Filling body based on multi-element fine tailings, preparation method and application

Abstract

The invention discloses a filling body based on multi-element fine tailings, a preparation method and application, and relates to the field of mine filling. The filling body provided by the invention comprises the following components in parts by weight: 3-6 parts of cement; 60 to 75 parts of fine tailings; 2 to 5 parts of attapulgite; 5 to 10 parts of gypsum; 3-8 parts of lime; 1-3 parts of an early strength agent; in the fine tailings, the proportion of the fine tailings with the particle size smaller than 20 microns is 50-70 wt%, and the proportion of the fine tailings with the particle size of 20-50 microns is The preparation method comprises the following steps: adding water into the fine tailings and the attapulgite, and uniformly mixing and stirring to obtain a mixture; and mixing the mixture with the cement, the gypsum, the lime and the early strength agent according to the formula ratio, and adding water to obtain the filling body based on the multi-element fine tailings. The filling body is applied to the field of mine filling. By adding the attapulgite and utilizing an internal porous structure of the attapulgite, fine tailings with relatively small particle sizes are adsorbed, and the phenomena that the fine tailings are difficult to dehydrate and easy to run and mix, so that the materials are unevenly distributed and the like are reduced; the adding amount of small-particle-size fine tailings is increased; meanwhile, the performance of a filling body is improved.

Description

Technical Field

[0001] This application relates to the technical field of mine filling, and in particular to a filling body based on multi-component fine tailings, a preparation method and an application thereof. Background Art

[0002] With the expansion of the scale of comprehensive utilization of mines, the amount of coarse tailings used for filling gradually decreases, and a large amount of classified fine tailings remaining after comprehensive utilization enter the sand bin and are used as aggregates for filling. Although the content of using fine tailings for filling has been preliminarily studied at present, it has been demonstrated that the classified fine tailings can meet the existing filling body strength requirements by increasing the ash-sand ratio. However, the current process of existing filling stations is still based on classified coarse tailings filling, and a series of problems still occur after a large amount of classified fine tailings enter the filling system at present.

[0003] The fine tailings with small particle size are difficult to dehydrate and easy to run and mix, resulting in uneven distribution of materials; the fine tailings with small particle size are easy to wrap free water, making it difficult to excrete, resulting in the inability to remove the excess water in the filling slurry; resulting in a low spread and a decrease in the compressive strength of the prepared filling body, especially the low 28-day compressive strength.

[0004] Therefore, how to use a large amount of fine tailings to prepare the filling body for filling mines is a problem that needs to be solved at present. Summary of the Invention

[0005] In order to solve at least one of the above technical problems and develop a filling body that can use a large amount of fine tailings to prepare for filling mines, this application provides a filling body based on multi-component fine tailings, a preparation method and an application thereof.

[0006] In the first aspect, a filling body based on multi-component fine tailings provided by this application is prepared from the following components in parts by weight:

[0007] Cement: 3 - 6 parts;

[0008] Fine tailings: 60 - 75 parts;

[0009] Attapulgite: 2 - 5 parts;

[0010] Gypsum: 5 - 10 parts;

[0011] Lime: 3 - 8 parts;

[0012] Early strength agent: 1 - 3 parts;

[0013] In the fine tailings, the proportion of particles with a particle size below 20μm is 50 - 70wt%, and the proportion of particles with a particle size of 20 - 50μm is 30 - 50wt%.

[0014] Optionally, the weight ratio of the fine tailings to the attapulgite is 20 - 28:1.

[0015] Optionally, the particle size of the attapulgite clay is 1 to 10 μm.

[0016] Optionally, the cement is early-strength Portland cement with a strength grade of 42.5R, and the alkali content is controlled at ≤1%.

[0017] Optionally, the early-strength agent uses a soil stabilizer.

[0018] In a second aspect, the present application provides a method for preparing the above-mentioned filling body based on multi-component fine tailings, including the following steps:

[0019] S1. Add water to the fine tailings and attapulgite clay, and mix and stir evenly to obtain a mixture;

[0020] S2. Mix the mixture prepared in S1 with cement, gypsum, lime, and an early-strength agent according to the formula amount, and add water to obtain a filling body based on multi-component fine tailings.

[0021] Optionally, the concentration of the filling body is 75 to 80 wt%.

[0022] In a third aspect, the present application provides the application of the above-mentioned filling body based on multi-component fine tailings in the field of mine filling.

[0023] In summary, by adding attapulgite clay and utilizing its internal porous structure, the present invention can adsorb fine tailings with smaller particle sizes, reducing the phenomena of difficult dehydration and easy mixing of fine tailings with small particle sizes, which may lead to uneven material distribution; while increasing the addition amount of fine tailings with small particle sizes, the spread and 7 / 28d compressive strength of the prepared filling body are improved. Specific Embodiments

[0024] The following further elaborates on the present application with reference to embodiments.

