A gel-coated silent breaker material and a method for preparing the same

Abstract

This invention discloses a gel-coated silent destructive agent material and its preparation method. The destructive agent material consists of a liquid component A and a solid component B. Liquid component A is prepared from the following raw materials in parts by weight: 20-30 parts water, 1.5-2.5 parts water-soluble alkali-resistant polymer, 0.3-1.0 parts sodium alginate, and 1.25-6.25 parts easily soluble calcium salt aqueous solution. Solid component B is prepared from the following raw materials in percentage by weight: 70%-86% calcium oxide, 6%-12% calcium chloride, 2.5%-6.0% dicalcium silicate, 2.5%-6.0% tricalcium silicate, and 3%-6% gypsum. The destructive agent material of this invention has an "eggshell" structure formed by the outer gel coating of destructive agent particles. The shell breaks after the reaction reaches a certain extent, and the reaction time is controllable. Moreover, due to the outer gel coating, it is not sensitive to environmental temperature, solving the problems of limited application scenarios (only usable in vertical holes) and great influence from environmental temperature of traditional destructive agent materials.

Description

Technical Field

[0001] This invention belongs to the field of static crushing technology in engineering blasting, specifically relating to a gel-coated silent crushing agent material and its preparation method. Background Technology

[0002] Silent fracturing agents, as a non-explosive fracturing material, play an important role in various fields such as building demolition, rock mining, and concrete component crushing due to their unique expansion and fracturing properties. Through the expansion pressure generated by the hydration reaction, they induce tensile stress within the material being broken. When the stress exceeds its tensile limit, fracturing occurs, avoiding the vibration, noise, and dust problems associated with traditional blasting. This offers significant advantages in applications with high environmental requirements.

[0003] However, the preparation process of silent destructive agents still has some shortcomings. Currently, its preparation usually involves complex chemical reaction processes and raw material ratio control. Some processes have high requirements for equipment and environment. For example, the calcination of certain raw materials requires high-temperature conditions, resulting in high energy consumption and increased production costs. At the same time, industrial production requires specialized mixing and molding equipment, resulting in high initial investment costs. When laboratory preparation processes are scaled up to industrial production, they often face problems such as difficulty in controlling reaction conditions and unstable product performance.

[0004] Furthermore, there is still room for improvement in the performance of existing silent destructive agents. In terms of mechanical properties, some silent destructive agent products do not perform well in terms of the continuous stability of expansion pressure, which affects the destructive effect; in terms of environmental adaptability, their hydration reaction rate and expansion effect will be affected to a certain extent in low-temperature or high-temperature environments, which limits their application in extreme environments. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a gel-coated silent destructive agent material and its preparation method. This material has high viscosity and low environmental sensitivity, solving the problems of limited application scenarios (only usable in vertical holes) and high susceptibility to environmental temperature of traditional destructive agent materials.

[0006] The technical solution adopted to achieve the above-mentioned objectives of this invention is as follows: A gel-coated silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 20-30 parts water 1.5-2.5 parts of water-soluble alkali-resistant polymer Sodium alginate 0.3~1.0 parts 1.25~6.25 parts of aqueous solution of readily soluble calcium salt; The solid component B is prepared from the following raw materials by mass percentage: Calcium oxide 70%~86% Calcium chloride 6%~12% Dicalcium silicate 2.5%~6.0% Tricalcium silicate 2.5%~6.0% Gypsum 3%~6%.

[0007] Furthermore, the water-soluble alkali-resistant polymer is selected from at least one of polyvinyl alcohol and polyacrylamide.

[0008] Furthermore, the readily soluble calcium salt is selected from at least one of calcium chloride and calcium formate.

[0009] Furthermore, the mass concentration of the readily soluble calcium salt aqueous solution is 8-10%.

