A method for preparing an emulsified explosive sensitizer using modified carbon black

Abstract

The present invention relates to the technical field of the preparation of emulsion explosives, and specifically discloses a method for preparing a sensitizer for emulsion explosives by using modified carbon black. The method comprises 100 to 150 parts by weight of aluminum powder and 10 parts by weight of modified carbon black, adding absolute ethanol, under the protection of an inert gas, through stirring and ultrasonic treatment, and then evaporating the absolute ethanol to obtain a CB-NH2-AI composite; then adding the CB-NH2-AI composite into dissolved paraffin and absolute ethanol, stirring, and then evaporating the absolute ethanol to obtain a sensitizer. The sensitizer prepared by the present invention can improve the explosion power of emulsion explosives, has good stability, and is inexpensive as shown by experimental data.

Description

Technical Field

[0001] The present invention relates to the technical field of emulsion explosive preparation, and specifically relates to a method for preparing a sensitizer for emulsion explosive by using modified carbon black. Background Art

[0002] The sensitizers of emulsion explosives are generally divided into physical sensitizers and chemical sensitizers. Among them, the physical sensitizers are mainly hollow glass microspheres, perlite, etc. Although the hollow glass microspheres have the advantages of high stability, strong dispersibility, and the ability to improve the detonation performance, they also have significant disadvantages. For example, they have low mechanical strength, are easily broken during the preparation of the sensitizer, and are easily deformed under high-temperature conditions, seriously affecting the performance of the sensitizer. At the same time, their high cost will affect the popularization and application of the sensitizer. Perlite, although low in cost, has significant disadvantages such as poor mechanical strength, strong hygroscopicity, uneven particle size, and impurity risks.

[0003] In order to improve the detonation performance of the sensitizer, some formulations also add some metal powders. Although the detonation performance is increased, these powders have the disadvantage of high activity, resulting in poor product stability.

[0004] Carbon black has characteristics such as high specific surface area and conductivity, but there is no report on its application in sensitizers in the prior art. The present invention endows carbon black with amino active groups (CB-NH2) through chemical modification, solving the compatibility problem with aluminum powder. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide a method for preparing a sensitizer for emulsion explosive by using modified carbon black, applying the modified carbon black to the sensitizer, and the prepared sensitizer can improve the explosion power of the emulsion explosive, has good stability, and is inexpensive as shown by experimental data.

[0006] To solve the above technical problem, the present invention provides the following technical solutions:

[0007] A method for preparing a sensitizer for emulsion explosive by using modified carbon black, the sensitizer for emulsion explosive is made of the following components in parts by weight: 100 - 150 parts of aluminum powder, 10 parts of modified carbon black, and 8 parts of paraffin; its preparation method includes the following steps:

[0008] a. Weigh 100 - 150 parts by weight of aluminum powder and 10 parts of modified carbon black, add an excessive amount of absolute ethanol, under the protection of an inert gas, stir and react at 40°C and 400 rpm for 4 hours under the condition of a pH value of 5 - 7. After the reaction is completed, ultrasonicate for 30 minutes; then evaporate the absolute ethanol at 90°C to obtain a CB-NH2-AI complex;

[0009] The modified carbon black is obtained by reacting carbon black with an excessive amount of nitric acid solution to obtain oxidized carbon black, and then refluxing it with γ-aminopropyltriethoxysilane KH-550 in an excessive amount of absolute ethanol to obtain the modified carbon black;

[0010] b. Add 8 parts by weight of paraffin to an excessive amount of absolute ethanol, stir and dissolve it at 60 °C and 400 rpm, then add the CB-NH2-AI composite obtained in step a and continue to stir for 60 minutes, and evaporate the absolute ethanol at 90 °C to obtain an emulsion explosive sensitizer.

[0011] Preferably, the weight part of the aluminum powder is 125 parts.

[0012] Preferably, the aluminum powder is nano-aluminum powder with a particle size of 50 - 100 nm.

