Emulsion explosive and preparation method thereof

Abstract

The invention discloses an emulsion explosive and a preparation method thereof. The raw materials of the emulsion explosive include an oil phase material and an aqueous phase material, the oil phase includes white oil, an oil phase emulsifier and an additive, and the additive is 2,6-di-tert-butyl-4-methylphenol; the aqueous phase includes an oxidant nitric acid aqueous solution and tea polyphenols. The preparation method comprises the following steps: (1) melting the oil phase raw materials and stirring to obtain an oil phase; (2) mixing the nitric acid aqueous solution and the tea polyphenols and completely dissolving them to obtain an aqueous phase; (3) adding the aqueous phase under the condition of heat preservation and stirring of the oil phase and emulsifying to obtain a latex matrix; (4) sensitizing the latex matrix to obtain the emulsion explosive. The emulsion explosive does not use ammonium nitrate and sodium nitrate, which are commonly used oxidants in emulsion explosives, but uses nitric acid as an emulsifier. The emulsion explosive has good performance, eliminates the processes of crushing, dissolving, heat preservation and conveying of ammonium nitrate, simplifies the preparation process of the emulsion explosive, has the advantages of low energy consumption and reduces production cost.

Description

Technical Field

[0001] The invention relates to an explosive, in particular to an emulsion explosive and a preparation method thereof. Background Art

[0002] Emulsion explosives are water-in-oil (W / O) latex-type water-resistant industrial explosives prepared by emulsification technology. They use fine droplets of an oxidant ammonium nitrate aqueous solution as the dispersed phase, and oil-like substances suspended with dispersed bubbles or hollow glass microspheres or other porous materials as the continuous phase, forming a special water-in-oil emulsion system. Since the invention of emulsion explosives and the realization of industrial production, its main component oxidant has always been ammonium nitrate and sodium nitrate as oxidants.

[0003] CN114133307B discloses an environmentally friendly emulsion explosive, which includes the following raw materials by mass fraction: 40% to 43% ammonium nitrate, 13% to 15% sodium nitrate, 5% to 7% modified combustible agent, 3% to 5% flame retardant, 2% to 4% composite emulsifier, 4% to 8% perlite, 1% to 3% foaming aid, 4% to 6% anti-hydrolysis additive and the balance is water. The invention can not only significantly improve the detonation speed, intensity and sympathetic detonation distance of the emulsion explosive, but also further improve the anti-hydrolysis ability of the emulsion explosive in an underwater environment.

[0004] CN101948362B discloses a high-power emulsion explosive and a preparation method thereof, aiming to provide a new type of explosive with strong explosive power, low energy consumption and stable quality; the explosive is prepared by mixing the following two components A and B, wherein the raw material ratio of component A by weight percentage is: 75-85% ammonium nitrate, 9-14% water, 3-5% nitrate, 0.3-2.0% urea, 0.3-3.5% modified Span-80 emulsifier, 0.3-3.5% composite oil phase, 1-1.5% paraffin and 0.8-3% fast foaming agent; component B is one of porous granular ammonium nitrate or granular ammonium nitrate or potassium nitrate; the weight ratio of component A to component B is 88-96:142; the processing method mainly includes the preparation of water phase, the preparation of oil phase, emulsification, sensitization, packaging, and adding porous granular ammonium nitrate or granular ammonium nitrate or potassium nitrate during sensitization.

[0005] CN102276372B discloses an emulsion explosive for deep water, which is sensitized by mixing a latex matrix and a sensitizer; the latex matrix is ​​emulsified by a water phase and an oil phase; wherein the weight ratio of the water phase to the oil phase is 93-94:67; the water phase is prepared by water, ammonium nitrate, sodium nitrate, and anionic surfactant in weight percentages of 8-11%, 75-80%, 10-15%, and 0.1-0.2%, and the anionic surfactant is sodium methylene bisnaphthalene sulfonate; the weight ratio of the latex matrix to the sensitizer is 96-98:42.

[0006] In the above-mentioned emulsion explosive patents, the main oxidant in the emulsion explosive formula is ammonium nitrate, and the auxiliary oxidant is sodium nitrate, the purpose of which is to adjust the oxygen balance of the formula and reduce the crystallization point of the water phase. However, ammonium nitrate as an oxidant requires crushing, dissolution, heat preservation, transportation and other processes, and the preparation process is complicated. Summary of the invention

[0007] Purpose of the invention: The first purpose of the present invention is to provide an emulsion explosive which does not use ammonium nitrate as an oxidant; the second purpose of the present invention is to provide a method for preparing the emulsion explosive.

