A high molecular retarder, a preparation method thereof and a long-storage-period double-liquid grouting material modified by a powder

Abstract

The present application relates to mine underground engineering grouting material, especially to a kind of high molecular retarder and its preparation method and glue powder modified long storage period double liquid grouting material.The preparation method of the high molecular retarder of the present application includes the following steps: (1) the pH of sodium lignosulfonate solution is adjusted to 9.0-10.0, add glyoxal solution, react for 30-45 min;(2) add L-arginine and L-aspartic acid, react for 3-5 h at 65-75 DEG C;(3) after cooling to room temperature, the high molecular retarder is obtained.The high molecular retarder of the present application can make A liquid, B liquid respectively long-term storage, can be pre-prepared by factory, barrel transportation to underground, greatly reduce the on-site grouting workload.

Description

Technical Field

[0001] This invention relates to grouting materials for underground mining engineering, and particularly to a polymeric retarder, its preparation method, and a long-storage-period two-component grouting material modified with adhesive powder. Background Technology

[0002] During underground roadway excavation and face mining in coal mines, geological structures such as roof fissures, loosened surrounding rock zones, and fault fracture zones are common sources of disaster. Grouting reinforcement is a key technical means to control surrounding rock deformation and prevent roof collapse and spalling, and it is widely used in coal mines, tunnels, and underground engineering. Currently, underground grouting reinforcement in coal mines mainly uses cement-based grouts or chemical grouts. Among them, ordinary silicate cement single-liquid grout is widely used due to its low cost and wide availability; for situations requiring rapid water stoppage or controlled setting time, cement-water glass two-liquid grout is often used. However, with the continuous increase in mining depth, rising ground stress, and increasingly complex geological conditions, existing grouting materials have revealed many insurmountable problems in practical applications: First, the setting time is uncontrollable, making long-term storage impossible. Ordinary cement grout typically takes only 2-4 hours from mixing to initial setting, and may be even shorter under high temperature or high water-cement ratio conditions. This means the grout must be prepared and used immediately, and cannot be prepared in batches in advance. In actual construction, grouting pumps, pipelines, and mixers must be cleaned immediately after each grouting operation; otherwise, the residual grout will solidify and clog the equipment, wasting not only a significant amount of labor and water but also cement grout. Statistics show that grout loss due to equipment cleaning can reach 10%-15%. This problem is particularly prominent for applications requiring intermittent grouting or long-distance transportation.

[0003] Secondly, traditional two-component grouting is highly dependent on specialized equipment and is complex to operate. While cement-water glass two-component grout can achieve a relatively fast setting speed, it requires a two-component grouting pump and a dedicated Y-type mixer. The two slurries react instantaneously after merging in the mixer, placing strict requirements on pumping pressure, flow rate ratio, and mixing uniformity. Any deviation in the synchronization of the two-component pump or partial blockage of the mixer will lead to grouting failure. Currently, a set of domestically produced two-component grouting pumps costs between 50,000 and 100,000 yuan, while imported equipment can cost hundreds of thousands of yuan. Furthermore, the equipment is bulky and difficult to transport in narrow underground tunnels. In addition, two-component grouting requires at least two operators to separately control the delivery of the A and B components, resulting in high labor costs and low grouting efficiency.

[0004] Third, ordinary cement grout has poor adhesion to coal and rock masses, resulting in short-lived reinforcement effects. The compatibility between cement hydration products (CSH gel and calcium hydroxide) and the surface of coal and rock masses is limited, making it difficult to form strong chemical bonds; the bonding relies mainly on mechanical interlocking. Under humid or water-filled conditions, the cement grout is easily diluted at the coal-rock interface, further reducing the interfacial bond strength. Laboratory tests show that the bond strength between ordinary cement grout and coal blocks is typically only 0.4–0.8 MPa, and it becomes brittle after curing, easily debonding and cracking under surrounding rock deformation or mining pressure, leading to grouting failure. This is one of the important reasons why many coal mines repeatedly treat grouting only to have it leak again and again.

[0005] Fourth, there is a lack of flexible grouting systems that allow for "pre-mixed storage and delayed activation." Underground grouting in coal mines is often limited by factors such as transportation distance, work shifts, and sudden water inrushes. Ideally, grouting materials should be able to be pre-mixed and stored in drums on the surface or underground, requiring no complex equipment and only simple mixing for rapid solidification. However, currently available grouts, whether ordinary cement grouts, two-component grouts, or various chemical grouts, cannot simultaneously meet the contradictory requirements of "long storage period" and "instant activation." While chemical grouts (such as polyurethane and epoxy resin) have a long storage period, they are expensive (thousands to tens of thousands of yuan per ton), highly toxic, and have a violent exothermic reaction, making them unsuitable for large-scale fracture grouting.

[0006] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0007] The purpose of this invention is to provide a polymeric retarder, its preparation method, and a long-storage-period two-component grouting material modified with adhesive powder, so as to help solve or improve the problems in the prior art where grouting materials cannot be pre-prepared or where the bonding strength of the grouting material to the coal and rock mass is low.

[0008] The present invention provides a method for preparing a polymeric retarder, which adopts the following technical solution: A method for preparing a polymeric retarder includes the following steps: (1) adjusting the pH of sodium lignosulfonate solution to 9.0-10.0, adding glyoxal solution, and reacting for 30-45 min; (2) adding L-arginine and L-aspartic acid, and reacting at 65-75℃ for 3-5 h; (3) cooling to room temperature to obtain the polymeric retarder.

[0009] Preferably, in step (1), the mass ratio of sodium lignin sulfonate in the sodium lignin sulfonate solution to glyoxal in the glyoxal solution is (50-70):(5-12); in step (2), the mass ratio of L-arginine to L-aspartic acid is (8-15):(5-10); and the mass ratio of L-arginine to sodium lignin sulfonate in the sodium lignin sulfonate solution is (8-15):(50-70).

