A filled gel material and a method for its production

Abstract

The application belongs to the technical field of gel filling materials, and specifically provides a filling gel material and a preparation method thereof. The filling gel material comprises the following components in parts by weight: 50-65 parts of phosphogypsum slurry, 10-15 parts of tailings, 15-20 parts of cement, 5-10 parts of blast furnace slag, and 0.3-0.5 parts of alkali activator. The phosphogypsum slurry is prepared by mixing phosphogypsum and a modified liquid. The modified liquid comprises a blocked polypropylene glycol and a calcium ion polysaccharide solution. The gel filling material prepared by the application has the advantages of good mechanical properties and low impurity dissolution.

Description

Technical Field

[0001] This application belongs to the field of gel filling material technology, and in particular relates to a filling gel material and its preparation method. Background Technology

[0002] Mine backfilling technology is one of the core technologies in mining operations. Its purpose is to mix solid waste such as waste rock, tailings, or industrial by-products generated during mining with cementing materials to prepare a slurry or paste, which is then backfilled into the underground goaf. This technology not only effectively controls ground pressure, prevents surface subsidence, and ensures mining safety, but also realizes the resource utilization of large quantities of industrial solid waste.

[0003] Traditional backfill materials primarily use cement as a binder and solid wastes such as river sand, tailings, waste rock, blast furnace slag, steel slag, and metal smelting slag as aggregates. Phosphogypsum, a solid waste generated from the industrial wet process of phosphoric acid production, produces approximately 4.5-5.5 tons of phosphogypsum as a byproduct for every ton of phosphoric acid produced. Its main component is calcium sulfate dihydrate, but it contains impurities such as soluble phosphorus, fluorine, organic matter, and heavy metals. Therefore, phosphogypsum also has significant potential for resource utilization and can be used as an aggregate component in gel backfill materials. However, the addition of phosphogypsum can lead to a deterioration in the mechanical and gelling properties of the backfill, making it prone to collapse, cracking, and instability.

[0004] Therefore, developing new phosphogypsum solid waste gel filling materials, systematically improving the cementing and mechanical properties of phosphogypsum-based gel filling materials, and realizing the resource utilization of phosphogypsum are of great technical significance. Summary of the Invention

[0005] To address the aforementioned problems and further improve the performance of gel filling materials, this application provides a filling gel material and its preparation method.

[0006] This application first provides a filling gel material comprising the following components in parts by weight: 50-65 parts phosphogypsum slurry, 10-15 parts tailings, 15-20 parts cement, 5-10 parts blast furnace slag, and 0.3-0.5 parts alkali activator; wherein the phosphogypsum slurry is prepared by mixing phosphogypsum with a modifying liquid; wherein the modifying liquid comprises end-capped polypropylene glycol and calcium ion polysaccharide solution.

[0007] Furthermore, the end-capped polypropylene glycol is prepared from 2-aldehyde phenylboronic acid and polypropylene glycol.

[0008] Furthermore, the calcium ion polysaccharide solution is prepared by the following steps:

[0009] 1) Mix the modified flaxseed gum solution with the saturated calcium hydroxide solution until homogeneous to obtain a mixture;

[0010] 2) Slowly add potassium bicarbonate solution to the mixture, mix thoroughly, then add tetrabutylammonium hydroxide solution and continue stirring until homogeneous.

[0011] Furthermore, in step 1), the modified flaxseed gum solution is prepared by reacting the flaxseed gum solution with a protease to remove protein, centrifuging and shaking to remove the precipitate, and then taking the supernatant.

[0012] Furthermore, in 1), the solid content of the modified flaxseed gum solution is 10-15%.

[0013] Furthermore, in step 2), the concentration of carbonate ions in the potassium bicarbonate solution is 0.25-0.5 mmol.

[0014] Furthermore, the cement is sulfoaluminate cement or aluminate cement.

[0015] Furthermore, the alkaline activator is at least one of calcium hydroxide and sodium hydroxide.

[0016] This application also provides a method for preparing a filler gel material, comprising the following steps:

[0017] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix;

[0018] S2: Add tailings, cement and water to the premix and mix well.

