Preparation method of high-molecular polymer sensitized emulsion explosive

Abstract

The application belongs to the technical field of application of emulsion explosive, and discloses a preparation method of high-molecular polymer sensitized emulsion explosive, which comprises the following steps: selecting a physical sensitizer; modifying the surface of the physical sensitizer to be lipophilic; foaming the physical sensitizer; and producing and preparing the explosive.The emulsion explosive matrix is sensitized by using a physical method, the content of the sensitizer is low, the original production line and basic process of the emulsion explosive are not changed, and the manufacturing cost of the emulsion explosive is not significantly increased; the selected high-molecular polymer foaming particles as the sensitizer can significantly improve the energy utilization rate of the explosive; the emulsion explosive prepared by the application retains the characteristics of the physical sensitized emulsion explosive that is less affected by the external environment, and is not prone to problems such as temperature difference and demulsification, while ensuring that the content of the sensitized bubbles will not be significantly reduced in extreme environments, so as to ensure the detonation capacity of the explosive in underwater, plateau and low-temperature environments.

Description

Technical Field

[0001] This invention belongs to the field of emulsion explosives application technology, and relates to a method for preparing a polymer-sensitized emulsion explosive. Background Technology

[0002] Currently, the production of emulsion explosives both domestically and internationally primarily employs chemical sensitization, with sodium nitrite aqueous solution being the most commonly used sensitizer. In the sensitization process, sodium nitrite, typically in liquid form, enters the emulsion matrix through a spray inlet. The acidity of the latex matrix reacts with the sodium nitrite to generate gas. This gas is evenly distributed within the latex matrix, forming bubbles, thus sensitizing the emulsion explosive. Due to its excellent explosive properties, water resistance, and safety performance, it has been widely used in engineering blasting operations.

[0003] Studies have shown that when the sodium nitrite content reaches a certain critical value (approximately 2%), the latex matrix exhibits detonator sensitivity. Based on this, chemical sensitization carries an unavoidable safety hazard. Furthermore, when chemically sensitized emulsion explosives are applied in special blasting environments such as high-altitude, low-pressure, or deep-water conditions, or when the operating environment changes significantly, the hot spots generated by the sensitized bubbles decrease significantly while their density increases, leading to a reduction in detonation workability or even failure to detonate. To address these engineering needs, physical sensitization of emulsion explosives is necessary. In the early stages of importing emulsion explosives into my country, expanded perlite and some low-quality glass microspheres were mainly used as sensitizers to reduce costs. Countries such as the United States, Sweden, and Japan primarily use hollow glass microspheres as physical sensitizers. These types of explosives have the following problems:

[0004] 1) The true density of glass microspheres or perlite is generally 0.1–0.2 g / cm³. 3 To give sensitized explosives detonation sensitivity, the amount added is generally 3% to 6%. Since materials such as glass microspheres or perlite are inert relative to explosives, adding an appropriate amount can improve the detonation sensitivity of the explosive, but it also consumes the energy of the explosive and significantly increases the production cost of the explosive.

[0005] 2) Glass microspheres and perlite contain a lot of broken microspheres, making it difficult to guarantee their quality. The quality of explosives produced from different batches of microspheres varies greatly. Broken microspheres are easily collapsed or gas escapes due to external influences, leading to pore failure.

[0006] 3) The large difference in specific heat capacity between glass microspheres and emulsion matrix can easily lead to a temperature difference between the glass microspheres and emulsion matrix, and can also cause a temperature difference in the droplets in the emulsion matrix and AN nucleation and demulsification.