[0010] Preferably, the total amount of water in the sodium lignosulfonate solution and the glyoxal solution is in the mass ratio of sodium lignosulfonate in the sodium lignosulfonate solution to (120-200):(50-70); in step (3), after cooling to room temperature, the step of adjusting the pH to 7.0-8.0 is also included.

[0011] The present invention also provides a polymeric retarder, which adopts the following technical solution: a polymeric retarder, wherein the polymeric retarder is prepared by the method described above.

[0012] The present invention also provides a long-shelf-life two-component grouting material modified with adhesive powder, which adopts the following technical solution: a long-shelf-life two-component grouting material modified with adhesive powder, wherein the components of the long-shelf-life two-component grouting material modified with adhesive powder include the polymeric retarder as described above.

[0013] Preferably, the modified adhesive powder long-storage two-component grouting material comprises separately packaged liquid A and liquid B; by weight, liquid A comprises: 100 parts of sulfoaluminate cement, 5-20 parts of adhesive powder, 1-2 parts of sulfoaluminate cement retarder, and 60-80 parts of water; by weight, liquid B comprises: 60-80 parts of dihydrate gypsum, 20-40 parts of lime, 0.5-1 parts of gypsum / lime retarder, and 80-120 parts of water; the sulfoaluminate cement retarder comprises the polymeric retarder as described above; and / or, the gypsum / lime retarder comprises the polymeric retarder as described above.

[0014] Preferably, the mass ratio of liquid A to liquid B is 1:(0.5 to 1.5).

[0015] Preferably, the rubber powder is redispersible latex powder (VAE) or styrene-butadiene rubber latex powder.

[0016] Preferably, the retarder for sulfoaluminate cement further comprises at least one of boric acid, tartaric acid and sodium gluconate; and / or, the retarder for gypsum / lime further comprises at least one of bone glue, citric acid and sodium tripolyphosphate.

[0017] Beneficial effects: (1) Long storage period: The polymer retarder of the present invention can be used to store liquid A and liquid B for more than 60 days each. It can be pre-prepared in the factory and transported to the well in barrels, which greatly reduces the amount of on-site slurry preparation work. (2) Instant activation: No waiting is required after mixing; the rapid setting process begins immediately, and the setting time is adjustable (the setting time can be adjusted by changing the ratio of liquid A to liquid B and the ratio of retarder); specifically: Solution B contains a high concentration of Ca. 2+ In a high pH environment (>12.5), after mixing solution A and solution B, the lime in solution B can activate the hydration activity of sulfoaluminate cement. The gypsum dihydrate reacts rapidly with the anhydrous calcium sulfoaluminate in the cement to generate needle-shaped ettringite crystals, which interweave to form a framework. The pH of the system increases after mixing, which further accelerates the hydration of silicate minerals in cement; During this process, the adhesive powder undergoes simultaneous demulsification, forming a polymer film inside the cured body, which enhances cohesion and interfacial adhesion. This triple mechanism works synergistically.

[0018] (3) Simplified equipment: No expensive dual-liquid grouting machine is required; ordinary single-liquid pumps or even manual grouting devices can be used, reducing labor costs by more than 50%. (4) Strong adhesion: The adhesive powder in the long-storage-period two-component grouting material modified by the present invention can form a polymer film on the surface of the coal and rock mass, which helps to improve the bonding strength of the two-component grouting material of the present invention (the bonding strength can be increased by 2 to 3 times compared with ordinary cement grout without adhesive powder); Specifically: taking redispersible adhesive powder as an example, on the one hand, redispersible adhesive powder contains surfactants, which helps to reduce the surface tension of the grout, enabling the grout to penetrate into the microcracks and pores on the surface of the coal and rock mass, increasing the effective bonding area; on the other hand, the polar groups contained in the molecular structure of redispersible adhesive powder can form hydrogen bonds with oxygen-containing functional groups in the coal and rock mass, and can also form coordination complexes with metal ions in coal, enhancing the bonding between cement and coal and rock mass.

[0019] (5) Strong environmental adaptability: It can solidify normally in humid and watery environments and is suitable for complex conditions in coal mines. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a schematic diagram of the structures of sodium lignosulfonate, glyoxal, L-arginine and L-aspartic acid used to prepare polymeric retarder. Figure 2 This is a schematic diagram illustrating the reaction principle between sodium lignosulfonate and glyoxal; Figure 3This is a schematic diagram illustrating the principle of grafting L-arginine and L-aspartic acid onto sodium lignin sulfonate after activation with glyoxal.

[0021] Figure 4 This is a state diagram of liquid A and liquid B in Example 1 after 60 days of storage.

[0022] Figure 5 This is a diagram showing the state of solution A in Comparative Example 2 after 40 days of storage. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0024] The present invention will now be described in detail with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other.

[0025] This invention addresses the problems in existing technologies where grouting materials cannot be pre-prepared or where the bonding strength of the grouting materials to coal and rock masses is low, by providing a method for preparing a polymeric retarder.

[0026] The preparation method of the polymeric retarder of the present invention includes the following steps: (1) adjusting the pH of the sodium lignosulfonate solution to 9.0-10.0 (e.g., 9.0, 9.2, 9.4, 9.6, 9.8, 10), adding glyoxal solution, and reacting for 30-45 min (e.g., 30 min, 35 min, 40 min, 45 min); (2) adding L-arginine and L-aspartic acid, and reacting at 65-75℃ (e.g., 65℃, 67℃, 69℃, 71℃, 73℃, 75℃) for 3-5 h (e.g., 3 h, 3.5 h, 4 h, 4.5 h, 5 h); (3) cooling to room temperature to obtain the polymeric retarder.

