A method for evaluating mineral dissociation based on microhardness testing

Abstract

The present application relates to a kind of mineral processing and related field research methods, specifically a kind of mineral dissociation evaluation method based on microhardness test;The present application uses the method of microhardness, carries out testing in depth mineral dissociation face, the data obtained is intuitive, accurate, and the columnar diagram of each mineral monomer dissociation difficulty evaluation value drawn is intuitive and clear;Process is simple, easy to master, can improve work efficiency, can be used for mineral processing engineering related professional scientific research, technology and management personnel master.

Description

TECHNICAL FIELD

[0001] The present application relates to a research method in the field of mineral processing and related fields, in particular to a mineral dissociation evaluation method based on microhardness testing. BACKGROUND

[0002] Mineral processing is one of the main methods to realize mineral separation, mainly including pre-selection operation, separation operation and solid-liquid separation operation, among which the pre-selection operation mainly includes crushing and screening, grinding and classification, aiming to make the useful minerals and gangue minerals or different useful minerals in the ore realize monomer dissociation or make the particle size of the material meet the requirements of the separation operation. The traditional method to study mineral monomer dissociation is grinding test, that is, using a laboratory grinding machine to grind a representative ore sample under different time conditions, and then identifying the minerals of the ground product or investigating the mineral dissociation by separation test index.

[0003] In recent years, some researchers have tested mineral dissociation degree by using new methods, such as "a method for obtaining mineral dissociation degree based on particle fracture characteristics" (application number: CN202010378131.9) and "a mineral dissociation system based on fracture characteristic criteria" (application number: CN202010378116.4) disclosed by China University of Mining and Technology, "a coarse-grained mineral dissociation device and method" (application number: CN202011171124.8) and "a device and method for mineral dissociation" (application number: CN202210324233.1) disclosed by China University of Geosciences (Beijing), etc. The currently disclosed methods for testing or researching mineral dissociation mainly test mineral dissociation degree based on the fracture generated by grinding or design mineral dissociation equipment, and the mineral dissociation evaluation method based on microhardness testing has not been reported. The mineral dissociation evaluation method based on microhardness testing is based on the correlation between the hardness value of a point in the ore body and the ability of the point to resist external force. By testing the microhardness distribution law inside the ore, the evolution process of cracks in the grinding process of the ore can be understood without carrying out grinding test, so as to understand the dissociation law of the mineral, and provide guidance for grinding and beneficiation.

[0004] The currently reported mineral dissociation degree tests all need to be obtained by grinding test, which requires a large amount of ore and high labor cost, and the test results have certain correlation with the test equipment and test conditions, so it is necessary to develop a mineral dissociation evaluation method based on microhardness testing to make up for the shortcomings of the prior art. SUMMARY

[0005] The present application provides a mineral dissociation evaluation method based on microhardness testing to solve the above problems.

[0006] Specifically, the following technical solutions are used to achieve the above purposes:

[0007] 1. A mineral dissociation evaluation method based on microhardness testing, comprising the following steps:

[0008] (1) Select a representative block sample from the ore sample to be tested, wash the surface and air dry, cut the sample into a suitable size cube using a cutting machine, and adjust the size according to the requirements of the microhardness tester, polarizing microscope, or scanning electron microscope used for testing. Use 100-2000 mesh sandpaper to polish the test surface in order from small to large, and then polish the surface to a bright finish using a polishing machine;

[0009] (2) Obtain the mineral composition of the collection surface using a polarizing microscope or other testing means, design hardness collection points according to each mineral and its connecting surface, use a microhardness tester equipped with a micro-image collection device for testing, calculate and draw a mineral monomer dissociation difficulty evaluation column chart, and evaluate the dissociation difficulty of each mineral in the ore and the relationship between the dissociation of the connected body during grinding.

[0010] Further, the hardness collection point design must cover each mineral, each mineral connecting surface, three-phase or four-phase and above mineral connecting points.

[0011] Further, the mineral monomer dissociation difficulty evaluation column chart is based on the lowest value of all collection points as the reference point, and the hardness values of all collection points are processed by ratio, and the average value of the hardness ratio of each mineral around is calculated, and the mineral monomer dissociation difficulty evaluation column chart is drawn.

[0012] Further, the drawing of the mineral monomer dissociation difficulty evaluation column chart has the following two steps:

[0013] First step: Take the lowest hardness value of the collection surface (such as A) as the reference hardness, and the ratio of the hardness values of all other collection points of the collection surface (such as B1, B2, B3…) to A is the hardness ratio x1, x2, x3… of each collection point. The calculation formula is as follows:

[0014] xn = Bn / A

[0015] Second step: Take each mineral as a unit, add the hardness ratio xn of the collection points around the mineral, and then calculate the average value, which is the monomer dissociation difficulty evaluation value M1 of the mineral. Draw a column chart of the monomer dissociation difficulty evaluation values M1, M2, M3… of each mineral, which can be used for the monomer dissociation evaluation of each mineral in the ore.

[0016] Further, the relationship between the dissociation difficulty and the connected dissociation is specifically as follows: when the mineral hardness ratio is lower than the mineral monomer dissociation difficulty evaluation value, the damage crack passes through the inside of the mineral; when the mineral hardness ratio is higher than the mineral monomer dissociation difficulty evaluation value, the dissociation order of the mineral is from low to high of the mineral monomer dissociation difficulty evaluation value.

