RU2439041C2 - Method of producing pellet powder - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of pellet powder for small arms. The method of producing pellet powder involves preparation of cellulose nitrate lacquer in an aqueous medium in the presence of ethyl acetate, dispersion, dehydration, distillation of the solvent, fractionation and drying. The solvent used is a mixture of ethyl acetate and toluene in volume ratio 90:10-70:30. Filler is added in amount of 0-50 wt % and dispersion is carried out at temperature 69-72°C.

EFFECT: invention increases output of coarse granules of gun powder.

1 tbl, 5 ex

Description

The invention relates to the field of production of spherical powders (TFP) for small arms.

Known methods for producing TFP [1-5], which include obtaining a powder of varnish in an aqueous medium in the presence of a solvent (eg, ethyl acetate), dispersing it onto spherical particles at a temperature of 62-68 ° C under the action of emulsifier of glue, gelatin or other surfactants, dehydration of the dispersed particles using sodium sulfate (upon receipt of dense granules), followed by distillation of the solvent. A disadvantage of the known methods is the unstable yield of the target fraction, due to the secondary dispersion when the temperature rises and the input of sodium sulfate.

The closest technical solution (prototype) is a method for producing TFP, according to which 300 parts of cellulose nitrate (SC), 3 parts of diphenylamine (DPA) and 2700 parts of water are loaded into a vessel with an agitator and external heating, 1026 parts of ethyl acetate are added ( EA), heated to 68 ° C, stirred for 1 hour at 68 ° C, add a protective colloidal solution of 10 parts of bone glue to 200 parts of water, slowly add another 405 parts of EA, partially EA is distilled off, 105 parts of sulfate are added sodium, 200 hours of water and drive away all EA. NC particles are separated, dried; granule size of approximately 0.2 mm [6].

The disadvantage of the prototype is the low yield of large granules of gunpowder (diameter more than 0.9 mm).

The aim of the invention is to increase the yield of large granules of gunpowder. This goal is achieved by the fact that in the method of producing TFP, which includes the preparation of NTs-varnish in an aqueous medium in the presence of EA, dispersion, dehydration, distillation of the solvent, a mixture of EA with toluene in a volume ratio of 90: 10-70: 30 is used, and filler in an amount of 0-50 wt.%, and the dispersion is carried out at a temperature of 69-70 ° C, the remaining operations are carried out in a known manner.

As a filler, finely dispersed aluminum powder or explosives (octogen, hexogen) are used.

In the case of water-dispersion granulation, it is necessary to create conditions under which the smallest changes in the shape and size of the particles of powder varnish occur after dispersion and shaping. This can be achieved by dispersing the powder varnish and shaping at a temperature as close as possible to the temperature at which the solvent is distilled off. A change in the shape and size of the varnish particles with increasing temperature is due to a decrease in the viscosity of the powder varnish. With an equally viscous state of varnish, the properties of the latter, determined by the physicochemical characteristics of the NTs and the content of nitroglycerin in the ballistic mass, can vary over a wide range.

Therefore, when using a mixture of EA-toluene as a solvent, the dispersion temperature is proposed to be increased to 69-72 ° С (the temperature of the onset of distillation of the EA-water azeotrope is 70.5-72.0 ° С). A dispersion temperature of less than 69 ° C leads to a decrease in the yield of the TFP fraction with large granule sizes.

The introduction of toluene of less than 10 vol.% Does not give the effect of additional compaction of the granules, reduces the solids content in it and the yield of large granules.

An increase in the toluene content of more than 30 vol.% Leads to an increase in the temperature of distillation of the azeotrope, the incompleteness of its removal from the composition, reducing the energy characteristics of the obtained TFP.

The introduction of the filler in the composition of the powder up to 50 wt.% Allows you to increase the solids content in the varnish particle, to a greater extent, ensuring the preservation of their size and shape, which are closest to the final size and shape of the TFP granules. An increase in its content of more than 50 wt.% Is impractical, since in this case the density of the granules of the TFP decreases.

The table shows examples of the method for producing TFP according to the known, developed options within the boundary conditions and beyond.

