The larger the capture area, the more the number of ore particles which can participate in the crushing process at the same time under the action of unit energy, the more uniform the spatial distribution of energy. Particularly, in the fine grinding stage mainly based on grinding, the sufficiently large effective capturing area is helpful for forming a stable 'material layer grinding' effect on the surface of a medium, so that the particle size distribution of a product can be remarkably improved, and the over-grinding phenomenon is reduced. Thus, the "capture area" may be regarded as a critical parameter of the grinding effect. Currently, the evaluation of the working behavior of media is almost entirely dependent on the traditional "grinding comparison experiment". This conventional approach has inherent drawbacks in that conventional experiments fail to strip the core operational capabilities (i.e., capture area and impact energy) of the individual media, and fail to reveal the microscopic mechanisms of media-ore interactions. Therefore, there is an urgent need in the art for a new method and technology system that can break through the traditional experimental paradigm, rapidly, directly and quantitatively evaluate the "capture area" of the grinding media in a laboratory, and establish a reliable predictive relationship between the parameter and the industrial grinding effect. The invention aims to solve the technical problem which exists for a long time and is straight. Disclosure of Invention The invention aims to solve the technical problems, and provides a grinding medium type selection method based on capture area evaluation. The invention aims to simply calculate kinetic energy or area, but to establish a technical chain of 'theoretical calculation-laboratory simulation-quantitative evaluation-industrial prediction', and finally achieve the aim of selecting the optimal grinding medium for specific ore and specific grinding machine. The technical scheme of the invention is that the ore grinding medium model selection method based on the capture area evaluation is characterized in that a value which cannot be measured in a mill is converted into a value which can be measured in a laboratory, and the method comprises the following steps of sequentially executing: s1, determining target working conditions and theoretical kinetic energy of a medium: s1.1, determining key operation parameters of a target mill, wherein the key operation parameters comprise a mill rotating speed n and an effective inner diameter; s1.2, selecting one or more grinding media to be evaluated, and acquiring physical properties including mass m, size and shape; s1.3, based on the operation parameters and the physical properties, according to the formula: wherein: m mass of grinding medium, kg; g is gravity acceleration, N.kg -1; R is the distance from the center of the medium to the center of the mill to the mill, and m; n is the rotating speed of the mill per minute, and r.min -1; And calculating theoretical kinetic energy A of the medium when the medium is thrown on the motion track of the outermost layer of the mill, wherein the kinetic energy A is used as an energy reference for the subsequent laboratory simulation. S2, constructing a laboratory simulation impact and quantifying a capture area: S2.1, preparing a standardize