[0013] Preferably, the inert gas is nitrogen or argon.

[0014] Preferably, the specific parameters of the ultrasonic treatment are: frequency 30 kHz, power 300 W; during the ultrasonic process, perform pulsed operation in batches, ultrasonic for 2 seconds and stop for 1 second.

[0015] Preferably, the modified carbon black is prepared by modifying N550 carbon black. The preparation process of the modified carbon black is as follows: Add carbon black to an excessive amount of nitric acid solution, react at 90 - 100 °C for 4 h, wash the reaction product with deionized water, and dry it at 60 - 70 °C for 2 h to obtain oxidized carbon black; the concentration of the nitric acid solution is 2 - 4%wt, and the mass ratio of carbon black to the nitric acid solution is 1:5 - 10; then reflux the oxidized carbon black with γ-aminopropyltriethoxysilane KH-550 (weight ratio 1:0.1 - 0.5) in an excessive amount of absolute ethanol (protected by inert gas nitrogen or argon) (80 °C, 6 hours) to generate modified carbon black (CB-NH2).

[0016] Furthermore, the mass ratio of the carbon black to the nitric acid solution is 1:7.5, the concentration of the nitric acid solution is 3%wt, and the reaction is carried out at 95 °C for 4 h; the weight ratio of the oxidized carbon black to γ-aminopropyltriethoxysilane KH-550 is 1:0.3; the inert gas is nitrogen.

[0017] Due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0018] The emulsion explosive sensitizer obtained by the present invention can replace traditional hollow particle sensitizers, especially hollow glass microspheres, can overcome the defects of hollow glass microspheres, and greatly reduce the cost of products containing hollow glass microspheres; it can also replace heavy metal sensitizers (such as lead styphnate) in traditional sensitizers, thereby reducing heavy metal pollution;

[0019] The product of the present invention can effectively enhance the detonation propagation efficiency and improve the explosion power of emulsion explosives; and through coating protection with paraffin, the stability of the product is increased;

[0020] The raw materials of the present invention are widely sourced, low in cost, and have a simple production process, with good market prospects.

[0021] In short, the emulsion explosive sensitizer prepared by the present invention can improve the explosion power of emulsion explosives, has good stability, and is inexpensive. Detailed implementation manners

[0022] The technical solutions of the present invention are further described below in conjunction with embodiments:

[0023] Example 1 Preparation of modified carbon black I

[0024] The modified carbon black is made of N550 carbon black, and its preparation process is as follows: Add carbon black into an excessive amount of nitric acid solution, react at 90 °C for 4 h, wash the reaction product with deionized water, and dry it at 70 °C for 2 h to obtain oxidized carbon black; the concentration of the nitric acid solution is 2%wt, and the mass ratio of carbon black to the nitric acid solution is 1:10; then react the oxidized carbon black with γ-aminopropyltriethoxysilane KH-550 at a weight ratio of 1:0.1 in an excessive amount of absolute ethanol (under argon protection, controlling the flow rate to ensure an oxygen-free system inside) and reflux at 80 °C for 6 hours to obtain the modified carbon black.

[0025] Example 2 Preparation of modified carbon black II

[0026] The modified carbon black is made of N550 carbon black, and its preparation process is as follows: Add carbon black into an excessive amount of nitric acid solution, react at 100 °C for 4 h, wash the reaction product with deionized water, and dry it at 60 °C for 2 h to obtain oxidized carbon black; the concentration of the nitric acid solution is 4%wt, and the mass ratio of carbon black to the nitric acid solution is 1:5; then react the oxidized carbon black with γ-aminopropyltriethoxysilane KH-550 at a weight ratio of 1:0.5 in an excessive amount of absolute ethanol (under nitrogen protection, controlling the flow rate to ensure an oxygen-free system inside) and reflux at 80 °C for 6 hours to obtain the modified carbon black.