[0007] To improve the temperature adaptability of physically sensitized explosives, other additives are usually mixed into the explosives, such as emulsion explosives for high and low temperature environments (with sodium perchlorate added) [Huang Ping, High and Low Temperature Resistant Emulsion Explosives and Their Preparation Method, Invention Patent, CN 111333473 A, 2020.06.26] and low temperature type (with phosphate added) [Bai Zhenhe, Liu Xiaoming, Liu Zhengdong et al., A Low Temperature Sensitized Emulsion Ammonium Fry Explosive, Chinese Patent, CN 105272787 A, 2016.01.27], and emulsion explosives for pressure-resistant environments [Zhu Guangjie, Lin Chun, Chen Tao et al., A Preparation Method of Pressure-Resistant Emulsion Explosive, Chinese Patent, CN 110903152 A, 2020.03.24], etc. In order to improve energy utilization or other functional uses, it is usually necessary to mix other reactive additives into the explosives, such as energy storage materials [Ma Honghao, Cheng Yangfan, Shen Zhaowu, et al., Magnesium hydride type hydrogen storage emulsion explosive, Chinese patent, CN 102432407 A, 2012.05.02], and titanium-containing materials [Huang Ping, Liao Lizhen]. Emulsion explosives and their preparation methods, Chinese Patent CN 111960907 A, 2020.11.20; sulfur-containing substances [Li Zhanrong, Quan Huifeng, Wu Dunwei et al., Low-detonation-velocity powdered emulsion explosive based on sodium sulfate, Chinese Patent CN 108002964 A, 2018.05.08]; and other substances [Deng Linghai, Xiao Jianbo, Zhang Yuqing et al., A rapid foaming agent for emulsion explosives, Chinese Patent CN 110922282 A, 2020.03.27], etc. In this type of emulsion explosive manufacturing technology, the use of multiple sensitizing additives not only complicates the production process and increases the cost of explosives, but some additives can also affect the safety of the explosives and may cause environmental problems.

[0008] Therefore, while physical sensitization is a good option to ensure the detonation capability of explosives in special blasting environments such as high altitude, low pressure, and deep water, ensuring the compatibility, stability, safety, and energy dissipation of the various sensitizing components remains a challenging technical hurdle. Therefore, this invention aims to minimize the sensitizer content and simultaneously improve the detonation energy utilization rate when physically sensitizing explosives. Summary of the Invention

[0009] This invention provides a physically sensitized polymer-sensitized emulsion explosive, which uses a type of thermoplastic polymeric acrylic resin foam particles (with a vinyl acrylate copolymer shell and an alkane gas core) as the emulsion explosive sensitizer, and employs appropriate surface treatment, foaming technology and processes to control the true density and particle size of the foam particles, thereby improving the detonation energy utilization rate while adding a small amount of sensitizer.

[0010] The technical solution of the present invention:

[0011] In the non-ideal detonation process of industrial explosives, pore closure not only generates "hot spots" for ignition but also produces vortex kinetic energy and pressure fluctuations, promoting detonation chemical reactions while simultaneously dissipating detonation energy. Therefore, when non-inert substances such as combustible polymer foam particles are used as sensitizers, pore collapse in industrial explosives is not merely a "hot spot" but can also act as fuel, promoting detonation chemical reactions and facilitating the transport and redistribution of matter and turbulent energy, thereby improving energy utilization. Because the specific heat difference between the polymer compound and the explosive matrix is ​​relatively small, problems such as temperature differences and demulsification are less likely to occur. Simultaneously, the appropriate elasticity generated can resist external pressure, ensuring that the sensitized bubble content of the explosive does not decrease significantly, thus guaranteeing the explosive's detonation capability.

[0012] Considering the uniformity and particle size distribution of the phases in the explosive, smaller pore sizes are not always better. Only when the pore size matches the particle size distribution of the explosive can the heat generated during combustion be utilized to the maximum extent. Taking into account hot spots, mixing, and vortex dissipation, the optimal pore diameter for emulsion explosives is between 10 and 100 μm. Based on this, foaming technology research was conducted on polymer-based foamed particles to control the size of the foamed particles to match the particle size distribution of the explosive, keeping it between 10 and 100 μm; to reduce the amount of sensitizer added, the true density was controlled at 0.015 g / cm³. 3 ~0.04g / cm 3 The density of the foaming agent particles should be kept within a certain range, and the true density of the foaming agent particles should be minimized as much as possible. To ensure the explosive has detonation sensitivity, the amount of sensitizer added should be controlled at 0.2-0.6%, and the density of the prepared explosive should be between 0.92 and 1.35 g / cm³. 3 To ensure maximum energy output of the explosive, the density of the explosive should be controlled between 1.13 and 1.2 g / cm³. 3 To prevent air bubbles from being introduced into the emulsion matrix when the physical sensitizer is added and to enhance the hydrophobicity and oleophilicity of the emulsion dispersion droplets, the physical sensitizer undergoes surface oleophilic treatment. After the continuous cooling device in a conventional emulsion explosive production line, the foaming modified physical sensitizer is added according to the dosage and mixed evenly with the emulsion matrix to become a polymer-sensitized emulsion explosive.

