Improvements in Nitroglycerin Safety Blasting Explosives.
Year: 1899

page_text: Date of Application, 19th Jan., 1899-Accepted, 25th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Nitroglycerin Safety Blasting Explosives.
I, GEORG ALEXANDER NAHNSEN, of Dömitz on the Elbe, near Hamburg,
Germany, Chemist, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The improvements in the manufacture of safety blasting explosives containing
nitroglycerin have not only been gradual but also of comparatively small impor-
tance. There are practically and theoretically no material differences between the
various kinds of carbonite, kynite, and similar compounds; the improvements were
sought to be obtained by small mysteriously acting additions and the success has
only been small.
My invention is based upon the ascertained knowledge that additions like
sulphurous tar oils, and chromate and permanganate salts are not only useless
but actually impair the efficiency as mere loading and filling materials, and
secondly that only the proportions of the ingredients can improve the effect of the
explosives without lowering their safety in the presence of firedamp and coal dust.
Among many proportions the one has proved the best which consists of 30 parts
nitroglycerin by weight and an admixture consisting of 8 parts cellulose and 32 parts
chilisaltpetre. This explosive is in the greatest quantity by weight safe against
the fire damp and coal dust, gives about 20 per cent, less explosive force, by about
25% more work than the so-called carbonite and shews a better composition of
gases in the after damp:
0
The chilisalpetre may according to requirement for keeping in store be replaced
by other kinds of salpetre or mixtures of same in molecular proportions. But
chilisalpetre answers perfectly to normal requirements and circumstances.
The cellulose may be fruit wood or bark meal, but I find that rye meal is the
best to work with. As the cellulose not only serves as carrier for the carbon but
also as an absorbent for the nitroglycerin, it is important to give particular
attention to these properties in the choice of the meal.
The nitroglycerin must of course be absolutely pure and free from acid.
The mixing proportions are within narrow limits of variation, especially the
powder admixture. The amount of nitroglycerin may vary within 2 or 3 per cent.
without impairing the effect and safety, but such great variations are not per-
missible as regards the saltpetre and still less as regards the cellulose addition.
The greatest care has to be taken that the additions in question are exact if
possible to a per cent. and in any case do not go beyond 1 per cent.
proportion of mixtures of 30 parts nitroglycerin, 30 parts saltpetre and 40 parts
meal is of considerably less value than a proportion of 32 salipetre and 38 meal,
because the former gives less yield of work, greater explosibility and inferior
afterdamp.
A
The manufacture of the explosive is comparatively simple. The several sub-
stances have to be practically dry. As I have already stated that the weight
proportions have to be kept very accurate, it naturally follows that the mixing has
to be most carefully done.

page_text: The result is a dry mass which can be conveniently made up into cartridges
either by hand or by machine. My new explosive is as regards its composition very
similar to the coal carbonite 2, but it shews very great differences as regards its
properties. The following table is founded on the calculations and observations
of the "bergassessor" Heise of. Gelsenkirchen:
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.