Water-retention and sand-fixation binder, and preparation and use methods thereof

Abstract

The invention provides a water-retaining and sand-fixing binder. The water-retaining and sand-fixing binder comprises the following components: a hydroxypropyl methyl cellulose aqueous solution with the solute concentration of 0.32-0.54%, a hydroxypropyl methyl cellulose-sodium bentonite mixed aqueous solution with the solute concentration of 3.25-6.38% and a sodium carboxymethyl cellulose aqueous solution with the solute concentration of 0.25-0.40%. According to the binder, hydroxypropyl methyl cellulose, sodium bentonite and sodium carboxymethyl cellulose serve as core raw materials, water is matched to prepare a multi-component water-based system, and the binder has the characteristics of efficient sand stabilization, excellent water retention and ecological environmental protection; through the synergistic effect of all the components, a continuous hard shell layer with a stable structure can be formed on the surface of the desert, the wind erosion resistance of sand grains is effectively improved, meanwhile, evaporation of water in a sand layer is blocked, the water is adsorbed and retained, and all the used raw materials are natural or biodegradable components, pollution to soil is avoided, and inhibition to plant growth is avoided.

Description

Technical Field

[0001] This invention relates to the field of desertification control and ecological restoration technology. Specifically, this application pertains to a water-retaining and sand-fixing binder, its preparation, and its application method. Background Technology

[0002] Currently, the mainstream sand-fixing measures in desertification control mainly cover three categories: physical sand fixation, biological sand fixation, and chemical sand fixation. However, each type of measure has significant limitations. Physical sand fixation, represented by straw checkerboard fences, requires a large amount of manpower for installation, resulting in extremely high labor intensity and very low production efficiency. Furthermore, this method consumes a considerable amount of plant resources, proving inadequate for large-scale desertification control needs and difficult to adapt effectively. Biological sand fixation primarily relies on planting psammophytes, but these plants require a continuous supply of water. In the arid and semi-arid desert regions of northern my country, water resources are extremely scarce, making it difficult to provide sufficient water for psammophytes in the long term, thus hindering the sustainable and effective implementation of biological sand fixation. Chemical sand fixation suffers from numerous problems. Its cost is generally high, and it is highly corrosive. Moreover, some chemical sand fixation agents can easily pollute the soil, and more seriously, inhibit the growth of native desert plants, thereby damaging the local ecological environment.

[0003] In view of the above, this application is hereby submitted. Summary of the Invention

[0004] The primary objective of this application is to provide a water-retaining and sand-fixing binder. This binder uses hydroxypropyl methylcellulose, sodium bentonite, and sodium carboxymethyl cellulose as core raw materials, combined with water to form a multi-component water-based system. It possesses efficient sand fixation, excellent water retention, and eco-friendly characteristics. Through the synergistic effect of each component, it can form a structurally stable and continuous hard crust layer on the desert surface, effectively improving the sand grains' resistance to wind erosion. At the same time, it blocks the evaporation of water from the sand layer and adsorbs and retains water. Moreover, all the raw materials used are natural or biodegradable, causing no pollution to the soil and no inhibition of plant growth.

[0005] The second objective of this application is to provide a method for preparing a water-retaining and sand-fixing binder. This method follows the core principles of slow feeding, thorough stirring, and static curing. The process is simple, easy to operate, and cost-controllable, achieving a green and environmentally friendly production process.

[0006] The third objective of this application is to provide a method for using a water-retaining and sand-fixing binder. This method involves first preventing the intrusion of external sand dunes through dam construction pretreatment, then spraying the binder in layers in sequence while controlling the spraying amount and interval time, and finally allowing it to dry naturally to form a complete hard shell layer. The process is clear and easy to operate.

[0007] To achieve the above objectives, this application provides the following technical solution: This invention provides a water-retaining and sand-fixing binder, comprising the following components: an aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.32-0.54%, a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 3.25-6.38%, and an aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.25-0.40%.

[0008] Preferably, the aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.40~0.52%, the mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 4.35~5.86%, and the aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.30~0.37% are used.

[0009] Preferably, the composition includes the following components: an aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.50%, a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 5.35%, and an aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.35%.

