A hardening agent for improving the stability of tailings slurry and a preparation method and use method thereof

Abstract

The present application relates to a kind of hardening agent for improving tailings slurry stability and its preparation method and use method, belong to geotechnical engineering technical field.The hardening agent for improving tailings slurry stability includes the following mass percentage components: ferrous sulfate crystal 6~8%, hydrogen peroxide 12~16%, fly ash 5~10%, cationic polyacrylamide 0.1~0.2%, quicklime 10~15% and cement 10~20%, the rest is water.The hardening agent of the present application can greatly improve the hardening degree of tailings slurry, and the volume reduction is easy to store, the hardness of tailings slurry treated by the hardening agent of the present application is much higher than that of untreated tailings slurry, and it is more compact and not easy to deform, can long-term maintain the strength of slurry after hardening treatment.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, specifically to a hardener for improving the stability of tailings slurry, and its preparation and application methods. Background Technology

[0002] Tailings mud is a byproduct of ore washing during mining operations. It is characterized by high clay content and fine particles, containing a large amount of clay colloids, which makes it difficult to dehydrate and settle. Tailings mud particles settle very slowly, with lower layers remaining in a fluid state for over 10 years. If the tailings dam is located in a karst area, leakage is highly likely. Muddy water enters underground rivers through sinkholes and caves, flowing downstream in alternating underground and surface currents, causing turbidity and pollution of groundwater and surface water. Furthermore, the high water content and low water circulation rate of the washed mud result in large land areas for tailings dams and increase the risk of dam failure.

[0003] Traditional tailings slurry treatment methods include constructing tailings dams, adding organic polymer flocculants, and microbial flocculants, but the degree of hardening is often low. Currently, the tailings slurry pressure filter press and dry stacking treatment method is difficult to dewater and extremely costly, making it unsuitable for industrial application. Therefore, continuing to seek more effective technical means to further economically and efficiently remove moisture from washing tailings and improve the stability of tailings slurry has become an inevitable path for stockpiling bauxite mining enterprises. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a hardener for improving the stability of tailings slurry. This invention prepares a hardener by mixing ferrous sulfate, hydrogen peroxide, fly ash, cationic polyacrylamide, quicklime, and cement, and then mixes it with tailings slurry. This significantly improves the hardening degree of the tailings slurry, while also reducing its volume and making it easier to store.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A hardener for improving the stability of tailings slurry, comprising the following components by mass percentage: 6-8% ferrous sulfate crystals, 12-16% hydrogen peroxide, 5-10% fly ash, 0.1-0.2% cationic polyacrylamide, 10-15% quicklime, and 10-20% cement, with the remainder being water.

[0006] Explanation of the principle of this invention:

[0007] This invention utilizes ferrous sulfate and hydrogen peroxide to prepare Fenton's reagent. By leveraging the oxidative breakdown mechanism during the Fenton reaction, the original charge balance in the tailings slurry is disrupted, thereby increasing the degree of slurry sedimentation and hardening. The cationic groups of cationic polyacrylamide dissociated in water are electrostatically attracted to the negative charges on the surface of the tailings slurry particles, causing the polyacrylamide to bind and flocculate with the particles. The hydration reaction of quicklime, cement, and fly ash releases heat to evaporate water, thus reducing the volume and weight of the tailings slurry. By controlling the proportions of the above raw materials, the hardening degree and volume and weight reduction of the tailings slurry are achieved. Specifically, if the amount of quicklime added is less than 10%, the tailings slurry has a lower degree of hardening and is easily deformed; if the amount of quicklime added is more than 15%, the tailings slurry easily forms clumps, cannot be fully mixed, and excessive use results in material waste.

[0008] The beneficial effects of the present invention are: the hardener of the present invention can greatly improve the hardening degree of tailings slurry, and reduce volume and weight for easy storage. The tailings slurry treated with the hardener of the present invention has a much higher hardness than the untreated tailings slurry, and is more compact and less prone to deformation, and can maintain the strength of the hardened slurry for a long time.

[0009] Based on the above technical solution, the present invention can be further improved as follows.

[0010] Furthermore, it includes the following components by mass percentage: 7-8% ferrous sulfate crystals, 14-16% hydrogen peroxide, 7-9% fly ash, 0.1-0.2% cationic polyacrylamide, 12-15% quicklime, and 13-17% cement, with the remainder being water.

