DE4036787A1 - Safe, environmentally friendly destruction of explosives - pref. propellant powder, by hydrolytic cleavage followed by biological degradation in a clarifying plant - Google Patents

Abstract

Destruction of explosives (esp. propellant powders) is effected by (i) hydolytic cleavage; followed by (ii) degradation in a biological clarifying plant. PROCESS - Step (i) is effected using a lye, eg NaOH, KOH or (s(OH)2, opt. in the presence of a dissolving aid, eg an alcohol or surfactant. The prod. from step (i) pref. has its pH adjusted (pref. by acid-addn) to make it suitable for step (ii). The plant used in step (ii) pref. has a suitable sequence of aerobic and anaerobic stages. ADVANTAGE - The process is safe and environmentally friendly

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 glowing, blowing up or shooting. But he shows all these procedures major disadvantages:

safety

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 burn off, 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.

Throughput

During the deflagration, roughly 40 million m ^{3 of} very aggressive gases (especially NO _x ) are made from the estimated 40,000 t of explosives from today's NVA stock, 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.

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. nitrate dissolved in water 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 about 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 when burned), 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 and
• b) subsequent degradation in a biological sewage treatment plant.

2. The method according to claim 1, characterized in that the hydrolytic cleavage is carried out with an alkali (for example Na OH, KOH, Ca (OH) ₂ ). 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 any one of claims 1 to 3, characterized by adjusting (lowering) the pH value after the hydrolyti rule split z. B. by adding acid to a value that is suitable for subsequent biodegradation. 5. The method according to any one of claims 1 to 4, characterized records that biodegradation in one for assembly suitable sequence of aerobic and anaerobic Procedural steps is carried out.