CN102010379A - Method for producing hexogen - Google Patents

Abstract

The invention discloses a method for producing hexogen. In the method, urotropine and concentrated nitric acid are taken as reaction materials, and the weight ratio of the urotropine to the concentrated nitric acid is 1:9-11. On the basis of a conventional direct-nitrolysis production process, the method comprises the following steps of: simultaneously and uniformly feeding the raw material urotropine with the fineness of 60 to 80 meshes into a device containing the concentrated nitric acid from at least two feed inlets, and reacting the urotropine with the concentrated nitric acid under the condition of 10 to 15 DEG C to prepare the hexogen. The method remarkably increases the yield of the hexogen from original 78.4 percent to over 85.2 percent only by changing the feeding way and fineness of the reaction material without increasing any investment.

Description

A kind of production method of RDX

technical field

The present invention relates to a production method of RDX, in particular to a method for producing RDX by direct nitrolysis method, specifically, the present invention is an improvement on the production method of RDX by direct nitrolysis method.

Background technique

RDX, whose chemical name is cyclotrimethylenetrinitramine, or RDX for short, was produced by Henning in the synthesis of medicine in 1899. In 1921, Hertz first confirmed that it was a valuable explosive, and successfully prepared it by nitrating hexamethamine with nitric acid at low temperature. Due to its good explosive performance and rich sources of raw materials, RDX is increasingly important in the field of explosives. During and after the Second World War, many countries conducted research on the production method of Hexogen. Now Hexogen has developed into one of the main charges of modern weapons and ammunition after TNT.

At present, the production methods of RDX in industry mainly adopt direct nitrification method and acetic anhydride method. Wherein, the direct nitration method is to directly nitrate urotropine with concentrated nitric acid, and the reaction formula is:

(CH ₂ ) ₆ N ₄ +4HNO ₃ -→(CH ₂ NNO ₂ ) ₃ +NH ₄ NO ₃ +3CH ₂ O

This method is an early method and is still in use today. The actual nitrification reaction is very complicated, and its production process includes: 1. The raw material hexatropine is crushed, screened and dried; Supplementary reaction is carried out to generate Hexogen, and the nitrification reaction is violent and exothermic; 3. Dilute the nitrifying liquid with water to increase the temperature, oxidize the unstable by-products, precipitate Hexogen crystals, and filter them; 4. Rinse and boil the filtered Hexogin with water to remove residual acid; 5. Coat the surface of the drug particles with passivating agents such as wax to reduce their mechanical sensitivity; 6. Vacuum dry to obtain qualified finished products.

The acetic anhydride method is to use urotropine, nitric acid, ammonium nitrate, and acetic anhydride to carry out nitrification reaction in acetic acid medium to prepare Hexogen, and the reaction formula is:

(CH ₂ ) ₆ N ₄ +4HNO ₃ +2NH ₄ NO ₃ +6(CH ₃ CO) ₂ O-→2(CH ₂ NNO ₂ ) ₃ +12CH ₃ COOH

The process of producing RDX by acetic anhydride method can be divided into two-step method and one-step method. The two-step method is to react dilute nitric acid with hexatropine to generate dinitrate of hexotropine, then separate and dry it and put it into a mixed solution of nitric acid, ammonium nitrate, acetic anhydride and acetic acid for nitrification to generate mesogen. The one-step method is to put hexotropine directly into the mixed nitrification agent for nitrification to obtain mexogen. The advantage of the acetic anhydride method is that it increases the yield of RDX, and its theoretical yield is double that of the direct nitrification method. However, a large amount of acetic acid and acetic anhydride will be used in the production of Hexogin by the acetic anhydride method, resulting in high product cost, and a certain amount of Octogen will be generated in the reaction process, and the separation is difficult. Compared with other methods, the formaldehyde utilization rate of the acetic anhydride method is the best, and it is a relatively economical method for countries with abundant raw materials and low prices of acetic anhydride.

The advantage of the direct nitrification method is that acetic anhydride is not consumed, but the disadvantage is that the theoretical yield is only 50% of that of the acetic anhydride method, and a large amount of nitric acid is consumed. Nevertheless, the research on the direct nitrolysis method of RDX has never stopped at home and abroad, and a lot of work has been done in increasing the product yield and improving the production process.

Our country is rich in nitric acid, so the only few RDX production lines currently adopt the direct nitrification production process. The process equipment and process conditions are the technology of the former Soviet Union in the 1950s and 1960s. There has been no major change for decades, and the equipment is outdated. The technology is backward, the yield is only about 74%, and the annual production capacity is about 10,000 tons, which is less than one-twentieth of that of the United States. At the same time, the production cost of RDX is very high, and the price is about four times that of TNT. The above-mentioned status quo has seriously hindered the extensive application of RDX in my country's weapon energy, making it impossible for our country to use RDX-based mixed explosive charges in large quantities like foreign countries. For this reason, it is of great practical significance to study the production process of Hessogen's direct nitrification method, optimize the process conditions and equipment, and increase its yield.

Contents of the invention

The purpose of the present invention is to improve the direct nitrification production process of RDX, and increase the yield of the product by changing the way of feeding raw materials.

