The Big Stone Gap post. [volume] (Big Stone Gap, Wise County, Va.) 1892-1928, 1893-04-27
CRAB ORCHARD, Va
What Is Put into a Blast Furnace.
walter j. Nav.
j AS. II. P LEGG.

Walter j. May.
Although most people are acqualnt-
cd with iron, steel, and other COM
pounds Of iron and other things, yet
comparatively few know what is used
to produce the metal or alloys, and
fewer still know how the metal is pro-
duccd from the ''coal and other
things" used. OF coure, those con-
ncctcd with the trade should know
about the matter so far as the process
of smelling is concerned, but away
from the iron works labratory, even
in the iron trade there are few who
know the constituents of the various
subtanccS used. AS to the chemical
changes which take place in convert
inc the orc into metallic iron it is now
intended to speak, but of course these
are more affected by the character of
the materials used, and to some eX-
tent the working of a furnace is af-
fectcd by the condition of materials
introduced.
Spcakinr roughly, steel is made
from hematitc ore, and much of the
common ore, both cast and wrought,
is made from ironstone, this substance
being previously calcined to get rid
of the carbonic acid which it contains.
70 huX the materials used, limestone
is put into the furnace, while to supply
both heat and carbon, coke is usually
adopted medium, although charcoal
is used to a small extent, our lack OF
available wood largely restricting its
more general adoption. Of course
the proportions of the various mate
rails vary more or less, and it is quite
apparent that the richer the orc the
less quantity required, and vica versa,
thus also causing some considerable
variation in the total weights of ma
tcrials put into the furnaces, so far
as the solid matters are concerned,
and the gaseous ones are not the sub
iect Of the present paper.
Taking coke first, this should of
course be pure carbon, but in prac-
ticc this theoretical excellence is new
cr obtained, and from t to 10 per
cent. of ash is usually present, many
complaints being rife recently as to
the Iare percentage Of ash present IN
coke of later years. Two reasons
for complaint is presented when coke
is rich in ash, as in the first place
the carbon is reduced in quantity,
and in the second the ash usually
carries a lrage proportion of slllceous
and luminous insolublcs, which nee
itates the use of limestone as tlux,
while their presence also increases the
Stag and the consequent cost of han
ding. Washing being adopted in
many places to free the coal from
all but the fixed ash, and the Luhrig
process proves very Successful i'll this
place. as the dirt-"ash" us remov-
ed with the minimum loss of coal,
and practically the loss of coal
amounts to only a few pounds i'll
each hundred tons of crude slack
treated. Besides the removal of the
Stag forming insoluables, pyrites,
which is the chief sulphur bearing
element in coal, is removed, and
washing therefore reduces the sulphur
in the coke, by largely preventing its
introduction.
Limestone usually contains sllic-
eous insolublcs, and these, of course.
add to the Stag, and also reduce the
efficiency of limestone itself as tiux.
This causes the election of limestone
as free as possible from all siliceous
and other insoluables, as Stag is de-
cided nuisance at most furnaces, and
very considerable increases the costs
which have to be borne by the pig
iron. OF course phosphate limestone
is usually carefully avoided, as more
than sufficient PHOSPHORUS is general
ly present without adding more.
Coming TO the ores used, they, o.
course, contain larger or smaller
Il - ~ m.