RU2242449C2 - Dibasic pyroxylin powder preparation method - Google Patents

Abstract

FIELD: explosives.

SUBSTANCE: invention relates to production of dibasic powders and can be used for charging gun cartridges. Method according to invention comprises impregnation of formed elements of pyroxylin powder with nitroglycerine, which is accomplished by mixing them in 10-80 vol % aqueous acetone solution in presence of nitroglycerine or nitroglycerine-containing gun powder mixture in the form of crumb or in powdered state at ratio of fine-grain pyroxylin powder to nitroglycerine-containing powder mixture between 1:1 and 1:5, mixing being carried out for 0.5 to 20 h at 20 to 50^оС.

EFFECT: increased energetic characteristics of gun powder and extended porosity range allowing high nitroglycerine contents to be achieved; increased resource of raw materials due to enabled involvement of overdue gun powder stock.

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Description

The invention relates to the production of dibasic powders and can be used to equip cartridges for small arms.

There is a method for producing ballistic powders (A.G. Horst. Gunpowder and explosives. M: Mechanical Engineering, 1972, p. 156). Gunpowder is dibasic. Components: cellulose nitrates (SC), nitroglycerin (NG) as a plasticizer, chemical stability stabilizer and other additives are mixed in warm water; in this case, the SC swells in the plasticizer. After squeezing the water, the powder mass is repeatedly passed through the hot rollers. Further water removal, compaction and plasticization of the powder mass occurs. The resulting web is cut into plates of a given size or rolled up and pressed through appropriate dies to form tubes or threads. Tubes and threads are further cut into elements of a given length. The method does not provide gunpowders of a modern technical level, and also it is laborious, dangerous.

There is a method of producing dibasic spherical powders (Schedule of the technological process for obtaining serial batches of varnish powder RTP 12-2001, FSUE "GosNIIHP", Kazan, 2001, p. 45-87). The method consists in obtaining a powder varnish from cellulose nitrates, a powder mixture based on nitroglycerin and a volatile solvent of ethyl acetate, dispersing the varnish onto spherical elements in an aqueous medium, removing the solvent, sorting, phlegmatization, drying.

The method allows to obtain dibasic spherical powder with a nitroglycerin content of up to 32 wt.%. Gunpowders are distinguished by a high technical level and are intended for a wide range of sporting and hunting, pistol, construction and mounting cartridges, including for a pistol cartridge of a modern technical level - Luger. But they have a high cost and there are technological difficulties in the formation of porous powders with a nitroglycerin content of more than 12 wt.%, With an apparent density of less than 1.4 kg / dm ³ , while a wide range of civilian powders are porous powders with a density of 1 , 1 ... 1.4 kg / dm ³ . The produced pyroxylin porous powders are monobasic powders. They are widely used in charges for small arms cartridges, they are distinguished by a large nomenclature, however they are inferior to spherical dibasic gunpowders in energy characteristics (specific heat of combustion of pyroxylin gunpowder is 3.6 ... 3.9 MJ / kg, and dibasic - 4.6. .4.9 MJ / kg). It is not possible to produce dibasic gunpowder of small grades according to the full cycle of producing pyroxylin powders by pressing from pyroxylin, nitroglycerin, an alcohol-ether solvent. The process has a high risk, since the alcohol-ether solvent has a high volatility, which will lead to the entrainment of the explosive substance - nitroglycerin in the gas phase and its accumulation in the communications. At the same time, requirements for modern gunpowder dictate the need to increase the energy characteristics of gunpowder.

The closest in technical essence (prototype) is a method for producing spherical dibasic gunpowder (E.N.Hyuman, I.R. Pereira, Conference Materials in Germany, Karlsruhe, 1982). The method consists in mixing cellulose nitrates with ethyl acetate (EA), a stabilizer of chemical resistance and obtaining varnish, when dispersed in an aqueous medium in the reactor, spherical elements of gunpowder are obtained and which solvent is removed. Even after the elements are sorted, operations are carried out by impregnating them with nitroglycerin (before its content in gunpowder 12 wt.%) In an aqueous mixture of ethyl acetate and, if necessary, a phlegmatizer - dibutyl phthalate (DBP), drying and polishing. The method has a limitation on the possibility of obtaining porous powders with a high (more than 12 wt.%) Nitroglycerin content and is realized only in the presence of production of pure nitroglycerin.

The objective of the invention is to improve the ballistic characteristics of gunpowder through the use of energy-intensive components, such as nitroglycerin, and to provide the required porosity of the powder elements.