[0008] Technical solution: The raw materials of the emulsion explosive of the present invention include oil phase material and water phase material, the oil phase includes white oil, oil phase emulsifier and additive, the additive is 2,6-di-tert-butyl-4-methylphenol; the water phase includes oxidant nitric acid aqueous solution, tea polyphenols and water.

[0009] The white oil was purchased from the drug library of Nanjing University of Science and Technology, and tea polyphenols were purchased from Tianjin Xiensiopude Technology Co., Ltd.

[0010] Preferably, the emulsifier is polyglycerol-3-diisostearate and n-octadecyl phosphoric acid. Since nitric acid has strong oxidizing properties, the emulsification effect and the stability of the matrix are improved by adding a nonionic water-in-oil emulsifier polyglycerol-3-diisostearate and an auxiliary emulsifier n-octadecyl phosphoric acid to the white oil.

[0011] Preferably, the raw materials include, by mass: 22-28 parts, 2-4 parts of polyglycerol-3-disostearate, 4-8 parts of n-octadecyl phosphoric acid, 235-247 parts of nitric acid, 0.1-0.3% of the mass of the nitric acid aqueous solution of tea polyphenols, and 0.3-0.5% of the mass of the nitric acid aqueous solution of 2,6-di-tert-butyl-4-methylphenol.

[0012] Preferably, the nitric acid concentration is 60-68 wt %. When the nitric acid concentration is greater than 68%, it cannot be emulsified into a latex matrix due to its strong oxidizing property, and the oil-water phase is still liquid after the emulsification time is reached.

[0013] In order to avoid the strong oxidizing property of concentrated nitric acid from oxidizing white oil, the additive 2,6-di-tert-butyl-4-methylphenol (BHT) is added to the integrated oil phase to improve the antioxidant capacity of the integrated oil phase. In addition, in order to avoid the strong acidity of concentrated nitric acid from affecting white oil, tea polyphenols are added to improve both the antioxidant capacity and the acid resistance by taking advantage of its excellent heat resistance and acid resistance in the pH range of 2 to 7. The synergistic effect of BHT and tea polyphenols is used to improve the antioxidant capacity and acid resistance of emulsion explosives containing concentrated nitric acid, thereby improving the stability of emulsion explosives and the safety of the preparation process. Without the addition of BHT and tea polyphenols, the emulsification effect will deteriorate, the matrix stability will decrease, the storage period will be shortened, and it will be easier to break the emulsion.

[0014] The method for preparing the emulsion explosive of the present invention comprises the following steps:

[0015] (1) melting the oil phase raw material, adding it into an emulsifier and stirring to obtain the oil phase;

[0016] (2) mixing the nitric acid aqueous solution and the tea polyphenols, completely dissolving them to obtain an aqueous phase, and removing the nitrogen oxides released by the nitric acid;

[0017] (3) adding the water phase to the oil phase under the condition of heat preservation and stirring to emulsify and obtain a latex matrix;

[0018] (4) Sensitizing the latex matrix to obtain the emulsion explosive.

[0019] Preferably, in step (3), the oil phase is kept warm at a temperature of 90 to 95° C. and the stirring speed is 800 to 1200 rpm.

[0020] Preferably, in step (3), the emulsification time is 5 to 7 minutes.

[0021] Preferably, in step (1), the melting temperature is 90-95°C.

[0022] Preferably, in step (2), the dissolving is stirred in a dissolver at a speed of 100 to 150 rpm. When concentrated nitric acid is used to prepare emulsion explosives, the nitrogen oxide gas volatilized from the concentrated nitric acid may produce a sensitizing effect during the emulsification process. In order to avoid the influence of its nitrogen oxides on the safety of the emulsification process, the concentrated nitric acid is allowed to absorb the nitrogen oxides and then allowed to stand. When no nitrogen oxides are volatilized, the emulsion explosive is prepared.

[0023] Preferably, in step (4), the sensitization method is: adding glass microspheres to the latex matrix for sensitization. The chemical sensitization method of emulsion explosives often uses sodium nitrite solution for sensitization, but since nitric acid is more likely to react with sodium nitrite, the reaction speed is faster, and a large number of bubbles are generated in a short time, causing the latex colloid to demulsify and reduce stability, so the chemical sensitization method is not suitable. The effect of the perlite sensitization method is not as good as that of glass microspheres, and the explosive performance is not as good as that of glass microspheres.