[0017] In conclusion, the beneficial effects of the present application are as follows: the present application uses the microhardness method to test the mineral dissociation surface, the obtained data is intuitive and accurate, the mineral monomer dissociation difficulty evaluation columnar chart is intuitive and clear, the process is simple and easy to master, the work efficiency can be improved, and the related professional scientific research, technology and management personnel of the mineral processing engineering can master and use. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The step flow chart of the present application is shown in the figure.

[0019] Figure 2 The mineral distribution map of the collection surface is shown in the figure, and the line between the minerals is the schematic diagram of the mineral connection surface.

[0020] Figure 3 The design schematic diagram of the microhardness collection point of the collection surface is shown in the figure, the line between the minerals is the schematic diagram of the mineral connection surface, and the red point is the designed hardness collection point.

[0021] Figure 4 The mineral monomer dissociation difficulty evaluation columnar chart drawn in Example 1 is shown in the figure. DETAILED DESCRIPTION

[0022] The specific embodiments of the present application are further described in detail below, but the present application is not limited to these embodiments, and any improvement or replacement in the basic spirit of the present embodiments still belongs to the scope of protection claimed by the present application.

[0023] Example 1

[0024] The mineral monomer dissociation difficulty evaluation columnar chart drawn in Example 1 is shown in the figure. Figure 1As shown, representative block samples are selected from the ore sample to be tested, the ore surface is washed with clean water, and then naturally air-dried; the sample is cut into a 10mmx10mmx10mm cube using a cutting machine; the representative surface is polished and polished, and all or part of the six surfaces can be processed as needed, the processing method is: using 100-2000 mesh sandpaper to gradually polish the test surface to flat, the mesh number of the sandpaper can be arbitrarily selected, but it must be gradually polished from small mesh to large mesh, and then the surface is polished to bright using a polishing machine to meet the requirements of the polarizing microscope and the microhardness tester for the test surface; the mineral species of the collection surface is identified using a polarizing microscope or other testing means, and the representativeness of the mineral composition of the collection surface can be evaluated according to the X-ray diffraction test results of the ore, and a collection surface mineral composition schematic diagram is drawn (such as Figure 2 As shown), if one sample cannot meet the requirements of ore representativeness, additional multiple pieces can be prepared, and the specific number is determined according to the representativeness evaluation results; the microhardness collection points of the collection surface are designed, as shown in Figure 3 The red dots are the designed hardness collection points, and the same test surface is tested using a microhardness tester equipped with a microimage collection device to determine the hardness values of each collection point; the lowest value among all the collection points is taken as the reference point, and the hardness values of all the collection points are processed by ratio; the dissociation evaluation value of each mineral is calculated, and the specific method is: the peripheral hardness ratio of each mineral is accumulated and averaged, and a mineral monomer dissociation difficulty evaluation column chart is drawn, as shown in Figure 4

[0025] In specific use, taking mineral A as an example, if the hardness value of mineral A is lower than the average hardness of the connecting surface, the damage crack passes through the inside of mineral A, i.e. mineral A is damaged before the peripheral connecting surface; if the hardness value of A is higher than the average hardness of the connecting surface, the damage crack tends to pass through the connecting surface first, and if the test result is as shown in Figure 4 In this way, mineral A is dissociated before other minerals, and the dissociation order of all minerals is: mineral A, mineral D, mineral F, mineral C, mineral E, and mineral B.​

Claims

1. A method for evaluating mineral liberation based on microhardness testing, characterized in that, Includes the following steps: S1: Select representative block samples from the ore samples to be tested, cut the samples into cubes of appropriate size using a cutting machine, grind the test surface with sandpaper step by step until it is flat, and then polish the surface with a polishing machine until it is shiny. S2: The mineral composition of the sampling surface is tested using a polarizing microscope. Hardness sampling points are designed according to each mineral and its connecting surface. A microhardness tester equipped with a microscopic image acquisition device is used for testing. A bar chart evaluating the ease of liberation of individual minerals is calculated and drawn. The bar chart is used to evaluate the ease of liberation of each mineral in the ore and the relationship of the interconnected liberation during the grinding process. The process of drawing a bar chart to evaluate the ease of mineral liberation includes the following two steps: Step 1: Take the lowest hardness value A on the sampling surface as the reference hardness. The ratio of the hardness values ​​B1, B2, B3...Bn at all other sampling points on the sampling surface to A is the hardness ratio of each sampling point. x 1. x 2. x 3‧‧‧ x n; the calculation formula is as follows: x n=Bn / A Step 2: Taking each mineral as a unit, calculate the hardness ratio of the sampling points around the mineral. x 1. x 2. x 3‧‧‧ x The values ​​of n are accumulated and then averaged to obtain the evaluation value of the ease of liberation of each mineral monomer. A bar chart of the ease of liberation of each mineral monomer is plotted and can be used to evaluate the liberation of each mineral monomer in the ore.

2. The mineral liberation evaluation method based on microhardness testing as described in claim 1, characterized in that, The design of hardness sampling points must cover all minerals, mineral interfaces, and mineral interfaces of three phases or more.

3. The mineral dissociation evaluation method based on microhardness testing as described in claim 1, characterized in that, The relationship between the degree of dissociation difficulty and the dissociation of conjoined minerals specifically refers to the following: when the mineral hardness ratio is lower than the mineral individual dissociation difficulty evaluation value, the fracture crack passes through the interior of the mineral; when the mineral hardness ratio is higher than the mineral individual dissociation difficulty evaluation value, the dissociation order of the minerals is in the order of mineral individual dissociation difficulty evaluation value from low to high.

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