[0027] Reference Figure 1-3 The synthesis and retarding mechanism of the polymeric retarder of this invention mainly involve the action of functional groups or structural segments: wherein, Figure 1 middle It provides steric hindrance and basic adsorption capacity for the sodium lignosulfonate framework; Figure 2 middle for This group can be electrostatically adsorbed onto the surface of cement / gypsum particles; Figure 2 middle for Sodium lignosulfonate bridges glyoxal ethers; Figure 3 In for Schiff base imine bond, reversible, can be hydrolyzed at high pH to achieve on-demand activation; Figure 3 In for The guanidinium group formed by L-arginine grafting strongly chelates Ca. 2+ ability, Figure 3 In for chelate Ca 2+ It delays hydration. The specific mechanism of its retarding is as follows: (1) The sulfonic acid groups on the lignin sulfonate skeleton preferentially adsorb onto the positive charge sites on the surface of sulfoaluminate cement particles, forming an electrostatic shielding layer; (2) The guanidino group of L-arginine carries a positive charge under alkaline conditions, and it undergoes electrostatic adsorption with the negatively charged sites on the surface of cement particles, while simultaneously reacting with Ca. 2+ chelation is formed; (3) The dicarboxyl group of L-aspartic acid and Ca 2+ Al 3+ Complexation occurs, reducing the concentration of calcium ions in the liquid phase and inhibiting the nucleation and growth of ettringite and gypsum crystals; (4) The lignin framework provides steric hindrance and extends the crystal growth path.

[0028] In a preferred embodiment of the preparation method of the polymeric retarder of the present invention, in step (1), the mass ratio of sodium lignosulfonate in the sodium lignosulfonate solution to glyoxal in the glyoxal solution is (50-70):(5-12) (e.g., 50:5, 50:8, 50:12, 60:5, 60:7, 60:12, 70:5, 70:9 or 70:12); in step (2), the mass ratio of L-arginine to L-aspartic acid is (8-15):(5-10) (e.g., 8:5, 8:10, 8:7, 11:5, 11:8, 11:10, 15:5, 15:7 or 15:10); L-arginine The mass ratio of acid to sodium lignosulfonate in the sodium lignosulfonate solution is (8–15):(50–70) (e.g., 8:50, 8:60, 8:70, 11:50, 11:60, 11:70, 15:50, 15:60 or 15:70); the mass ratio of the total amount of water in the sodium lignosulfonate solution and glyoxal solution to the mass ratio of sodium lignosulfonate in the sodium lignosulfonate solution is (120–200):(50–70) (e.g., 120:50, 120:60, 120:70, 160:50, 160:60, 160:70, 200:50, 200:60 or 200:70). If the proportion of glyoxal is too small, the grafting reaction will be incomplete, resulting in low product purity, low molecular weight, and insufficient retarding performance. If the proportion of glyoxal is too large, the water solubility of the product will decrease, potentially leading to excessive cross-linking and uncontrolled molecular weight. If the proportion of L-arginine is too small, the guanidine group density will be insufficient, causing a decrease in the high alkalinity stability of solutions A and B due to the lack of guanidine groups, thus reducing the retarding effect. If the proportion of L-arginine is too large, excessive steric hindrance will hinder the grafting of aspartic acid, resulting in a relative deficiency of carboxylic acid groups. After mixing, the retarding effect will be difficult to be completely neutralized by solution B, prolonging the activation time.

[0029] Preferably, step (3) further includes adjusting the pH to 7.0–8.0 (e.g., 7.0, 7.2, 7.4, 7.6, 7.8, 8.0) after cooling to room temperature. Adjusting the pH helps to better improve the storage stability of the polymeric retarder of the present invention and its compatibility with liquids A and B.

[0030] The present invention also proposes a polymeric retarder, which is prepared by the method described above in the embodiments of the present invention.

[0031] The present invention also proposes a long-shelf-life two-liquid grouting material modified with adhesive powder. The components of the long-shelf-life two-liquid grouting material modified with adhesive powder in the embodiments of the present invention include the polymeric retarder as described above.

[0032] In a preferred embodiment of the long-shelf-life two-component grouting material modified with adhesive powder of the present invention, the long-shelf-life two-component grouting material modified with adhesive powder includes separately packaged component A and component B; by weight, component A (component A contains Ca...) 2+ Less, Al 3+ (A relatively large amount) includes: 100 parts sulfoaluminate cement, 5-20 parts adhesive powder (e.g., 5, 10, 15, or 20 parts), 1-2 parts sulfoaluminate cement retarder (e.g., 1, 1.2, 1.4, 1.6, 1.8, or 2 parts), and 60-80 parts water (e.g., 60, 65, 70, 75, or 80 parts); by weight, liquid B (liquid B contains Ca...) 2+ More, Al 3+ (Basically none) includes: 60-80 parts of dihydrate gypsum (e.g., 60, 65, 70, 75, or 80 parts), 20-40 parts of lime (e.g., 20, 25, 30, 35, or 40 parts), 0.5-1 part of gypsum / lime retarder (e.g., 0.5, 0.6, 0.7, 0.8, 0.9, or 1 part), and 80-120 parts of water (e.g., 80, 90, 100, 110, or 120 parts); the components of the sulfoaluminate cement retarder include the polymeric retarder as described above; and / or, the components of the gypsum / lime retarder include the polymeric retarder as described above. If the amount of retarder for sulfoaluminate cement and / or retarder for gypsum / lime is too small, the storage period of liquid A or liquid B will be significantly shortened, failing to meet the design target of more than 60 days. At the same time, early hydration of cement in liquid A may cause demulsification of the binder powder, and gypsum in liquid B may solidify prematurely (if the polymeric retarder of this invention is used, liquid B can be stored for more than 60 days and maintain good flow properties; if the polymeric retarder of this invention is not added, other similar retarders will gradually become ineffective in a high-alkali environment, and the lime in liquid B will gradually hydrate into calcium hydroxide and release a large amount of heat, and then the gypsum crystals will undergo a dissolution-recrystallization process, causing the gypsum crystals to grow and the slurry of liquid B to thicken). If the proportion of retarders for sulfoaluminate cement and / or retarders for gypsum / lime is too high, the storage period of liquid A or liquid B may be abnormally prolonged. More seriously, the retarding effect of liquid A and liquid B is difficult to be completely neutralized after mixing, resulting in a setting time of more than 60 minutes or even several days without setting, thus losing the grouting advantage of "instant activation".

