Low-sensitivity activator as well as preparation method and application thereof

Abstract

The invention discloses a low-sensitivity activator as well as a preparation method and application thereof, and belongs to the technical field of gas fracturing. Potassium perchlorate is used as an oxidizing agent of the low-sensitivity activator, flour is used as a combustible agent of the low-sensitivity activator, and the mass ratio of the potassium perchlorate to the flour in the low-sensitivity activator is (50-70): (10-20). The low-sensitivity activator provided by the invention has the advantages that the mechanical sensitivity, flame sensitivity and static sensitivity of the low-sensitivity activator are at extremely low levels, and the low-sensitivity activator has excellent stability and higher ignition temperature; related tests carried out according to the Program on Dangerous Goods Transport of the United National further show that the activator not only has remarkable gas production rate, but also shows extremely low sensitivity to shock waves, the insensitive characteristic of the activator is even superior to that of a conventional insensitive explosive, and practical application verification shows that the cracking effect of the activator is completely not lower than the level of a metal powder activator.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas fracturing, and particularly relates to a low-sensitivity activator as well as a preparation method and application thereof. BACKGROUND

[0002] Liquid carbon dioxide fracturing technology is to use liquid carbon dioxide to be heated and gasified to expand and release high-pressure gas to break rocks or coal seams. The liquid carbon dioxide fracturing technology realizes rock breaking by using an activator to trigger phase change and expansion of liquid carbon dioxide, and solves the problems of great damage, high risk and ore crushing in previous blasting mining and pre-fracturing. The liquid carbon dioxide fracturing technology provides reliable guarantee for safe mining and pre-fracturing of mines, and is widely applied in the field of mine exploitation. The activator is a core functional material, and directly determines the energy release efficiency and operation reliability by precisely controlling the phase change triggering process. The activator is a key basis for safe and efficient application of technology.

[0003] Most of the activators used in current mainstream liquid carbon dioxide fracturing equipment are still produced by using modified rocket propellants or military explosives. Such activators have high safety indexes such as flame sensitivity, impact sensitivity, friction sensitivity and electrostatic sensitivity, which brings safety hazards to production and use. In addition, some manufacturers select raw materials with strong toxicity and corrosion in order to pursue higher economic benefits, which not only harms the health of workers, but also causes adverse effects on the surrounding environment. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a low-sensitivity activator with higher safety performance and environmental protection, and a preparation method and application thereof, which can meet the explosion heat of liquid carbon dioxide fracturing equipment.

[0005] To solve the technical problems, the technical scheme adopted by the present application is as follows: In one aspect, the present application provides a low-sensitivity activator, which uses potassium perchlorate as an oxidizing agent and flour as a combustible agent.

[0006] Preferably, in the low-sensitivity activator, the mass ratio of potassium perchlorate to flour is (50-70):(10-20).

[0007] Preferably, in the low-sensitivity activator, the mass ratio of potassium perchlorate to flour is 63.7:16.1.

[0008] Preferably, the low-sensitivity activator further comprises ammonium oxalate.

[0009] Preferably, the low-sensitivity activator further comprises salicylic acid and a binder.

[0010] Preferably, the adhesive is bentonite.

[0011] Preferably, the low-sensitivity activator comprises 50-70 parts potassium perchlorate, 2-10 parts salicylic acid, 5-20 parts ammonium oxalate, 10-20 parts flour, and 2-10 parts binder.

[0012] Another aspect of the present invention provides a method for preparing the above-mentioned low-sensitivity activator, comprising the following steps: The raw materials for the low-sensitivity activator are mixed and dried to obtain the low-sensitivity activator.

[0013] Preferably, the mixing speed is 5-15 r / min and the mixing time is 15-25 min.

[0014] Preferably, before drying, an energy test is performed. Specifically, three samples are taken from different parts of the mixing pot and then a heat explosion test is conducted. If the measured results all meet the requirement that the calorific value is not less than 6000 J / g, the product is deemed qualified.