[0010] A method for preparing a gel-coated silent destructive agent material includes the following steps: S1. Dissolve water-soluble alkali-resistant polymer and sodium alginate in water to obtain a mixed solution. Then, add an aqueous solution of easily soluble calcium salt dropwise to the mixed solution to crosslink the polymer and obtain an alkali-resistant composite hydrogel with an "egg box" structure inside the molecule. S2. Grind and disperse the alkali-resistant composite hydrogel at room temperature until a uniform, transparent, viscous sol is formed, i.e., liquid component A; S3. Mix calcium oxide, calcium chloride, dicalcium silicate, tricalcium silicate, and gypsum evenly to obtain solid component B; S4. The liquid component A and solid component B are stored independently before use. When using, the liquid component A and solid component B are mixed so that the liquid component A coats the surface of the solid component B particles to obtain the gel-coated silent destructive agent material. This destructive agent material must be used up within 4 hours.

[0011] Furthermore, in the liquid component A, the particle size of the solid particles is 180-220 nm, preferably about 200 nm.

[0012] Furthermore, in step S4, when in use, the mass ratio of the liquid component A to the solid component B is 2.5-4.5:10.

[0013] Furthermore, in step S4, liquid component A and solid component B are mixed by stirring at a uniform speed.

[0014] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: 1. The material of the present invention is an "eggshell" structure formed by the outer gel coating of the material. The shell breaks after the reaction reaches a certain level. The reaction time is controllable. Moreover, due to the outer gel coating, it is not sensitive to the ambient temperature.

[0015] 2. The fracturing agent material of the present invention does not require freeze drying during the preparation process, reducing energy consumption by more than 50%.

[0016] 3. The material of the present invention is an "eggshell" structure formed by the outer gel coating of the crushing agent particles, which ensures that the crushing agent particles react synchronously and fully, the energy release is more concentrated, and higher and more continuous expansion pressure is generated, thereby enhancing the predictability of the cracking time of the component to be crushed.

[0017] 4. The fracturing agent material of the present invention generates no dust during construction and use, eliminating the health hazards of alkaline dust to operators, improving construction conditions, and belonging to a green and environmentally friendly construction method. Detailed Implementation

[0018] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0019] Example 1

[0020] A gel-coated silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 25 parts water Polyvinyl alcohol (PVA) 2.0 parts 0.5 parts sodium alginate 2.5 parts calcium formate aqueous solution The mass concentration of the calcium formate aqueous solution is 8%.

[0021] The solid component B is prepared from the following raw materials in the following mass percentages: Calcium oxide 76.5% Calcium chloride 10.0% 4.5% dicalcium silicate Tricalcium silicate 4.5% 4.5% gypsum.

[0022] The preparation method of the above-mentioned gel-coated silent destructive agent material includes the following methods: S1. Polyvinyl alcohol (PVA) and sodium alginate are fully dissolved in water to obtain a mixed solution. Then, calcium formate aqueous solution is added dropwise to the mixed solution to crosslink the molecules and obtain an alkali-resistant composite hydrogel with an "egg box" structure inside the molecule. S2. Add the alkali-resistant composite hydrogel to a colloid mill and grind and disperse it at room temperature until a uniform, transparent, viscous sol with solid particles of about 200 nm in diameter is formed, which is liquid component A. Store it separately for later use. S3. Add calcium oxide, calcium chloride, dicalcium silicate, tricalcium silicate, and gypsum into a dry powder mixer and stir for 15 minutes to ensure uniformity, to obtain solid component B, which is stored separately for later use. S4. When conducting the experiment, weigh 250.0g of liquid component A and 1000.0g of solid component B and mix them. Stir with a high-speed stirrer (1200 rpm) for 60 seconds to obtain a uniform and viscous coated slurry, which is the gel-coated silent breaking agent material.

[0023] Under normal temperature conditions, the gel-coated silent rock-breaking agent material of this embodiment was injected into a white PE pipe. The material has a high apparent viscosity and thickens rapidly; the hydrogel network effectively fixes the position of the solid rock-breaking agent particles. The initial reaction is controlled, and after a certain degree of reaction, it breaks through the gel to form a hard block, resulting in significant rock-breaking effect and no dust throughout the process.

[0024] Example 2

[0025] A gel-coated silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 20 parts water Polyacrylamide (PAM) 1.5 parts 0.8 parts sodium alginate 3.75 parts of calcium formate aqueous solution The mass concentration of the calcium formate aqueous solution is 8%.

