In recent years a number of explosive blends including ANFO, emulsion
and watergel products have been used in a variety of ground types and
applications. These `standard' explosives' technologies are not new, but
out of the uses and applications, have sprung a new generation of tailored
explosives that match the ground type and the operating environment.
This is in stark contrast to the norm, where various patterns and loading
configurations have traditionally been designed to accommodate the
explosive. This paper discusses these tailored explosives and the explosives'
technology behind why they work. Active tailoring of explosive
formulations can save mining dollars while essentially leaving the
explosive price unchanged. Tailoring explosives may lead to increased
rock breakage, heave, digging rates; lower digging maintenance costs and
in some cases replacing earth moving machinery altogether. Tailored
explosives may have other benefits such as reduced over pressure
compared with standard alternatives. The tailoring of explosive performance generally involves three major
methods (other than changing the bulk density and sensitivity): (i)
replacing fast burning reactants with slower burning reactants or vice
versa; or (ii) leaving the explosive intact and diluting the entire explosive
with slow burning or `inert' material; or (iii) changing the concentration
of the fuel/oxidiser mix. When tailoring explosives for particular
applications, authorising, testing, costing, manufacturing, and delivery
systems must also be taken into account.