The Black Hills union and western stock review. [volume] (Rapid City, S.D.) 1904-19??, 1906-02-23
(Continued From Page a.

these furnaces was from four to eight tons
per day.
The modern blast furnace is many times
larger and has automatic devices Tor the
handling of the charges and products, With
q capacity as high as 100 tons of pig iron
per day.
furnaces are divided into two great
classes; first, those in which the charge and
fnel are in intimate contact and second,
those in which the fuel and ore are Kept
separate. ghe first may be subdivided ac-
cording to their construction (a) hearths
Tincluding piles, stalls, pits and kilns and
1b) blast furnaces The latter may again
be divided into, first, reverberatory fur
naces and second, retort furnaces, the
details of which may be omitted. Improve
ments have been made on all these furnaces
from time to time, such as the introduction
Of water cooled mechanical rabbles, auto
matte feeders and discharging devices. In
furnaces in which hot blast is used, valuable
improvements in construction and design
Of friedrich stoves have been made.
The difficulty met in the treatment OF
blast furnace was minimized by the alter
atoms in the design and power OF the
blowing engines; while the rapid consump-
ton Of the furnace Innings was remedled by
the use of water jackets, chromite bricks
and other neutral material.
IRON AND STEEL. The improvements
and inventions governing the enormous
yearly output Of iron and steel are many
These are mechanical rather than metal
lurgical improvements. In the last twenty
years, the worlds production OF pig iron
has more than doubled while the steel pro-
duction has increased five fold. During
this period, the basic open-hearth and basic
Bessmer process rose from mere beginnings
to those Of vast Importance. The great de-
mand for structural steel, rails, armor plate,
etc., has brought out the Importance OF
heat treatment and has aided IN the dls-
covery and utilization OF many alloys
steels, the demand for which has caused
concentration of the industry into extern
sive establishments, operating on a large
scale. In the last ten years, the cost OF
labor alone has been reduced one halt with
out reducing the rate Of wages, due to the
installment of powerful and and costly
labor saving machines:
Details in the metallurgy Of iron and
steel have been so perfected that in some
Bessemer plants, the material is never al
lowed to cool between the time it enters the
blast furnace in state Of ore until it is de-
liyered from the roller mills, in form OF
rails or billets. The continuous working OF
the Bessemer converter is insured by the use
Of q mixer, which is large reservoir into
which the molten metal is poured from
the blast furnace. By the use of this mixer
8 very uniform product can be OBJ
3 tanned. Alloy steels have come into
extensive use for special purposes. The
chief of these are steels containing certain
Der cent Of nickel, manganese, chrome,
molybdemum Of tungsten, the merit Of the
4 special properties Of which are unqnestioned.
Today, practically all the iron ore mined is
B reduced il the iron blast furnace to cast or
# MO iron from which it is converted into
wrought iron and steel
Processes for obtaining wrought iron and
steel direct from ore are at present not in
nee for the reason that blast furnace practice
Is much cheaper.
The advantage Of the blast furnace over
the pudding and other direct processes l.
that &c RECEIVERS nearly all the iron, it's
3 operation is continuous and has a high Of
1 ficency d Il disulp hurizing agent The low
cost Is mainly effected by the mechanical
Isa appliances for handling ore, lux, fuel, iron
and alag las 8 shown q the automatic hoist,
M and charging devices capable Of handl-
~ from 100 70 5000 tonso material pei
twenty years ago an ore assay
nv twenty dollars il gold 70 the ton. rep