[0011] Furthermore, the hardener used to improve the stability of tailings slurry comprises the following components by mass percentage: 8% ferrous sulfate, 16% hydrogen peroxide, 8% fly ash, 0.2% cationic polyacrylamide, 15% quicklime, and 15% cement, with the remainder being water.

[0012] The beneficial effect of adopting the above-mentioned further scheme is that the above parameters are the optimal parameters, and the resulting hardener has the best performance.

[0013] Furthermore, the ferrous sulfate crystals have a purity of 99.5% to 99.8%, and the hydrogen peroxide has a mass fraction of 28% to 32%.

[0014] The beneficial effect of adopting the above-mentioned further scheme is that the reaction between the above-mentioned ferrous sulfate and hydrogen peroxide is stable and not easily volatilized during the mixing process, resulting in the best curing agent effect.

[0015] Furthermore, the ferrous sulfate crystals have a purity of 99.7%, and the hydrogen peroxide has a mass fraction of 30%.

[0016] The beneficial effect of adopting the above-mentioned further scheme is that the above parameters are the optimal parameters, and the resulting hardener has the best performance.

[0017] To achieve the second objective mentioned above, this invention provides a method for preparing a hardener to improve the stability of tailings slurry.

[0018] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for preparing a hardener for improving the stability of tailings slurry, the preparation method comprising:

[0019] Ferrous sulfate is dissolved in water, and then hydrogen peroxide is added to obtain Fenton's reagent.

[0020] Cationic polyacrylamide was added to water and stirred until the granular and lumpy forms disappeared, and then mixed with Fenton's reagent, quicklime, fly ash and cement.

[0021] It should be noted that in this invention, there is no requirement for the order in which the aqueous solution of cationic polyacrylamide is mixed with Fenton's reagent, quicklime, fly ash, and cement.

[0022] The beneficial effects of adopting the above scheme are: the preparation method of the hardener of the present invention is simple, easy to operate, low in cost, has broad market prospects, and is suitable for large-scale promotion and application.

[0023] Furthermore, when the ferrous sulfate crystals are dissolved in water, the ratio of the ferrous sulfate crystals to water is 8g / 100ml.

[0024] To achieve the third objective mentioned above, this invention provides a method for using a hardener to improve the stability of tailings slurry.

[0025] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method of using a hardener for improving the stability of tailings slurry, the method comprising: mixing the hardener for improving the stability of tailings slurry with tailings slurry at a dry mass ratio of quicklime to tailings slurry of (10-15):100.

[0026] It should be noted that the hardener of this invention can be used at room temperature.

[0027] The beneficial effects of adopting the above scheme are: the processing scheme of the present invention is simple and efficient. By controlling the amount of tailings slurry and hardener, the hardening degree of tailings slurry can be greatly improved, the stability of the slurry can be improved, environmental pollution can be reduced, and the strength of the hardened slurry can be maintained for a long time.

[0028] Furthermore, the dry mass ratio of the quicklime to the tailings slurry is 15:100.

[0029] The beneficial effect of adopting the above scheme is that, with the above parameters, the treatment effect of the hardener is the best.

[0030] Furthermore, the stirring time is 30 min to 40 min.

[0031] The beneficial effects of adopting the above-mentioned further scheme are as follows: Using the above-mentioned mixing time ensures a more thorough reaction between ferrous sulfate, hydrogen peroxide, fly ash, cationic polyacrylamide, quicklime, cement, and tailings slurry, thereby guaranteeing the treatment effect. Attached Figure Description

[0032] Figure 1 This is a diagram of tailings slurry obtained after treatment with a hardener for improving the stability of tailings slurry, as provided in Embodiment 1 of the present invention.

[0033] Figure 2 This is a diagram of tailings slurry obtained after treatment with a hardener to improve the stability of tailings slurry, as provided in Embodiment 2 of the present invention.

[0034] Figure 3 This is a diagram of the tailings slurry obtained after treating the tailings slurry with the hardener provided in Comparative Example 1 of the present invention.

[0035] Figure 4 This is a diagram of the tailings slurry obtained after treating the tailings slurry with the hardener provided in Comparative Example 2 of the present invention.