[0019] Furthermore, in step S1, polysuccinimide is added during the mixing process, and the amount added is 0.05-0.1% of the mass of the premix.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] The gel filling material of this application uses phosphogypsum slurry as the aggregate component, which can effectively solve the resource utilization problem of phosphogypsum solid waste. By mixing phosphogypsum with a modifying liquid, the calcium ion polysaccharide solution in the modifying liquid can neutralize the acidic components of phosphogypsum, promote the hydration reaction between phosphogypsum and the cementitious material, and improve the mechanical properties of the filling material. Furthermore, the hydration products can absorb calcium ions provided by the calcium ion polysaccharide solution, neutralize the zeta negative potential, increase the repulsive force between cementitious particles, and improve the flowability and cementing effect of the gel filling material. In addition, the end-capped polypropylene glycol and the calcium ion polysaccharide solution can effectively solidify the soluble impurity anions in phosphogypsum. The 2-aldehyde phenylboronic acid end-capped polypropylene glycol and flaxseed gum polysaccharide molecules can form a reinforcing network, adsorbed on the particle surface of the gel filling material, which not only improves the cementing effect but also reduces the porosity of the filling material, reduces stress concentration during curing, inhibits the generation of curing cracks, and further improves the strength and toughness of the filling material. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the gelation and diffusion test data of the filling gel material in Examples 1-2 and Control Groups 1-2 of this application.

[0023] Figure 2 This is a schematic diagram showing the compressive strength data of the filling gel material in Examples 1-2 and Control Groups 1-2 of this application.

[0024] Figure 3 This is a schematic diagram showing the solidification data of the dissolved substances in the filling gel material of Examples 1-2 and Control Groups 1-2 of this application. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] When using “including,” “having,” and “contains” as described herein, the intention is to cover non-exclusive inclusion, unless an explicit qualifying term such as “only,” “consisting of,” etc., is used, in which case another component may be added.

[0028] The terms "preferred," "more preferably," "better," and "even better" used in this application refer to embodiments of this application that provide certain beneficial effects under certain circumstances. However, other embodiments may also be preferred under the same or other circumstances. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferred," "more preferably," "better," and "even better" are merely descriptions of implementations or embodiments with better effects, but do not constitute a limitation on the scope of protection of this application.

[0029] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0030] In this application, "at least one" means one or more, such as one, two, or more. "Multiple" or "several" means at least two, such as two, three, etc., and "multi-layered" means at least two layers, such as two layers, three layers, etc., unless otherwise explicitly specified. In the description of this application, "several" means at least one, such as one, two, etc., unless otherwise explicitly specified.

[0031] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0032] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method comprising steps (a) and (b) indicates that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc. Unless otherwise stated, singular terms may include plural forms and should not be construed as having a quantity of one.

[0033] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0034] In this application, room temperature refers to 0~40℃, including but not limited to 10~40℃, or further to 20~30℃.

[0035] Based on extensive experimental research, this application provides a filling gel material comprising the following components in parts by weight: 50-65 parts phosphogypsum slurry, 10-15 parts tailings, 15-20 parts cement, 5-10 parts blast furnace slag, and 0.3-0.5 parts alkali activator; wherein the phosphogypsum slurry is prepared by mixing phosphogypsum with a modifying liquid; wherein the modifying liquid comprises end-capped polypropylene glycol and calcium ion polysaccharide solution.

[0036] In some specific embodiments, typically but not limitingly, the filling gel material comprises the following components in parts by weight: 60 parts phosphogypsum slurry, 10 parts tailings, 15 parts cement, 7.5 parts blast furnace slag, and 0.4 parts alkali activator. This allows for a better proportioning effect.

[0037] Furthermore, the end-capped polypropylene glycol is prepared from 2-aldehyde phenylboronic acid and polypropylene glycol.

[0038] Furthermore, the calcium ion polysaccharide solution is prepared by the following steps:

[0039] 1) Mix the modified flaxseed gum solution with the saturated calcium hydroxide solution until homogeneous to obtain a mixture;

[0040] 2) Slowly add potassium bicarbonate solution to the mixture, mix thoroughly, then add tetrabutylammonium hydroxide solution and continue stirring until homogeneous.