Technological parameters of the method Name of indicator Example 1 Example 2 Example 3 Example 4 Example 5 Prototype Solvent module (EA / toluene ratio) 3.00 (90/10) 2.93 (80/20) 2.56 (70/30) 3.70 (75/25) 1.93 (90/10) Solvent module relative to NC 3.0 3.34 3,58 3.08 4.34 Filler, wt.% - PAP-1 30 octogen 50 octogen 10 octogen 60 - Dispersion Temperature, ° С 69-70 70-71 72 64-66 66-68 66-68 Dosage of Na ₂ SO ₄ , wt.% To water 2.0 1,5 1.25 2.0 7.0 3.0 Gunpowder characteristics The diameter of the granules of the main fraction, mm 2.5-3.0 1.5-2.5 1.0-1.5 0.7-0.9 0.4-0.63 0.2-0.4 Density, g / cm ³ 1,58 1,59 1,60 1.48 1.45 1,54 Bulk density, g / cm ³ 0.94 0.95 0.97 0.92 0.80 twenty The output of the fraction is more than 1.0 mm,% fifty 55 65 35 thirty twenty Ballistic characteristics in the hunting cartridge "Magnum" with a shotgun mass of 45 g Mass propellant charge, g 2.90 2.89 2.87 2.70 2.54 2.10 Shot shell velocity, V ₁₀ , m / s 326 327 325 321 319 321 The average pressure of the powder gases, MPa 64.9 65,2 63,4 90.7 91.2 94.3 Requirements for the cartridge "Magnum" with a sleeve length of 76 mm: the velocity of the shot projectile is not less than 315 m / s, the average maximum pressure of the powder gases is not more than 90.0 MPa

Example 1. In a volumetric type reactor equipped with a stirrer and a heating jacket, 12 L of water is poured, 3 kg of pyroxylin or its mixture with process waste is loaded, and 9.0 L of a mixture of EA and toluene with dissolved DFA is poured. The mixture is heated to 69-70 ° C and mixed for 15 minutes. Then 0.09 kg of emulsifier is loaded and the contents of the reactor are mixed for 10-15 minutes. The temperature in the reactor rises to 74-75 ° C, and partial solvent distillation is carried out.

Then 0.06 kg (2%) of sodium sulfate is charged and the remainder of the solvent is distilled off. Subsequently, the gunpowder is washed, fractionated and dried.

Example 2. In a volumetric type reactor equipped with a stirrer and a heating jacket, 12 liters of water are poured, 2.1 kg of pyroxylin or its mixture with process waste is loaded, and a suspension of 0.9 kg of filler (aluminum powder, for example PAP-1, is poured ) in 8.775 l of a mixture of EA and toluene in a ratio of 80:20 with dissolved DFA. The mixture is heated to 70-71 ° C and mixed for 15 minutes. Then 0.09 kg of emulsifier is loaded and the contents of the reactor are mixed for 10-15 minutes. The temperature in the reactor rises to 77-78 ° C, and partial solvent distillation is carried out. Then 0.06 kg (2%) of sodium sulfate is charged and the remainder of the solvent is distilled off. Subsequently, the gunpowder is washed, fractionated, graphitized and dried.

Example 3. In a volumetric type reactor equipped with a stirrer and a heating jacket, 12 L of water is poured, 1.5 kg of pyroxylin or its mixture with process waste is loaded, and a suspension of 1.5 kg of filler (for example, highly dispersed HMX) is poured into 6 , 55 l of a mixture of EA and toluene in a ratio of 70:30 with dissolved DFA. The mixture is heated to 72 ° C and mixed for 15 minutes. Then 0.09 kg of emulsifier is loaded and the contents of the reactor are mixed for 10-15 minutes. The temperature in the reactor rises to 78-79 ° C, and partial distillation of the solvent is carried out. Then 0.06 kg (2%) of sodium sulfate is charged and the remainder of the solvent is distilled off. Subsequently, the gunpowder is washed, fractionated, graphitized and dried.

The remaining samples are made analogously to examples 1-3 and have a lower dispersion temperature and a filler content (example 4) or a lower dispersion temperature and a higher filler content (highly dispersed octogen; example 5).

From the data of the table it can be seen that the TFP obtained by the declared modes have a granule diameter of 1.0-3.0 mm with a bulk density of 0.94-0.97 g / cm ³ . The yield of the fraction with a granule size of 1.0-3.0 mm is 50-65%.

Gunpowder provides ballistic characteristics in the hunting cartridge "Magnum". The manufacture of gunpowder outside the boundary conditions leads to the production of smaller and porous granules, which burn more degradingly, causing an increase in the pressure of the powder gases above the indicated norms (examples 4,5).

Thus, the developed method for producing TFP provides the formation of large granules with a diameter of 1.0-3.0 mm by water-dispersion technology.

LITERATURE

1. Patent of Russia No. 1814805 from 10/11/1992.

2. Patent of Russia No. 1727375 dated October 13, 1993.

3. Patent of Russia No. 2226184 dated 03/27/2004.

4. Swiss patent No. 3777259 of 06/15/1964.

5. US patent No. 2891055 from 06.16.1959.

6. US patent No. 33979743.

Claims (1)

A method of producing spherical powder, including the preparation of cellulose nitrate varnish in an aqueous medium in the presence of ethyl acetate, dispersion, dehydration, distillation of the solvent, fractionation and drying, characterized in that a mixture of ethyl acetate and toluene in a volume ratio of 90: 10-70: 30 is used as a solvent. filler is introduced in an amount of 0-50 wt.%, and the dispersion is carried out at a temperature of 69-72 ° C.