[0024] Invention mechanism: The present invention uses concentrated nitric acid to prepare emulsion explosives. Since concentrated nitric acid has strong oxidizing properties, it is necessary to solve the influence of its strong oxidizing properties on the emulsification effect. By adding a non-ionic water-in-oil emulsifier polyglycerol-3-diisostearate to white oil, and adding an auxiliary emulsifier n-octadecyl phosphoric acid, the emulsification effect and the stability of the matrix are improved. In order to avoid the strong oxidizing property of concentrated nitric acid on the oxidation of white oil, an additive 2,6-di-tert-butyl-4-methylphenol (BHT) is added to the integrated oil phase to improve the antioxidant capacity of the integrated oil phase. In addition, in order to avoid the influence of the strong acidity of concentrated nitric acid on white oil, tea polyphenols are added, and its excellent heat resistance and acid resistance in the pH range of 2 to 7 are utilized to improve both the antioxidant capacity and the acid resistance. The synergistic effect of BHT and tea polyphenols is utilized to improve the antioxidant capacity and acid resistance of the emulsion explosive containing concentrated nitric acid, thereby improving the stability of the emulsion explosive and the safety of the preparation process.

[0025] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The emulsion explosive does not use the commonly used oxidants ammonium nitrate and sodium nitrate in emulsion explosives, but uses nitric acid as an emulsifier, and the emulsion explosive has good performance; (2) The method eliminates the processes of crushing, dissolving, heat preservation, and transportation of ammonium nitrate, simplifies the preparation process of emulsion explosives, has the advantages of low energy consumption, and reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A latex matrix prepared in Example 2;

[0027] Figure 2 The latex matrix prepared in Comparative Example 1;

[0028] Figure 3 The latex matrix prepared in Comparative Example 2;

[0029] Figure 4 The latex matrix prepared in Comparative Example 3;

[0030] Figure 5 This is the latex matrix prepared in Comparative Example 4. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below in conjunction with embodiments.

[0032] Example 1

[0033] The emulsion explosive of the present invention comprises: 28g of white oil, 2g of polyglycerol-3-diisostearate, 8g of n-octadecyl phosphoric acid, 235g of nitric acid with a mass fraction of 68%, 0.24g of tea polyphenols, and 0.71g of 2,6-di-tert-butyl-4-methylphenol; and the preparation method thereof comprises the following steps:

[0034] (1) 28 g of white oil, 2 g of polyglycerol-3-distearate, 8 g of n-octadecyl phosphoric acid and 0.71 g of BHT were added into a wax melter, melted at 95° C., stirred and kept warm to prepare an oil phase material;

[0035] (2) adding 235 g of nitric acid with a mass fraction of 68% and 0.24 g of tea polyphenols into a dissolver and stirring at room temperature, and after being fully dissolved and no nitrogen oxides are volatilized, transferring them to the emulsifier feeding device;

[0036] (3) adding the melted oil phase material into an emulsifier and stirring, keeping the temperature at 95° C., turning on the nitric acid feeding device for emulsification, the emulsification time is 5 min, the rotation speed is 1200 rpm, and a latex matrix is ​​obtained;

[0037] In the fourth step, the latex matrix is ​​sensitized with 4% glass microspheres to obtain an emulsion explosive product. The detonation velocity is measured to be 4400-4500 m / s.

[0038] Example 2

[0039] The emulsion explosive of the present invention comprises: 26g of white oil, 4g of polyglycerol-3-diisostearate, 8g of n-octadecyl phosphoric acid, 241g of nitric acid with a mass fraction of 68%, 0.72g of tea polyphenols, and 1.21g of 2,6-di-tert-butyl-4-methylphenol; and the preparation method thereof comprises the following steps:

[0040] (1) 26 g of white oil, 4 g of polyglycerol-3-diisostearate, 8 g of n-octadecyl phosphoric acid and 1.21 g of BHT were added into a wax melter, melted at 90° C., stirred and kept warm to prepare an oil phase material;

[0041] (2) adding 241 g of nitric acid with a mass fraction of 68% and 0.72 g of tea polyphenols into a dissolver and stirring at room temperature, and after being fully dissolved and no nitrogen oxides are volatilized, transferring them to the emulsifier feeding device;

[0042] (3) adding the oil phase material into an emulsifier and stirring, keeping the temperature at 90° C., turning on the nitric acid feeding device for emulsification, the emulsification time is 6 min, the rotation speed is 1200 rpm, and a latex matrix is ​​obtained;

[0043] (4) After the latex matrix is ​​discharged, it is sensitized with 4% glass microspheres to obtain an emulsion explosive product. The measured detonation velocity is 4600-4800 m / s.