[0027] Example 3 Preparation of modified carbon black III

[0028] The modified carbon black uses N550 carbon black, and its preparation process is as follows: Add carbon black to an excessive amount of nitric acid solution, react at 95°C for 4 hours, rinse the reaction product with deionized water, and dry it at 65°C for 2 hours to obtain oxidized carbon black; the concentration of the nitric acid solution is 3%wt, and the mass ratio of carbon black to the nitric acid solution is 1:7.5; then reflux the oxidized carbon black and γ-aminopropyltriethoxysilane KH-550 at a weight ratio of 1:0.3 in an excessive amount of absolute ethanol (under nitrogen protection, controlling the flow rate to ensure no oxygen in the system) at 80°C for 6 hours to obtain the modified carbon black. The preferred parameters (nitric acid concentration 3%wt, temperature 95°C) are determined through orthogonal experiments, which can balance the oxidation efficiency and the structural integrity of carbon black.

[0029] Example 4 Preparation of Sensitizer for Emulsion Explosive I

[0030] a. Weigh 100 parts by weight of nano-aluminum powder and 10 parts by weight of the modified carbon black prepared in Example 3, add an excessive amount of absolute ethanol (15 times the mass of the modified carbon black), and under the protection of an inert gas (argon protection, controlling the flow rate to ensure no oxygen in the system), stir and react at 40°C and 400 rpm for 4 hours under the condition of pH value 5. After the reaction is completed, ultrasonicate for 30 minutes (on for 2 seconds and off for 1 second); then evaporate the absolute ethanol at 90°C to obtain the CB-NH2-AI composite.

[0031] b. Add 8 parts by weight of paraffin to an excessive amount of absolute ethanol (20 times the mass of paraffin), stir and dissolve at 60°C and 400 rpm, then add the CB-NH2-AI composite obtained in step a and continue stirring for 60 minutes, and evaporate the absolute ethanol at 90°C to obtain the sensitizer.

[0032] Example 5 Preparation of Sensitizer for Emulsion Explosive II

[0033] a. Weigh 150 parts by weight of nano-aluminum powder and 10 parts by weight of the modified carbon black prepared in Example 3, add an excessive amount of absolute ethanol (15 times the mass of the modified carbon black), and under the protection of an inert gas (nitrogen protection, controlling the flow rate to ensure no oxygen in the system), stir and react at 40°C and 400 rpm for 4 hours under the condition of pH value 7. After the reaction is completed, ultrasonicate for 30 minutes (on for 2 seconds and off for 1 second); then evaporate the absolute ethanol at 90°C to obtain the CB-NH2-AI composite.

[0034] b. Add 8 parts by weight of paraffin to an excessive amount of absolute ethanol (20 times the mass of paraffin), stir and dissolve at 60°C and 400 rpm, then add the CB-NH2-AI composite obtained in step a and continue stirring for 60 minutes, and evaporate the absolute ethanol at 90°C to obtain the sensitizer.

[0035] Example 6 Preparation of Sensitizer for Emulsion Explosive III

[0036] a. Weigh 125 parts by weight of nano-aluminum powder and 10 parts by weight of the modified carbon black prepared in Example 3, add an excessive amount of absolute ethanol (15 times the mass of the modified carbon black), and under the protection of an inert gas (nitrogen protection, controlling the flow rate to ensure no oxygen in the system), stir and react at 40 °C and 400 rpm for 4 hours under the condition of pH value 6. After the reaction, ultrasonicate for 30 minutes (on for 2 seconds and off for 1 second); then evaporate the absolute ethanol at 90 °C to obtain the CB-NH2-AI composite;

[0037] b. Add 8 parts by weight of paraffin wax to an excessive amount of absolute ethanol (20 times the mass of paraffin wax), stir and dissolve at 60 °C and 400 rpm, then add the CB-NH2-AI composite obtained in step a and continue to stir for 60 minutes, and evaporate the absolute ethanol at 90 °C to obtain the sensitizer.

