Environmental Engineering Reference
In-Depth Information
explosives. Subsequently, these explosives were subject to explosion brisance tests
and blasting power tests, and the results were shown in Table
7.29
.
As shown in Table
7.29
, the brisance and blasting power of liquid explosives
seem to increase with the rise of nitric acid concentration. Notably, the explosives
prepared with more than 85 % nitric acid concentration can be detonated with no. 8
detonator, whereas the explosives prepared with less than 80 % nitric acid con-
centration do not possess stable explosion properties; instead, they tend to separate
into layers after being stored for a short period of time. Moreover, layer separation
turned out to be worse for explosives prepared with lower concentration nitric acid.
The no. 8 detonator is not able to detonate explosives with separated layers.
②
Effect of Oxygen Balance on the Properties of Explosives
To understand the effect of oxygen balance on the properties of explosives, the
concentration of nitric acid was maintained at constant, while the oxygen balance
has been changed gradually, and the results were shown in Table
7.30
.
As shown in Table
7.30
, the optimal outcome is obtained when the oxygen
balance in XJ-I type explosives is close to zero. When oxygen balance is too high or
too low, the explosion properties seem to be inferior. Particularly, severe layer
separation is evident in the liquid explosives when the value of oxygen balance is
adequately negative, which certainly would prohibit the full usage of the work
capacity of explosives. Based on these results, two formulations which have been
primarily considered for the production of XJ-I explosives were illustrated in
Table
7.31
.
(2) Preparation of XJ-I Explosives
①
Determination of Conditions used in Preparation Process
(1) Effect of different charging sequence on explosion properties
Under stirring conditions, toluene is slowly added into nitric acid while the
addition speed and reaction temperature are effectively controlled.
Alternatively, toluene can be
flask, and then nitric
acid is added portion-wise with stirring and cooling. Initially, the reaction rate is
slow, and it dramatically increases when the temperature of reaction solution
reaches certain values like 30
first charged into a reaction
fl
C, which in turn would increase the reaction
temperature enormously. However, if too much nitric acid is added at the begin-
ning, it will be extremely dif
40
°
-
cult to control the reaction rate and temperature. The
explosion properties of explosives prepared through different charging sequences
appear to be quite similar, as illustrated in Table
7.32
.
Table 7.29 Effect of nitric acid concentration on explosion brisance and blasting power
No.
Concentration
of nitric acid
(%)
Ratio% (mass)
Oxygen
balance
(%)
Brisance
(mm)
Explosion crater
volume in re
ne
ore (L)
Nitric
acid
Toluene
1
80
86
14
0.132
21.46
10.2
−
2
85
85
15
1.061
22.18
16.5
−
3
90
84.5
15.5
−
0.223
22.56
17.6
4
95
84
16
+0.57
24.29
22.5