[0026] The solid component B is prepared from the following raw materials in the following mass percentages: Calcium oxide 80.0% Calcium chloride 12.0% 2.5% dicalcium silicate Tricalcium silicate 2.5% Gypsum 3.0%.

[0027] The preparation method of the gel-coated silent breaking agent material in this embodiment is the same as that in Example 1, except that the mass of liquid component A added during the experiment is 350.0g.

[0028] The gel-coated silent detonator material of this embodiment was injected into a white PE tube at a low temperature of 5°C. The high concentration of calcium chloride and the increased calcium oxide, encapsulated in the hydrogel, ensured hydration activity in the low-temperature environment. The gel network formed by PAM exhibited excellent toughness, and after 5 hours of reaction, it ruptured and released energy, resulting in large cracks in the tube. This demonstrates that the detonator material successfully overcomes the problem of slow reaction or even "dud" reaction of traditional detonators at low temperatures.

[0029] Example 3

[0030] A gel-coated silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 30 parts water Polyvinyl alcohol (PVA) 2.5 parts 1.0 part sodium alginate 6.25 parts of calcium formate aqueous solution The mass concentration of the calcium formate aqueous solution is 8%.

[0031] Due to the high concentration of polymers, the prepared liquid component A has a higher viscosity and stronger encapsulation properties.

[0032] The solid component B is prepared from the following raw materials in the following mass percentages: Calcium oxide 75.0% Calcium chloride 7.0% Dicalcium silicate 6.0% Tricalcium silicate 6.0% Gypsum 6.0%.

[0033] The preparation method of the gel-coated silent destructive agent material in this embodiment is the same as that in Example 1, except that the mass of liquid component A added during the experiment is 450.0g.

[0034] The gel-coated silent destructive agent material of this embodiment was injected into a white PE tube at a high temperature of 40°C. At high temperatures, ordinary debriding agents are prone to "blowout" hazards due to excessively rapid reactions. However, the debriding agent material in this embodiment, due to the high concentration of PVA-sodium alginate hydrogel forming a thick three-dimensional "egg-box" coating layer, combined with the upper limit proportion of gypsum retarder in the solid components, perfectly suppresses the initial explosive exothermic polymerization of calcium oxide. The temperature rise of the white PE pipe body is gradual, with no steam ejection, and it cracks steadily after 4 hours. This demonstrates that the material has excellent safety and reliability in high-temperature summer conditions or deep-hole drilling.

[0035] Comparative Example 1 A silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 25 parts water Polyvinyl alcohol (PVA) 2.0 parts Sodium alginate 0 parts 2.5 parts calcium formate aqueous solution The mass concentration of the calcium formate aqueous solution is 8%.

[0036] The raw materials and their mass percentages for solid component B are exactly the same as in Example 1: Calcium oxide 76.5% Calcium chloride 10.0% 4.5% dicalcium silicate Tricalcium silicate 4.5% 4.5% gypsum.

[0037] The preparation method of the silent destructive agent material in this comparative example is the same as that in Example 1. Because sodium alginate was not added, the calcium ion cross-linking reaction could not occur after adding the calcium formate aqueous solution to the mixed solution in step S1, and a hydrogel network with an "egg-box" structure was not formed; only a common mixed aqueous solution of polyvinyl alcohol and calcium formate was obtained. During the experiment, due to the loss of the adhesive and coating effect of the hydrogel, the liquid came into direct and violent contact with calcium oxide.

[0038] When the silent cracking agent material of this comparative example was injected into a white PE pipe at room temperature, the reaction was extremely out of control. Within 10 minutes, the temperature of the pipe exceeded 100°C and a serious "blowout" phenomenon occurred, with a large amount of slurry and high-temperature dust being sprayed out. Not only did it fail to achieve silent cracking, but it also posed a great safety hazard.

[0039] Comparative Example 2 A silent destructive agent material, composed of liquid component A and solid component B; The liquid component A is prepared from the following raw materials in parts by weight: 45 parts water Polyvinyl alcohol (PVA) 0.5 parts 0.5 parts sodium alginate 2.5 parts calcium formate aqueous solution The mass concentration of the calcium formate aqueous solution is 8%.