[0041] Furthermore, in step 1), the modified flaxseed gum solution is prepared by reacting the flaxseed gum solution with a protease to remove protein, centrifuging and shaking to remove the precipitate, and then taking the supernatant.

[0042] Preferably, the protease is papain.

[0043] Furthermore, in 1), the solid content of the modified flaxseed gum solution is 10-15%.

[0044] In some specific embodiments, in step 1), the solid content of the modified flaxseed gum solution can be 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, or 15%. Generally, in step 1), a solid content of 12% or 12.5% ​​of the modified flaxseed gum solution yields better experimental results.

[0045] Furthermore, in step 2), the concentration of carbonate ions in the potassium bicarbonate solution is 0.25-0.5 mmol.

[0046] In some specific embodiments, in step 2), the concentration of carbonate ions in the potassium bicarbonate solution can be 0.25 mmol, 0.3 mmol, 0.35 mmol, 0.4 mmol, 0.45 mmol, or 0.5 mmol. Generally, in step 2), a concentration of 0.25 mmol of carbonate ions in the potassium bicarbonate solution yields better experimental results.

[0047] Furthermore, the cement is sulfoaluminate cement or aluminate cement.

[0048] Furthermore, the alkaline activator is at least one of calcium hydroxide and sodium hydroxide.

[0049] This application also provides a method for preparing a filler gel material, comprising the following steps:

[0050] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix;

[0051] S2: Add tailings, cement and water to the premix and mix well.

[0052] Furthermore, in step S1, polysuccinimide is added during the mixing process, and the amount added is 0.05-0.1% of the mass of the premix.

[0053] In some specific embodiments, in step S1, polysuccinimide is added during the mixing process, and the amount added can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1% of the premix mass. Generally, in step S1, adding polysuccinimide during the mixing process at 0.06% of the premix mass yields better experimental results.

[0054] The present application will be further illustrated by the following examples, but these examples do not limit the scope of the present application.

[0055] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are conventional products that can be purchased commercially. In addition to the specific methods, equipment, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, equipment, and materials similar to or equivalent to those described, used, or made by the methods, equipment, and materials in the embodiments of this application may be used to implement this application.

[0056] Table 1 shows the main chemical composition and parameter data of the phosphogypsum, tailings and blast furnace slag used in this embodiment. The unit of chemical composition is mass percentage (%), and the rest are trace components and impurities, totaling 100%.

[0057] Example 1

[0058] The filling gel material of this embodiment includes the following components by weight: 60 kg of phosphogypsum slurry, 10 kg of tailings, 15 kg of cement, 7.5 kg of blast furnace slag, and 400 g of alkali activator.

[0059] The cement used is CA50-II aluminate cement. The alkali activator is sodium hydroxide.

[0060] The preparation method of phosphogypsum slurry in this embodiment includes the following steps: 100 kg of phosphogypsum and 50 kg of modified liquid are mixed and stirred in a mixer for 1.5 h to obtain the slurry.

[0061] The preparation method of the modified liquid in this embodiment includes the following steps: take 100 kg of water, 500 g of end-capped polypropylene glycol, and 15 kg of calcium ion polysaccharide solution and mix them evenly to obtain the modified liquid.

[0062] The preparation method of end-capped polypropylene glycol in this embodiment includes the following steps: 100 mL of anhydrous ethanol, 0.05 mol of end-amino polypropylene glycol 800, and 0.11 mol of 2-aldehyde phenylboronic acid are added to a 500 mL four-necked flask equipped with a stirrer, thermometer, dropping funnel, and condenser. After mixing evenly, sodium borohydride and a small amount of PBS buffer solution are added, and the mixture is reacted at room temperature under nitrogen protection to obtain the final product.

