Table Of ContentINTERNATIONAL SYMPOSIUM ON
MINING
RESEARCH
PROCEEDINGS OF A SYMPOSIUM
HELD AT THE UNIVERSITY OF MISSOURI,
FEBRUARY 1961
Edited by
GEORGE B. CLARK
Missouri School of Mines and Metallurgy
VOLUME 1
SYMPOSIUM PUBLICATIONS DIVISION
PERGAMON PRESS
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1962
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Copyright © 1962
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PREFACE
MINING research in a very large portion of its efforts must be concerned with
full scale field investigations and, hence, is costly and time consuming. In
spite of these and related difficulties, investigations into this branch of the
earth sciences are making rapid and significant advances in many categories.
Two ot these are dynamic and static rock mechanics, and explosives and
blasting.
The research described in the papers given at the International Symposium
on Mining Research is of both basic and applied character, which is note
worthy in itself. Some research results may not have immediate application,
but many of the greatest scientific truths have been disclosed by research
which was performed for the sake of discovering new scientific truths,
whether or not they could be used in the foreseeable future. Real progress in
mining engineering must be accompanied by comparable research efforts
which will be concerned more and moie with scientific principles as well as
their application.
SYMPOSIUM COMMITTEE
MARLING J. ANKENY, Director ALVIN W. KNOERR, Editor
U.S. Bureau of Mines Engineering and Mining Journal
GEORGE B. CLARK, Chairman WILLIAM C MILLER
Department of Mining Engineering Mining Methods Research Engineer
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
ROBERT F. BRUZEWSKI, Associate Professor JOHN J. REED, Professor
Department of Mining Engineering Department of Mining
Missouri School of Mines and Metallurgy Colorado School of Mines
RODNEY D. CAUDLE, Research Engineer RAYMOND G. TRAVIS
Department of Mining Engineering Mining Methods Research Engineer
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
CARL R. CHRISTIANSEN, Associate Professor Louis A. TURNBULL, Assistant Chief
Department of Mining Engineering Division of Foreign Activities
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
MORRIS T. WORLEY, Instructor
Department of Mining Engineering
Missouri School of Mines and Metallurgy
CONTRIBUTORS TO THE
FINANCIAL SUPPORT OF THE SYMPOSIUM
Airmite-Midwest, Inc. Missouri School of Mines and Metallurgy
American Metal Climax, Inc., Mining and
Monsanto Chemical Company
Exploration Division
American Smelting and Refining Company National Science Foundation
The Anaconda Company Peabody Coal Company
Bureau of Mines, U.S. Department of the Phelps Dodge Corporation
Interior
Sahara Coal Company, Inc.
Hanna Coal Company, Division of Con
solidation Coal Company
Spencer Chemical Company
Kennecott Copper Corporation, Western
Mining Division The United Electric Coal Companies
vii
SYMPOSIUM COMMITTEE
MARLING J. ANKENY, Director ALVIN W. KNOERR, Editor
U.S. Bureau of Mines Engineering and Mining Journal
GEORGE B. CLARK, Chairman WILLIAM C MILLER
Department of Mining Engineering Mining Methods Research Engineer
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
ROBERT F. BRUZEWSKI, Associate Professor JOHN J. REED, Professor
Department of Mining Engineering Department of Mining
Missouri School of Mines and Metallurgy Colorado School of Mines
RODNEY D. CAUDLE, Research Engineer RAYMOND G. TRAVIS
Department of Mining Engineering Mining Methods Research Engineer
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
CARL R. CHRISTIANSEN, Associate Professor Louis A. TURNBULL, Assistant Chief
Department of Mining Engineering Division of Foreign Activities
Missouri School of Mines and Metallurgy U.S. Bureau of Mines
MORRIS T. WORLEY, Instructor
Department of Mining Engineering
Missouri School of Mines and Metallurgy
CONTRIBUTORS TO THE
FINANCIAL SUPPORT OF THE SYMPOSIUM
Airmite-Midwest, Inc. Missouri School of Mines and Metallurgy
American Metal Climax, Inc., Mining and
Monsanto Chemical Company
Exploration Division
American Smelting and Refining Company National Science Foundation
The Anaconda Company Peabody Coal Company
Bureau of Mines, U.S. Department of the Phelps Dodge Corporation
Interior
Sahara Coal Company, Inc.