[0010] Preferably, in the aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, the mass ratio of solute hydroxypropyl methylcellulose to sodium bentonite is (0.25~0.38):(3~6).

[0011] Preferably, in the aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, the mass ratio of solute hydroxypropyl methylcellulose to sodium bentonite is 0.35:5.

[0012] Among the above components, an integrated sand-fixing system of "deep stabilization, middle water retention, and surface compaction" is constructed through the triple synergy of "layering effect, molecular interaction, and structural complementarity" of aqueous solutions of hydroxypropyl methylcellulose (HPMC), mixed aqueous solutions of hydroxypropyl methylcellulose and sodium bentonite, and aqueous solutions of sodium carboxymethyl cellulose (CMC).

[0013] HPMC, as a water-soluble cellulose, contains a large number of hydroxyl and methoxy groups in its molecular structure. After dissolving in water, it forms a viscous colloidal solution, playing a dual role in penetration and solidification as well as synergistic film formation. Hydroxypropyl methylcellulose aqueous solution has good permeability, and after spraying, it can penetrate into the sand layer through the gaps between sand grains. Its molecular chains can form hydrogen bonds with the silanol groups on the surface of sand grains through hydroxyl groups. At the same time, the intermolecular entanglement bridges the dispersed sand grains, forming a stable basic bonding layer inside the sand layer, providing support for the subsequent construction of the hard shell layer. Moreover, the viscosity increases with the increase of concentration. When the concentration is controlled within a certain range, it can ensure sufficient permeability to solidify deep sand grains, while avoiding uneven spraying or insufficient penetration due to excessive viscosity. If the concentration is too low, the bonding force is weak and a stable bonding layer cannot be formed. If the concentration is too high, the fluidity is poor, and it only stays on the surface of the sand layer, making it difficult to play a deep solidification role.

[0014] Sodium-based bentonite, as a layered silicate mineral, has silanol groups distributed on its surface and freely moving Na⁺ cations between its layers. When these two come into contact, the hydroxyl groups of HPMC form strong hydrogen bonds with the silanol groups on the bentonite surface, while the Na⁺ between the bentonite layers forms coordinate bonds with the lone pairs of electrons of the oxygen atoms in the HPMC molecules. This dual force tightly anchors the HPMC molecules between the bentonite layers. This combination effectively disperses the bentonite particles, preventing them from agglomerating due to excessive surface energy and ensuring the uniformity of the subsequent film formation. Furthermore, the layered structure of bentonite enhances the rigidity of the HPMC molecular chains, resulting in a final film with both good toughness and sufficient strength. In contrast, a pure HPMC film lacks sufficient rigidity and is easily damaged by wind erosion, significantly reducing its resistance to wind erosion.

[0015] Based on this, the carboxyl group of CMC can form hydrogen bonds with the hydroxyl group of HPMC and the silanol group of bentonite. At the same time, the -COO⁻ ionized from the carboxyl group can form electrostatic attraction with the interlayer cations of bentonite, which is equivalent to building a bridge between the composite structure of HPMC and bentonite and the surface of sand particles. On the one hand, it fills the tiny pores of the hydroxypropyl methylcellulose-bentonite membrane, and on the other hand, it enhances the adhesion between the membrane layer and the sand layer, preventing the hard shell layer from falling off.

[0016] The present invention also provides a method for preparing the above-mentioned water-retaining and sand-fixing binder, characterized by comprising the following steps: Take the appropriate mass of hydroxypropyl methylcellulose and add it to a stirred tank containing water while stirring until it is completely dissolved to obtain an aqueous solution of hydroxypropyl methylcellulose. Then, the remaining amount of hydroxypropyl methylcellulose and the corresponding amount of sodium bentonite are mixed evenly, and then added to a stirred tank containing water. The mixture is stirred while adding the mixture until there are no particles, thus obtaining a hydroxypropyl methylcellulose-sodium bentonite mixed aqueous solution. Take an appropriate amount of sodium carboxymethyl cellulose and add it to a stirred tank containing water. Stir while adding the sodium carboxymethyl cellulose until it is completely dissolved to obtain an aqueous solution of sodium carboxymethyl cellulose. Finally, the aqueous solutions of hydroxypropyl methylcellulose, the mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, and the aqueous solution of sodium carboxymethyl cellulose were allowed to stand and mature separately to obtain the final product.