[0044] Example 3

[0045] The emulsion explosive of the present invention comprises: 22g of white oil, 4g of polyglycerol-3-diisostearate, 4g of n-octadecyl phosphoric acid, 247g of nitric acid with a mass fraction of 60%, 0.48g of tea polyphenols, and 1g of 2,6-di-tert-butyl-4-methylphenol; and the preparation method thereof comprises the following steps:

[0046] In the first step, 22 g of the integrated oil phase, 4 g of polyglycerol-3-diisostearate, 4 g of n-octadecyl phosphoric acid and 1 g of BHT phase were added into a wax melter, melted at 95° C., stirred and kept warm, to obtain an oil phase material;

[0047] The second step is to add 247g of nitric acid with a mass fraction of 60% and 0.48g of tea polyphenols into a dissolver and stir at room temperature. After being fully dissolved and without volatilization of nitrogen oxides, they are transferred to the emulsifier feeding device;

[0048] The third step is to add the oil phase material into the emulsifier and stir it, keep it at 95°C, start the nitric acid feeding device for emulsification, the emulsification time is 7 minutes, the rotation speed is 800 rpm, and the latex matrix is ​​obtained;

[0049] In the fourth step, the latex matrix is ​​sensitized with 4% glass microspheres to obtain an emulsion explosive product. The detonation velocity is measured to be 4200-4400 m / s.

[0050] Comparative Example 1

[0051] On the basis of Example 2, the mass fraction of nitric acid was changed to 84% and the other conditions remained unchanged.

[0052] like Figure 2 As shown, due to the excessive concentration of nitric acid, its strong oxidizing property causes side reactions and cannot be emulsified into a latex matrix. After the emulsification time is reached, the oil-water phase is still liquid.

[0053] Comparative Example 2

[0054] On the basis of Example 2, BHT and tea polyphenols were not added, and other conditions remained unchanged.

[0055] like Figure 3 As shown, the emulsification effect becomes worse, the matrix stability decreases, the storage period is shortened, and it is easier to demulsify.

[0056] Comparative Example 3

[0057] On the basis of Example 2, BHT was not added, and other conditions remained unchanged.

[0058] like Figure 4 As shown, without adding BHT, the latex matrix has low viscosity and is easier to demulsify.

[0059] Comparative Example 4

[0060] On the basis of Example 2, tea polyphenols were not added, and other conditions remained unchanged.

[0061] like Figure 5 As shown, without adding tea polyphenols, the emulsification effect is poor, the matrix viscosity is low, water droplets seep out on the surface of the matrix, and it is easy to break the emulsion.

Claims

1. An emulsion explosive, characterized in that: The raw materials include oil phase material and water phase material, the oil phase material includes white oil, oil phase emulsifier and additive, the oil phase emulsifier is polyglycerol-3-diisostearate and n-octadecyl phosphoric acid; the additive is 2,6-di-tert-butyl-4-methylphenol; the water phase material includes oxidant nitric acid aqueous solution and tea polyphenol; the above raw materials are calculated by weight as follows: 22-28 parts of white oil, 2-4 parts of polyglycerol-3-diisostearate, 4-8 parts of n-octadecyl phosphoric acid, and 235-247 parts of nitric acid aqueous solution; the concentration of the nitric acid aqueous solution is 60-68 wt%; the tea polyphenol is 0.1-0.3% of the mass of the nitric acid aqueous solution, and the 2,6-di-tert-butyl-4-methylphenol is 0.3-0.5% of the mass of the nitric acid aqueous solution; the emulsion explosive is sensitized by adding glass microspheres.

2. A method for preparing the emulsion explosive according to claim 1, characterized in that: The following steps are involved: (1) Melting the oil phase raw material, adding it into an emulsifier and stirring to obtain the oil phase; (2) mixing the nitric acid aqueous solution and tea polyphenols, completely dissolving them to obtain an aqueous phase, and removing nitrogen oxides released by the nitric acid; (3) adding the water phase to the oil phase under the condition of heat preservation and stirring to emulsify and obtain a latex matrix; (4) The emulsion explosive is obtained by sensitizing the latex matrix.

3. The method for preparing the emulsion explosive according to claim 2, characterized in that: In step (3), the oil phase is kept warm at a temperature of 90-95° C. and the stirring speed is 800-1200 rpm.

4. The method for preparing the emulsion explosive according to claim 2, characterized in that: In step (3), the emulsification time is 5 to 7 minutes.

5. The method for preparing the emulsion explosive according to claim 2, characterized in that: In step (1), the melting temperature is 90-95°C.

6. The method for preparing the emulsion explosive according to claim 2, characterized in that: In step (2), the dissolving is carried out in a dissolver with stirring at a rotation speed of 100-150 rpm.

7. The method for preparing the emulsion explosive according to claim 2, characterized in that: In step (4), the sensitization method is: adding the latex matrix to the glass microspheres for sensitization.

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