[0015] In another aspect, the present invention provides the application of the aforementioned low-sensitivity activator in liquid carbon dioxide-induced cracking technology.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a low-sensitivity activator with extremely low mechanical sensitivity, flame sensitivity, and electrostatic sensitivity, while possessing excellent stability and a high ignition temperature. Further experiments conducted according to the United Nations Recommendations on the Transport of Dangerous Goods demonstrate that this activator not only produces a significant amount of gas but also exhibits extremely low sensitivity to shock waves. Its insensitivity characteristics are even superior to conventional insensitive explosives. Practical application verification shows that the fracturing effect of this activator is no less than that of metal powder activators. Furthermore, the activator component of this application innovatively does not contain any metal powder (such as aluminum powder, magnesium powder, or other chemically active metal components). Through this key design, a series of safety hazards can be systematically eliminated from the source: it effectively reduces the risk of dust explosions during material production and significantly weakens its sensitivity to humid environments and heat sources during transportation and storage. In particular, its sensitivity to mechanical stimuli such as friction and impact has been specifically optimized. Based on the above improvements, this activator provides higher safety margins and reliability guarantees for operators and safety management systems throughout its entire life cycle of production, transportation, storage, and filling operations. Finally, it should be emphasized that the flour in this activator is mainly composed of carbohydrates, which is significantly more environmentally friendly than traditional metal powder activators. At the same time, the raw materials are not only cheaper and more readily available, but also do not leave a large amount of difficult-to-clean residue in the fracturing tube, as with activators containing metal powder, which affects the reuse of the fracturing tube. Attached Figure Description

[0017] Figure 1 This is an analysis diagram of the activator sample provided in an embodiment of the present invention; Figure 2 This is a picture of the activator before atmospheric pressure ignition test provided in an embodiment of the present invention; Figure 3 The image shows the activator after atmospheric pressure ignition test provided in the embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of specific embodiments of the present invention will now be described in detail and completely with reference to the accompanying drawings. Obviously, the described embodiments are only some specific implementations of the overall technical solution of the present invention, and not all implementations. Based on the overall concept of the present invention, all other embodiments obtained by those skilled in the art fall within the protection scope of the present invention.

[0019] This invention provides a low-sensitivity activator, which uses potassium perchlorate as an oxidant and flour as a combustible agent.

[0020] It should be noted that currently, the combustible agents in activator formulations are mainly metallic combustible agents, such as those containing aluminum, magnesium, and other metals. Although they can provide high calorific value, they pose significant safety hazards in practical applications. On the one hand, metal powders are highly prone to forming explosive dust environments during material production, transportation, and mixing. Their small particle size and large specific surface area lead to flammable and explosive mixtures upon contact with air. Especially in confined spaces, when exposed to external stimuli such as friction, impact, or electrostatic sparks, they can easily trigger violent dust explosions, posing a significant safety threat to workers and production facilities. On the other hand, for the special operating conditions of reusable carbon dioxide fracturing devices, the fracturing tube needs to be cycled multiple times. The metal oxides (such as Al2O3, MgO, etc.) generated after the reaction of metallic combustible agents will firmly adhere to the inner wall of the fracturing tube. With the accumulation of usage, these dense deposits will not only reduce the thermal conductivity of the tube but also change the structural integrity of the tube, significantly affecting the reusability and service life of the fracturing tube.

[0021] More importantly, similar to non-metallic flammable agents such as sulfur, phosphorus, and carbon, the use of metallic flammable agents in combination with potassium perchlorate oxidizers significantly increases the safety risks of the activator system throughout the entire process of production, transportation, storage, and actual use. The strong redox properties of metals and oxidizers increase the overall sensitivity of the system. Even slight external stimuli (such as friction, impact, or local overheating) may trigger unexpected and violent reactions, leading to reduced mixing safety of the activator during production, increased vibration sensitivity during transportation, decreased tolerance to changes in environmental temperature and humidity during storage, and increased risk of uncontrollable reactions during fracturing, thus adversely affecting the safety and stability of the entire activator system.

