DE4036787C2 - - Google Patents

Description

The invention relates to a method for the destruction of explosives, ins special of propellant powders.

Very large amounts of ammunition must be destroyed as part of the disarmament will. The largest part consists of explosives or propellant charge neg.

Annihilation processes by burning, burning out, out are known glow, blast or shoot (Erhardt Heckmann: ammunition disposal at the NVA, magazine Wehrtechnik 10/90, pages 76, 77). All these However, processes have considerable disadvantages:

• - Security: through local imbalances, hot spots or catalytic In some cases, influences can be unintentional from burning off or burning detonation can damage the system or can destroy.
• - Environment: When the explosives are burned, the material problem becomes shifted into aggressive product gases, which in turn have to be cleaned sen, whereupon liquid or solid waste is generated again, which is their  are to be disposed of.
• - Volume throughput: From the estimated 40,000 t of explosives from today's NVA stock, roughly 40 million m ^{3 of} very aggressive gases (especially NO _x ) become deflagrated, whereby the composition of the gases is subject to considerable fluctuations depending on the combustion parameters and the type of ammunition. There are no gas cleaning systems that can be adjusted to the required size.

For these reasons, an annihilation process that does not require the disadvantages described works.

From Ullmann's Encyclopedia of Technical Chemistry, 3rd edition, 12th volume, 1960, page 791 is the decomposition of nitrocellulose by acids and Known bases of medium concentration.

From the book Hans G. Schlegel: Allgemeine Mikrobiologie, 4th edition, 1976, Pages 336 to 339 is the biodegradation of cellulose under aerobic and anaerobic conditions.

From Chemical Abstract 109: 20079e, Vol. 109, 1988, page 348 is the Biodegradation of TNT known by bacteria. Because TNT is a water insoluble Is solid, the bacteria can only ever touch the surface of the Attack the fabric, which makes the process very slow. Remedy would be achievable by fine grinding, which however due to its dangerous nature Disposal of larger quantities is eliminated.

In Wolfgang Langenbeck's textbook on organic chemistry, 11/12. Edition  1952, pages 46 and 47 is the ester cleavage in alcohol known as saponification and acids.

Chemical saponification 107 (26): 241949z describes the saponification of nitric acid esters known in ammunition waste water. This idea comes from the Fraunhofer Institute. For the disposal of ammunition and explosives the Fraunhofer Institute suggests on course B 7.08 on September 27, 1990: "Technical aspects of arms control" from 24.09. until 28.09. 1990 in Because on the Rhine, however, not a reductive process, but the high-pressure burn-up in front.

The object of the invention is to provide a method of destruction for explosives, propose specifically for propellant powder that is safe and environmentally friendly Lich and is suitable for large quantities.

According to the invention, this object is achieved by the hydrolytic cleavage the propellant powder, the neutralization of the resulting solution and the subsequent biodegradation with the characteristics of the main saying.

Embodiments of the invention are the subject of subclaims.

The driftwood removed from the ammunition or filled into the sacks Powder for artillery projectiles consists of a wide variety of compos nenten. The main components, however, are:

• - nitrocellulose,  
• - nitroguanidine,
• - nitroglycerin,
• - dinitroglycerin,
• - di-, triglycol dinitrate,
• - nitrotoluenes.

The compounds are nitric acid esters of organic compounds or nitro compounds. Even the stabilizers such as acardite or centralite, which are also contained in small amounts in the powder, consist of organic raw materials (urea derivatives). These compounds can be hydrolytically cleaved if the powders are added to alkaline aqueous media. By reaction with alkalis in aqueous solution (e.g. Na OH, KOH or Ca (OH) ₂ ), possibly with the addition of a solubilizer made of nitrocellulose z. B. dissolved in water nitrate and pure cellulose.

The basic summary reaction of the nitrates (R-NO ₃ ) is:

R-NO ₃ + OH⁻ → R-OH + NO ₃ ⁻.

The basic summary reaction of the nitro compound (R-NO ₂ ) is:

R-NO ₂ + OH⁻ RH + NO ₃ ⁻.

In addition to the nitrate (NO ₃ ⁻) formed in aqueous solution, nitrite (NO ₂ ⁻) can also be formed by side reactions.

The propellant powder is formed during the reaction of the components mentioned hen dissolved in water nitrate and nitrite and the associated organic Compounds (or other hydrolysis products of these compounds):

• - cellulose,
• - guanidine,
• - glycerin,
• - glycol,
• - toluene.

The difficultly soluble components such. B. cellulose form a muddy sediment, the rest goes into solution.

All of these reaction products from the first step are biodegradable. After lowering the pH or neutralizing with an acid e.g. B. pH 7 could therefore the entire solution in an appropriately designed biological treatment plant.

The clarification takes place in water basins, their connection in series and Process control is adapted to the specific wastewater. An important The main component is a denitrification stage, in which anaerobic Process bacteria such as B. Pseudomonas, Micrococcus or Denitrobacillus the organic components such as cellulose, guanidine etc. in their building blocks disassemble and use the nitrate dissolved in the water as an oxygen supplier. This removes both the organic components and the nitrate removed from the water, with the formation of gaseous nitrogen corresponding biomass forms. After the sedimentation tank that can be clarified Water is drained into a receiving water and the sludge is further processed  be operated as it is in established sewage plants with biological purification is usual, z. B. as fertilizer in agriculture or for energy extraction via methane gas formation in a digester. The Schlammver application seems less problematic than with municipal wastewater treatment plants, because contamination with heavy metals is hardly to be feared.

In comparison to the conventional methods (combustion), the method according to the invention is simpler and less dangerous. Since the destruction takes place in aqueous solution, there are no safety problems due to unwanted detonations. The residues (sewage sludge or fertilizer) can still be used. The environment is not polluted. Since 40,000 t of propellant powder, depending on the concentration of the solution, turns out to be approximately 100,000-300,000 m ^{3 of} wastewater to be treated in the sewage treatment plant (compared to 40 million m ^{3 of} aggressive gas during combustion) the amount of ammunition is also not more the excellent problem. Because biological wastewater treatment plants with a throughput of millions m ³ per year are standard.

The first step or steps (hydrolytic cleavage, neutralization) can advantageously carried out in mobile containers (containers, tanks) those who are then driven to the designated sewage treatment plants.

Claims (5)

1. A method for the destruction of explosives, in particular propellant powders, with the steps:

• a) hydrolytic cleavage
• b) adjustment of the pH to a value which is suitable for the subsequent biodegradation,
• c) subsequent biodegradation in a sewage treatment plant.

2. The method according to claim 1, characterized in that the hydrolytic cleavage with an alkali (e.g. NaOH, KOH, Ca (OH) ₂) is carried out. 3. The method according to claim 1 or claim 2, characterized records that solubilizers such as Alcohol or surfactants can be used. 4. The method according to claim 1, characterized in that the pH is adjusted by adding acid becomes. 5. The method according to any one of claims 1 to 4, characterized records that the biodegradation depends on the composition the solution in a suitable sequence of aerobic and performing anaerobic process steps.