[0013] A method for preparing a polymer-sensitized emulsion explosive, comprising the following steps:

[0014] 1) Select a physical sensitizer

[0015] The physical sensitizer is a thermoplastic polymer acrylic copolymer hollow microsphere with a shell of vinyl acrylate copolymer and a core of alkane gas;

[0016] in,

[0017] Thermoplastic acrylic copolymer hollow microspheres have a diameter of 10-30 μm and a density of 1.05-1.2 g / cm³. 3 ;

[0018] Alkane gases are methane or ethane;

[0019] 2) Surface lipophilic modification of physical sensitizers

[0020] To ensure that no additional air bubbles are introduced during the mixing process of the physical sensitizer and the emulsion matrix, which would affect the explosive density and detonation performance, and to prevent dust pollution, other possible chemical reactions, and mechanical wear during the mixing process, the foaming particles undergo surface oleophilic modification treatment before being added to the emulsion matrix. This is because the surfactant density (0.8–1.0 g / cm³) 3 The true density of the relative foamed particles (0.015~0.04 g / cm³) 3 The surface area is too large to be suitable for addition after foaming. This invention performs surface group adsorption lipophilic and hydrophobic treatment on the particles before foaming, followed by the foaming process. The surfactant used modifies the surface of the physical sensitizer to be lipophilic. The surfactant used is a mixture of nonionic water-soluble surfactants containing elements other than carbon, hydrogen, oxygen, and nitrogen, and amide-type oil-soluble surfactants. The lipophilic modification of the physical sensitizer surface is completed by uniformly dispersing the physical sensitizer on the surfactant.

[0021] in,

[0022] The nonionic water-soluble surfactants include alkylphenol polyoxyethylene ethers and sorbitan esters; the amide-type oil-soluble surfactants include diene polyisobutylene succinimide and monoalkenyl polyisobutylene succinimide, with a mass ratio of 1:5 between the nonionic water-soluble surfactants and the amide-type oil-soluble surfactants.

[0023] The mass ratio of the surfactant to the physical sensitizer is 2 to 5;

[0024] 3) Physical sensitizer foaming

[0025] Foaming temperature: T0 = 100-110℃;

[0026] Foaming time: t = 120~150s;

[0027] After foaming, the particle size of the physical sensitizer is between 10 and 100 μm;

[0028] 4) Explosives production and preparation

[0029] On existing emulsion explosive production lines, the emulsion explosive matrix is ​​mixed with a foamed and surface-modified physical sensitizer to form an emulsion explosive;

[0030] in,

[0031] The physical sensitizer is added after the continuous cooling device in the emulsion explosive production line and mixed evenly with the emulsion explosive matrix to produce a polymer-sensitized emulsion explosive.

[0032] The amount of physical sensitizer added is 0.2% to 0.6% of the mass of the emulsion explosive.

[0033] The density of the emulsion explosive is 1.13–1.35 g / cm³. 3 The minimum detonation velocity is 4878 m / s, the maximum detonation velocity is 6975 m / s, and the saturation is 17.7 to 19.4 mm.

[0034] The beneficial effects of this invention are as follows: 1) The emulsion explosive matrix is ​​sensitized by a physical method, resulting in a low sensitizer content. This does not alter the original production line and basic process of the emulsion explosive, and does not significantly increase the manufacturing cost of the emulsion explosive; 2) The selected polymer foam particles as sensitizers can significantly improve the energy utilization rate of the explosive; 3) No other chemical substances are added except for the polymer foam particles. The physical sensitizer has good compatibility and stability with the emulsion explosive matrix, making it easy to store for a long time. After detonation, it will not pollute the surrounding environment, ensuring the safety of explosive production, storage, and use; 4) The pre-modified surface oleophilic physical sensitizer does not generate dust pollution during the production process, isolates other possible chemical reactions, and prevents mechanical wear. This ensures that no additional air bubbles are introduced during the mixing process of the physical sensitizer and the emulsion matrix, and does not affect the stability of the explosive density; 5) By testing the true density of the foamed physical sensitizer in advance, the theoretical density of the emulsion explosive can be predicted, thereby predicting and pre-evaluating the detonation capability of the explosive and adjusting it in real time according to the blasting operation environment, making it more convenient for practical engineering applications. 6) It retains the characteristic of physical sensitized emulsion explosives being less affected by the external environment, and is not prone to problems such as temperature difference and demulsification. At the same time, it ensures that the content of sensitized bubbles will not decrease significantly under extreme environments, thus ensuring the detonation capability of explosives in underwater, high-altitude and low-temperature environments. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below in conjunction with the technical solution.

