The Chemistry of Powder and Explosives - Sciencemadness Dot Org

CHLORATE AND PERCHLORATE EXPLOSIVES 357
oxygen and liquid nitrogen) containing 33% of oxygen gave no
explosion; with 40% oxygen an enlargement of 9 cc; with 50%
80 cc, with 55% 147 cc.; and with 98% oxygen an enlargement
of 384 cc, about 20% greater than the enlargement produced by
60% straight dynamite. The higher temperatures of explosion of
the liquid oxygen explosives cause them to give higher results in
the Trauzl test than correspond to their actual explosive power.
Liquid oxygen explosives are used in this country for open-cut
mining or strip mining, not underground, and are generally prepared
near the place where they are to be used. The cartridges
are commonly left in the "soaking box" for 30 minutes, and on
occasions have been transported in this box for several miles.
One of the most serious faults of liquid oxygen explosives is
the ease with which they inflame and the rapidity with which
they burn, amounting practically and in the majority of cases to
their exploding from fire. Denues 34 has found that treatment of
the granular carbonaceous absorbent with an aqueous solution
of phosphoric acid results in an explosive which is non-inflammable
by cigarettes, matches, and other igniting agents. Monoand
diammonium phosphate, ammonium chloride, and phosphoric
acid were found to be suitable for fireproofing the canvas wrappers.
Liquid oxygen explosives made up from the fireproofed
absorbent are still capable of being detonated by a blasting cap.
Their strength, velocity of detonation, and length of life after
impregnation are slightly but not significantly shorter than those
of explosives made up from ordinary non-fireproofed absorbents
containing the same amount of moisture.
Chlorate and Perchlorate Explosives
The history of chlorate explosives goes back as far as 1788
when Berthollet attempted to make a new and more powerful
gunpowder by incorporating in a stamp mill a mixture of potassium
chlorate with sulfur and charcoal. He used the materials in
the proportion 6/1/1. A party, had been organized to witness the
manufacture, M. and Mme. Lavoisier, Berthollet, the Comrnissaire
M. de Chevraud and his daughter, the engineer M. Lefort,
and others. The mill was started, and the party went away for
34 A. R. T. Denues, "Fire Retardant Treatments of Liquid Oxygen
Explosives," U. S. Bur. Mines Bull. 429, Washington, 1940.