[0063] The calcium ion polysaccharide solution in this embodiment was prepared using the following steps:

[0064] 1) Take 1 kg of flaxseed gum solution with a solid content of 5%, add 2 g of papain, react at a constant temperature of 60℃ for 3 h, centrifuge and shake to remove the precipitate, and concentrate to obtain a modified flaxseed gum solution with a solid content of 12.5%; mix 0.75 kg of modified flaxseed gum solution with 10 kg of saturated calcium hydroxide solution evenly to obtain a mixed solution;

[0065] 2) Slowly add an equal volume of 0.25 mmol potassium bicarbonate solution to the mixture, mix thoroughly, then add 30 g of 25% tetrabutylammonium hydroxide solution and continue stirring until homogeneous.

[0066] The method for preparing the filling gel material in this embodiment includes the following steps:

[0067] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix;

[0068] S2: Add tailings, cement and water to the premix, control the solid mass concentration to 70%, and stir evenly to obtain the final product.

[0069] Example 2

[0070] The filling gel material of this embodiment includes the following components by weight: 60 kg of phosphogypsum slurry, 10 kg of tailings, 15 kg of cement, 7.5 kg of blast furnace slag, 400 g of alkali activator, and 40.7 g of polysuccinimide.

[0071] The cement used is CA50-II aluminate cement. The alkali activator is sodium hydroxide.

[0072] The preparation method of phosphogypsum slurry in this embodiment includes the following steps: 100 kg of phosphogypsum and 50 kg of modified liquid are mixed and stirred in a mixer for 1.5 h to obtain the slurry.

[0073] The preparation method of the modified liquid in this embodiment includes the following steps: take 100 kg of water, 500 g of end-capped polypropylene glycol, and 15 kg of calcium ion polysaccharide solution and mix them evenly to obtain the modified liquid.

[0074] The preparation method of end-capped polypropylene glycol in this embodiment includes the following steps: 100 mL of anhydrous ethanol, 0.05 mol of end-amino polypropylene glycol 800, and 0.11 mol of 2-aldehyde phenylboronic acid are added to a 500 mL four-necked flask equipped with a stirrer, thermometer, dropping funnel, and condenser. After mixing evenly, sodium borohydride and a small amount of PBS buffer solution are added, and the mixture is reacted at room temperature under nitrogen protection to obtain the final product.

[0075] The calcium ion polysaccharide solution in this embodiment was prepared using the following steps:

[0076] 1) Take 1 kg of flaxseed gum solution with a solid content of 5%, add 2 g of papain, react at a constant temperature of 60℃ for 3 h, centrifuge and shake to remove the precipitate, and concentrate to obtain a modified flaxseed gum solution with a solid content of 12.5%; mix 0.75 kg of modified flaxseed gum solution with 10 kg of saturated calcium hydroxide solution evenly to obtain a mixed solution;

[0077] 2) Slowly add an equal volume of 0.25 mmol potassium bicarbonate solution to the mixture, mix thoroughly, then add 30 g of 25% tetrabutylammonium hydroxide solution and continue stirring until homogeneous.

[0078] The method for preparing the filling gel material in this embodiment includes the following steps:

[0079] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer. Polysuccinimide is added during the mixing process to obtain a premix.

[0080] S2: Add tailings, cement and water to the premix, control the solid mass concentration to 70%, and stir evenly to obtain the final product.

[0081] Control group 1

[0082] The filling gel material in this control group consisted of the following components by weight: 60 kg of phosphogypsum slurry, 10 kg of tailings, 15 kg of cement, 7.5 kg of blast furnace slag, and 400 g of alkali activator.

[0083] The cement used is CA50-II aluminate cement. The alkali activator is sodium hydroxide.

[0084] The preparation method of the filling gel material in this control group includes the following steps:

[0085] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix;

[0086] S2: Add tailings, cement and water to the premix, control the solid mass concentration to 70%, and stir evenly to obtain the final product.

[0087] Control group 2

[0088] The filling gel material in this control group consisted of the following components by weight: 60 kg of phosphogypsum slurry, 10 kg of tailings, 15 kg of cement, 7.5 kg of blast furnace slag, and 400 g of alkali activator.

[0089] The cement used is CA50-II aluminate cement. The alkali activator is sodium hydroxide.