[0022] In addition, a few reports have indicated the use of oils or charcoal powder as combustibles. This can improve the safety of the production process and reduce the environmental impact of the byproducts. However, the main drawback of oil-based combustibles lies in the limitations of their physical state and mixing process: First, oils are liquid substances, and the uniformity of mixing with solid oxidants and other components is difficult to control precisely, which can easily lead to local enrichment or phase separation. This not only increases the potential risks of leakage and fire during production but may also cause uneven energy release during cracking, affecting the stability of the cracking effect. Second, oils are volatile during mixing, storage, and transportation, which not only causes the loss of effective components but may also form flammable vapors in confined environments, further increasing the danger of the working environment. Charcoal powder is a solid form of combustible material, which is easier to process than oil. However, during the high-temperature decomposition process, charcoal powder tends to form hard coke residues. These residues are highly adhesive and firmly adhere to the inner wall of the rupture tube, making them difficult to clean. Furthermore, the raw materials for charcoal powder come from complex sources, and the fixed carbon content, volatile matter ratio, and ash composition vary greatly between different batches, resulting in unstable calorific value output and combustion characteristics.

[0023] To address the above problems, this invention uses potassium perchlorate as an oxidant and flour as a combustible agent. The specific reasons are as follows: Oxidizing agents and combustibles are the basis of activators. Due to the actual use of this product, combustibles cannot burn with the help of oxygen in the air, so they must be self-oxygenated and can burn under air-isolated conditions to carry the reaction to completion. The following principles should generally be followed when selecting oxidizing agents: (1) The oxidizing agent should be a solid with a melting point of not less than 60°C and remain stable within the range of ±60°C; (2) It should contain a large amount of effective oxygen (>30%) and be easily released during combustion; (3) It should have low hygroscopicity and not decompose when exposed to water; (4) The activator made should have low mechanical and frictional sensitivity and be safe and reliable. Currently, most oxidizing agents in the activator formulations on the market are perchlorates such as potassium perchlorate and ammonium perchlorate. Although most perchlorates are easily soluble in water, potassium perchlorate has the lowest solubility among all perchlorates (1.5g / 100g, 25°C). Furthermore, it has a high melting point (approximately 610°C), an effective oxygen content of 46%, and is superior to ammonium perchlorate in terms of safety. Therefore, this invention selects potassium perchlorate as the oxidant.

[0024] The present invention chooses flour as a combustible agent for the following reasons: First, flour, as a non-metallic organic flammable agent, does not contain active metal components such as aluminum and magnesium. When combined with potassium perchlorate oxidant, it avoids the high sensitivity risk brought about by strong oxidation-reduction reaction. Its safety throughout the entire process of production, transportation, storage and use is significantly higher than that of metallic flammable agents. At the same time, its thermal decomposition process is mild and there is no problem of metal powder friction and impact sensitivity, which reduces the risk of dust explosion in the production process from the source. Secondly, the high-temperature decomposition products of flour are mainly carbohydrates (such as carbon dioxide, carbon monoxide, water vapor and loose carbon-based residues), without the generation of harmful substances such as metal oxides, making it significantly more environmentally friendly than metal powder activators; moreover, the residues are mainly loose carbonaceous, with weak adhesion and easy cleaning, and will not form a large amount of hard and difficult-to-remove coke residue in the fracturing tube like inorganic combustibles such as metal powder and charcoal powder, effectively ensuring the reusability of the fracturing tube. Finally, compared to oil-based liquid flammable agents (poor mixing uniformity, easy to volatilize and leak) and charcoal powder (highly hygroscopic, easy to clump and separate), flour is a solid powder with better flowability and mixing uniformity. Its production process is simple and there is no risk of leakage or fire. Its raw materials are common agricultural by-products, which are widely available and inexpensive. The convenience of procurement and cost control are significantly better than metal powder and charcoal powder.

[0025] In a preferred embodiment, the mass ratio of potassium perchlorate to flour in the low-sensitivity activator is (50-70):(10-20).

[0026] In a preferred embodiment, the mass ratio of potassium perchlorate to flour in the low-sensitivity activator is 63.7:16.1.