[0036] Example 1

[0037] 1) Select a physical sensitizer

[0038] The selected physical sensitizer is a thermoplastic polymeric acrylic copolymer hollow microsphere. The outer shell is a vinyl acrylate copolymer with a monomer molecular weight of 114.142, and the core is methane. The diameter is 10-30 μm, and the density is 1.05 g / cm³. 3 ;

[0039] 2) Surface lipophilic modification of physical sensitizers

[0040] OP-10 and diene-based polyisobutylene succinimide were mixed, with a total mass twice that of the physical sensitizer. The mass ratio of OP-10 to diene-based polyisobutylene succinimide was 1:5, and the mixture was uniformly dispersed.

[0041] 3) Physical sensitizer foaming process

[0042] Foaming temperature: T=110℃; Foaming time: t=150s; Foaming true density g / cm 3 .

[0043] 4) Explosives production and preparation

[0044] Adding 0.2% (by weight of the emulsion explosive) of a modified and foamed physical sensitizer to the emulsion explosive matrix yielded an emulsion explosive with a density of 1.23 g / cm³. 3 , the diameter of the medicine roll is 32mm; the explosion speed is 4878m / s; the violence is 16.5mm.

[0045] Add 0.25% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix. The explosive cartridge diameter is 90 mm, and the theoretical density is... g / cm 3 , explosive speed m / s (altitude 4500m) and m / s (altitude 5000m);

[0046] Add 0.275% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix. The explosive cartridge diameter is 32 mm, and the theoretical density is... g / cm 3 , explosion velocity 5025m / s; fierceness 18.5mm; plateau explosion velocity m / s (altitude 4500m) and m / s (altitude 5000m).

[0047] Add 0.3% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix; the explosive cartridge diameter is 32 mm, and the theoretical density is 1.14 g / cm³. 3 Detonation velocity 5077.5 m / s; saturation 19.4 mm; cartridge diameter 90 mm; high-altitude detonation velocity. m / s (altitude 4500m) and m / s (altitude 5000m);

[0048] Add 0.35% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix. The explosive cartridge diameter is 32 mm, and the theoretical density is... g / cm 3 , plateau explosion speed m / s (altitude 4500m) and m / s (altitude 5000m).

[0049] Example 2

[0050] 1) Select a physical sensitizer

[0051] The selected physical sensitizer is a thermoplastic polymeric acrylic copolymer hollow microsphere with a shell of vinyl acrylate copolymer, a monomer molecular weight of 114.142, a core of ethane, a diameter of 10-30 μm, and a density of 1.05 g / cm³. 3 ;

[0052] 2) Surface lipophilic modification of physical sensitizers

[0053] OP-10 and monoalkenyl polyisobutylene succinimide were mixed, with a total mass four times that of the physical sensitizer. The mass ratio of OP-10 to monoalkenyl polyisobutylene succinimide was 1:5, and the mixture was uniformly dispersed.

[0054] 3) Physical sensitizer foaming process

[0055] Foaming temperature: T=108℃; Foaming time: t=120s; Foamed true density: 0.0425g / cm³ 3 ;

[0056] 4) Explosives production and preparation

[0057] Add 0.25% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix; the explosive cartridge diameter is 32 mm, and the theoretical density is 1.33 g / cm³. 3 Detonation velocity 5040.7 m / s; saturation 17.7 mm;

[0058] Add 0.35% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix. The explosive cartridge diameter is 32 mm, and the theoretical density is... g / cm 3 Detonation velocity 5138.9 m / s; saturation 18.4 mm.

[0059] Example 3

[0060] 1) Select a physical sensitizer

[0061] The selected physical sensitizer is a thermoplastic polymeric acrylic copolymer hollow microsphere with a shell of vinyl acrylate copolymer, a monomer molecular weight of 384.51, a core of ethane, a diameter of 10-30 μm, and a density of 1.2 g / cm³. 3 ;

[0062] 2) Surface lipophilic modification of physical sensitizers

[0063] OP-10 and diene-based polyisobutylene succinimide were mixed, with a total mass three times that of the physical sensitizer. The mass ratio of OP-10 to diene-based polyisobutylene succinimide was 1:5, and the mixture was uniformly dispersed.