[0017] Preferably, the settling and ripening time is controlled to be 12-24 hours.

[0018] Preferably, the stirring speed during the process of adding and stirring until no particles are present is 200 r / min to 300 r / min.

[0019] Preferably, the stirring temperature for complete dissolution is 25~35℃.

[0020] In the above preparation method, it is ensured that each component forms a stable system: in view of the characteristics of HPMC and CMC being prone to agglomeration, the "adding and stirring at the same time" method is used to disperse and dissolve them; in view of the problem of bentonite being prone to agglomeration, it is first mixed with HPMC and then water is added and stirred, and the agglomerates are broken up at a speed of 200r / min~300r / min; the dissolution of cellulose ether is accelerated by stirring at a temperature of 25~35℃ and the system is allowed to reach thermodynamic stability by standing for 12~24h, which finally lays the foundation for the subsequent sand fixation performance.

[0021] The present invention also provides a method for using the above-mentioned water-retaining and sand-fixing binder and the water-retaining and sand-fixing binder obtained by the above preparation method, comprising the following steps: A water-retaining and sand-fixing binder is sprayed onto the sandy area. The spraying sequence of the water-retaining and sand-fixing binder is: aqueous solution of hydroxypropyl methylcellulose, mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, and aqueous solution of sodium carboxymethyl cellulose. Then, it is dried until completely dry to form a continuous and complete hard shell layer.

[0022] For the above application method, the layers are sprayed in the following order: first, penetration and consolidation; second, film formation and water retention; and third, filling defects and densifying. This allows each binder to work synergistically: First, spray an aqueous solution of hydroxypropyl methylcellulose to penetrate deep into the sand layer and solidify the bottom sand particles through molecular bonding, laying a stable foundation; then, spray a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite to form a film layer on the surface that has both strength and water retention capacity, locking in the moisture of the sand layer; finally, spray an aqueous solution of sodium carboxymethyl cellulose to fill the pores of the film layer, making the film layer denser; finally, after drying, a complete hard shell layer is formed with a deep stable layer, a middle water-retaining layer, and a surface wind-erosion resistant layer, maximizing the sand fixation and water retention effect.

[0023] Compared with the prior art, the beneficial effects achieved by this application are as follows: This breakthrough is reflected in the comprehensive improvement of sand-fixing performance, ecological safety, economy, and practicality, effectively overcoming the limitations of traditional sand-fixing technologies. Regarding sand-fixing and water retention, this technology utilizes a multi-component synergistic "deep consolidation - mid-layer water retention - surface wind erosion resistance" hard shell layer. This not only provides superior wind erosion resistance, significantly lower than physical sand-fixing and traditional chemical sand-fixing agents, but also leverages the synergistic water-locking effect of sodium-based bentonite and cellulose components, achieving a high water retention rate far exceeding the 42% of traditional chemical sand-fixing agents. This provides continuous moisture for subsequent vegetation restoration in desert areas, compensating for the shortcomings of biological sand-fixing relying on artificial water replenishment.

[0024] In terms of ecological safety, the HPMC and CMC used in this technology are both biodegradable cellulose ethers, and sodium bentonite is a natural mineral. None of the three are chemically corrosive, nor will they release toxic or harmful substances into the soil. They do not inhibit the growth of native desert plants, thus avoiding soil pollution caused by the long-term use of existing sand-fixing agents. At the same time, this technology does not require the consumption of large amounts of plant straw as physical sand fixation, thus avoiding additional occupation of ecological resources.

