RU2421434C2 - Method of preparing pellet powder with particle diameter of up to 2,5 mm - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to preparation of pellet powder for large-calibre machine guns and 30 mm air guns. The method involves preparation powder varnish in an aqueous medium in the presence of 1 pts. wt pyroxyline 1 Pl or powder mass, 8 … 10 pts. wt water and 2 … 3 pts. wt ethyl acetate, dispersing said varnish onto spherical particles with addition of 0.5...1.0 wt % protective colloid and 2.0...3.5 wt % sodium sulphate with respect to water to the dispersion medium, followed by removal of solvent.

EFFECT: method enables to obtain pellet powder with particle size of up to 2,5 mm.

1 tbl, 3 ex

Description

The invention relates to the field of production of spherical defects for heavy machine guns and 30 mm aircraft guns.

US patents [1, 2] propose a method for producing spherical gunpowder for small arms, which consists in grinding fine-grained pyroxylin gunpowders (MZPP) in an aqueous medium, followed by dissolving them in a solvent, dispersing the powder varnish onto spherical particles and removing the solvent from them.

The disadvantage of these methods is the inability to obtain large spherical powders.

The closest technical solution is a method for producing spherical gunpowder for hunting weapons [3] (prototype), including the preparation of powder varnish with stirring of pyroxylin 1 Pl or pyroxylin 1 Pl with return-technological waste (WTO) for 10 ... 15 minutes in 4 ... 5 parts by weight water together with diphenylamine (DFA) in an amount of 0.6 ... 1.2 wt.% and carbon black in an amount of 0.3 ... 1.0 wt.%, coming in the form of an aqueous suspension with a concentration of 20 ... 30 wt.%, and copper (II) - lead (II) phthalate oxide (FMS) in an amount of 0.5 ... 2.5 wt.% by weight of pyroxylin 1 Pl and with 2.4 ... 3.6 wt.h. ethyl acetate (EA), adding bone glue to the varnish, dispersing the powder varnish on spherical particles and removing EA when the mixture is heated to 92 ... 94 ° C.

The disadvantage of this method is that the obtained spherical powder has a size of powder particles with a diameter of not more than 0.63 mm The obtained particles according to this method with a diameter of more than 0.63 mm have an irregular shape.

The objective of the invention is to obtain large spherical powders with a diameter of the powder elements up to 2.5 mm

при дроблении на пороховые частицы в дисперсионной среде, содержащей по отношению к воде 0,5…1,0 мас.% защитного коллоида, способствует получению пороховых сферических элементов до 2,5 мм. Введение в дисперсионную среду по отношению к воде 2,0…3,5 мас.% сернокислого натрия обеспечивает плотную структуру пороховых элементов, при этом пористость сферических частиц равномерно распределена по объему сферических частиц и не превышает 5,0%.The technical result is achieved in that the preparation of powder varnish is carried out in a dispersion medium (in 8 ... 10 mass parts of water), where 2 ... 3 mass parts of EA are taken per 1 mass part of pyroxylin 1 Pl or powder mass. The resulting powder viscosity varnish

when crushed into powder particles in a dispersion medium containing 0.5 ... 1.0 wt.% protective colloid with respect to water, it contributes to the production of spherical powder elements up to 2.5 mm. The introduction of 2.0 ... 3.5 wt.% Sodium sulfate into the dispersion medium with respect to water provides a dense structure of powder elements, while the porosity of the spherical particles is evenly distributed over the volume of spherical particles and does not exceed 5.0%.

Examples of the method for producing large spherical powders with a diameter of powder elements up to 2.5 mm within the boundary conditions outside them, as well as by a known method are shown in the table.

Example 1. In a reactor with a volume of V = l, 57 m ^3, 560 liters of water are poured, 70 kg of powder mass is loaded and mixed for 15 minutes. Then 140 liters of EA are poured into the reactor and a powder varnish is prepared for 30 minutes at a temperature of 50 ... 55 ° C. After introducing a protective colloid in the amount of 2.8 kg at a temperature of 55 ... 65 ° C, dispersion of the powder varnish on spherical particles is carried out. Dehydration of the spherical particles is carried out at a temperature of 65 ... 68 ° C for 30 minutes with the introduction of 11.2 kg of sodium sulfate into the dispersion medium, then the solvent is distilled off from the powder elements in a known manner. The characteristics of gunpowder are given in the table.