[0025] Unless otherwise specified, the main components involved in the following embodiments of the present application are all purchased from commercially available products.

[0026] Cement: Anhui Tongling Conch Cement Co., Ltd.

[0027] Gypsum: Purchased from Tongling Puruifa Materials Co., Ltd.

[0028] Lime: Purchased from Tongling Hongyun Calcium Industry Co., Ltd.

[0029] Early-strength agent: The soil stabilizer is used in the following embodiments of the present application and is purchased from Tongling Puruifa Materials Co., Ltd.

[0030] Preparation Examples 1 to 5 are used to prepare multi-component fine tailings, which include fine tailings with a particle size below 20 μm and fine tailings with a particle size of 20 to 50 μm; specifically as follows.

[0031] Preparation Example 1

[0032] In the multi-component fine tailings prepared in this preparation example, the fine tailings with a particle size below 20 μm accounted for 50 wt%; the fine tailings with a particle size of 20 - 50 μm accounted for 50 wt%; the fine tailings with a particle size below 20 μm and the fine tailings with a particle size of 20 - 50 μm were mixed evenly by adding water and then through mechanical mixing, and the water content in the prepared multi-component fine tailings did not exceed 20 wt%.

[0033] Preparation Example 2

[0034] In the multi-component fine tailings prepared in this preparation example, the fine tailings with a particle size below 20 μm accounted for 55 wt%; the fine tailings with a particle size of 20 - 50 μm accounted for 45 wt%; the fine tailings with a particle size below 20 μm and the fine tailings with a particle size of 20 - 50 μm were mixed evenly by adding water and then through mechanical mixing, and the water content in the prepared multi-component fine tailings did not exceed 20 wt%.

[0035] Preparation Example 3

[0036] In the multi-component fine tailings prepared in this preparation example, the fine tailings with a particle size below 20 μm accounted for 60 wt%; the fine tailings with a particle size of 20 - 50 μm accounted for 40 wt%; the fine tailings with a particle size below 20 μm and the fine tailings with a particle size of 20 - 50 μm were mixed evenly by adding water and then through mechanical mixing, and the water content in the prepared multi-component fine tailings did not exceed 20 wt%.

[0037] Preparation Example 4

[0038] In the multi-component fine tailings prepared in this preparation example, the fine tailings with a particle size below 20 μm accounted for 65 wt%; the fine tailings with a particle size of 20 - 50 μm accounted for 35 wt%; the fine tailings with a particle size below 20 μm and the fine tailings with a particle size of 20 - 50 μm were mixed evenly by adding water and then through mechanical mixing, and the water content in the prepared multi-component fine tailings did not exceed 20 wt%.

[0039] Preparation Example 5

[0040] In the multi-component fine tailings prepared in this preparation example, the fine tailings with a particle size below 20 μm accounted for 70 wt%; the fine tailings with a particle size of 20 - 50 μm accounted for 30 wt%; the fine tailings with a particle size below 20 μm and the fine tailings with a particle size of 20 - 50 μm were mixed evenly by adding water and then through mechanical mixing, and the water content in the prepared multi-component fine tailings did not exceed 20 wt%. Specific Examples

[0042] Example 1

[0043] This embodiment is used to prepare a filling body based on multiple fine tailings for mine filling, as follows.

[0044] Add 75 kg of the fine tailings prepared in Preparation Example 1 and 2 kg of attapulgite clay to water, mix and stir evenly to obtain a mixture; then add 3 kg of cement, 5 kg of gypsum, 5 kg of lime, and 1 kg of early strength agent and mix according to the formula amount, and add water to obtain a filling body based on multiple fine tailings with a paste concentration of 78 wt%.

[0045] Example 2

[0046] This embodiment is used to prepare a filling body based on multiple fine tailings for mine filling, as follows.

[0047] Add 70 kg of the fine tailings prepared in Preparation Example 1 and 3 kg of attapulgite clay to water, mix and stir evenly to obtain a mixture; then add 4 kg of cement, 10 kg of gypsum, 3 kg of lime, and 3 kg of early strength agent and mix according to the formula amount, and add water to obtain a filling body based on multiple fine tailings with a paste concentration of 78 wt%.

[0048] Example 3

[0049] This embodiment is used to prepare a filling body based on multiple fine tailings for mine filling, as follows.

[0050] Add 65 kg of the fine tailings prepared in Preparation Example 1 and 4 kg of attapulgite clay to water, mix and stir evenly to obtain a mixture; then add 5 kg of cement, 5 kg of gypsum, 8 kg of lime, and 2 kg of early strength agent and mix according to the formula amount, and add water to obtain a filling body based on multiple fine tailings with a paste concentration of 78 wt%.