[0033] The principle behind the retarding of liquid A and liquid B in this invention, and the rapid setting achieved after mixing liquid A and liquid B, is as follows: the sulfoaluminate cement in liquid A, with the aid of a retarder, prevents the sulfoaluminate cement from initial setting within 60 days; and the key role of the adhesive powder is to uniformly disperse in liquid A, coexisting with the sulfoaluminate cement without breaking the emulsion; liquid B can remain unhardened within 60 days; before mixing liquid A and liquid B, the polymeric retarder in liquid A reduces the free Ca in the liquid phase. 2+This keeps cement hydration in a dormant state; the hydration of CaO in solution B is inhibited.

[0034] However, when liquid A and liquid B are mixed, the slurry environment changes; the free Ca in liquid B... 2+ This causes a shift in the chelation equilibrium in solution A, and the chelation sites of the polymeric retarder in solution A are affected by excess Ca. 2+ Saturated and passivated, Al that was originally complexed with carboxyl groups 3+ It is also released because the carboxylic acid group forms an insoluble calcium salt under highly alkaline conditions. 2+ And Al 3+ After being released, the anhydrous calcium sulfoaluminate in the sulfoaluminate cement ( The cement particles in the grout react rapidly with the gypsum dihydrate in solution B to form ettringite (AFt), while C2S hydrates to form CSH gel. The grout solidifies within 50-100 minutes. After mixing, the cement particles in the grout continuously hydrate, consuming water. The adhesive particles gradually approach, compress, deform, and fuse due to physical forces, forming a polymer film. The cement particles hydrate within and between the adhesive particles, gradually forming a stone body and a rigid network dominated by AFt, covered by the polymer film containing adhesive. When used for grouting, the adhesive undergoes a series of reactions in the cement particles and coal / rock bodies, increasing the adhesion of the grouting material.

[0035] In other words, after mixing liquid A and liquid B, the reaction between the sulfoaluminate cement in liquid A and the gypsum and lime in liquid B will cause the polymer retarder to become ineffective. After mixing, the two will quickly trigger a rapid setting reaction, and the setting time can be adjusted within 55 to 100 minutes. In addition, after mixing liquid A and liquid B, the adhesive powder particles form a film in an alkaline environment, filling the micro-fractures in the coal and rock mass and forming a flexible bonding layer. The bonding strength test (coal-coal interface) shows that the bonding strength after adding adhesive powder can reach 1.2 to 2.9 MPa, which is 150% to 300% higher than that without adhesive powder.

[0036] In a preferred embodiment of the modified adhesive powder long-life two-component grouting material of the present invention, the mass ratio of liquid A to liquid B is 1:(0.5-1.5) (e.g., 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5). If there is too much liquid A, the setting rate is slow, resulting in early brittleness and low compressive strength. If there is too much liquid B, the setting is too fast, resulting in poor flexural strength.

[0037] In a preferred embodiment of the long-storage-period two-component grouting material modified with rubber powder of the present invention, the rubber powder is redispersible latex powder (VAE) or styrene-butadiene rubber latex powder. The VAE or styrene-butadiene rubber latex powder contains a polyvinyl alcohol protective colloidal layer, which forms a sterically stable emulsion system upon contact with water; the sulfoaluminate cement hydration system has a relatively low alkalinity (pH 11.5–12.5), resulting in a weak hydrolytic effect on the polymer protective colloid; the retarder added to solution A can chelate Ca... 2+ Adsorbed on the surface of cement particles, it significantly inhibits early cement hydration and maintains a low Ca content in the liquid phase. 2+ Concentration and pH value; in solution A, both polymer particles (e.g., redispersible polymer powder particles) and cement particles carry negative charges on their surfaces, and electrostatic repulsion hinders their adsorption and binding; trace amounts of hydration products form a physical isolation layer on the surface of cement particles, further reducing direct contact between polymer particles and cement particles. The synergistic effect of these factors allows the polymer powder to be stably stored in solution A for more than 60 days without demulsification or precipitation.

[0038] In a preferred embodiment of the long-storage-period two-component grouting material modified with adhesive powder of the present invention, the retarder for sulfoaluminate cement further includes at least one of boric acid, tartaric acid and sodium gluconate; and / or, the retarder for gypsum / lime further includes at least one of bone glue, citric acid and sodium tripolyphosphate.

[0039] Preferably, in the retarder for sulfoaluminate cement, at least one of boric acid, tartaric acid and sodium gluconate has a mass ratio of 1:(3-4) to the polymeric retarder; in the retarder for gypsum / lime, at least one of bone glue, citric acid and sodium tripolyphosphate has a mass ratio of 1:4 to the polymeric retarder.

[0040] This invention also proposes a method for preparing a long-storage-period dual-liquid grouting material modified with adhesive powder: including the following steps: (1) Pre-preparation: Prepare liquid A and liquid B separately, stir them evenly and then seal and store them (storage period can reach more than 60 days); (2) On-site activation: Pour liquid A and liquid B into any container (e.g., plastic mixing bucket) according to the design ratio (recommended A:B=1:1, mass ratio), and stir manually or mechanically for 10-30s (e.g., 10s, 15s, 20s, 25s or 30s); (3) Grouting: Inject the mixed grout directly into the cracks of the coal and rock mass; (4) Curing. The long-storage-period dual-liquid grouting material modified with adhesive powder of this invention can be fully hardened within 2 hours of grouting (this does not mean that it will have maximum strength after 2 hours of grouting); the 1-day strength can reach 85% of the 28-day strength, the 7-day strength can reach 95% of the 28-day strength, the 28-day strength reaches the maximum, and the strength growth is slow or slightly decreases in the later stage.

