A clay-improved copper tailings roadbed filler and a method for confirming its proportion

Abstract

The present invention belongs to the technical field of roadbed engineering, in particular to a clay-modified copper tailings roadbed filler and a method for confirming its proportion. The specific steps of the present invention are as follows: S1, take copper tailings to fill a compaction cylinder, scrape the surface after tamping, and measure its tamping density; S2, use SEM to scan the scraped surface of the copper tailings, collect images of the scraped surface, filter the image and perform histogram equalization processing; S3, extract the circumference and area of ​​the tailings sand particles in the SEM scanned image; S4, calculate the mixing ratio of clay and copper tailings. The present invention can be used to scientifically guide the mixing ratio of the two, exert the best effect, and ensure good construction quality.

Description

Technical Field

[0001] The invention belongs to the technical field of roadbed engineering, and in particular relates to a clay-improved copper tailings roadbed filler and a method for confirming its proportion. Background Art

[0002] During the copper ore dressing process, 95% of its material forms tailings, which are mainly backfilled into the mine in the form of paste filling. It cannot be completely consumed. The main treatment method for a large amount of copper tailings that have not been comprehensively utilized is stacking. This not only forces companies to build tailings ponds and bear high infrastructure costs, but also occupies precious land resources.

[0003] Since copper tailings do not contain sticky components, they cannot form good cohesion and are difficult to compact. However, clay particles have strong cohesion, are low in cost and easy to obtain. Clay-modified tailings are used as roadbed fillers to enhance solidification cohesion and have friction and cohesion, so they are excellent roadbed fillers. However, the current interaction effect and blending ratio between clay and copper tailings are completely dependent on indoor tests, which require multiple tests to obtain the best blending ratio, and the performance is difficult to achieve the optimal state. Therefore, a clay-modified copper tailings roadbed filler and a method for confirming its ratio are urgently needed to solve the above problems. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention provides a clay-modified copper tailings roadbed filler and a method for confirming its proportion. The present invention can be used to scientifically guide the mixing proportion of the roadbed filler to achieve the best effect and ensure good construction quality.

[0005] To achieve one of the above purposes, the present invention adopts the following technical solution:

[0006] A method for confirming the proportion of clay-modified copper tailings roadbed filler, the specific steps are as follows:

[0007] S1. Fill the container with copper tailings, tamp it, scrape the surface flat, and measure its tamped density;

[0008] S2, using SEM to scan the scraped surface of the copper tailings, collect images of the scraped surface, and perform filtering and histogram equalization processing on the images;

[0009] S3, extracting the perimeter and area of ​​each copper tailings particle in the SEM scanning image;

[0010] S4. Calculate the blending ratio of clay and copper tailings according to the following formula:

[0011] ;

[0012] ;

[0013] ;

[0014] ;

[0015] ;

[0016] ;

[0017] ;

[0018] Where:

[0019] S n￣ Clay area covering copper tailings in the SEM image field, μm 2 ;

[0020] j ￣ The number of copper tailings in the SEM image;

[0021] r o￣ Average particle size of clay, μm;

[0022] ￣ The perimeter of the kth copper tailing, μm;

[0023] P n￣ Area ratio coefficient of clay to copper tailings;

[0024] ￣ The area of ​​the kth copper tailing, μm 2 ;

[0025] V n1￣ 1 cubic meter of clay volume encapsulating copper tailings in the clay-improved copper tailings roadbed material, m 3 ;

[0026] V w￣ Volume of copper tailings in 1 cubic meter of clay-improved copper tailings roadbed material, m 3 ;

[0027] S s￣ Total image field area, μm 2 ;

[0028] δ ￣ Volume expansion coefficient after clay wraps copper tailings;

[0029] V k￣ The compacted void ratio of copper tailings in 1 cubic meter of clay-improved copper tailings roadbed material, %;

[0030] ρ z￣ Compacted density of copper tailings, g / cm 3 ;

[0031] ρ w￣ Apparent density of copper tailings, g / cm 3 ;

[0032] V n￣ 1 cubic meter of clay volume in the copper tailings roadbed material, m 3 ;

[0033] VV ￣ The designed void ratio of 1 cubic meter of clay-improved copper tailings roadbed material is %.

[0034] Preferably, in step S2, the sample is a square with a side length of 3 mm to 5 mm.

[0035] Preferably, the designed porosity of 1 cubic meter of clay-improved copper tailings roadbed material is 4-7%.

[0036] Preferably, in the copper tailings, the content of copper tailings with a particle size greater than 0.045 mm is ≥50%.

[0037] Preferably, in step S1, the moisture content of the copper tailings is ≤13%.

[0038] Preferably, in step S4, the moisture content of the clay is ≤11%, and the particle size of the clay is ≤0.02 mm.

[0039] To achieve the second of the above objectives, the present invention provides a roadbed filler obtained by a method for confirming the proportion of a clay-modified copper tailings roadbed filler.

[0040] The advantages of the present invention are:

[0041] (1) The present invention combines image processing technology to analyze the accumulation state of copper tailings. According to the principles of volume filling and clay bonding, the basic structure of copper tailings accumulation is that clay wraps the copper tailings and bonds with each other to form good cohesion. The clay fills the remaining space volume of the copper tailings accumulation densely, thereby having higher strength. Through theoretical calculation, the optimal blending ratio between the two is determined, which greatly reduces the amount of experiments and maximizes the performance of the two materials after combination.

