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slakes and causes the coke to crumble and fall
apart.
Physical Tests,
Run-of-Mine Basic Coke—
Coke. 12*% Limestone.
Shatter test 70.5% 31.9%
Porosity 38.8 43.9
Apparent Sp. Gr 900 934
Real Sp. Gr 1.470 1.666
The shatter test is the crucial test. It is made
according to the U. S. government's specifications,
i. e., 4 drops of a given quantity of coke as a
height of 6 feet are made and then the broken
coke is passed over a 2-inch screen. The percentage
passing through constitutes the test. In
the above examples, 70 V- per cent, of run-of-mine
coke and 31.9 per cent, basic coke passed through
the 2-inch screen. The latter figure is about
standard for by-product coke.
The porosity and the specific gravity of the basic
coke is better than the run-of-mine coke. In
fact, we believe it is possible to take an inferior
grade of coking coal, and, by the scientific use of
crushed limestone in the by-product process, make
A-l blast furnace coke, where otherwise a total
failure would result. As before stated, this is
due to the formation of a slag binder in the coke.
By this feature of basic coke, vast quantities of
low grade, or semi-coking coals, would be opened
up for by-product use. Whether or not "the
game is worth the candle," at present is without
the scope of this article. There might be some
advantage to the furnaceman in having limestone
added to the coke instead of with it. There are
also some natural advantages to the by-product
operator. The total ammonia yield would be
increased by the addition of limestone to the coal,
and the percentage of fixed ammonia decreased,
which would lessen the work of the stills in the
indirect or semi-direct processes.
Finally, referring again to the underlying principle
of basic coke, i. e., the formation of a slag
carrying the sulphur in it, even if this were possible
during the coking process, it could not be
safely assumed that the sulphur would not get into
the iron in passing through the blast furnace
just as it does now without the proper safeguards.
In fact, we believe the old assumption in this respect,
that calcium sulphide passes through the
blast furnace unchanged, is erroneous, and that it
would avail nothing, from the sulphur standpoint.
to have basic coke. Calcium sulphide is stable
only at high temperatures and in a reducing atmosphere.
As the matter stands now, we think
that the sulphur in basic coke would be acted
upon by the iron ore in the top of the blast furnace
and changed back into its original harmful
form ready to be assimilated by the pig iron, unless
slagged off as usual, due to the action of the
THE COAL TRADE BULLETIN. 45
metallic oxides on calcium sulphide (CaS) at com
paratively low temperature.
In view of the foregoing, we conclude: First,
that basic coke, in the chemical sense, is not practically
feasible, nor wholly desirable. Secondly,
in the physical sense, it has possibilities in utilizing
low grade semi-coking coals for by-product
use.
ADDENDA.
TABLE FOR TIIE CALCUI.AT10X OF MONOSILICATES.
The following table shows in the second column
the weight of the bases required to bind 1 part by
weight of silica (SiO_.) as monosilicates.
The fourth column shows the weight of silica
(SiO,) required to bind 1 part by weight of the
various bases as monosilicates.
Monosilicates.
1 part of SiO_. combines 1 part of base combines
with: with:
1.0 SiO.. 1.86 CaO 1.0 CaO 0.535 S'02
1.0 SiO, 1.33 MgO 1.0 MgO 0.750 PiO,
1.0 SiO. 1.14 A1..0, 1.0 Al.,0, 0 873 SiO.
1.0 SiO. 2.40 FeO 1.0 FeO 0.416 SiO.,
1.0 SiO., 1.77 Fe..O, 1.0 Fe.O, 0.562 SiO.
1.0 SiO, 2.36 MnO 1.0 MnO 0.422 SiO„
1.0 SiO, 1.91Mn,Oi 1-0 Mn.,0, 0.524 SiO,
1.0 SiO. 7.43 PbO 1.0 PbO 0.134 SiO.
1.0 SiO_, 3.32CaCO,
To calculate CaO as CaCO, multiply by 1.7S57.
Example.
Composition of Ash.
Silica 47.85%
Iron oxide 15.84
Alumina 23.98
Lime 4.41
Magnesia 1.66
4.41 x .535 = 2.36% Silica (SiO.)
1.66 x .750 = 1.24 Silica (SiO..)
Total 3.60 Si'ica (SIO,)
47.85 — 3.60 =^ 44.25% Silica (SiO.) to take care of
44.25 x 3.32=140.88
146.88x8.61
= 12.65% CaCO, or limestone needed
100 to flux ash.
The towboat Sprague, of tie Pittsburgh Coal Co..
lost 45 of her tow* of 56 coal boats and barges at
Island Nc. 30, in the Mississippi river Dec. 2. when
a strong side current through a chute drove her
on a stone dyke iieing erected by the government
engineers. The Joss will be about $100,000. The
coal is being salvaged and reshipped on other
boats.
The Brothers Valley Coal Co. has opened a
branch office in tbe Merchants National Bank building,
Indianapolis, lnd., and Mr. J. R. Morris has
been placed in charge as resident manager.
The secind issue of the Employes' Magazine,
published by the Lehigh Valley Coal Co., is out
and is filled with interesting matter relative to the
welfare and efficiency of the employes.