[0027] The ratio of potassium perchlorate to flour is determined by whether the oxygen released by the oxidant can meet the oxygen requirements for combustion of the combustible. The operating environment of a carbon dioxide cracking project is zero oxygen balance; ideally, the oxygen released by the oxidant should exactly meet the oxygen requirements of the combustible. If the operating environment is negatively oxygenated, then more oxidant should be used. If the environment is positively oxygenated, then less oxidant should be used. Verification showed that the optimal mass ratio of potassium perchlorate to flour in the actual operating conditions of a carbon dioxide cracking project is 63.7:16.1.

[0028] In a preferred embodiment, the low-sensitivity activator further includes ammonium oxalate.

[0029] The above technical solution involves adding ammonium oxalate. The main function of ammonium oxalate is to act as an initiator for the exothermic chemical reaction. Through rapid decomposition, it generates a large amount of heat, causing the liquid CO2 to rapidly vaporize and produce high-pressure gas, thus achieving an explosion. In addition, ammonium oxalate can also determine the burning rate of the agent and the relative molecular mass of the product.

[0030] In a preferred embodiment, the low-sensitivity activator further includes salicylic acid and a binder.

[0031] The aforementioned technical solution limits the use of low-sensitivity activators to include salicylic acid and binders. The most crucial role of salicylic acid is as a reaction promoter. Salicylic acid has a low melting point and sublimates upon heating. Under high heat flux, it can undergo localized eutectic with the surface of potassium perchlorate particles, forming an extremely thin liquid reaction film. This liquid medium greatly promotes ion diffusion and mass transfer processes, facilitating the reaction between oxygen generated from the decomposition of potassium perchlorate and the flour.

[0032] In a preferred embodiment, the adhesive comprises bentonite.

[0033] The above technical solution specifies that the main component of the adhesive is bentonite, which mainly functions to reduce the mechanical sensitivity of the activator and improve safety. It can also improve the stability of the activator and increase the heat of combustion of the activator.

[0034] In a preferred embodiment, the adhesive is a mixture of bentonite and epoxy resin in a mass ratio of 92:8.

[0035] In a preferred embodiment, the low-sensitivity activator includes 50-70 parts of potassium perchlorate, 2-10 parts of salicylic acid, 5-20 parts of ammonium oxalate, 10-20 parts of flour, and 2-10 parts of binder.

[0036] The above technical solution limits the amounts of potassium perchlorate, salicylic acid, ammonium oxalate, flour, and adhesive. It is understood that the amount of potassium perchlorate can also be any value within the range of 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, etc.; the amount of salicylic acid can also be any value within the range of 4 parts, 6 parts, 8 parts, 10 parts, etc.; the amount of ammonium oxalate can also be any value within the range of 5.5 parts, 12.5 parts, 15 parts, 20 parts, etc.; the amount of flour can also be any value within the range of 12.5 parts, 15 parts, 20 parts, etc.; and the amount of adhesive can also be any value within the range of 2.5 parts, 5 parts, 10 parts, etc.

[0037] Another aspect of the present invention provides a method for preparing the above-mentioned low-sensitivity activator, comprising the following steps: The raw materials for the low-sensitivity activator are mixed and dried to obtain the low-sensitivity activator.

[0038] It should be noted that the low-sensitivity activator provided by this invention can be prepared by directly mixing all raw materials. This is because this invention uses flour as a combustible agent, which has good dispersibility and reactivity, and is relatively stable chemically at room temperature. When mixed with other components (such as ammonium oxalate, salicylic acid, potassium perchlorate, bentonite, etc.), it is not prone to violent reactions, thus simplifying the preparation process and improving operational safety. In contrast, the activators used in traditional liquid carbon dioxide cracking equipment usually use metal powders (such as aluminum powder, magnesium powder, etc.) as combustible agents. Metal combustible agents have high reactivity and high sensitivity, but they also increase the sensitivity of the system and the difficulty of preparation. In comparison, this invention uses flour as a combustible agent, which not only reduces the overall sensitivity but also simplifies the mixing process and improves the safety and controllability of the preparation process.

[0039] In a preferred embodiment, the mixing speed is 5-15 r / min and the mixing time is 15-25 min.