[0041] Unless otherwise specified, all raw materials used in the following experiments are commercially available; the main raw materials in the following examples are sourced from: sodium lignosulfonate, glyoxal, L-arginine, L-aspartic acid, boric acid, tartaric acid, sodium gluconate, and other components of sulfoaluminate cement retarder, as well as bone glue, citric acid, sodium tripolyphosphate, and other components of gypsum / lime retarder, all from Tianjin Kemei Chemical Reagent Co., Ltd.; adhesive powder from Anhui Wanwei Group Co., Ltd.; gypsum dihydrate, lime, sulfoaluminate cement ( The cement components, including those from Jiaozuo Qianye Cement Co., Ltd., are sourced from this company.

[0042] Example 1 The preparation method of the polymeric retarder in this embodiment includes the following steps: (1) Weigh 600g of sodium lignosulfonate using an electronic balance (accuracy 0.01 to g) and place it in a beaker. Add 1500g of deionized water to the beaker and heat it in a water bath to 60°C. Stir magnetically until completely dissolved to obtain a sodium lignosulfonate solution. (2) Adjust the pH of the sodium lignosulfonate solution to 10.0 using 0.1 mol / L NaOH solution, add 250 g of 40% glyoxal solution to a beaker, and react at 25°C for 40 min to activate the ortho-position of the lignin phenolic hydroxyl groups. (3) Slowly add a mixture of 100g L-arginine and 80g L-aspartic acid to a beaker and keep it in a water bath at 65°C for 3 hours. (4) After the reaction is complete, cool to room temperature and adjust the pH to 7.0 with 0.1 mol / L dilute hydrochloric acid to obtain a dark brown transparent liquid, which is the polymer retarder (solid content about 35%) in this example.

[0043] The long-storage-period two-component grouting material modified with adhesive powder in this embodiment includes separately packaged liquid A and liquid B; The components of liquid A include: 100 kg of sulfoaluminate cement, 20 kg of VAE adhesive powder, 4.29 kg of polymeric retarder (actual content 1.5 kg) in this embodiment, 0.5 kg of boric acid, and 80 kg of water; The components of liquid B include: 60 kg of gypsum dihydrate, 40 kg of quicklime (CaO), 2.29 kg of polymeric retarder (actual content 0.8 kg) in this embodiment, 0.2 kg of bone glue, and 80 kg of water.

[0044] The preparation method of the long-shelf-life two-component grouting material modified with adhesive powder in this embodiment includes the following steps: S1. Preparation of Solution A: Using an electronic balance (accuracy 1g), weigh out 100kg of sulfoaluminate cement, 20kg of VAE adhesive powder, 4.29kg of polymeric retarder (actual content 1.5kg), 0.5kg of boric acid and 80kg of water by weight, put them into a mixing tank and stir. After stirring evenly, seal and store at room temperature away from light.

[0045] S2. Preparation of Solution B: Using an electronic balance (accuracy 1g), weigh 60kg of gypsum dihydrate, 40kg of lime, 2.29kg of polymeric retarder (actual content 0.8kg), 0.2kg of bone glue, and 80kg of water respectively, put them into a mixing tank and stir. After stirring evenly, seal and store at room temperature away from light.

[0046] S3. When using, mix liquid A and liquid B at a mass ratio of 1:1; after mixing, initial setting takes 28 minutes and final setting takes 57 minutes; the test shows that the grouting material-coal bonding strength reaches 2.1 MPa after 28 days.

[0047] like Figure 4 As shown, liquid A will naturally settle to the bottom during storage (natural sedimentation under gravity), but the lower particles do not show any coagulation or hardening within 60 days of storage. A small amount of flocculation appears at the bottom after 45 days, which can be restored to fluidity by re-stirring. Liquid B remains viscous throughout the storage process, and a small amount of particles will naturally settle to the bottom (natural sedimentation under gravity). There is no coagulation or hardening within 60 days of storage.

[0048] Figure 4 In the middle, from left to right, are: the physical image after 60 days of storage, the physical image after thorough mixing, the state image verifying fluidity (fluidity and injectability can be effectively restored after mixing), and the physical image after 1 hour of mixing (stable and does not separate within 1 hour).

[0049] The flowability and Zeta potential of solutions A and B during storage were tested, and the results are shown in the table below: Table 1. Test results of the change in flowability (mm) of liquid A and liquid B with storage time.

[0050] Table 2. Test results of Zeta (mV) of solutions A and B as a function of storage time.

[0051] As shown in Tables 1 and 2 above, after 60 days of storage, the fluidity of liquid A decreased from the initial 340 mm to 275 mm, and the Zeta potential decreased to +4.62 mV; after 60 days of storage, the fluidity of liquid B decreased from the initial 285 mm to 220 mm, and the Zeta potential decreased to +3.25 mV. Only thickening occurred, which did not affect its use.

[0052] Example 2 The preparation method of the polymer retarder in this embodiment differs from that in Example 1 only in that the reaction time in step (3) is 5 hours; the rest is the same as in Example 1.

[0053] The only difference between the long-storage-period two-component grouting material modified with adhesive powder in this embodiment and that in Example 1 is that the polymeric retarder is replaced with the polymeric retarder prepared in this embodiment.

[0054] The long-storage-period two-component grouting material modified with adhesive powder in this embodiment: Component A shows no coagulation within 60 days of storage; the fluidity can reach over 280 mm; the Zeta potential is +4.86 mV after 60 days; a small amount of flocculation occurs at the bottom, which can be restored to fluidity by re-stirring. Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 260 mm and a Zeta potential of +3.34 mV after 60 days of storage. When using, liquid A and liquid B are mixed at a mass ratio of 1:1; initial setting takes 32 minutes and final setting takes 68 minutes; the grouting material-coal bonding strength was tested to reach 2.3 MPa after 28 days.