Hanna Coal Company, Division of Con
solidation Coal Company
Spencer Chemical Company
Kennecott Copper Corporation, Western
Mining Division The United Electric Coal Companies
vii
AMMONIUM NITRATE-FUEL-SURFACTANT
EXPLOSIVES—THEIR FUNDAMENTALS AND
PERFORMANCE
K. HINO* and M. YoKOGAWAf
Nippon Kayaku Co. Ltd., Asa, Yamaguchi-ken, Japan
1. SELECTION OF SURFACE ACTIVE AGENTS
THE detonation ability of ammonium nitrate-fuel mixtures depends heavily
on the reaction rate between an oxidizer, ammonium nitrate, and a reducer
fuel. One of the ways to increase the mass reaction rate is to pulverize
ammonium nitrate so that we can increase the specific surface of the oxidizer.
However, this method has its limit because ammonium nitrate and oily fuels
usually repel each other. Therefore, we cannot achieve an intimate mixture
on molecular scale, and this situation in turn hinders rapid reaction between
an oxidizer and a reducer. Physico-chemically speaking ammonium nitrate
is quite similar to water and they have strong affinity for each other, while
water repels oil or coal tar.
Some organic compounds, called the surface active agents or surfactants,
have an atomic group called a hydrophilic group at one end which has a
strong affinity for water and another atomic group called lipophilic group at
an opposite end which has a strong affinity for oily substances.
In Tables 1, 2 and 3 the effect of the surfactant on the detonation ability
of explosives has been classified as follows: A weight percent of 0-5 of the
surfactant was added to the basic composition which contains 93-3%
Ammonium nitrate and 6-2% coal tar and the three components were mixed by
a heavy edge runner mill. In tables 1, 2 and 3, A indicates the best detonation
ability, B a good one, while C indicates an unsatisfactory one. In the case of
A the composition detonates with diameters of around 20-24 mm initiated
by a No. 6 electric detonator. The best surfactants are all anionic ones and
they are :
(1) Sodium dinaphthylmethane disulfonate (S.D.D.).
(2) Sodium laurylsulphate (S.L.S.).
(3) Sodium dodecylbenzene sulfonate (S.D.B.).
* Dr. Eng. Chief, Explosives Research Section.
f M. Eng. Head, Powdery Explosives Research Group.
1
2 Κ. ΗΙΝΟ AND M. YOKOGAWA
TABLE 1. ANIONIC SURFACTANT
No. Chemical Trade Brand Detonation Caking
ability
1 Sodium laurylsulfate (S.L.S.) I A A
II A A
III B C
2 Sodium stearylsulfate I A C
II B C
ITI B C
3 Sodium higher alcohol sulfate I A C
II B C
III B C
IV B C
V B C
VI B C
4 Sodium alkylphosphite I A C
II B C
5 Alkylphosphate triethanolamine A c
6 Sodium stearyl amide methylethylsulfonate B c
7 Sodium aliphatic amide alkylethylsulfonate A A
8 Sodium dodecylbenzenesul fonate (S.D.B.) I A A
II A c
III B
C
IV C
C
9 Butylnaphthalene sulfonate C C
II B C
10 Alkylbenzene sulfonate I B A
II B B
III B j A
11 Alkylnaphtalene sulfonate I 1 A C
II B ! A
c
III B
12 Sodium dinaphtylmethane disulfonate
(S.D.D.) I A A
II B A
III B A
AMMONIUM NITRATE-FUEL-SURFACTANT EXPLOSIVES 3
TABLE 2. CATIONIC SURFACTANT
No. Chemical Trade Brand Detonation Caking
ability
13 Laurylamine acetate 1 C A
11 B A
14 Dioctadecyl-dimethyl ammonium chloride I C C
II B A
15 Octadecyl-trimethyl-ammonium chloride C C
16 Dodecyl-trimethyl-ammonium chloride B C
17 Quarternary ammonium salt I A C
II C C
III C C
IV C C
V C B
VI C C