[0040] The raw materials and their mass percentages for solid component B are exactly the same as in Example 1: Calcium oxide 76.5% Calcium chloride 10.0% 4.5% dicalcium silicate Tricalcium silicate 4.5% 4.5% gypsum.

[0041] The preparation method of the silent destructive agent material in this comparative example is the same as that in Example 1. During the experiment, due to excessive water addition and excessively low PVA concentration, the resulting gel-coated slurry was extremely thin and had severely insufficient apparent viscosity.

[0042] After the silent rock-breaking agent material of this comparative example was injected into the white PE pipe, severe "bleeding" and stratification of solid particles quickly occurred. The upper layer contained only clear liquid, while the lower layer consisted of hardened solid particles. After 24 hours of observation, only minor cracks appeared at the bottom of the pipe, with no expansion or destructive effect in the middle and upper parts. The expansion pressure of the rock-breaking agent could not be evenly transmitted to the borehole wall, indicating that the rock-breaking attempt had failed.

[0043] Comparative Example 3 A common fracturing agent material, composed of 250.0g water and 1000.0g solid components; The solid component B is prepared from the following raw materials in the following mass percentages: Calcium oxide 76.5% Calcium chloride 10.0% 4.5% dicalcium silicate Tricalcium silicate 4.5% 4.5% gypsum.

[0044] The preparation method of the above-mentioned common debriding agent material is as follows: S1. Add calcium oxide, calcium chloride, dicalcium silicate, tricalcium silicate, and gypsum into a dry powder mixer and stir for 15 minutes to ensure uniformity, thereby obtaining a solid component. S2. During the test, water and solid components are mixed and stirred for 60 seconds using a high-speed stirrer (1200 rpm) to obtain a uniform, viscous slurry, which is the ordinary fracturing agent material.

[0045] Experiment 1: Flowability Test Test method: The flowability of the cracking agent materials in Examples 1-3 and Comparative Examples 1-2 was tested using a cement mortar flowability tester: the material was bounced at a specified frequency and drop distance to flatten it in the truncated cone mold. The technical parameters were: drop distance of 10.0 mm ± 0.2 mm and cam speed of 60 r / min ± 2 r / min.

[0046] The specific experimental steps are as follows: 1) Take 450g of the fracturing agent material from Example 1 (i.e., the mixture of liquid component A and solid component B) as specified in GB / T 17671; 2) Place the truncated cone mold in the center of the jumping table, and fill it with the silent breaking agent material in two batches, tamping it 15 times each time with a tamping rod in a spiral motion; 3) After lifting the circular mold, start the jumping table, which will jump 25 times at a frequency of once per second; 4) Measure the diameter of the bottom surface of the silent cracking agent material in two mutually perpendicular directions using calipers, and take the average value as the flowability; 5) The fracturing agent materials of Examples 2-3 and Comparative Examples 1-3 were tested according to the methods in steps 1)-4).

[0047] Experimental results: The flowability test results of the fracturing agent materials in Examples 1-3 and Comparative Examples 1-3 are shown in Table 1 below: Table 1. Flowability of different silent destructive agents:

[0048] As can be clearly seen from Table 1 above, the flowability of the silent cracking agent materials in Examples 1-3 is significantly lower than that of ordinary cracking agents and the silent cracking agent materials in Comparative Examples 1-2, especially Example 3, which shows the largest decrease, indicating that its components have the strongest effect on inhibiting flowability. The silent cracking agent materials in Comparative Examples 1-2 are close to the level of ordinary cracking agents, indicating that their modification strategies have failed to effectively change their rheological properties. The silent cracking agent material component in Example 3 has the strongest effect on inhibiting flowability, but it is also the most difficult to fill.

[0049] Experiment 2: Maximum Expansion Force Test Test method: To test the maximum expansion force of the ordinary fracturing agent material in Comparative Example 3 and the fracturing agent material in Example 1, two C20 concrete square test blocks with lengths, widths, and heights of 250 mm, 250 mm, and 500 mm, respectively, were cast. The cylindrical test blocks were wrapped with 2 mm thick steel pipes.