[0036] Figure 5 This is a diagram of the tailings slurry obtained after treating the tailings slurry with the hardener provided in Comparative Example 3 of the present invention. Detailed Implementation

[0037] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0038] Example 1

[0039] A hardener for improving the stability of tailings slurry comprises the following components by mass percentage: 8% ferrous sulfate (99.7% purity), 16% hydrogen peroxide (30% by mass), 8% fly ash, 0.2% cationic polyacrylamide, 15% quicklime, and 15% cement, with the remainder being water.

[0040] The preparation method of the above-mentioned hardener for improving the stability of tailings slurry includes:

[0041] Fenton's reagent is obtained by dissolving ferrous sulfate in water and then adding hydrogen peroxide dropwise.

[0042] Cationic polyacrylamide was added to water and stirred until the granular and lumpy particles disappeared. Then it was mixed with Fenton's reagent, quicklime, fly ash and cement.

[0043] The above-mentioned methods of using hardeners to improve the stability of tailings slurry include:

[0044] The hardener used to improve the stability of tailings slurry was mixed with the tailings slurry at a dry weight ratio of quicklime to tailings slurry of 15:100 and stirred for 35 minutes. The resulting tailings slurry was as follows: Figure 1 As shown.

[0045] Example 2

[0046] A hardener for improving the stability of tailings slurry comprises the following components by mass percentage: 7% ferrous sulfate (99.5% purity), 15% hydrogen peroxide (28% by mass), 8% fly ash, 0.2% cationic polyacrylamide, 14% quicklime, and 13% cement, with the remainder being water.

[0047] The preparation method of the above-mentioned hardener for improving the stability of tailings slurry includes:

[0048] Fenton's reagent is obtained by dissolving ferrous sulfate in water and then adding hydrogen peroxide dropwise.

[0049] Cationic polyacrylamide was added to water and stirred until the granular and lumpy particles disappeared. Then it was mixed with Fenton's reagent, quicklime, fly ash and cement.

[0050] The above-mentioned methods of using hardeners to improve the stability of tailings slurry include:

[0051] The aforementioned hardener used to improve the stability of tailings slurry was mixed with the tailings slurry at a dry weight ratio of quicklime to tailings slurry of 14:100 and stirred for 30 minutes. The resulting tailings slurry is as follows: Figure 2 As shown.

[0052] Example 3

[0053] A hardener for improving the stability of tailings slurry comprises the following components by mass percentage: 6% ferrous sulfate (99.7% purity), 12% hydrogen peroxide (30% by mass), 10% fly ash, 0.1% cationic polyacrylamide, 10% quicklime, and 20% cement, with the remainder being water.

[0054] The preparation method of the above-mentioned hardener for improving the stability of tailings slurry includes:

[0055] Fenton's reagent is obtained by dissolving ferrous sulfate in water and then adding hydrogen peroxide dropwise.

[0056] Cationic polyacrylamide was added to water and stirred until the granular and lumpy particles disappeared. Then it was mixed with Fenton's reagent, quicklime, fly ash and cement.

[0057] The above-mentioned methods of using hardeners to improve the stability of tailings slurry include:

[0058] The above-mentioned hardener used to improve the stability of tailings slurry was mixed with the tailings slurry at a dry weight ratio of quicklime to tailings slurry of 10:100 and stirred for 40 minutes.

[0059] Example 4

[0060] A hardener for improving the stability of tailings slurry comprises the following components by mass percentage: 7% ferrous sulfate (99.7% purity), 14% hydrogen peroxide (30% by mass), 5% fly ash, 0.2% cationic polyacrylamide, 12% quicklime, and 10% cement, with the remainder being water.

[0061] The preparation method of the above-mentioned hardener for improving the stability of tailings slurry includes:

[0062] Fenton's reagent is obtained by dissolving ferrous sulfate in water and then adding hydrogen peroxide dropwise.

[0063] Cationic polyacrylamide was added to water and stirred until the granular and lumpy particles disappeared. Then it was mixed with Fenton's reagent, quicklime, fly ash and cement.

[0064] The above-mentioned methods of using hardeners to improve the stability of tailings slurry include:

[0065] Mix the hardener used to improve the stability of tailings slurry with the tailings slurry at a dry mass ratio of quicklime to tailings slurry of 12:100 and stir for 30 minutes.

[0066] Comparative Example 1

[0067] The difference between this comparative example and Example 1 is that polyaluminum chloride is used instead of cationic polyacrylamide, while the rest are the same.