[0055] Example 3 The preparation method of the polymer retarder in this embodiment differs from that in Example 2 only in that 150g of L-arginine and 100g of L-aspartic acid are added in step (3); the rest are the same as in Example 2.

[0056] The only difference between the long-storage-period two-liquid grouting material modified with adhesive powder in this embodiment and that in Example 2 is that the polymeric retarder is replaced with the polymeric retarder prepared in this embodiment.

[0057] The long-storage-period two-component grouting material modified with adhesive powder in this embodiment: Component A shows no coagulation within 60 days of storage; the fluidity can reach over 295 mm; the Zeta potential (60 days) is +4.99 mV; a small amount of flocculation occurs at the bottom, which can be restored to fluidity by re-stirring; Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 275 mm and a Zeta potential of +3.73 mV after 60 days of storage. When using, liquid A and liquid B are mixed at a mass ratio of 1:1; initial setting takes 34 minutes and final setting takes 72 minutes; the grouting material-coal bonding strength was tested to reach 2.2 MPa after 28 days.

[0058] Example 4 The polymeric retarder in this embodiment is the same as that in Example 3.

[0059] In this embodiment, the long-storage-period two-component grouting material modified with rubber powder includes the following components in component A: 100 kg of sulfoaluminate cement, 20 kg of styrene-butadiene rubber powder, 4.29 kg of polymeric retarder (actual content 1.5 kg), 0.5 kg of boric acid, and 80 kg of water. Solution B comprises the following components: 60 kg of gypsum dihydrate, 40 kg of lime, 2.29 kg of polymeric retarder (actual content 0.8 kg), 0.2 kg of citric acid, and 80 kg of water.

[0060] Among them, solution A showed no condensation within 60 days of storage, with a fluidity of over 275 mm and a Zeta potential (60 days) of +4.67 mV. A small amount of flocculation occurred at the bottom, but the fluidity could be restored by stirring again. Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 280 mm and a Zeta potential (60 days) of +4.27 mV. The mixture of liquid A and liquid B was prepared at a mass ratio of 1:1. After mixing, the mixture underwent initial setting in 30 minutes and final setting in 64 minutes. The test showed that the grouting material-coal bonding strength reached 2.5 MPa after 28 days.

[0061] Example 5 The polymeric retarder in this embodiment is the same as that in Example 3.

[0062] In this embodiment, the long-storage-period two-component grouting material modified with rubber powder includes the following components in component A: 100 kg of sulfoaluminate cement, 20 kg of styrene-butadiene rubber powder, 4.29 kg of polymeric retarder (actual content 1.5 kg), 0.5 kg of sodium gluconate, and 80 kg of water. Solution B comprises the following components: 80 kg of gypsum dihydrate, 20 kg of lime, 2.29 kg of polymeric retarder (actual content 0.8 kg), 0.2 kg of citric acid, and 80 kg of water.

[0063] Among them, solution A showed no condensation within 60 days of storage, with a fluidity of over 285 mm and a Zeta potential of +4.92 mV after 60 days. A small amount of flocculation occurred at the bottom, but the fluidity could be restored by stirring again. Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 290 mm and a Zeta potential of +4.58 mV after 60 days. When using it, liquid A and liquid B are mixed at a mass ratio of 1:1; after mixing, initial setting takes 35 minutes and final setting takes 78 minutes. The test results show that the grouting material-coal bonding strength reaches 2.6 MPa after 28 days.

[0064] Example 6 The polymeric retarder in this embodiment is the same as that in Example 3.

[0065] In this embodiment, the long-storage-period two-component grouting material modified with rubber powder includes the following components in component A: 100 kg of sulfoaluminate cement, 5 kg of styrene-butadiene rubber powder, 4.29 kg of polymeric retarder (actual content 1.5 kg), 0.5 kg of boric acid, and 80 kg of water. Solution B comprises the following components: 80 kg of gypsum dihydrate, 20 kg of lime, 2.29 kg of polymeric retarder (actual content 0.8 kg), 0.2 kg of citric acid, and 80 kg of water.

[0066] Among them, solution A showed no condensation within 60 days of storage, with a fluidity of over 300 mm and a Zeta potential of +5.25 mV after 60 days. A small amount of flocculation occurred at the bottom, but the fluidity could be restored by stirring again. Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 290 mm and a Zeta potential of +4.58 mV after 60 days. When using, liquid A and liquid B are mixed at a mass ratio of 1:1; after mixing, it can initially set in 46 minutes and finally set in 89 minutes. The test results show that the grouting material-coal bonding strength reaches 1.2 MPa after 28 days.

[0067] Example 7 The polymeric retarder in this embodiment is the same as that in Example 3.

[0068] In this embodiment, the long-storage-period two-component grouting material modified with rubber powder includes the following components in Component A: 100 kg of sulfoaluminate cement, 20 kg of styrene-butadiene rubber powder, 2.29 kg of polymeric retarder (actual content 0.8 kg), 0.2 kg of boric acid, and 80 kg of water. Solution B comprises the following components: 60 kg of gypsum dihydrate, 40 kg of lime, 1.14 kg of polymeric retarder (actual content 0.4 kg), 0.1 kg of citric acid, and 80 kg of water.

[0069] Among them, liquid A showed partial coagulation within 60 days of storage, with a fluidity of over 220 mm and a Zeta potential of +3.67 mV after 60 days. A large amount of flocculation occurred at the bottom, and the fluidity could be restored by re-stirring. Within 60 days of storage, solution B showed no condensation in some parts, and its fluidity could reach over 215 mm. The Zeta potential was +2.96 mV after 60 days. The mixture of liquid A and liquid B was prepared at a mass ratio of 1:1. After mixing, the mixture underwent initial setting in 22 minutes and final setting in 48 minutes. The test showed that the grouting material-coal bonding strength reached 2.3 MPa after 28 days.

