RU2386607C2 - Method of preparing pellet powder - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to preparation of pellet powder for small-arms weapons and small-calibre artillery. The method of preparing pellet powder involves preparation of powdered lacquer by mixing pyroxylin or its mixture with recyclable production wastes and ethylacetate in an aqueous medium, dispersing the powdered lacquer onto spherical particles, addition of 0.1-0.3 pts. wt pellet powder of the same composition with particle size of 0.2-0.8 mm per 1 pts. wt pyroxylin or its mixture with recyclable production wastes, stirring for 20-40 minutes, addition of a dehydrating agent, removal of ethylacetate, washing the powder, fractionation, graphitation and drying.

EFFECT: invention enables obtaining dense pellet powder with particle size of 1,0-3,0 mm.

1 tbl, 5 ex

Description

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

Known methods for producing TFP, which include obtaining a powder of varnish in an aqueous medium in the presence of a solvent (e.g. ethyl acetate), dispersing it onto spherical particles of a given size under the action of an emulsifier (glue, gelatin or other surfactants), dehydrating the dispersed particles (upon receipt of dense granules ) and subsequent distillation of the solvent [1-3]. The gunpowder obtained by this method is highly and medium dispersed (fraction of not more than 0.7-0.8 mm) and does not provide ballistic characteristics of propelling charges, for example, small-caliber artillery.

The closest technical solution (prototype) is a method for producing TFP [5], including the preparation of powder varnish with stirring in an aqueous medium of pyroxylin or its mixture with recycling waste (WTO) together with diphenylamine, an aqueous suspension of carbon black and ethyl acetate (EA), dispersing varnish onto spherical particles and removing EA by heating the mixture to 92-94 ° C, characterized in that in order to increase efficiency by reducing the intensity of gas production of gunpowder in the initial period of its production anija, the slurry concentration is 1 part by weight soot for 8-10 parts by weight water, and the initial removal of EA in the amount of 70-75% is carried out at a speed of 0.4-1.2 l / s per cubic meter of mixture.

Thus obtained powder has the required density only within the fractional composition of not more than 0.7-0.8 mm. The disadvantage of this method is the impossibility of obtaining a dense TFP with a pellet diameter of 1.0-3.0 mm, providing ballistic characteristics, for example, in a hunting cartridge "Magnum" with a shotgun mass of up to 50 g.

The objective of the invention is to obtain a dense TFP with a diameter of granules of 1.0-3.0 mm

The technical result is achieved by the fact that in the method for producing TFP, which includes the preparation of powder varnish in an aqueous medium with stirring of pyroxylin or its mixture with WTO together with diphenylamine and EA, dispersing the powder varnish onto spherical particles and removing EA when the mixture is heated to 92-94 ° C , in order to obtain dense granules with a diameter of 1.0-3.0 mm, 0.1-0.3 parts by weight are introduced into the mixture after dispersion. TFP of the same composition with a grain size of 0.2-0.8 mm with respect to 1 wt.h. pyroxylin or its mixture with WTO, stirred for 20-40 minutes, dehydrated salt is added, EA is removed, gunpowder is washed, fractionated to obtain a 1.0-3.0 mm fraction, graphitized and dried.

Controlling the size of spherical particles, in particular, achieving a diameter of up to 3.0 mm as part of a regular water-dispersion process, is a new and rather complicated task. To obtain granules with a diameter of 1.0-3.0 mm, it is necessary to adjust the viscosity of the powder varnish. With low viscosity varnish, fine granules of gunpowder are obtained; viscous varnish is broken into granules of unfixed size and shape. To preserve the required sizes and shapes, it is proposed to introduce TFP of the same composition with a granule size smaller than the size of the obtained TFP in order to compensate for the decrease in the viscosity of the varnish particles when the temperature rises to dehydration, before distillation and for the adsorption of the “salted out” EA when the dewatering salt is introduced, thereby eliminating the change particle shape or secondary dispersion. After completion of the formation process, the introduced TFP is separated by fractionation. In fact, the introduced TFP is the WTO, but differs in the stage of the process at which it is introduced and the depth of processing. According to calculations, the introduction of 0.1-0.3 wt.h. TFP is equivalent to a decrease in the EA module by 0.2-0.85 depending on the properties of cellulose nitrate raw materials. These values compensate for the decrease in the viscosity of the particles of the dispersed varnish when the temperature rises to the temperatures of dehydration, distillation, and the effect of the salted out EA when the dehydrator is introduced.

Granule size 0.2-0.8 mm is determined by the need for further fractionation, i.e. separation from the target fraction (1.0-3.0 mm). These granules are constantly in the technological cycle of the formation of TFP.

Obviously, the proposed technical solution is acceptable for the case of the use of ballistic mass, which in addition to pyroxylin includes NHC [4].

The table shows examples of the method for producing TFP within the boundary conditions and beyond them according to the known variant.