[0051] Example 4

[0052] This embodiment is used to prepare a filling body based on multiple fine tailings for mine filling, as follows.

[0053] Add 60 kg of the fine tailings prepared in Preparation Example 1 and 5 kg of attapulgite clay to water, mix and stir evenly to obtain a mixture; then add 6 kg of cement, 10 kg of gypsum, 5 kg of lime, and 2 kg of early strength agent and mix according to the formula amount, and add water to obtain a filling body based on multiple fine tailings with a paste concentration of 78 wt%.

[0054] The filling bodies prepared in the above Examples 1 to 4 were subjected to performance tests according to 《GB / T 51450-2022》, and the results are shown in Table 1.

[0055] Table 1

[0056] Backfill Fine tailings Sand-silt ratio Spread / cm 7d compressive strength / MPa 28d compressive strength / MPa Example 1 Preparation Example 1 37.50 23 2.35 4.34 Example 2 Preparation Example 1 23.33 26 3.11 5.92 Example 3 Preparation Example 1 16.25 24 2.48 4.66 Example 4 Preparation Example 1 12.00 22 2.74 4.87

[0057] As can be seen from Examples 1 to 4 and Table 1, the spread of the filling body prepared by the technical solution of the present application is between 22 and 26 cm, the 7-day compressive strength reaches above 2.35 MPa, and the 28-day compressive strength reaches above 4.34 MPa, meeting the performance requirements of the mine filling body.

[0058] Moreover, the inventor found that the performance of the filling body prepared in Example 2 is superior to that of other examples. Therefore, on the basis of Example 2, the applicant adopted the sand-to-soil ratio (weight ratio of fine tailings to attapulgite), and made the following Examples 5 to 8, which are specifically as follows.

[0059] Example 5

[0060] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, and the specific steps are as follows.

[0061] 70 kg of the fine tailings prepared in Preparation Example 1 and 4 kg of attapulgite were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0062] Example 6

[0063] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, and the specific steps are as follows.

[0064] 70 kg of the fine tailings prepared in Preparation Example 1 and 3.5 kg of attapulgite were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0065] Example 7

[0066] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, and the specific steps are as follows.

[0067] 70 kg of the fine tailings prepared in Preparation Example 1 and 2.5 kg of attapulgite were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0068] Example 8

[0069] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, and the specific steps are as follows.

[0070] 70 kg of the fine tailings prepared in Preparation Example 1 and 2 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0071] The filling bodies prepared in Examples 5 to 8 above were subjected to performance tests according to 《GB / T 51450-2022》, and the results are shown in Table 2.

[0072] Table 2

[0073]

[0074]

[0075] By comparing Examples 5 to 8 with Example 2 and the data in Table 2, it can be seen that in the technical solution of the present application, when the sand-tailings ratio is limited in the range of 20-28:1, the spread of the prepared filling body can reach more than 25 cm, the 7-day compressive strength reaches more than 3 MPa, and the 28-day compressive strength reaches more than 5 MPa, which is better than other examples.

[0076] In order to verify the influence of the fine tailings prepared in different preparation examples on the filling body prepared in the present application, the inventors made the following Examples 9 to 12, which are specifically as follows.

[0077] Example 9

[0078] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, which is specifically as follows.

[0079] 75 kg of the fine tailings prepared in Preparation Example 1 and 2 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 3 kg of cement, 5 kg of gypsum, 5 kg of lime and 1 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0080] Example 10

[0081] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, which is specifically as follows.

[0082] 70 kg of the fine tailings prepared in Preparation Example 1 and 3 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0083] Example 11

[0084] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, as follows.

[0085] 65 kg of the fine tailings prepared in Preparation Example 1 and 4 kg of attapulgite clay are added with water and mixed and stirred evenly to obtain a mixture; then 5 kg of cement, 5 kg of gypsum, 8 kg of lime and 2 kg of early strength agent are mixed according to the formula amount, and water is added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0086] Example 12

[0087] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, as follows.

[0088] 60 kg of the fine tailings prepared in Preparation Example 1 and 5 kg of attapulgite clay are added with water and mixed and stirred evenly to obtain a mixture; then 6 kg of cement, 10 kg of gypsum, 5 kg of lime and 2 kg of early strength agent are mixed according to the formula amount, and water is added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0089] The filling bodies prepared in Examples 9 to 12 above are subjected to performance tests according to 《GB / T 51450-2022》, and the results are shown in Table 3.