18 Tetradecyl-pyridinium chloride B C
19 Hexadecyl-pyridinium chloride B C
20 Alkyl pyridinium salt I B C
III B C
III B C
21 Stearylamide methyl-pyridinium chloride B C
TABLE 3. NON-IONIC SURFACTANT
No. Chemical Trade Brand Detonation Caking
ability
22 Polyoxyethylene-alkylether 1 B C
11 B C
III B c
23 Polyoxyethylene-oleate B c
24 Polyoxyethylene-alkylphenol 1 B B
II C A
25 Polyoxyethylene-sorbitan laurate B C
26 Polyoxyethylene-sorbitan stéarate C C
27 Polyoxyethylene-sorbitan oleate B C
4 Κ. ΗΙΝΟ AND M. YOKOGAWA
2. MEASUREMENT OF THE DETONATION ABILITY
The detonation ability was measured as follows :
A cylindrical charge of an explosive whose length is 230 mm wrapped with
a thin paper shell is placed on a sand bed and a total body of an industrially
standard No. 6 detonator is inserted into the longitudinal axis of cartridges
of various diameters and is fired electrically. In general at least 10 shots are
fired for each diameter. The diameter at which 100% detonation takes place
is defined as the " practical minimum diameter 2 R " and the diameter at
w
which 50% detonation occurs is defined as the " critical diameter 2 R "
c
while the diameter at which no detonation occurs is defined as the " failure
diameter 2 R ". The smaller the value of R , R or R respectively, the
f w c /5
better the detonation ability of the composition is found to be.
Figure 1 shows the numerical values of R , R and R for ammonium
w c f
nitrate-coal tar mixtures with and without surfactants and it shows high
detonation ability of a mixture with the surfactant S.D.D. In the following
the surfactant used is S.D.D. if not otherwise stated.
AN - coal tar - surfactant AN - coal tar explosive
explosives (A-3) (A-l)
2R mm 50
OR Failure Practical
m diameter minimum
diameter
Diameter of cartridge
FIG. 1. Practical minimum diameter R , Critical diameter R and Failure dia
m c
meter Rf of AN-coal tar explosives with (A-3) and without (A-l) surfactant.
3. EFFECT OF THE PERCENTAGE OF SURFACTANTS
ON THE DETONATION ABILITY
The relation between the content of the surfactant and the critical diameter
is shown in Fig. 2. C.M.C, indicates that there exists the " critical micelle
concentration " which is widely observed in the effect of the surfactant. In
Other words, the surfactant affects the reaction on the boundary between
AMMONIUM NITRATE-FUEL-SURFACTANT EXPLOSIVES 5
two components and the phenomenon of saturation may be expected. Only
a small amount of the surfactant is needed to achieve the purpose and this
characteristic makes its industrial applications quite economical.
5ör
> Surfactant %
FIG. 2. Saturation effect of surfactant.
4. DETONATION VELOCITY AND STRUCTURE OF
REACTION ZONE
Figure 3 indicates the detonation velocity of D in m/sec for various dia
meters of cartridges measured by a streak camera. It indicates that the
surfactant increases the detonation velocity remarkably. The structure of
the reaction zone has been calculated on the basis of the theory proposed by
one of the authors,1»2 the result being summarized in Fig. 4. The critical
reaction time is reduced from 10*3 microseconds to 7-90 microseconds for
the explosive A-3 with the surfactant.
5. EXPLOSIVE PROPERTIES
Explosive properties of the explosive A-3 with the surfactant compared
with those of a conventional semi-gelatine dynamite are summarized in
Table 4.