[0025] The raw materials for this technology, HPMC, sodium bentonite, and CMC, are all commonly used industrial basic raw materials, and the water is ordinary water, which is readily available and inexpensive. The preparation process follows a simple logic of slow feeding, thorough stirring, and static maturation, requiring no complex equipment and enabling rapid large-scale production with efficiency far exceeding that of manual paving for physical sand fixation. Detailed Implementation

[0026] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are only some embodiments of the present invention, not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0027] Example 1 Add 100 kg of water to a stirring vessel and turn on the stirring machine at a speed of 250 r / min. Slowly add 0.32 kg of hydroxypropyl methylcellulose to the stirring vessel. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring machine, transfer the solution to a maturation tank and let it stand at 25°C for 24 h to obtain an aqueous solution of hydroxypropyl methylcellulose. Next, mix 0.25 kg of hydroxypropyl methylcellulose and 3 kg of sodium bentonite evenly, then add it to a stirred tank containing 100 kg of water while stirring until it is completely dissolved and free of particles. After turning off the stirring, transfer the solution to a curing tank and let it stand at 25°C for 24 hours to obtain a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite. Next, add 100 kg of water to the mixing tank and start stirring. Slowly add 0.25 kg of sodium carboxymethyl cellulose to the mixing tank. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring, transfer the solution to a maturation tank and let it stand at 25°C for 12 hours to obtain an aqueous solution of sodium carboxymethyl cellulose.

[0028] Example 2 Add 100 kg of water to a stirring vessel and turn on the stirring machine at a speed of 200 r / min. Slowly add 0.54 kg of hydroxypropyl methylcellulose to the stirring vessel. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring machine, transfer the solution to a maturation tank and let it stand at 30°C for 24 h to obtain an aqueous solution of hydroxypropyl methylcellulose. Next, mix 0.38 kg of hydroxypropyl methylcellulose and 6 kg of sodium bentonite evenly, then add it to a stirred tank containing 100 kg of water while stirring until it is completely dissolved and free of particles. After turning off the stirring, transfer the solution to a curing tank and let it stand at 30°C for 24 hours to obtain a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite. Next, add 100 kg of water to the mixing tank, turn on the stirring, and slowly add 0.40 kg of sodium carboxymethyl cellulose to the mixing tank. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring, transfer the solution to a maturation tank and let it stand at 30°C for 15 hours to obtain an aqueous solution of sodium carboxymethyl cellulose.

[0029] Example 3 Add 100 kg of water to a stirring vessel and turn on the stirring machine at a speed of 300 r / min. Slowly add 0.40 kg of hydroxypropyl methylcellulose to the stirring vessel. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring machine, transfer the solution to a maturation tank and let it stand at 35°C for 24 h to obtain an aqueous solution of hydroxypropyl methylcellulose. Next, mix 0.35 kg of hydroxypropyl methylcellulose and 4 kg of sodium bentonite evenly, then add it to a stirred tank containing 100 kg of water while stirring until it is completely dissolved and free of particles. After turning off the stirring, transfer the solution to a curing tank and let it stand at 35°C for 24 hours to obtain a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite. Next, add 100 kg of water to the mixing tank and start stirring. Slowly add 0.30 kg of sodium carboxymethyl cellulose to the mixing tank. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring, transfer the solution to a curing tank and let it stand at 35°C for 12 hours to obtain an aqueous solution of sodium carboxymethyl cellulose.

[0030] Example 4 Add 100 kg of water to a stirring vessel and turn on the stirring machine at a speed of 200 r / min. Slowly add 0.52 kg of hydroxypropyl methylcellulose to the stirring vessel. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring machine, transfer the solution to a maturation tank and let it stand at 25°C for 24 h to obtain an aqueous solution of hydroxypropyl methylcellulose. Next, mix 0.30 kg of hydroxypropyl methylcellulose and 5.56 kg of sodium bentonite evenly, then add it to a stirred tank containing 100 kg of water while stirring until it is completely dissolved and free of particles. After turning off the stirring, transfer the solution to a curing tank and let it stand at 25°C for 24 hours to obtain a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite. Next, add 100 kg of water to the mixing tank and start stirring. Slowly add 0.37 kg of sodium carboxymethyl cellulose to the mixing tank. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring, transfer the solution to a maturation tank and let it stand at 25°C for 12 hours to obtain an aqueous solution of sodium carboxymethyl cellulose.