[0090] Table 3

[0091] Backfill Fine tailings Sand-silt ratio Spread / cm 7d compressive strength / MPa 28d compressive strength / MPa Example 9 Preparation Example 2 37.50 22 2.32 4.45 Example 10 Preparation Example 3 23.33 25 3.08 6.01 Example 11 Preparation Example 4 16.25 23 2.35 4.44 Example 12 Preparation Example 5 12.00 21 2.65 4.58

[0092] It can be seen from Examples 9 to 12 and Table 3 that in the case of the multi-component fine tailings prepared in Preparation Examples 2 to 5 with more fine tailings smaller than 20 μm in size selected by the technical solution of the present application; the spread of the prepared filling body is between 21 and 25 cm, the 7-day compressive strength reaches more than 2.32 MPa, and the 28-day compressive strength reaches more than 4.44 MPa, meeting the performance requirements of the mine filling body.

[0093] Compared with Examples 1 to 4, the spread and 7-day compressive strength decrease slightly, but the 28-day compressive strength increases slightly. Due to the addition of attapulgite clay, the finer tailings with smaller particle size can better cooperate with the attapulgite clay to improve the strength of the filling body.

[0094] In order to verify whether the sand-soil ratio has an impact on the performance of the filling body using the fine tailings prepared by different preparation examples, the inventors made the following Examples 13 to 16, as follows.

[0095] Example 13

[0096] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, as follows.

[0097] 70 kg of the fine tailings prepared in Preparation Example 1 and 4 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0098] Example 14

[0099] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, specifically as follows.

[0100] 70 kg of the fine tailings prepared in Preparation Example 1 and 3.5 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0101] Example 15

[0102] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, specifically as follows.

[0103] 70 kg of the fine tailings prepared in Preparation Example 1 and 2.5 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0104] Example 16

[0105] This example is used to prepare a filling body based on multi-component fine tailings for mine filling, specifically as follows.

[0106] 70 kg of the fine tailings prepared in Preparation Example 1 and 2 kg of attapulgite clay were added with water and mixed and stirred evenly to obtain a mixture; then 4 kg of cement, 10 kg of gypsum, 3 kg of lime and 3 kg of early strength agent were mixed according to the formula amount, and water was added to obtain a filling body based on multi-component fine tailings with a paste concentration of 78 wt%.

[0107] The filling bodies prepared in Examples 13 to 16 above were subjected to performance tests in accordance with 《GB / T 51450-2022》, and the results are shown in Table 4.

[0108] Table 4

[0109] Backfill Fine tailings Sand-silt ratio Spread / cm 7d compressive strength / MPa 28d compressive strength / MPa Example 13 Preparation Example 3 17.50 22 2.78 4.72 Example 14 Preparation Example 3 20.00 24 3.02 5.57 Example 10 Preparation Example 3 23.33 25 3.08 6.01 Example 15 Preparation Example 3 28.00 23 3.01 5.59 Example 16 Preparation Example 3 35.00 22 2.85 4.71

[0110] By comparing Examples 13 to 16 with Example 10 and referring to Table 4, it can be seen that for the technical solution of the present application, when using fine tailings prepared by different preparation examples, the sand-tailings ratio still has a significant impact on the performance of the filling body.

[0111] When the sand-tailings ratio is limited within the range of 20 to 28:1, the performance of the prepared filling body is better than that of other examples.

[0112] The above are all preferred embodiments of the present application. The protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application shall be covered within the protection scope of the present application.

Claims

1. A filling body based on multi-component fine tailings, characterized in that: The method is prepared by comprising the following components in parts by weight: 3-6 parts of cement; 60-75 parts of fine tailings; 2-5 parts of attapulgite; 5-10 parts of gypsum; 3-8 parts of lime; 1 to 3 parts of early strength agent; Among the fine tailings, particles with a diameter below 20 μm account for 50 to 70 wt%, and particles with a diameter of 20 to 50 μm account for 30 to 50 wt%.

2. The filling body based on multi-component fine tailings according to claim 1, characterized in that: The weight ratio of the fine tailings to attapulgite is 20 to 28:

1.

3. The filling body based on multi-component fine tailings according to claim 1, characterized in that: The particle size of the attapulgite is 1 to 10 μm.

4. The filling body based on multi-component fine tailings according to claim 1, characterized in that: The cement is early strength silicate cement with a strength grade of 42.5R and an alkali content controlled at ≤1%.

5. The filling body based on multi-component fine tailings according to claim 1, characterized in that: The early strength agent is a soil solidifying agent.

6. A method for preparing a filling body based on multi-component fine tailings according to claim 1, characterized in that: The following steps are involved: S1. Add water to the fine tailings and attapulgite, mix and stir evenly to obtain a mixture; S2. Mix the mixture prepared in S1 with cement, gypsum, lime and early strength agent according to the formula amount, add water, and obtain a filling body based on multi-element fine tailings.

7. The preparation method according to claim 6, characterized in that: The concentration of the filling body is 75-80wt%.

8. Application of the filling body based on multi-component fine tailings as claimed in claim 1 in the field of mine filling.

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