ANNM

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ANNM (or AN/NM), short for Ammonium nitrate-Nitromethane is a binary explosive with limited use in various domains, due to it's relative low stability.

Composition

ANNM consists of 60% ammonium nitrate and 40% nitromethane by mass. Methanol is usually added to reduce sensitivity.

The relative effectiveness factor of ANNM varies depending on the mix, but does not exceed 1.0 (ANNM+AL = R.E.F. of 1.0-1.1).

Properties

ANNM is a white gel or paste-like material (depending on the NM or MeOH percentage), which is slightly soluble in water and more soluble in lower-chain alcohols. It is slightly hygroscopic, but NM's poor solubility in water limits this effect.

ANNM is a very powerful AN-based explosive material, though it's more sensitive than ANFO or most AN-based explosives, which makes it easier to detonate. It has a detonation velocity of 6125 m/s.

The detonation of ANNM, it produces water vapors, carbon dioxide, nitrogen, as well as various NOx if the oxygen balance is negative. The balanced equation is as follows:

3 NH4NO3 + 2 CH3NO2 -> 2 CO2 + 9 H2O + 4 N2

The addition of more nitromethane will increase the negative OB, the same effect can also be achieved by adding a desensitiver, like methanol or xylene.

Availability and preparation

ANNM is rarely sold by any explosive manufacturing companies, however it's components are much more accessible.

Pure nitromethane is getting difficult to find in recent years, and the only accessible source is nitro fuel, where it's mixed with methanol and various oils. The sale of ammonium nitrate is also restricted in many countries.

The manufacturing of ANNM is done by people who don't know better. While it's relative easy to prepare this material, the main issue in obtaining a good product is the quality of the AN used. Readily available AN, like the garden variety tends to be "wet", as in have high humidity, and drying ammonium nitrate is difficult. Likewise, in many countries commercial AN is mixed with calcium carbonate/nitrate/sulfate to inhibit its explosive potential, a safety measure taken after numerous AN-related tragedies. Such AN cannot explode no matter what you mix it with, and thus required purification, which is relative difficult to do, as AN is very soluble in water and as mentioned, difficult to dry. Nitromethane tends to increase the sensitivity of the ammonium nitrate, meaning that ANNM is much easier to detonate than ANFO, though for safety a booster is still recommended.

Projects

  • Mining and blasting rocks apart

Safety

Handling and storage

Unlike most AN-based explosives, ANNM is more hazardous to handle as it is more sensitive. ANNM tends to readily give off nitromethane fumes, which causes it to lose potency as well as sensitivity. Contact with bases must be avoided at all cost!

Storing it is not recommended for safety precautions.

Legality

Manufacturing and use of ANNM, like other AN-based explosives, without a license is a crime in most countries.

In USA, ATF rules that the components of binary explosives are not considered explosive materials, when kept separate. However, when mixed, the resulting ANNM mixture is classified as explosive material.[1]

Disposal

Controlled incineration should suffice. ANNM can also be used as fertilizer if diluted in plenty of water.

See also

References

  1. https://www.atf.gov/explosives/binary-explosives

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