[0031] Example 5 Add 100 kg of water to a stirring vessel and turn on the stirring machine at a speed of 200 r / min. Slowly add 0.50 kg of hydroxypropyl methylcellulose to the stirring vessel. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring machine, transfer the solution to a maturation tank and let it stand at 25°C for 24 hours to obtain an aqueous solution of hydroxypropyl methylcellulose. Next, mix 0.35 kg of hydroxypropyl methylcellulose and 5 kg of sodium bentonite evenly, then add it to a stirred tank containing 100 kg of water while stirring until it is completely dissolved and free of particles. After turning off the stirring, transfer the solution to a curing tank and let it stand at 25°C for 24 hours to obtain a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite. Next, add 100 kg of water to the mixing tank and start stirring. Slowly add 0.35 kg of sodium carboxymethyl cellulose to the mixing tank. After the addition is complete, keep stirring until completely dissolved. After turning off the stirring, transfer the solution to a curing tank and let it stand at 25°C for 12 hours to obtain an aqueous solution of sodium carboxymethyl cellulose.

[0032] Comparative Example 1 The specific implementation method is the same as in Example 5, except that the amount of sodium bentonite in the aqueous solution of hydroxypropyl methylcellulose-sodium bentonite is changed to 1 kg.

[0033] Comparative Example 2 The specific implementation method is the same as in Example 5, except that the amount of sodium carboxymethyl cellulose in the sodium carboxymethyl cellulose aqueous solution is changed to 8 kg.

[0034] Comparative Example 3 The specific implementation method is the same as in Example 5, except that the amount of hydroxypropyl methylcellulose in the aqueous solution of hydroxypropyl methylcellulose is changed to 5 kg.

[0035] Comparative Example 4 Commercially available acrylic chemical sand-fixing agents are used, with a mass ratio of sand-fixing agent to water of 1:10; the main components of this sand-fixing agent are acrylate copolymer and methanol.

[0036] Experimental Example 1 The performance of the sand-fixing agents prepared in the above examples and comparative examples was tested. All tests were conducted in the same desert area (sand particle size 0.1~0.5mm, wind speed 3~5m / s, temperature 25~30℃). Before the tests, the sand-fixing operations were completed on-site according to the usage methods of each group of sand-fixing agents. After a continuous hard shell layer was formed on the surface of the sand layer, the compressive strength of the hard shell layer, the 15-day water retention rate, the germination rate of Artemisia argyi, and the sand loss rate after a level 8 wind were tested.

[0037] Among them, the compressive strength test of the hard shell layer was carried out by a pressure testing machine. Three sampling points were randomly selected from each group of sand-fixing areas. A cubic sample of 10cm×10cm×2cm was made at each point. Pressure was applied to the sample surface at a loading speed of 5mm / min. The maximum pressure value when the sample was damaged was recorded. The average value of the three test results was taken as the compressive strength data of the group. Before sand fixation, the water retention rate test should be conducted by using a soil moisture meter to randomly select 5 test points with a depth of 10cm in each group of areas, measuring the initial sand layer moisture content and taking the average value. After normal curing for 15 days, the moisture content should be measured again at the same test points. The water retention rate should be calculated using the formula (15-day moisture content / initial moisture content) × 100%. Ecological safety testing: Three 1m³ quadrats were delineated in each sand fixation area. 100 plump Artemisia seeds were evenly sown in each quadrat. After 7 days, the number of normally germinated seeds in each quadrat was counted, and the average germination rate of the three quadrats was taken as the data for that group. Wind erosion resistance testing: After simulating a Force 8 wind in a wind tunnel, the wind speed was set to 18 m / s. A 1 m³ test sample from each sand-fixing area was continuously blown for 2 hours. The total mass of the sample was measured before and after blowing. The sand loss rate was calculated using the formula: (mass before blowing - mass after blowing) / mass before blowing × 100%. The final data for each indicator were the average of three parallel tests to ensure accuracy. The test results are shown in Table 1.