[0040] In a preferred embodiment, before drying, an energy test is performed. Specifically, three samples are taken from different parts of the mixing pot, and then a deflagration test is performed according to the deflagration and combustion heat adiabatic method of method 701.1 of GJB 770B—2005 "Test Methods for Gunpowder". If the measured results all meet the requirement that the combustion heat value is not less than 6000J / g, it is judged to be qualified.

[0041] In another aspect, the present invention provides the application of the aforementioned low-sensitivity activator in liquid carbon dioxide-induced cracking technology.

[0042] To provide a clearer and more detailed description of the low-sensitivity activator, its preparation method, and its application provided in the embodiments of the present invention, the following description will be based on specific embodiments.

[0043] In the following examples and comparative examples, the binder is composed of bentonite and epoxy resin mixed in a mass ratio of 92:8.

[0044] Example 1: Preparation of Low-Sensitivity Activator 1. Composition of raw materials (parts by mass): potassium perchlorate 63.7 parts, salicylic acid 2.1 parts, ammonium oxalate 15.9 parts, flour 16.1 parts, binder 2.2 parts; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing equipment, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation of energy detection is as follows: Take three samples from different parts of the mixing pot, and then conduct a heat of explosion test according to Method 701.1 Heat of Explosion and Heat of Combustion Adiabatic Method in GJB 770B—2005 "Gunpowder Test Methods". If the measured results all meet the requirement that the heat of combustion value is not less than 6000 J / g, it is judged as qualified.

[0045] Example 2: Preparation of Low-Sensitivity Activator 1. Composition of raw materials (parts by mass): potassium perchlorate 50 parts, salicylic acid 10 parts, ammonium oxalate 20 parts, flour 10 parts, binder 10 parts; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing equipment, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation of energy detection is as follows: Take three samples from different parts of the mixing pot, and then conduct a heat of explosion test according to Method 701.1 Heat of Explosion and Heat of Combustion Adiabatic Method in GJB 770B—2005 "Gunpowder Test Methods". If the measured results all meet the requirement that the heat of combustion value is not less than 6000 J / g, it is judged as qualified.

[0046] Example 3: Preparation of Low-Sensitivity Activator 1. Composition of raw materials (parts by mass): potassium perchlorate 65 parts, salicylic acid 5 parts, ammonium oxalate 13 parts, flour 15 parts, binder 2 parts; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing equipment, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation of energy detection is as follows: Take three samples from different parts of the mixing pot, and then conduct a heat of explosion test according to Method 701.1 Heat of Explosion and Heat of Combustion Adiabatic Method in GJB 770B—2005 "Powder Test Methods". If the measured results all meet the requirement that the heat of combustion value is not less than 6000 J / g, it is judged as qualified.

[0047] Example 4: Preparation of Low-Sensitivity Activator 1. Raw material composition (parts by mass): 70 parts of potassium perchlorate, 2 parts of salicylic acid, 6 parts of ammonium oxalate, 20 parts of flour, 2 parts of binder; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing device, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation of energy detection is as follows: Take three samples from different parts of the mixing pot, and then conduct a heat of explosion test according to Method 701.1 Heat of Explosion and Heat of Combustion Adiabatic Method in GJB 770B—2005 "Powder Test Methods". If the measured results all meet the requirement that the heat of combustion value is not less than 6000 J / g, it is judged as qualified.

[0048] Comparative Example 1 1. Raw material composition (parts by mass): 73 parts of potassium perchlorate, 2 parts of salicylic acid, 5 parts of ammonium oxalate, 18 parts of flour, 2 parts of binder; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing device, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation of energy detection is as follows: Take three samples from different parts of the mixing pot, and then conduct a heat of explosion test according to Method 701.1 Heat of Explosion and Heat of Combustion Adiabatic Method in GJB 770B—2005 "Powder Test Methods".

