pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER NO. PA-115
(Page 74)
at predetermined intervals to make recordings. A 70 , -0" long
eleventh probe, equipped with eight thermocouples, was inserted
permanently into the burden vertically from the furnace top. The
data which these probes provided was expected not only to lead to
improved production but also to give engineers vital information
concerning future blast furnace design.
An exceptional feature of Dorothy's casting facilities was
its two tap holes or iron notches. Located at a 90 degree angle
from each other, the tap holes emptied into two sets of parallel
iron runners, each of which fed four 175-ton "submarine" ladle
cars. The ladle cars were run into the one story, 80'-0" wide x
250'-0" long cast house on four parallel hot metal tracks located
on each side of the iron runners. One runner, then, served two
hot metal tracks. As such, the relationship between the casting
facilities inside of the cast house and the furnace's two tap
holes significantly shortened the delivery time of the molten
iron to the work's steelmaking plant. 6
The plant's iron and ferromanganese production and delivery
system changed significantly between the late 1960s and 1980
because of events within the plant, corporate reorganization
policies, and an investment in advanced desulphurization
technology. The production of ferromanganese at Duquesne, for
example, received a mortal blow when a breakout of the molten
material destroyed blast furnace number two in the late 19 60s.
The most consistent producer of ferromanganese in the plant, the
furnace was eventually torn down in the mid-1970s.
Coming on the heels of the accident, corporate officials
decided to merge the National Works in McKeesport with the
Duquesne Works in 1969. Based on the more modern iron and steel
making facilities on the Duquesne site, the move required that
the National Works shut down its own iron and steelmaking
operations while drawing upon Duquesne for all its semi-finished
steel needs. As a result of its increased iron making
responsibilities, all of the Duquesne furnaces were put on iron
production. Additionally, the working volume of blast furnace
number four (from 31,504 to 35,215 cu. ft.) was upgraded as was
Dorothy Six's (to 58,045 cu. ft.). All ferromanganese
operations, moreover, were shifted to the McKeesport site.
The decision to build a modern desulphurization facility in
1980 on blast furnace plant grounds was taken to increase the
efficiency of Duquesne ! s basic oxygen steelmaking furnaces. With
the advent of basic oxygen steelmaking, iron desulphurization was
performed externally by blowing calcium carbide through a lance
into the molten bath and skimming off the resulting slag before
the iron was charged into the oxygen furnace. At Duquesne, the