[0050] The specific experimental steps are as follows: 1) Drill a hole downwards on the upper surface of the test block, with a diameter of 40mm and a depth of 400mm; 2) Attach strain gauges horizontally around the test block at 100mm, 200mm, and 300mm from the top of the test block. The strain gauge model is BFH120-3AA-D150. 3) Connect the ST-3C dynamic and static strain gauge; 4) Pour the silent breaking agent material of Example 1 (i.e., the mixture of liquid component A and solid component B) into the hole; 5) Start collecting real-time micro-strain data.

[0051] 6) The ordinary fracturing agent material of Comparative Example 3 was tested according to the methods in steps 1)-5).

[0052] Experimental results: Test results show that the maximum micro-strain of the ordinary destructive agent material is 986, while the maximum micro-strain of the silent destructive agent material in Example 1 is 1368. Through finite element simulation calculation, the maximum expansion force of the ordinary destructive agent is 26 MPa, and the maximum expansion force of the silent destructive agent material in Example 1 is 35 MPa.

[0053] Experiment 3: On-site test of concrete pier A C30 concrete pier with dimensions of 2m × 1.5m × 1.5m was cast at the blasting test site. A row of rotating holes was made downwards from the top surface of the concrete pier. The holes were 40mm in diameter, spaced 40cm apart, and 1m deep. The outermost rotating hole was 20cm away from the side of the concrete pier.

[0054] The gel-coated silent rock-breaking agent material of Example 1 (i.e., the mixture of liquid component A and solid component B) was injected into a row of drill holes. The material generated a strong and uniform expansion pressure, successfully inducing straight, penetrating, and wide cracks along the preset hole positions in the concrete pier, ultimately achieving complete splitting. The entire cracking process was smooth and controllable, with no traces of injection holes or dust on site. This perfectly demonstrates that the gel-coated silent rock-breaking agent material of this application possesses excellent static rock-breaking capabilities in a silent, safe, and environmentally friendly manner, making it highly valuable for practical engineering applications.

Claims

1. A gel-coated silent breaking agent material, characterized by: It consists of liquid component A and solid component B, with a mass ratio of liquid component A to solid component B of 2.5-4.5:10; The liquid component A is prepared from the following raw materials in parts by weight: 20-30 parts water 1.5-2.5 parts of water-soluble alkali-resistant polymer Sodium alginate 0.3~1.0 parts 1.25~6.25 parts of aqueous solution of readily soluble calcium salt; The solid component B is prepared from the following raw materials by mass percentage: Calcium oxide 70%~86% Calcium chloride 6%~12% Dicalcium silicate 2.5%~6.0% Tricalcium silicate 2.5%~6.0% 3%~6% gypsum; The water-soluble, alkali-resistant polymer is selected from at least one of polyvinyl alcohol and polyacrylamide.

2. The gel-coated silent destructive agent material according to claim 1, characterized in that: The readily soluble calcium salt is selected from at least one of calcium chloride and calcium formate.

3. The gel-coated silent destructive agent material according to claim 1, characterized in that: The mass concentration of the readily soluble calcium salt aqueous solution is 8%~10%.

4. A method for preparing the gel-coated silent destructive agent material according to claim 1, characterized in that... Including the following methods: S1. Dissolve a water-soluble alkali-resistant polymer and sodium alginate in water to obtain a mixed solution. Then, add an easily soluble calcium salt aqueous solution to the mixed solution for cross-linking to obtain an alkali-resistant composite hydrogel with an "egg box" structure inside the molecule. S2. Grind and disperse the alkali-resistant composite hydrogel at room temperature until a uniform, transparent, viscous sol is formed, i.e., liquid component A; S3. Mix calcium oxide, calcium chloride, dicalcium silicate, tricalcium silicate, and gypsum evenly to obtain solid component B; S4. The liquid component A and solid component B are stored independently before use. When using, the liquid component A and solid component B are thoroughly mixed so that the liquid component A coats the surface of the solid component B particles, thus obtaining the gel-coated silent breaking agent material.

5. The preparation method of the gel-coated silent destructive agent material according to claim 4, characterized in that: In the liquid component A, the particle size of the solid particles is 180-220 nm.

6. The method for preparing the gel-coated silent destructive agent material according to claim 4, characterized in that: In step S4, liquid component A and solid component B are thoroughly mixed by stirring.

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