Editing ANFO (section)

== Industrial use ==
[[File:Charging with anfo.jpg|thumb|Charging a hole with ANFO for rock blasting]]

In the mining industry, the term ANFO specifically describes a mixture of solid ammonium nitrate prills and diesel fuel. Other explosives based on the ANFO chemistry exist; the most commonly used are [[emulsion]]s. They differ from ANFO in the physical form the reactants take. The most notable properties of emulsions are water resistance and higher bulk density.

While the density of pure crystalline ammonium nitrate is 1700&nbsp;kg/m<sup>3</sup>, individual prills of explosive-grade AN measure approximately 1300&nbsp;kg/m<sup>3</sup>. Their lower density is due to the presence of a small spherical air pocket within each prill: this is the primary difference between AN sold for blasting and that sold for agricultural use. These voids are necessary to sensitize ANFO: they create so-called "hot spots".{{efn|It was found by the IRA, in response to using low-[[brisance]] AN fertilizers, that "hot spots" can be created by blending powdered sugar into the ANFO mixture, effectively sensitizing the mixture to mining-standard [[prilled]] ammonium nitrate effectiveness in which the interaction of the detonation front with a spherical void concentrates energy. Blasting-grade AN prills are typically between 0.9 and 3.0&nbsp;mm in diameter.}} Finely powdered aluminium can be added to ANFO to increase both sensitivity and energy;<ref name=improve/> in commercial usages however, this has fallen out of favor due to cost.

ANFO has a [[bulk density]] of about 840&nbsp;kg/m<sup>3</sup>. In surface mining applications, it is typically loaded into boreholes by dedicated trucks that mix the AN and FO components immediately before the product is dispensed. In underground mining applications, ANFO is typically blow-loaded.

AN is highly [[hygroscopic]], readily absorbing water from air. In humid environments, absorbed water interferes with its explosive function.{{citation needed|date=September 2013}} AN is fully water-soluble; as such, it cannot be loaded into boreholes that contain standing water. When used in wet mining conditions, considerable effort must be taken to remove standing water and install a liner in the borehole; it is generally more productive to instead use a water-resistant explosive such as emulsion.