[0042] (2) When designing the roadbed filler ratio, the method of the present invention adopts image processing technology to identify the distribution of clay and copper tailings after the interaction according to the volume of the remaining space after the copper tailings are wrapped with clay and filled. The influence of the clay-wrapped copper tailings on the space expansion is also considered, and the mixing ratio of copper tailings to clay is accurately calculated to ensure the accuracy of the calculation results.

[0043] (3) The roadbed filler in the present invention uses copper tailings as raw materials, and regenerates industrial waste copper tailings to achieve waste resource utilization, resource conservation, high efficiency and environmental protection. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0045] Example 1

[0046] A method for confirming the proportion of clay-modified copper tailings roadbed filler, the specific steps are as follows:

[0047] 1. The moisture content and apparent density of copper tailings and clay were tested respectively, and the copper tailings were screened. The average particle size of clay was determined to be 0.0042 mm. Other test results are shown in Table 1-2 below:

[0048] Table 1 Raw material test results

[0049] ;

[0050] Table 2 Proportion of different particle sizes of copper tailings

[0051] .

[0052] 2. Take the copper tailings and put them into a compaction cylinder with an inner diameter of 92mm to fill the entire compaction cylinder. Scrape the surface and measure its compaction density to be 1.408g / cm 3 .

[0053] 3. Use SEM to scan the scraped surface of the copper tailings, collect images of the scraped surface, the size of the collected image is 3.3 mm square, and the image is filtered and histogram equalized.

[0054] 4. Extract the perimeter and area of ​​each copper tailings particle in the SEM scan image, as shown in Table 3 below:

[0055] Table 3

[0056] ;

[0057] 5. Through SEM scanning pictures, extract and count the area of ​​voids, and calculate the mixing ratio of clay and copper tailings according to the following formula, where the design void ratio VV of clay-improved copper tailings roadbed material is 5%:

[0058] =1858605um 2 ;

[0059] ;

[0060] ;

[0061] ;

[0062] ;

[0063] ;

[0064] ;

[0065] After calculation, the volume of clay in 1 cubic meter of clay-improved copper tailings roadbed material is V n =0.438m 3 , the volume of copper tailings is V w =0.512m 3 .

[0066] According to the above ratio results, the proportion of copper tailings in the ratio is calculated as follows:

[0067] ;

[0068] The performance of the mix ratio was verified by compaction test and CBR test, and the results are shown in Table 4 below:

[0069] Table 4

[0070] ;

[0071] It can be seen from Table 4 that compared with other blending ratios, the filler obtained by the ratio confirmation method of the present invention has the largest maximum dry density and the highest CBR value, indicating that the filler prepared by the ratio confirmation method of the present invention has better compactness and higher strength.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for confirming the proportion of clay-modified copper tailings roadbed filler, characterized in that: The specific steps are as follows: S1. Fill the container with copper tailings, tamp it, scrape the surface flat, and measure its tamped density; S2, using SEM to scan the scraped surface of the copper tailings, collect images of the scraped surface, and perform filtering and histogram equalization processing on the images; S3, extracting the perimeter and area of ​​each copper tailings particle in the SEM scanning image; S4. Calculate the blending ratio of clay and copper tailings according to the following formula: ； ； ； ； ）； ； ； Where: S n￣ Clay area covering copper tailings in the SEM image field, μm 2 ; j ￣ The number of copper tailings in the SEM image; r o￣ Average particle size of clay, μm; ￣ The perimeter of the kth copper tailing, μm; P n￣ Area ratio coefficient of clay to copper tailings; ￣ The area of ​​the kth copper tailing, μm 2 ; V n1￣ 1 cubic meter of clay volume encapsulating copper tailings in the clay-improved copper tailings roadbed material, m 3 ; V w￣ Volume of copper tailings in 1 cubic meter of clay-improved copper tailings roadbed material, m 3 ; S s￣ Total image field area, μm 2 ; δ ￣ Volume expansion coefficient after clay wraps copper tailings; V k￣ The compacted void ratio of copper tailings in 1 cubic meter of clay-improved copper tailings roadbed material, %; ρ z￣ Compacted density of copper tailings, g / cm 3 ; ρ w￣ Apparent density of copper tailings, g / cm 3 ; V n￣ 1 cubic meter of clay volume in the copper tailings roadbed material, m 3 ; VV ￣ The designed void ratio of 1 cubic meter of clay-improved copper tailings roadbed material is %.

2. The method for confirming the proportion of clay-improved copper tailings roadbed filler according to claim 1, characterized in that: In step S2, a square with a side length of 3 mm to 5 mm is collected.

3. The method for confirming the proportion of clay-improved copper tailings roadbed filler according to claim 1, characterized in that: The design void ratio of 1 cubic meter of clay-improved copper tailings roadbed material is 4-7%.

4. The method for confirming the proportion of clay-improved copper tailings roadbed filler according to claim 1, characterized in that: In the copper tailings, the content of copper tailings with a particle size greater than 0.045 mm is ≥50%.

5. The method for confirming the proportion of clay-improved copper tailings roadbed filler according to claim 1, characterized in that: In step S1, the moisture content of the copper tailings is ≤13%.

6. The method for confirming the proportion of clay-improved copper tailings roadbed filler according to claim 1, characterized in that: In step S4, the moisture content of the clay is ≤11%, and the particle size of the clay is ≤0.02 mm.

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