Table.
Technological parameters of the method Name of indicator Example 1 Example 2 Example 3 Example 4 Example 5 Prototype Water module four four four four four four EA module 1.8 2.0 3,5 3,5 1,5 3.5 The number of injected TFP, wt.h. 0.1 0.2 0.3 0.4 0.05 The size of the granules introduced SFP, mm 0.2-0.4 0.4-0.63 0.63-0.8 0.63-0.8 0.2-0.4 - Mixing with TFP, min twenty thirty 40 fifty 10 - Dosage of Na ₂ SO ₄ , wt.% (To water) 2.0 4.0 6.0 7.0 1,5 - Gunpowder characteristics The diameter of the granules, mm 2.5-3.0 1.5-2.5 1.0-1.5 1.0-2.0 0.7-0.9 0.4-0.63 Exit, % fifty 63 70 - - - Density, g / cm ³ 1,58 1,59 1,60 1.43 1,60 1.40 Bulk density, g / cm ³ 0.94 0.95 0.97 0.83 0.97 0.80 Ballistic characteristics in the hunting cartridge "Magnum" with a shotgun mass of 50 g Mass propellant charge, g 2.90 2.89 2.87 2.70 2.54 2.60 Shot shell velocity, V ₁₀ , m / s, average 326 327 325 319 321 321 The average maximum pressure of the powder gases, P _m.s. MPa 64.9 65,2 63,4 91.2 90.7 94.3 Requirements ND to the cartridge "Magnum" with a sleeve length of 76 mm: V _{10 sr} not less than 315 m / s, P _m.av. not more than 90 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 WTO and 5.4 L of EA are loaded. The mixture is heated to 68 ° C and mixed for 15 minutes. Then 0.09 kg of glue is loaded. After dispersion, 0.3 kg (0.1 parts by weight) of TFP of the same composition with a grain size of 0.2-0.4 mm is introduced and the dispersion is mixed for 20 minutes. Then 0.24 kg (2 wt.%) Of dehydrator - (sodium sulfate) is introduced. The temperature rises to 75-94 ° C and EA is removed by distillation. Subsequently, the gunpowder is washed, fractionated into a fraction of 1.0-3.0 mm and dried.

The remaining samples are made similarly with a constant load of pyroxylin (ballistic mass) of 3 kg. Examples 2-5 (see table) differ from example 1 by the granule size, the amount of introduced TFP, and the corresponding technological parameters (EA module, duration of mixing, dosage of sodium sulfate).

From the data of the table it can be seen that TFP made according to the declared modes (examples 1-3) have a granule diameter of 1.0-3.0 mm with a bulk density of 0.94-0.97 g / cm ³ , which provides ballistic characteristics in hunting cartridge "Magnum". Moreover, with an increase in EA module, granule size of the introduced TFP and dosage of sodium sulfate, the duration of mixing (EA adsorption) increases. The yield of the target fraction 1.0-3.0 mm is 50-70%. The manufacture of gunpowder outside the boundary conditions (examples 4,5) leads to the production of more porous or smaller granules, which burn more degradingly, which causes an increase in the pressure of the powder gases above the above norms.

The decrease in the number of input TFP less than 0.1 wt.h. with respect to pyroxylin or its mixture with the WTO, a short duration (Example 5) leads to insufficient adsorption of the salted EA from the dispersion medium upon introduction of a dehydrator (sodium sulfate) and, as a result, loss of the shape and size of granules of the obtained TFP. The increase in the number of introduced TFP more than 0.3 wt.h. it is impractical, since all the “salted out” amount of EA is bound, an excessive redistribution of EA from the varnish particles occurs, which prevents their compaction during dehydration.

Thus, the proposed method for the manufacture of TFP provides for the production of water-dispersion technology of dense large granules with a diameter of 1.0-3.0 mm and a bulk density of not less than 0.94 g / cm ³ .

LITERATURE

1. US patent No. 3824108, CL. C06B 21/12, 1974.

2. Auth. St. USSR No. 1727375, MKI C06B 21/00.

3. US Patent No. 2915519, Cl. C06B 21/12, 1959.

4. Spherical gunpowder / Yu.M. Mikhailov, N.M. Lyapin, V.F. Sopin, etc. // Chernogolovka: IPCP RAS, 2003. - P. 22.

5. RF patent No. 1806462, MKI C06B 21/00 (prototype).

Claims (1)

A method of producing spherical powder, including the preparation of powder varnish with stirring of pyroxylin or its mixture with recycling waste and ethyl acetate in an aqueous medium, dispersing the powder varnish on spherical particles and removing ethyl acetate, characterized in that 0.1-0.3 are introduced after dispersion parts by weight spherical powder of the same composition with a granule size of 0.2-0.8 mm in relation to 1 wt.h. pyroxylin or its mixture with technological waste, stirred for 20-40 minutes, a dehydrator is introduced, after removal of ethyl acetate, the gunpowder is washed, fractionated to obtain a 1.0-3.0 mm fraction, graphitized and dried.