A method is proposed that involves impregnating the formed powder elements of gunpowder with nitroglycerin and removing the solvent, characterized in that the impregnation of the formed elements of gunpowder, which is used as fine-grained pyroxylin powder, with nitroglycerin is carried out while stirring them in a reactor in an aqueous solution of acetone with a concentration of 10 ... 80 vol .% in the presence of nitroglycerin or a powder mixture in the form of crumbs or powder containing nitroglycerin, with a ratio of fine-grained pyroxylin powder to the powder mixture and in the form of crumbs or gunpowder containing nitroglycerin, 1: 1 ... 1: 5, a process temperature of 20 ... 50 ° C, a duration of 0.5 ... 20 hours.

The proposed method allows to obtain the required porosity of the powder elements, including its high values with a high NG content, to improve ballistic gunpowder, making it possible to use it in cartridges for modern small arms.

Moreover, when using dibasic spherical gunpowder based on high-nitrogen pyroxylin 1Pl (with nitrous oxide content of 210.5 ml / g) as nitroglycerin donor after extraction of NG from it, it is also used for its intended purpose. Obsolete gunpowder or powder mix in the form of crumbs containing nitroglycerin can be used as a nitroglycerin donor. And as an NG acceptor, obsolete pyroxylin gunpowder to be destroyed can also be used. Therefore, the method has a wide raw material base and can function without the presence of hazardous nitroglycerin production. The use of conversion raw materials, i.e. gunpowder, scattered from the State Reserve and subject to destruction, increases the economic efficiency of production.

Examples of the method are presented in tables 1, 2.

Analysis of these tables shows that the method allows to obtain dibasic powders with fine porosity (apparent density 1.16 ... 1.2 kg / dm ³ ) from fine-grained pyroxylin powders, with NG content up to 30.0 wt.%, With specific calorific value up to 4.8 MJ / kg. The dibasic gunpowder obtained from P-125 fine-grained gunpowder by impregnating it in an aqueous acetone medium in the presence of a nitroglycerin donor followed by removal of acetone provides ballistic characteristics for the dibasic gunpowder used in modern sports cartridges for a Luger pistol with a lower mass of powder charge Also from this brand of gunpowder, a high-quality dibasic gunpowder for hunting cartridges of 12 caliber was obtained, providing the required fraction speed with a minimum charge mass and (Example 3).

By impregnating NGV pyroxylin powder VUfl in aqueous acetone in the presence of dibasic spherical powder, VBfl was obtained from VUfl dibasic powder with NG content of 15.2 wt.% And an apparent density of 1.35 kg / dm ³ , i.e. gunpowder density decreased by 0.22 kg / dm ³ (from 1.57 to 1.35 kg / dm ³ ). The manufactured gunpowder meets the technical requirements when tested in hunting cartridges of 12 caliber with a charge mass of 1.65 g, i.e. It is at the level of the best domestic and foreign analogues

In addition, when using spherical gunpowder based on high-nitrogen pyroxylin as a donor of nitroglycerin, this powder after extraction of NG from it (example 4a) can also be used for its intended purpose, the powder density decreased from 1.52 to 1.16 kg / dm ³ . This powder meets the requirements of regulatory documentation in hunting cartridges of 12 caliber.

At low concentrations of acetone of 20 vol.% From fine-grained pyroxylin gunpowder VTM, a dense dibasic powder was obtained with an apparent density of 1.62 kg / dm ³ with an NG content of 18.7 wt.%, Providing ballistic characteristics when tested in rifle cartridges (example 5 )

Thus, the dibasic gunpowders made by this method by impregnating small grades of pyroxylin gunpowder provide requirements for modern cartridges by increasing the energy characteristics of the gunpowder and the formation of powder elements with the required porosity.

Claims (1)

A method of producing dibasic pyroxylin powder, comprising impregnating the formed elements of the powder with nitroglycerin, removing a solvent, characterized in that the impregnation of the formed elements of the powder, which use fine-grained pyroxylin powder, with nitroglycerin, is carried out while stirring them in a reactor in an aqueous solution of acetone with a concentration of 10 ... 80 vol.% In the presence of nitroglycerin or a powder mixture in the form of crumbs or gunpowder containing nitroglycerin, with a ratio of fine-grained pyroxylins of powder to the powder mixture in the form of crumbs or powder containing nitroglycerin, 1: 1 ... 1: 5, the process temperature is 20 ... 50 ° C, duration of 0.5 ... 20 h.