[0038] The method of using the sand-fixing agent in Examples 1-5 and Comparative Examples 1-3 is as follows: First, three continuous protective dams are built around the arid site to be stabilized using sand. Each dam is about 1m high and the distance between adjacent dams is 1m. Then, the surface of the protective dams is evenly sprayed with the corresponding group of hydroxypropyl methylcellulose aqueous solution to form a pretreatment layer to prevent sand intrusion. After the pretreatment layer has been left to stand for 2 hours, three aqueous solutions are sprayed sequentially onto the core sand-fixing area. The first step is to spray a hydroxypropyl methylcellulose aqueous solution to ensure that the solution completely penetrates the sand layer. The second step is to spray a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, with the same amount as the hydroxypropyl methylcellulose aqueous solution in the first step. After spraying, the mixture is allowed to dry naturally for 4-6 hours until 50% of the moisture in the film formed by the mixed aqueous solution has evaporated (the film is not sticky to the touch and is semi-transparent). The third step is to spray a sodium carboxymethyl cellulose aqueous solution, with the amount being 50%-60% of the amount sprayed in the first step. After spraying, the mixture is allowed to dry naturally for 12-24 hours until a continuous and complete hard shell layer is formed on the surface of the sand layer.

[0039] The commercially available sand-fixing agent in Comparative Example 4 was used by mixing the sand-fixing agent with water and spraying it at a rate of 3 L / m², followed by natural drying for 24 hours.

[0040] Table 1. Test Results

[0041] Based on the above data, the following conclusions can be drawn: The water-retaining and sand-fixing binder of the present invention is significantly superior to traditional commercially available acrylic chemical sand-fixing agents in terms of comprehensive performance, and the dosage of each component must be controlled within a reasonable range to achieve the best sand-fixing effect. Data from Examples 1-5 show that the compressive strength of the hard shell layer of the binder of this invention is above 0.85 MPa, with Examples 1-4 showing outstanding performance, approaching or even exceeding the 0.98 MPa of commercially available sand-fixing agents; the 15-day water retention rate is above 68%, with Example 5 reaching 76% and Example 2 reaching 75%, far exceeding the 42% of commercially available sand-fixing agents, indicating that the synergistic effect of sodium-based bentonite and cellulose components in this invention can effectively lock in sand moisture; the germination rate of Artemisia argyi is above 68%, with Example 3 reaching 78% and Example 1 reaching 72%, significantly better than the 23% of commercially available sand-fixing agents, proving that the raw materials of this invention do not inhibit plant growth and have excellent ecological safety; the sand loss rate after a level 8 wind is below 3.2%, with Example 5 at only 2.0% and Example 2 at only 2.1%, lower than the 4.8% of commercially available sand-fixing agents, indicating a more stable wind erosion resistance effect.

[0042] The comparative examples further validated the importance of the dosage of each component. Regarding sand-fixing strength and wind erosion resistance, the hard shell structure formed by the binder of this invention is stable and effectively resists wind erosion. The compressive strength of the hard shell in the examples is generally high; the strength of the optimal group not only exceeds that of the basic formulation group but is also slightly better than that of commercially available acrylic sand-fixing agents (Comparative Example 4). The corresponding sand loss rate is also significantly lower. Even the wind erosion resistance of the basic formulation group is better than that of commercially available products and Comparative Examples 1-3, where the dosage of components is either too high or too low. This indicates that the synergistic effect of the aqueous solution of hydroxypropyl methylcellulose, the mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, and the aqueous solution of sodium carboxymethyl cellulose can construct a dense and high-strength protective layer. The appropriate addition of sodium bentonite is crucial for improving the toughness of the hard shell. Insufficient dosage will lead to easy cracking of the hard shell and increased sand loss, while excessive dosage may make the film too brittle and affect the overall strength. In terms of water retention, the water-locking capacity of the binder of this invention far exceeds that of traditional chemical sand-fixing agents. In the examples, the water retention rate remained at a high level for 15 days, with the optimal water retention rate significantly higher than that of commercially available products. This is attributed to the synergistic water-locking mechanism of sodium-based bentonite and cellulose-based components. Sodium-based bentonite can adsorb a large number of water molecules, while HPMC and CMC can slow down water evaporation. The role of CMC in filling the pores of the membrane layer further reduces the evaporation channels. In contrast, the comparative example with insufficient sodium-based bentonite showed a significant decrease in water retention rate, proving that it is the core influencing factor on water retention performance. At the same time, excessively high curing temperatures may slightly weaken the water absorption structure between molecules, thus affecting the water retention effect.