[0070] Example 8 The polymeric retarder in this embodiment is the same as that in Example 3.

[0071] In this embodiment, the long-storage-period two-component grouting material modified with rubber powder includes the following components in component A: 100 kg of sulfoaluminate cement, 20 kg of styrene-butadiene rubber powder, 3.43 kg of polymeric retarder (actual content 1.2 kg), 0.3 kg of boric acid, and 80 kg of water. Solution B comprises the following components: 60 kg of gypsum dihydrate, 40 kg of lime, 1.71 kg of polymeric retarder (actual content 0.6 kg), 0.15 kg of citric acid, and 80 kg of water.

[0072] Among them, liquid A showed no condensation within 60 days of storage, with a fluidity of over 255 mm and a Zeta potential of +4.59 mV after 60 days. A large amount of flocculation occurred at the bottom, and the fluidity could be restored by re-stirring. Solution B showed no condensation within 60 days of storage, with a fluidity exceeding 240 mm and a Zeta potential of +3.25 mV after 60 days. The mixture of liquid A and liquid B was prepared at a mass ratio of 1:1. After mixing, the mixture underwent initial setting in 27 minutes and final setting in 55 minutes. The test showed that the grouting material-coal bonding strength reached 2.9 MPa after 28 days.

[0073] Example 9 The polymeric retarder in this embodiment is the same as that in Example 1.

[0074] In this embodiment of the long-storage-period two-component grouting material modified with adhesive powder, the components of liquid A and liquid B are the same as in Example 1.

[0075] When using it, liquid A and liquid B are mixed at a mass ratio of 1:0.5; after mixing, the initial setting time is 51 minutes and the final setting time is 96 minutes. The test results show that the grouting material-coal bonding strength reaches 1.8 MPa after 28 days.

[0076] The 28-day grouting material-coal bonding strength in this embodiment is significantly lower than that in Example 1. This is mainly because: on the one hand, the amount of liquid B is reduced, and the calcium ions introduced and the pH value increased when liquid A and liquid B are mixed are insufficient, resulting in a longer coagulation time; on the other hand, the amount of liquid B is reduced, resulting in insufficient gypsum introduced. As hydration of liquid A proceeds, after the gypsum is consumed, the high-strength AFt will be transformed into AFm, leading to a decrease in strength.

[0077] Example 10 The polymeric retarder in this embodiment is the same as that in Example 1.

[0078] In this embodiment of the long-storage-period two-component grouting material modified with adhesive powder, the components of liquid A and liquid B are the same as in Example 1.

[0079] When using it, liquid A and liquid B are mixed at a mass ratio of 1:1.5; after mixing, initial setting takes 26 minutes and final setting takes 55 minutes. The test results show that the grouting material-coal bonding strength reaches 1.5 MPa after 28 days.

[0080] The 28-day grouting material-coal bonding strength in this embodiment is significantly lower than that in Example 1. This is mainly because: on the one hand, the amount of liquid B is increased, and too many calcium ions are introduced during mixing, and the pH value is increased, resulting in a shorter coagulation time; on the other hand, the increased amount of liquid B introduces too much gypsum. As liquid A undergoes hydration, it will generate high-strength AFt, but after the cement is consumed, the excess gypsum will not participate in the reaction, resulting in defects in the hardened body and a decrease in strength.

[0081] Comparative Example 1 The only difference between this comparative example and Example 1 is that the components of liquid A do not contain VAE adhesive powder; otherwise, they are consistent with those of Example 1.

[0082] Liquid A showed no condensation within 60 days of storage. After 60 days of storage, its fluidity decreased to 295 mm, its Zeta potential dropped to +5.16 mV, and a small amount of flocculation occurred at the bottom. The fluidity could be restored by stirring again.

[0083] When using it, mix liquid A and liquid B at a mass ratio of 1:1; after mixing, the initial setting time is extended to 32 min and the final setting time is extended to 69 min, but the 28-day grouting material-coal bonding strength is reduced to 0.8 MPa.

[0084] Comparative Example 2 The only difference between this comparative example and Example 1 is that the retarder in solution A and solution B is different from that in Example 1 (specifically, the retarder in solution A is 1.5 kg of sodium gluconate and 0.5 kg of boric acid; the retarder in solution B is 0.8 kg of citric acid and 0.2 kg of bone glue); all other aspects are the same as in Example 1.

[0085] like Figure 5 As shown, after 40 days of storage, liquid A partially coagulated, with a large amount of flocculation at the bottom. Re-stirring did not restore the fluidity of the bottom. The state diagram of liquid A after 40 days of storage is shown below. Figure 5 As shown, it lacks fluidity and is difficult to pour out of the container.

[0086] Liquid B showed no condensation within 45 days of storage, but its fluidity decreased to 150 mm; after 60 days, it became a paste-like substance with no fluidity. At 20 days, liquid A and liquid B were mixed at a mass ratio of 1:1. After mixing, compared with Example 1, the initial setting time was 41 min, the final setting time was 82 min, and the grouting material-coal bonding strength was 1.7 MPa.

[0087] Comparative Example 3 The preparation method of the polymer retarder in this comparative example differs from that in Example 1 only in that step (3) is carried out in a water bath at 60°C; the rest is the same as in Example 1.

[0088] The only difference between the A and B components of the modified long-storage two-component grouting material of this comparative example and Example 1 is that the high-molecular-weight retarder of this comparative example is used; all other aspects are the same as those of Example 1.

[0089] Among them, liquid A showed no condensation within 60 days of storage. After 60 days of storage, the fluidity decreased from 275 mm in Example 1 to 255 mm, the Zeta potential decreased from +4.62 mV to +4.32 mV, and a small amount of flocculation occurred at the bottom. The fluidity could be restored by stirring again. Liquid B showed no condensation within 60 days of storage, and its fluidity after 60 days was 210 mm. The Zeta potential decreased from +3.25 mV to +2.89 mV compared to Example 1. When using, liquid A and liquid B are mixed at a mass ratio of 1:1. After mixing, the initial setting time is extended from 28 min to 35 min compared to Example 1, and the final setting time is extended from 57 min to 79 min compared to Example 1. However, the 28-day grouting material-coal bonding strength is reduced from 2.1 MPa to 1.9 MPa compared to Example 1.