On the basis of the existing direct nitrification production process, the present invention researches the process of preparing hexogin by changing the feeding method and the fineness of the raw materials, and finds that when increasing the fineness of hexamethamine, and adopting two points Or when adding hexotropine to the reaction system by multi-point feeding method, the yield of methogen can be greatly improved.

The existing production technology of direct nitrification method to prepare methogen is to use hexotropine with a weight ratio of 1:9-11 and concentrated nitric acid as reaction materials, and react at 10-15° C. to prepare methogen. The present invention improves the existing production process, using urotropine with a fineness of 60-80 meshes as the reaction material, and uniformly adding it into the device filled with concentrated nitric acid at the same time from no less than 2 feeding ports and mixing with the concentrated nitric acid. Nitric acid reacts.

Among them, the time for adding urotropine to concentrated nitric acid should be controlled within 12 to 15 minutes.

The nitrification reaction stage in the process of preparing RDX by direct nitrification method is a solid-liquid two-phase reaction with large heat release. The feeding method is very important, and the feeding method is determined according to the main reaction mechanism and the controlled type of reaction. Decide. On the basis of the existing technology, the present invention adopts no less than two feeding ports for simultaneous feeding, so as to increase the exothermic reaction area of urotropine, improve the effect of heat diffusion, reduce the degree of local overheating, and improve heat transfer. Improve process efficiency, thereby reducing the oxidative decomposition of urotropine and avoiding the ignition of urotropine during the feeding process. At the same time, the use of refined urotropine effectively increases its specific surface area and the uniformity of particles, thereby increasing the uniformity of solid-liquid phase reactions and reducing the decomposition of urotropine caused by local overheating, thereby Increased Hexogen yield.

On the basis of the existing direct nitrolysis production process, the present invention does not increase any investment, only changes the feeding method of the reaction materials, and adds the refined urotropine from two or more points of the reaction device, so that The yield of RDX has been significantly improved, from 78.4% to over 85.2%. At the same time, the obtained RDX product was analyzed, and the measured value of the melting point was 200.2-202.5°C, which had a relatively high purity.

Detailed ways

Example 1

After drying the urotropine, grind it to 70 mesh with a mortar and set it aside.

Add 75ml of concentrated nitric acid to a 500ml four-necked flask equipped with a stirrer, a thermometer and an addition funnel, place the four-necked flask in an ice-water bath, start stirring, cool to 13°C, and gradually uniformize the mixture through the two inlets of the four-necked flask Add 12g of refined urotropine, control the nitrification temperature at 12°C, and add all urotropine within 12 minutes. After the addition, continue to stir and keep warm at 15°C for 25min. Then the reaction solution was poured into a beaker filled with 300ml of ice water, stirred sufficiently to crystallize RDX, filtered and dried to obtain 13.54 g of RDX product with a yield of 85.4% and a melting point of 201°C.

Example 2

After drying the urotropine, grind it to 60 mesh with a mortar and set it aside.

Add 70ml of concentrated nitric acid into a 500ml four-necked flask equipped with a stirrer, a thermometer and an addition funnel, place the four-necked flask in an ice-water bath, start stirring, cool to 12°C, and gradually uniformize the mixture through the two inlets of the four-necked flask Add 10 g of refined urotropine, control the nitrification temperature at 10°C, and add all urotropine within 15 minutes. After the addition, the stirring was continued at 12°C for 20 minutes. Then the reaction solution was poured into a beaker filled with 300ml of ice water, stirred sufficiently to crystallize dersogen, filtered, and dried to obtain 13.51 g of hexogen product with a yield of 85.2% and a melting point of 200°C.

Example 3

After drying the urotropine, grind it to 80 mesh with a mortar and set it aside.

Add 73ml of concentrated nitric acid to a 500ml four-necked flask equipped with a stirrer, a thermometer and an addition funnel, place the four-necked flask in an ice-water bath, and start stirring. Cool to 10°C, gradually and uniformly add 11g of refined urotropine through the two inlets of the four-necked flask, control the nitrification temperature at 13°C, and add all the urotropine within 13 minutes. After the addition, the stirring was continued at 14°C for 30 minutes. Then the reaction solution was poured into a beaker filled with 300ml of ice water, stirred thoroughly to crystallize dersogen, filtered, and dried to obtain 13.64 g of hesogen product, with a yield of 86.0% and a melting point of 202°C.

Claims (2)

1. the production method of a Cyclotrimethylene trinitramine, with weight ratio is that 1: 9～11 urotropine and concentrated nitric acid are reaction mass, prepared in reaction Cyclotrimethylene trinitramine under 10～15 ℃ of conditions, the fineness that it is characterized in that the reaction mass urotropine that uses is 60～80 orders, urotropine is evenly added the device that fills concentrated nitric acid simultaneously from the charging opening that is no less than 2 react with concentrated nitric acid.

2. the production method of Cyclotrimethylene trinitramine according to claim 1 is characterized in that the time that urotropine joins in the concentrated nitric acid is controlled at 12～15min.