Improvements in Explosives.
Year: 1897

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by
the decision of the Chief Examiner of the 2nd day of February 1899.
Date of Application, 26th Apr., 1897-Accepted, 3rd July, 1897
COMPLETE SPECIFICATION (AMENDED).
Improvements in Explosives.
I, OSCAR FREDRIK CARLSON, of Kornhamnstorg 4, Stockholm, in the Kingdom of
Sweden, Managing Director of "Stockholms Superfosfat Fabriks Aktiebolag," 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 :-
This invention relates to improvements in explosives.
It is well known that chloric acid possesses the property of exploding with great
violence under certain conditions without any external impulse.
Perchloric acid, however, which is of a much more permanent nature or more stable
is of a different character and for this reason its salts are well adapted, when mixed
with inflammable substances, to form powerful and safe explosives which can be
exploded only by a powerful impulse.
For instance, dry mixtures of chlorates and flowers of sulphur explode spontaneously
if the latter contains the least trace of free sulphuric acid. Chlorate of ammonia also
forms a substance which explodes spontaneously with violence even at ordinary
temperatures. On the other hand a mixture of perchlorate and flowers of sulphur
containing sulphuric acid is perfectly safe, and perchlorate of ammonia is a stable,
safe substance which can only be exploded by the most powerful impulses.
That an important advantage can be gained by the employment of perchlorate of
ammonia (ammonium perchlorate) instead of a perchlorate in which a metal constitutes
the base is evident from the fact that in the former case gases only are formed when
explosion occurs, whilst in the latter case both gases and solid substances are formed.
The use of perchlorate of ammonia and carbon on the one hand, and perchlorate of
potash and carbon on the other may be illustrated by the following examples:
(1) NHO CI+ 2 C when exploding form HCl + NH₂ + 2 CO₂
(2) KO CI +2 C when exploding form KCl + 2 CO₂
In the latter case a quantity of potassium chloride amounting to 46 % of the weight
of the explosive is obtained. Evidently the potassium chloride has no expansive
action, being instead detrimental. In the former case, on the contrary, the whole of
the explosive is converted into gas, the volume of which is consequently twice as

page_text: great as in the second case and the blasting power of the explosive is thereby
considerably increased.
The heat liberated in the explosion, in the case where perchlorate of ammonia is
employed in the explosive, being distributed throughout a larger volume of gas, the
temperature produced must be lower than when another perchlorate is used. If this
were not the case, the heat would become so intense as to give rise to dissociation of
the gases and, inasmuch as the dissociation is accompanied by absorption of heat, to
a corresponding loss in blasting power.
Perchloric acid contains an abundance of oxygen, and by mixing perchlorate of
ammonia with inflammable substances, such for instance as carbon, sulphur, starch,
cellulose, fatty oils, hydrocarbons and nitro compounds, as have not sufficient oxygen
to effect their own complete combustion in such proportions as give a maximum
blasting power, explosives may be produced which can be exploded only by powerful
external impulses such as by the ignition of dynamite detonating caps, and which
are capable of developing considerable energy in their explosion as shewn by the
results of both theoretical and practical investigations.
This may be illustrated by a few simple examples. It should first be mentioned,
however, that perchlorate of ammonia, though evaporating quietly when heated on a
sheet of platinum brought to incandescence, is to be regarded as an explosive
although of inferior quality. It cannot be exploded by fulminate of silver caps of the
size employed in blasting with dynamite. A material increase in the percussive
action is required for the purpose.
When perchlorate of ammonia is exploded, the equation of combustion is as
follows:-
(1) NHO,C1 =2 H2O + NO2 + Cl, one kilogramme of perchlorate of ammonia
giving 665-2 litres of gas although only developing 244.4 Calories of heat.
:-
By adding carbon in varying quantities the following results will be obtained :-
(2) 3 NHO CI + C = 6 H₂O + CO2 + N + 3 C1 + 2 NO,, one kilogramme of
perchlorate of ammonia now giving 673-9 litres of gas and developing 547.4
Calories.
This explosive consists of 96.5 % perchlorate of ammonia and 3.5 % carbon. This
slight addition of carbon more than doubles the heat developed and produces an
explosive of quite satisfactory blasting power.
(3) NH OCI + 2 C = 2 CO2 + NH3 + HCl, one kilogramme now giving 631.6
litres of gas and developing 1123-7 Calories.
This explosive consists of 83.1 % perchlorate of ammonia and 16.9 % carbon.
By the further addition of carbon a still greater amount of heat can be developed,
the latter now being five times that developed when using perchlorate of ammonia
alone, and a corresponding increase in the power of the explosive being attained.
In the above calculation all the carbon is assumed to be active in forming CO₂ in
combination with the oxygen of the perchlorate.
Still more favorable results are obtained by the use of hydrocarbons, for instance :—
A mixture of 5 molecules of sugar and 48 molecules of perchlorate of ammonia
gives the following equation :-
5 C,H,On + 48 NHOC1 = 60 CO₂+ 48 HCl + 127 H2O + 48 N, one kilo-
gramme of the mixture when exploding giving 789-8 litres of gas and 1056
Calories, a result obtainable, no doubt, by few explosives. It consists of 76.7 %
perchlorate of ammonia and 23.3 % sugar.
With another mixture, consisting of
C12H22O11 + 6 NHOCl = 12 CO₂ + 11 H2O + 6 HCl + 6 NH3, all the carbon con-
tained in the sugar will be oxidized by the oxygen of the perchlorate of ammonia ;
this mixture consists of 67.4 % perchlorate of ammonia and 32.6 % sugar.
As in the case of the carbon, the proportion of sugar may be considerably increased
without appreciable inconvenience. The table given below, contains a few examples
of explosives formed of perchlorate of ammonia and an inflammable substance or
substances, which can be used in any percentage between the limits marked, the

page_text: perchlorate of ammonia being finely pulverised and thoroughly mixed with the
inflaminable substances.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I make no claim to
compounding perchlorate of ammonia with explosive substances containing sufficient
oxygen to effect their explosion, but I declare that what I claim is :-
--
Explosives composed of perchlorate of ammonia mixed with one or more inflammable
substances and in which the proportion of perchlorate of ammonia varies from 40 to
98 per cent. by weight and that of the inflammable substance or substances mixed with
the perchlorate of ammonia from 60 to 2 per cent. by weight.
D
1
.
+1 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.