A deflagrating or low explosive compound, consisting
of a mixture of an alkali nitrate, usually potassium
or sodium nitrate, mixed with charcoal and sulphur,
which is mostly pressed, granulated and classified
into definite grain fractions.
It is easily ignited,
friction sensitive, and produces dense smoke. Still
used as a propellant in fireworks although the advent
of so-called smokeless powder has now reduced its
role in commercial military type rockets, few remaining
military uses, such as igniters, in fuses to give
short delay, in black ammunition and as spotting charges.
It deflagrates faster than it donates; and is thus
classified as a low explosive. The standard composition
is 75% potassium nitrate, 10% sulphur and 15% charcoal.
There are also graded compositions containing 74,70,68
or 64% potassium nitrate. Corresponding compositions
based on sodium nitrate are known as B-Black Powder.