[0090] Comparative Example 4 The only difference between this comparative example and Example 4 is that, in the preparation of the polymer retarder, L-arginine in step (3) is replaced with an equal amount of L-aspartic acid; all other aspects are the same as in Example 4.

[0091] Liquid A partially coagulates after 30 days of storage, with a large amount of clumps and flocculation at the bottom. Re-stirring does not restore the fluidity of the bottom. Liquid B partially coagulates within 35 days of storage, exhibiting an overall paste-like consistency. Re-stirring does not restore the fluidity of the bottom.

[0092] When used for 20 days, mix liquid A and liquid B at a mass ratio of 1:1. After mixing, the initial setting time is shortened to 25 minutes and the final setting time is shortened to 46 minutes, but the bonding strength of the grouting material-coal is reduced to 1.8 MPa after 28 days.

[0093] Comparative Example 5 The only difference between this comparative example and Example 4 is that, in the preparation of the polymer retarder, L-aspartic acid in step (3) is replaced with an equal amount of L-arginine; all other aspects are consistent with Example 4.

[0094] Solution A showed no condensation after 60 days of storage, and its fluidity increased to 285 mm and Zeta potential increased to +4.84 mV. A small amount of flocculation occurred at the bottom, but its fluidity was restored by re-stirring. Solution B partially condensed after 45 days of storage, with a large amount of flocculation and agglomeration at the bottom; re-stirring did not restore its fluidity. When used for 20 days, liquid A and liquid B are mixed at a mass ratio of 1:1. After mixing, the initial setting time is extended to 47 minutes and the final setting time is extended to 93 minutes, but the bonding strength of the grouting material-coal is reduced to 1.4 MPa after 28 days.

[0095] The experimental results of the above embodiments and comparative examples are summarized in the table below: Table 3 Summary of the performance of solutions A and B after 60 days of storage

[0096] The data in the above experimental cases were tested according to GB / T 50448-2015 "Test Method for Homogeneity of Concrete Admixtures" to measure the fluidity of liquid A and liquid B; according to GB / T 1346-2024 "Test Method for Standard Consistency Water Requirement, Setting Time and Soundness of Cement" to measure the setting time of the mixture of liquid A and liquid B; and with reference to DL / T 5721-2015 "Test Procedure for Hydraulic Shotcrete" to measure the bond strength between the grouting material and the coal and rock mass. Liquid A and liquid B were stirred evenly at different storage times. 250 mL of the test liquid was taken, and the Zeta potential of the cement paste was measured every minute at a rate of 300 r / min using a Colloidal Dynamics Zeta potential meter (USA), for a total of 10 measurements. The average value was taken as the test result.

[0097] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a polymeric retarder, characterized in that, Includes the following steps: (1) Adjust the pH of the sodium lignosulfonate solution to 9.0-10.0, add glyoxal solution, and react for 30-45 min; (2) Add L-arginine and L-aspartic acid, and react at 65-75℃ for 3-5 hours; (3) After cooling to room temperature, the polymer retarder is obtained.

2. The preparation method of the polymeric retarder as described in claim 1, characterized in that, In step (1), the mass ratio of sodium lignosulfonate in the sodium lignosulfonate solution to glyoxal in the glyoxal solution is (50-70):(5-12); In step (2), the mass ratio of L-arginine to L-aspartic acid is (8-15):(5-10); the mass ratio of L-arginine to sodium lignin sulfonate in the sodium lignin sulfonate solution is (8-15):(50-70).

3. The method for preparing the polymeric retarder as described in claim 1, characterized in that, The total amount of water in the sodium lignosulfonate solution and glyoxal solution is in a mass ratio of (120-200):(50-70) to sodium lignosulfonate in the sodium lignosulfonate solution. In step (3), after cooling to room temperature, the pH is adjusted to 7.0 to 8.

0.

4. A polymeric retarder, characterized in that, The polymeric retarder is prepared using the method described in any one of claims 1-3.

5. A long-shelf-life two-component grouting material modified with adhesive powder, characterized in that: The components of the modified adhesive powder long-storage two-liquid grouting material include the polymeric retarder as described in claim 4.

6. The long-shelf-life two-component grouting material modified with adhesive powder as described in claim 5, characterized in that: The modified adhesive powder long-storage two-component grouting material includes separately packaged liquid A and liquid B; By weight, liquid A comprises: 100 parts of sulfoaluminate cement, 5-20 parts of adhesive powder, 1-2 parts of sulfoaluminate cement retarder and 60-80 parts of water. By weight, the B solution comprises: 60-80 parts of gypsum dihydrate, 20-40 parts of lime, 0.5-1 parts of gypsum / lime retarder, and 80-120 parts of water; The components of the sulfoaluminate cement retarder include the polymeric retarder as described in claim 4; and / or, The components of the gypsum / lime retarder include the polymeric retarder as described in claim 4.

7. The long-shelf-life two-component grouting material modified with adhesive powder according to claim 6, characterized in that: The mass ratio of liquid A to liquid B is 1:(0.5 to 1.5).

8. The long-shelf-life two-component grouting material modified with adhesive powder according to claim 6, characterized in that: The rubber powder is redispersible latex powder (VAE) or styrene-butadiene rubber latex powder.

9. The long-shelf-life two-component grouting material modified with adhesive powder according to claim 6, characterized in that: The components of the sulfoaluminate cement retarder also include at least one of boric acid, tartaric acid, and sodium gluconate; and / or, The components of the gypsum / lime retarder also include at least one of bone glue, citric acid, and sodium tripolyphosphate.

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