[0038] Example 7 Preparation of sensitizer for emulsion explosive IV

[0039] Change the modified carbon black in Example 6 to the modified carbon black prepared in Example 1, and other conditions remain unchanged.

[0040] Example 8 Preparation of sensitizer for emulsion explosive V

[0041] Change the modified carbon black in Example 6 to the modified carbon black prepared in Example 2, and other conditions remain unchanged.

[0042] Comparative Example 1

[0043] Replace the nano-aluminum powder in Example 6 with ordinary aluminum powder, and the conditions remain unchanged.

[0044] Comparative Example 2

[0045] Replace the modified carbon black in Example 6 with unmodified N550 carbon black, and the conditions remain unchanged.

[0046] Comparative Example 3

[0047] Prepare the sensitizer with the following parts by weight of materials: 33 parts of glass hollow microspheres, 63 parts of aluminum powder, and 7 parts of paraffin wax. The preparation method is the same as that in Example 6.

[0048] Product test results and analysis:

[0049] Perform BAM friction sensitivity (German Federal Institute for Materials Research standard (DIN EN 13631-3), load 360 N, swing angle 90°), BAM impact sensitivity (falling weight 10 kg, falling height 50 cm), DSC / TGA thermal analysis, and combustion tube test (combustion rate) on the products obtained in Examples 4-8 and Comparative Examples 1-3. The results are shown in Table 1.

[0050] Table 1 Test results of products prepared in Examples 4-8 and Comparative Examples 1-3

[0051]

[0052] Comparative Example 4

[0053] Emulsion explosive prepared with the following parts by weight of components: 80 parts of ammonium nitrate, 7.5 parts of sodium nitrate, 6 parts of paraffin wax, 2 parts of sorbitan monooleate (Span80), 6.5 parts of hollow glass microspheres (sensitizer), 0.3 part of benzoic acid; the specific steps are as follows: 1. Add 80 parts of ammonium nitrate and 7.5 parts of sodium nitrate into a heating kettle with stirring, add an appropriate amount of water, start stirring and heating, control the heating temperature at about 120°C, and dissolve the ammonium nitrate and sodium nitrate completely to form a uniform aqueous solution; the stirring speed is generally 150 r / min, and the dissolution time is about 25 minutes until the solution is clear and transparent without solid particles; after dissolution, keep the aqueous solution warm for standby, and keep the temperature at 95°C; 2. In another heating kettle with stirring, add 6 parts of paraffin wax, 2 parts of sorbitan monooleate (Span80) and 0.3 part of benzoic acid, heat and stir, control the heating temperature at 85°C, and melt and mix the paraffin wax, Span80 and benzoic acid completely to form an oil phase; the stirring speed is 130 r / min, and the mixing time is about 13 minutes; 3. Slowly add the prepared aqueous solution into the oil phase system, and at the same time start a high-shear emulsifier, control the rotation speed of the emulsifier at 4000 r / min, and keep the system temperature at 85°C during the emulsification process, and the emulsification time is about 8 minutes to fully emulsify the aqueous phase and the oil phase to form a stable latex matrix; 4. Transfer the emulsified latex matrix to a sensitizing device, and slowly add 6.5 parts of hollow glass microspheres under stirring (stirring speed 100 r / min), and continue to stir for 8 minutes to make the hollow glass microspheres evenly dispersed in the latex matrix to complete the sensitization process, and package the sensitized emulsion explosive through a packaging device.

[0054] Comparative Example 5

[0055] Replace the sensitizer prepared in Example 6 with the sensitizer in Comparative Example 4, and keep other conditions unchanged.