[0090] The preparation method of the phosphogypsum slurry in this control group includes the following steps: 100 kg of phosphogypsum and 50 kg of modified liquid are mixed and stirred in a mixer for 1.5 h to obtain the slurry.

[0091] The preparation method of the modified solution in this control group includes the following steps: take 100 kg of water and 15 kg of saturated calcium hydroxide solution and mix them evenly.

[0092] The preparation method of the filling gel material in this control group includes the following steps:

[0093] S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix;

[0094] S2: Add tailings, cement and water to the premix, control the solid mass concentration to 70%, and stir evenly to obtain the final product.

[0095] Performance testing

[0096] 1. The gelation and diffusion properties of the filling gel materials from Examples 1-2 and Control Groups 1-2 were tested. 9mm diameter glass beads were used as the bulk material, filled into a 12cm diameter cylindrical glass container to a height of 20cm. Then, 800mL of the gel material was poured into the container using a 12cm diameter funnel, ensuring consistent pouring position and height. The diffusion depth of the gel material within the bulk was observed over time. Specific test results are as follows: Figure 1 As shown.

[0097] 2. Take the filling gel materials from Examples 1-2 and Control Groups 1-2, and conduct 28-day compressive strength tests according to JGJ / T70-2009 "Standard for Test Methods of Basic Performance of Building Mortar". The test results are as follows: Figure 2 As shown. After the strength test, sample fragments were taken, crushed to an average particle size of 1 mm, placed in an extraction bottle, and mixed with deionized water at a solid-liquid ratio of 1:10. The mixture was shaken and leached for 12 hours, then filtered to obtain the water sample to be tested. The concentrations of F and P elements in the water sample were determined. The P element concentration is the sum of the concentrations of soluble organic P and soluble inorganic P. The test results are shown below. Figure 3 As shown.

[0098] analyze Figure 1 and Figure 2 It can be seen that the filling gel material of this application has excellent mechanical and gelling properties, and can effectively solidify the leached substances of phosphogypsum, making it suitable for filling operations in mining. It also provides a harmless treatment method for phosphogypsum solid waste.

[0099] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A filled gel material, characterized by: The product comprises the following components in parts by weight: 50-65 parts phosphogypsum slurry, 10-15 parts tailings, 15-20 parts cement, 5-10 parts blast furnace slag, and 0.3-0.5 parts alkali activator; the phosphogypsum slurry is prepared by mixing phosphogypsum with a modifying liquid; the modifying liquid includes end-capped polypropylene glycol and a calcium ion polysaccharide solution; The end-capped polypropylene glycol is prepared from 2-aldehyde phenylboronic acid and polypropylene glycol; the calcium ion polysaccharide solution is prepared by the following steps: 1) Mix the modified flaxseed gum solution with a saturated calcium hydroxide solution to obtain a mixed solution; the modified flaxseed gum solution is obtained by reacting the flaxseed gum solution with a protease to remove protein, centrifuging and shaking to remove the precipitate, and taking the supernatant. 2) Slowly add potassium bicarbonate solution to the mixture, mix thoroughly, then add tetrabutylammonium hydroxide solution and continue stirring until homogeneous.

2. The filled gel material of claim 1, wherein: In step 1), the solid content of the modified flaxseed gum solution is 10-15%.

3. The filled gel material of claim 1, wherein: In step 2), the concentration of carbonate ions in the potassium bicarbonate solution is 0.25-0.5 mmol / L.

4. The filled gel material of claim 1, wherein: The cement is sulfoaluminate cement or aluminate cement.

5. The filled gel material of claim 1, wherein: The alkaline activator is at least one of calcium hydroxide and sodium hydroxide.

6. A method of preparing a gel-filling material as claimed in claim 1, characterized by: Includes the following steps: S1: Phosphogypsum slurry, blast furnace slag, and alkali activator are mixed in a mixer to obtain a premix; S2: Add tailings, cement and water to the premix and mix well.

7. The method of claim 6, wherein: In step S1, polysuccinimide is added during the mixing process, and the amount added is 0.05-0.1% of the mass of the premix.

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