Ammonium-Nitrate

TAN, or Technical Ammonium Nitrates, are essential components-oxidizers used in producing civil explosives for blasting operations.

TAN is produced synthetically by means of the three following stages:

1. The forming of nitric acid by combining oxygen, derived from air, and ammonia



2. The nitric acid and ammonia is combined to form an ammonium nitrate solution



3. The ammonium nitrate solution concentrate is then processed to have it form droplets of crystallised ammonium nitrate. When the droplets solidify they become known as prills. These prills, when dried and cooled are known as TAN (Technical Grade Ammonium Nitrate).

The ammonium nitrate chemical compound, or nitrate salt of ammonia, is a water soluble white crystalline solid that has the chemical formula of NH4NO3. It is used as an explosive in the mining industry as the main ingredient of ANFO (Ammonium Nitrate Fuel Oil). This is a common explosive that accounts for most of the explosives used in Australia.

The bulk industrial explosive, ANFO, that contains six percent fuel oil and 94 percent ammonium nitrate, is widely used in; civil construction, mineral mining, quarrying and coal mining operations. Its advantage is its low cost and ease of use.

In Australia the use of TAN in the form of the explosive compound ANFO, is regulated under the Dangerous Goods Regulations that came into law in 2005. Licences to use the product are only granted to industrial applicants who have the appropriate security measures in place to prevent misuse. Individual use is not allowed, although use for research or education purposes can be considered. ANFO is only to be used by employees who are appropriately licenced to handle the product and even then must be under the supervision of authorised personnel. Licences are only granted to people who can pass a police and security check.

Ammonium nitrate is a natural mineral found as an ammonium analogue of saltpetre, ammonia nitre and other minerals such as sodium nitrate. It is often found in conjunction with other nitrate, iodate, chlorate and halidide minerals, as a crust on the ground in the drier areas of the Atacama Desert in Chile. It has been mined in Chile in the past but today TAN (Technical Grade Ammonium Nitrate) is completely manufactured as a synthetic product.

Ammonium nitrate is widely used in agriculture as a fertiliser and has also been used by farmers to blast land away when undertaking dam construction. As a strong oxidant, ammonium nitrate readily reacts with reducing and combustible materials. It is also used to modify the detonation levels of other explosives. As it will absorb moisture from the atmosphere when exposed to a critical relative humidity level of 59.4 percent, it has to be stored in a tightly sealed container, if not, it will coalesce into a solid mass. It can also absorb sufficient moisture to form a liquid.