COAL - Clpdigital.org

42 THE COAL TRADE BULLETIN.
36 million tons of coal used in the I'nited States
last year, only S million tons were washed before
they were coked.
The I'nited States were not the pioneers in coke
making, but they are the leading producers at
tne present time by a large majority.
Italy and Denmark each produce something
over 16,000 tons annually, Sweden 60,000, Australia
126,000, then Canada. Spain, Austria-Hungary,
France, Russia, Belgium, Great Britain, Germany
and the United States produce an increased tonnage
in Hie order named.
Eliminating Great Britain from the list, the
I nited States makes more coke than all the balance
of the world combined; with over 24 million
tons in 1904, and over one-half of this enormous
tonnage is made about Pittsburgh. The United
States imported 180,000 tons and exported 585,000
tons in 1904, showing the home consumption of
this product, and by way of further swelling
ourselves with pride, we can say that five out of
every seven tons of coal are produced by Englishspeaking
people.
Our most formidable rival for honors in the
manufacture of coke?—the German empire—with
±4 million tons, is worthy of mention, although
eclipsed by our state of Pennsylvania alone, which
has an annual iiroduction of nearly 15,000,000 tons.
It is safe to say, however, that the profit in the
manufacture of Germany's 14 million tons equaled
that of our 24 million tons, as their coke is
almost entirely made in by-product ovens, where
haraly anything is lost in smoke. Coke was
made and used
I.\ THE MAM FACTURE OF PIG IKON
in England in 1735. and became general in 1750.
Germany commenced in 1768, but coke was not
used in America until a hundred years after it
was first used in England. In 1S37 coke was used
to some extent in the Lonaconing furnaces in
Maryland. The first attempt in Pennsylvania
was in 1841, and was unsuccessful. Not until
I860 was its manufacture commenced regularly,
and in 1880 the reports at Washington indicate
about 3 million tons produced in the United States
that year, and in 1904 nearly 25 million tons.
The original method of coking coal was in
mounds of earth upon the ground, much the same
as lime was burned. Later, ovens of different
types were employed. The coke ovens of the
present are all included in the two types—bee-hive
and retort or by-product. The standard oven in
England and America is the bee-hive pattern, deriving
its name from the fact that its interior is
modeled after the exterior of the conventional beehive
on a large scale.
The process of the beehive oven is almost
identical to the original mound of coal covered
with soil upon the ground. The bee-hive process
has no provision for reclaiming any of the byproducts;
everything else is sacrificed for the
benefit of the coke. It is also known as the slow
combustion process in the manufacture of coke.
On the other hand, the
RETORT OVEN RETAINS CONTROL
of all the gas or volatile matter that the bee-hive
oven gives off. as well as the coke, and its process
is more rapid. Results are governed largely by
the nature of the eoal to be treated and which of
the by-products are most desired. The object of
many retort oven inventors has been to reclaim byproducts
other than coke, making that secondary,
as is the case in the manufacture of gas from
bituminous coal. The coke remaining is of no
special value, and that grade is not included in my
estimates.
The best c-oal for gas producing is not the best
coal for coke making in any coking device. The
coal used for that purpose is high in volatile and
thus naturally low in carbon, and lacks the necessary
caking properties of coking coal; where the
reverse conditions exist in the coal, there, coke is
the all-important product.
The standard or universal coke ovens used in
this state are of the bee-hive pattern and their
outward appearance is tbat of a continuous wall
with holes here and there at regular intervals
emitting flame and smoke.
The individual oven is the shape of the domestic
hive; is made of fire brick and the shell-like forms
are constructed in a row with a retaining wall in
front and rear, then tbe space around the domes
or ovens is filled with soil and thoroughly tamped
to top of oven, giving the effect of a solid wall.
Not only does this help to retain the heat in the
ovens, but protects them from weight of horses,
mine cars or the horseless larry which may cross
and re-cross the ovens to supply them with coal.
The interior of the bee-hive oven is about twelve
feet in diameter on the floor and eight feet from
floor or base to top of dome where there is an
opening to receive coal and permit smoke and gas
to escape. An opening about two feet wide by
three feet high in the front is used to
TAKE OUT.THE FINISHED CORK.
In starting up new bee-hive ovens, or those
which have been shut down, it is necessary to
build a fire in the ordinary way with wood and
coal upon the floor of the oven until the degree
of heat in the walls is sufficient to ignite the coal
by spontaneous combustion. After coke is drawn,
the heat is sufficient to ignite the new charge of
coal which follows almost immediately; no further
heat is applied or necessary to continue the
coking process. From five to seven tons of coal
are dropped into the oven from the top, while the
door or opening in front is being closed with loose
brick and plastered with mud, allowing only suffl-