[0056] Test the emulsion explosives prepared in Comparative Example 4 and Comparative Example 5 for density, specific impulse, specific shock wave energy and specific bubble energy, and the obtained results are shown in Table 2:

[0057] Table 2 Test Results of Emulsion Explosives Prepared in Comparative Examples 4 - 5

[0058]

[0059] As can be seen from the data in Table 1 and Table 2, the modified carbon black prepared in Example 3 of the present invention and the sensitizer prepared therefrom have the best data (the data in Example 8 is significantly lower than that in Example 6 because the modified carbon black in Example 2 has excessive oxidation on the carbon black surface due to the relatively high nitric acid concentration (4%wt), affecting the stability of the composite). Moreover, the specific impulse, specific shock wave energy, and specific bubble energy of the emulsion explosive prepared by replacing the hollow glass microspheres in the prior art with this sensitizer are all significantly improved, proving that it can completely replace the sensitizer in the prior art.

[0060] It should be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A method for preparing an emulsified explosive sensitizer using modified carbon black, characterized in that: The sensitizer for emulsion explosive is made from the following components in parts by weight: 100 - 150 parts of aluminum powder, 10 parts of modified carbon black, and 8 parts of paraffin wax; its preparation method includes the following steps: a. Weigh 100 - 150 parts by weight of aluminum powder and 10 parts of modified carbon black, add excessive absolute ethanol, under the protection of inert gas, stir and react at 40°C and 400 rpm for 4 hours under the condition of pH value 5 - 7. After the reaction ends, perform ultrasonic treatment for 30 minutes; then evaporate the absolute ethanol at 90°C to obtain the CB - NH2 - AI composite; The modified carbon black is obtained by reacting carbon black with excessive nitric acid solution to get oxidized carbon black, and then refluxing with γ - aminopropyltriethoxysilane KH - 550 in excessive absolute ethanol; b. Add 8 parts of paraffin wax to excessive absolute ethanol, stir and dissolve at 60°C and 400 rpm, then add the CB - NH2 - AI composite obtained in step a and continue to stir for 60 minutes, evaporate the absolute ethanol at 90°C to obtain the sensitizer for emulsion explosive.

2. The method for preparing an emulsion explosive sensitizer using modified carbon black according to claim 1, wherein: The weight of the aluminum powder is 125 parts.

3. The method for preparing an emulsion explosive sensitizer using modified carbon black according to claim 1, wherein: The aluminum powder is nano - aluminum powder with a particle size of 50 - 100 nm.

4. The method for preparing an emulsified explosive sensitizer using modified carbon black according to claim 1, characterized in that: The inert gas is nitrogen or argon.

5. The method for preparing an emulsified explosive sensitizer using modified carbon black according to claim 1, characterized in that: The specific parameters of the ultrasonic treatment are: frequency 30 kHz, power 300 W; during the ultrasonic process, perform pulsed operation in batches, ultrasonic for 2 seconds and stop for 1 second.

6. The method for preparing an emulsion explosive sensitizer by using modified carbon black according to claim 1, wherein: The modified carbon black is prepared by modifying N550 carbon black. The preparation process of the modified carbon black is as follows: Add carbon black into excessive nitric acid solution, react at 90 - 100°C for 4 h, wash the reaction product with deionized water, and dry at 60 - 70°C for 2 h to obtain oxidized carbon black; the concentration of the nitric acid solution is 2 - 4%wt, and the mass ratio of carbon black to nitric acid solution is 1:5 - 10; then reflux the oxidized carbon black and γ - aminopropyltriethoxysilane KH - 550 with a weight ratio of 1:0.1 - 0.5 in excessive absolute ethanol under the protection of nitrogen or argon at 80°C for 6 hours to generate the modified carbon black.

7. The method for preparing an emulsified explosive sensitizer by using modified carbon black according to claim 6, characterized in that: The mass ratio of carbon black to nitric acid solution is 1:7.5, the concentration of the nitric acid solution is 3%wt, react at 95°C for 4 h; the weight ratio of oxidized carbon black to γ - aminopropyltriethoxysilane KH - 550 is 1:0.3; the inert gas is nitrogen.

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