[0068] The tailings slurry obtained after hardening treatment as described in Comparative Example 1 is as follows: Figure 3 As shown.

[0069] Comparative Example 2

[0070] The difference between this comparative example and Example 1 is that polyferric chloride is used instead of cationic polyacrylamide, while the rest are the same.

[0071] The tailings slurry obtained after hardening treatment as described in Comparative Example 1 is as follows: Figure 4 As shown.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 1 is that quicklime was not added to the hardener, but all other aspects are the same.

[0074] The tailings slurry obtained after hardening treatment as described in Comparative Example 1 is as follows: Figure 5 As shown.

[0075] Comparative Example 4

[0076] The difference between this comparative example and Example 1 is that the amount of quicklime added to the hardener is 5%, while the rest are the same.

[0077] Comparative Example 5

[0078] The difference between this comparative example and Example 1 is that the amount of quicklime added to the hardener is 20%, while the rest are the same.

[0079] The parameters of the tailings slurry after treatment with the hardeners of Examples 1-4 and Comparative Examples 1-5 are shown in Table 1. The calculation methods for water content, density and void ratio are in accordance with GB / T50123-2019 "Standard for Geotechnical Testing Methods". The pH was tested using a Mettler-Tolly pH meter and the hardness was tested using a WXGR-5.0 micro-penetrator.

[0080] Table 1. Parameters of tailings slurry after treatment with hardeners from Examples 1-4 and Comparative Examples 1-5.

[0081]

[0082]

[0083] As shown in Table 1, compared with polyaluminum chloride and polyferric chloride, cationic polyacrylamide is more conducive to obtaining a hardener with high hardening degree and less deformation. At the same time, the hardening degree can be significantly enhanced by controlling the amount of quicklime added.

[0084] Depend on Figures 1-5 It is known that the tailings slurry treated with the hardener provided in this application has a high degree of hardening and is not easily deformed. In contrast, the tailings slurry treated with the hardeners in Comparative Examples 1 to 3 has a low degree of hardening and is easily deformed, making it unsuitable for storage.

[0085] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0086] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A hardener for improving the stability of tailings slurry, characterized in that, Components including the following mass percentages: The composition consists of 6-8% ferrous sulfate crystals, 12-16% hydrogen peroxide, 5-10% fly ash, 0.1-0.2% cationic polyacrylamide, 10-15% quicklime, and 10-20% cement, with the remainder being water. The method of using the hardener for improving the stability of tailings slurry includes: mixing the hardener for improving the stability of tailings slurry with tailings slurry at a dry mass ratio of quicklime to tailings slurry of 15:

100. The stirring time is 30 min to 40 min.

2. The hardener for improving the stability of tailings slurry according to claim 1, characterized in that, It includes the following components by mass percentage: 7-8% ferrous sulfate crystals, 14-16% hydrogen peroxide, 7-9% fly ash, 0.1-0.2% cationic polyacrylamide, 12-15% quicklime, and 13-17% cement, with the remainder being water.

3. The hardener for improving the stability of tailings slurry according to claim 1, characterized in that, The composition includes the following components by mass percentage: 8% ferrous sulfate, 16% hydrogen peroxide, 8% fly ash, 0.2% cationic polyacrylamide, 15% quicklime, and 15% cement, with the remainder being water.

4. The hardener for improving the stability of tailings slurry according to claim 1, characterized in that, The ferrous sulfate crystals have a purity of 99.5%–99.8%, and the hydrogen peroxide has a mass fraction of 28%–32%.

5. The hardener for improving the stability of tailings slurry according to claim 1, characterized in that, The ferrous sulfate crystals have a purity of 99.7%, and the hydrogen peroxide has a mass fraction of 30%.

6. The method for preparing the hardener for improving the stability of tailings slurry according to any one of claims 1 to 5, characterized in that, The preparation method includes: Ferrous sulfate crystals are dissolved in water, and then hydrogen peroxide is added to obtain Fenton's reagent. Cationic polyacrylamide was added to water and stirred until the granular and lumpy forms disappeared. Then it was mixed with Fenton's reagent, quicklime, fly ash and cement to obtain the hardener.

7. The preparation method according to claim 6, characterized in that: When the ferrous sulfate crystals are dissolved in water, the ratio of the ferrous sulfate crystals to water is 8g / 100ml.

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