[0064] 3) Physical sensitizer foaming process

[0065] Foaming temperature: T=100℃; Foaming time: t=140s; Foaming true density g / cm 3 ;

[0066] 4) Explosives production and preparation

[0067] Add 0.6% (by weight of the emulsion explosive) of modified and foamed physical sensitizer to the emulsion explosive matrix. The explosive cartridge diameter is 32mm, and the theoretical density is... g / cm 3 , the explosion velocity is 5155m / s; the violence is 15.0mm.

[0068] Example 4

[0069] 1) Select a physical sensitizer

[0070] The selected physical sensitizer is a thermoplastic polymeric acrylic copolymer hollow microsphere with a shell of vinyl acrylate copolymer, a monomer molecular weight of 114.14, a core of methane, a diameter of 10-30 μm, and a density of 1.05 g / cm³. 3 ;

[0071] 2) Surface lipophilic modification of physical sensitizers

[0072] A mixture of sorbitan ester and monoalkenyl polyisobutylene succinimide was used, with a total mass five times that of the physical sensitizer. The mass ratio of sorbitan ester to monoalkenyl polyisobutylene succinimide was 1:5, and the mixture was uniformly dispersed.

[0073] 3) Physical sensitizer foaming process

[0074] Foaming temperature: T=109℃; Foaming time: t=130s; Foaming true density g / cm 3 .

[0075] 4) Explosives production and preparation

[0076] Add emulsion explosive mass to emulsion explosive matrix 0.6% Foamed modified polymer granules, roll diameter 32mm, theoretical density g / cm 3 , the explosion velocity is 5051m / s; the violence is 14.5mm.

Claims

1. A method for preparing a polymer-sensitized emulsion explosive, characterized in that, The steps are as follows: 1) Select a physical sensitizer The physical sensitizer is a thermoplastic polymer acrylic copolymer hollow microsphere with a shell of vinyl acrylate copolymer and a core of alkane gas; 2) Surface lipophilic modification of physical sensitizers The surfactant used is used to modify the surface of the physical sensitizer to be lipophilic. The surfactant used is a mixture of nonionic water-soluble surfactants containing elements other than carbon, hydrogen, oxygen, and nitrogen and amide-type oil-soluble surfactants. The lipophilic modification of the physical sensitizer surface is completed by uniformly dispersing the physical sensitizer on the surfactant. 3) Physical sensitizer foaming process Foaming temperature: T0 = 100-110℃; Foaming time: t = 120~150s; After foaming, the particle size of the physical sensitizer is between 10 and 100 μm; 4) Explosives production and preparation On existing emulsion explosive production lines, emulsion explosive matrix is ​​mixed with surface-oil-modified and foamed physical sensitizers to form emulsion explosives; the amount of surface-oil-modified and foamed physical sensitizers added is 0.2% to 0.6% of the mass of the emulsion explosive.

2. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The aforementioned thermoplastic acrylic copolymer hollow microspheres have a diameter of 10-30 μm and a density of 1.05-1.2 g / cm³. 3 .

3. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The alkane gas mentioned is methane or ethane.

4. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The nonionic water-soluble surfactants include alkylphenol polyoxyethylene ethers and sorbitan esters; the amide-type oil-soluble surfactants include diene polyisobutylene succinimide and monoalkenyl polyisobutylene succinimide, with a mass ratio of 1:5 between the nonionic water-soluble surfactants and the amide-type oil-soluble surfactants.

5. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The mass ratio of the surfactant to the physical sensitizer is 2 to 5.

6. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The physical sensitizer is added after the continuous cooling device in the emulsion explosive production line and mixed evenly with the emulsion explosive matrix to produce a polymer-sensitized emulsion explosive.

7. The method for preparing polymer-sensitized emulsion explosives according to claim 1, characterized in that, The density of the emulsion explosive is 1.13–1.35 g / cm³. 3 The minimum detonation velocity is 4878 m / s, the maximum detonation velocity is 6975 m / s, and the saturation is 17.7 to 19.4 mm.