Example 2. In a reactor with a volume of V = 1.57 m ^3, 630 liters of water are poured, 70 kg of powder mass is loaded and mixed for 15 minutes. Then 175 liters of EA are poured into the reactor and a powder varnish is prepared for 30 minutes at a temperature of 50 ... 55 ° C. After entering the protective colloid in the amount of 4.72 kg at a temperature of 55 ... 65 ° C, the dispersion of the powder varnish on spherical particles is carried out. Spherical particles are dehydrated at a temperature of 65 ... 68 ° C for 30 minutes with 17.3 kg of sodium sulfate introduced into the dispersion medium, then the solvent is distilled off from the powder elements in a known manner. The characteristics of gunpowder are given in the table.

Example 3. In a reactor with a volume of V = l, 57 m ^3, 700 liters of water are poured, 70 kg of powder mass is loaded and mixed for 15 minutes. Then 210 liters of EA are poured into the reactor and a powder varnish is prepared for 30 minutes at a temperature of 50 ... 55 ° C. After introducing a protective colloid in an amount of 7.0 kg at a temperature of 55 ... 65 ° C, dispersion of the powder varnish on spherical particles is carried out. Dehydration of spherical particles is carried out at a temperature of 65 ... 68 ° C for 30 minutes with the introduction of 24.5 kg of sodium sulfate into the dispersion medium, then the solvent is distilled off from the powder elements in a known manner. The characteristics of gunpowder are given in the table.

Outside the boundary conditions in examples 4, 5, the results obtained are shown in the table.

From the results of the table it can be seen that the obtained large spherical gunpowder according to the method developed by the authors (example 1, 2, 3) provides the yield of the target fraction of gunpowder with a spherical particle size from 0.9 to 2.5 mm within 60 ... 62%. The bulk density of spherical powder is in the range from 0.995 to 1.035 kg / dm ³ with a uniformly distributed porosity in the powder elements from 4.4 to 5.0%.

Outside the boundary conditions (example 4, 5), large spherical gunpowder practically does not provide a given shape. According to the known method (example 6), it is impossible to obtain large spherical gunpowder, because in a cramped flow, the particles take an elongated shape. Therefore, the method developed by the authors ensures the production of large spherical powders with a diameter of spherical particles up to 2.5 mm, high bulk density and low porosity.

Literature

1. US patent No. 2843584.

2. US Patent No. 3378545.

3. RF patent No. 1727375 (С06В 21/00).

Table Technological modes of obtaining large spherical powder with a diameter of powder elements up to 2.5 mm and its characteristics No. p / p The name of indicators According to the proposed method By a known method Example 1 Example 2 Example 3 Example 4 Example 5 one 2 3 four 5 6 7 8 one Download pyroxylin 1 PL or powder mass, kg 70 70 70 70 70 one hundred 2 The amount of water in the reactor, l 560 630 700 400 720 300 3 The amount of ethyl acetate to dissolve the powder mass, l 140 175 210 120 220 300 four The amount of protective colloid, kg 2,8 4.72 7.0 1,6 7.1 2.5 5 The amount of sodium sulfate, kg 11.2 17.3 24.5 10,2 2.5 3.0 6 The yield of the target fraction of spherical powder with a diameter of spherical particles of 0.9 ... 2.5 mm,% 60 62 61 10 There is no suitable fraction There is no suitable fraction 7 The bulk density of spherical powder, g / cm ³ 0,995 1.012 1,035 0.86 - - 8 Conditional porosity,% 2.0 2.5 2,4 8.0 - -

Claims (1)

A method of producing spherical powders, including the preparation of a powder varnish in an aqueous medium, dispersing it onto spherical particles, followed by removal of solvent from them, characterized in that in order to obtain spherical powder with a particle diameter of up to 2.5 mm, the preparation of powder varnish is carried out in the presence of 1 mass part pyroxylin 1 Pl or powder mass, 8 ... 10 mass parts of water and 2 ... 3 mass parts of ethyl acetate, dispersion of powder varnish in a dispersion medium onto spherical particles is carried out with the introduction of dispersion with meal 0.5 ... 1.0 wt.% protective colloid and 2.0 ... 3.5 wt.% of sulfuric acid relative to the sodium water.