[0043] In terms of ecological safety, the binder of this invention is friendly to the growth of native desert vegetation and has excellent environmental compatibility. In the examples, the germination rate of Artemisia argyi was consistently high, with some groups having particularly high germination rates due to their balanced formulations. In contrast, the sand-fixing agent in Comparative Example 4, containing non-biodegradable components and toxic co-solvents, had an extremely low germination rate. Imbalances in the component dosages of Comparative Examples 1-3 severely impacted ecological safety. Excessive CMC led to poor membrane permeability, and excessive HPMC formed a dense membrane that hindered seed respiration, both significantly reducing germination rates. This confirms that the HPMC, CMC, and sodium bentonite selected in this invention are all eco-friendly raw materials. Within a reasonable dosage range, they can balance sand fixation and water retention performance with plant growth needs, solving the problems of traditional chemical sand-fixing agents polluting the soil and inhibiting vegetation growth.

[0044] In summary, the water-retaining and sand-fixing binder of this invention achieves a balance in sand-fixing strength, water retention effect, ecological safety, and wind erosion resistance through reasonable component ratios and preparation and application methods.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A water-retaining and sand-fixing binder, characterized in that, It consists of the following components: an aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.32~0.54%, a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 3.25~6.38%, and an aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.25~0.40%.

2. The water-retaining and sand-fixing binder according to claim 1, characterized in that, It consists of the following components: an aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.40~0.52%, a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 4.35~5.86%, and an aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.30~0.37%.

3. The water-retaining and sand-fixing binder according to claim 1, characterized in that, It consists of the following components: an aqueous solution of hydroxypropyl methylcellulose with a solute concentration of 0.50%, a mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite with a solute concentration of 5.35%, and an aqueous solution of sodium carboxymethyl cellulose with a solute concentration of 0.35%.

4. The water-retaining and sand-fixing binder according to any one of claims 1-3, characterized in that, In the aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, the mass ratio of solute hydroxypropyl methylcellulose to sodium bentonite is (0.25~0.38):(3~6).

5. The water-retaining and sand-fixing binder according to claim 4, characterized in that, In the aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, the mass ratio of the solute hydroxypropyl methylcellulose to sodium bentonite is 0.35:

5.

6. A method for preparing a water-retaining and sand-fixing binder as described in any one of claims 1-5, characterized in that, Includes the following steps: Take the appropriate mass of hydroxypropyl methylcellulose and add it to a stirred tank containing water while stirring until it is completely dissolved to obtain an aqueous solution of hydroxypropyl methylcellulose. Then, the remaining amount of hydroxypropyl methylcellulose and the corresponding amount of sodium bentonite are mixed evenly, and then added to a stirred tank containing water. The mixture is stirred while adding the mixture until there are no particles, thus obtaining a hydroxypropyl methylcellulose-sodium bentonite mixed aqueous solution. Take an appropriate amount of sodium carboxymethyl cellulose and add it to a stirred tank containing water. Stir while adding the sodium carboxymethyl cellulose until it is completely dissolved to obtain an aqueous solution of sodium carboxymethyl cellulose. Finally, the aqueous solutions of hydroxypropyl methylcellulose, the mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, and the aqueous solution of sodium carboxymethyl cellulose were allowed to stand and mature separately to obtain the final product.

7. The method for preparing the water-retaining and sand-fixing binder according to claim 6, characterized in that, The settling and ripening time is controlled to be 12-24 hours.

8. The method for preparing the water-retaining and sand-fixing binder according to claim 6, characterized in that, The stirring speed for adding and stirring until no particles are present is 200 r / min to 300 r / min.

9. The method for preparing the water-retaining and sand-fixing binder according to claim 6, characterized in that, The stirring temperature for complete dissolution is 25~35℃.

10. A method of using the water-retaining and sand-fixing binder as described in any one of claims 1-5 and the water-retaining and sand-fixing binder prepared by any one of claims 6-9, characterized in that, Includes the following steps: A water-retaining and sand-fixing binder is sprayed onto the sandy area. The spraying sequence of the water-retaining and sand-fixing binder is: aqueous solution of hydroxypropyl methylcellulose, mixed aqueous solution of hydroxypropyl methylcellulose and sodium bentonite, and aqueous solution of sodium carboxymethyl cellulose. Then, it is dried until completely dry to form a continuous and complete hard shell layer.

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