[0049] Comparative Example 2 1. Raw material composition (parts by mass): 46 parts of potassium perchlorate, 10 parts of salicylic acid, 20 parts of ammonium oxalate, 14 parts of flour, 10 parts of binder; 2. The preparation steps of the low-sensitivity activator designed according to the above components are as follows: Add potassium perchlorate, salicylic acid, ammonium oxalate, flour and binder into a three-dimensional mixing device, and mix for 20 min under the condition of a rotation speed of about 10 r / min. After energy detection, discharging and drying, the low-sensitivity activator is obtained; The specific operation for energy detection is as follows: take three samples from different parts of the mixing pot, and then conduct a heat explosion test according to the heat explosion and combustion heat adiabatic method of method 701.1 of GJB 770B—2005 "Test Methods for Gunpowder".

[0050] The heat of combustion of the activators prepared in Examples 1-4 and Comparative Examples 1-2, as determined by energy analysis, is shown in Table 1.

[0051] Table 1. Heat of combustion of the activators prepared in Examples 1-4 and Comparative Examples 1-2

[0052] Test case The performance of the activator prepared in Example 1 was tested by the National Civil Explosives Quality Supervision and Inspection Center (Chemical Materials Testing Center of Nanjing University of Science and Technology).

[0053] 1. Testing Method 1.1 Sensitivity and Safety Tests 1.1.1 Impact Sensitivity Test Impact sensitivity refers to the sensitivity of gunpowder to external impacts. The greater the impact energy required to cause a gunpowder explosion, the lower the impact sensitivity. Two groups of 25 tests were conducted on potassium nitrate powder according to Method 601.1 of GJB772A "Test Methods for Explosives"—the impact sensitivity explosion probability method. Test conditions: hammer weight 10 kg, explosive charge 50 mg, drop height 500 mm, temperature 18℃, relative humidity 54%. Explosion probability 0.08.

[0054] 1.1.2 Friction Sensitivity Test Friction sensitivity refers to the ease with which gunpowder explodes under mechanical friction. Two groups of 25 tests were conducted on potassium nitrate powder according to Method 602.1 of GJB 772A "Test Methods for Explosives"—the friction sensitivity explosion probability method. Test conditions: hammer weight: 1.500 kg, swing angle: 96°, gauge pressure: 4.90 MPa, charge: 20 mg, temperature: 17℃, relative humidity: 56%. Explosion probability: 0.14.

[0055] 1.1.3 Flame Sensitivity Test According to GJB5383-2005 "Test Methods for Sensitivity and Stability of Pyrotechnic Charges", if the charge does not ignite when the charge surface is 1cm away from the bottom of the fuse, the rising and falling method cannot be used. 25 tests were conducted under the condition of a height of 1cm, and the ignition frequency was calculated to be 0 / 25.

[0056] 1.1.4 Electrostatic Sensitivity Test According to Part 8 of GJB5383-2005 "Test Methods for Sensitivity and Stability of Pyrotechnics," the electrostatic spark sensitivity increase / decrease method was used, with a charge of 30 mg. Test conditions: discharge capacitance 0.22 Uf, discharge gap 0.50 mm, discharge resistance 100 KΩ. Temperature 24℃, relative humidity 48%. At the instrument's highest setting of 15 KV, ignition still failed, making the increase / decrease method unusable. 25 tests were conducted under a fixed voltage of 15 KV, and the ignition frequency was calculated to be 0 / 25.

[0057] 1.2 Stability and compatibility tests 1.2.1 75℃ Stability Test Stability is one of the important performance indicators of gunpowder. Besides the composition of the gunpowder, the quality of stability also depends on the rate at which its chemical and physical properties change under external conditions. The slower the change in physicochemical properties, the better the stability. According to GJB5383.14-2005 "Test Methods for Sensitivity and Stability of Pyrotechnics", Part 14, the stability test uses the 75℃ heating method. Test conditions: test temperature 75℃, test time 48h. The sample mass reduction was 3.27%, and the sample moisture content was 3.31%.

[0058] 1.2.2 Compatibility Test The degree of insensitivity to chemical reactions between gunpowder components or between gunpowder and contact materials is called compatibility. No reaction or a very slow reaction indicates compatibility; otherwise, incompatibility exists. Compatibility testing is of practical significance for selecting gunpowder components and product packaging materials. According to GJB 770B—2005 "Test Methods for Gunpowder" Method 501.1 Vacuum Stability Test (Mercury Manometer Method), the test conditions are: test temperature 100℃, test time 48h. Standard requirements: R < 3.0 mL - Compatible; R = 3.0 mL ~ 5.0 mL - Moderate reaction; R > 5.0 mL - Incompatible. Test results: Net increase in gas release (R, mL) was: 0.20, -0.20, -0.10.

[0059] 1.2.3 Ignition Temperature Test According to GB / T 19469-2004 "Determination of Ignition Temperature of Pyrotechnic Agents" differential thermal analysis-thermogravimetric analysis, the test results showed that the sample did not have an obvious exothermic peak within 500℃.

[0060] 1.2.4 United Nations Partition Test According to the United Nations Recommendation on the Transport of Dangerous Goods, Manual of Tests and Criteria (6th Revision), 12.4.1 Test 2(a), UN partition test, GB / T 14372-2013 "Acceptance and Sub-test Methods for Explosives in the Transport of Dangerous Goods", 4.1 2(a), UN partition test, in both tests, the steel pipe did not completely break, and the verification plate was not penetrated.

[0061] 1.2.5 Krona Test According to the United Nations Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria (6th Revision), 12.5.1 Test 2(b) Kronen test, GB / T 14372-2013 "Acceptance and Sub-test Methods for Explosives in the Transport of Dangerous Goods", 4.22(b) Kronen test, with a limit diameter greater than 2.0 mm. The test result is "+".

[0062] 1.3 Heat Explosion Test Heat of explosion refers to the heat released when one kilogram of gunpowder burns adiabatically at constant volume and the combustion gas cools to 25°C. Gunpowder with a high heat of explosion has a greater work capacity. A heat of explosion test was conducted according to Method 701.1, Adiabatic Method for Heat of Explosion and Heat of Combustion, of GJB 770B—2005 "Test Methods for Gunpowder". The test result, Q = 6780 kJ / kg, meets the technical requirements.

[0063] 2. Test Results: Table 2

[0064] The experiment shows that the activator of this application has very low mechanical sensitivity to flame and electrostatics, good thermal stability, high ignition temperature, and is not sensitive to shock waves, and should be an insensitive agent.

Claims

1. A low-sensitivity activator, characterized in that, The low-sensitivity activator uses potassium perchlorate as an oxidant and flour as a combustible agent.

2. The low-sensitivity activator according to claim 1, characterized in that, In the low-sensitivity activator, the mass ratio of potassium perchlorate to flour is (50-70):(10-20).

3. The low-sensitivity activator according to claim 2, characterized in that, In the low-sensitivity activator, the mass ratio of potassium perchlorate to flour is 63.7:16.

1.

4. The low-sensitivity activator according to claim 1, characterized in that, The low-sensitivity activator also includes ammonium oxalate.

5. The low-sensitivity activator according to claim 3, characterized in that, The low-sensitivity activator also includes salicylic acid and a binder.

6. The low-sensitivity activator according to claim 4, characterized in that, The low-sensitivity activator comprises 50-70 parts potassium perchlorate, 2-10 parts salicylic acid, 5-20 parts ammonium oxalate, 10-20 parts flour, and 2-10 parts binder.

7. The method for preparing the low-sensitivity activator according to any one of claims 1-6, characterized in that, Includes the following steps: The raw materials of the low-sensitivity activator according to any one of claims 1-6 are mixed and dried to obtain the low-sensitivity activator.

8. The preparation method according to claim 7, characterized in that, The mixing speed is 5-15 r / min, and the mixing time is 15-25 min.

9. The preparation method according to claim 7, characterized in that, Before drying, energy testing is performed. Specifically, three samples are taken from different parts of the mixing pot and then a heat explosion test is conducted. If the measured results all meet the requirement that the calorific value is not less than 6000 J / g, the product is considered qualified.

10. The application of the low-sensitivity activator according to any one of claims 1-6 in liquid carbon dioxide cracking technology.

Images