Stockpiles of limestone (white or light gray in tone), iron ore (medium
to light gray in tone), and coke (black in tone)
A stock trestle
Groups of tall, cylindrical hot stoves
Blast house(s) and blast mains
A roasting and sintering plant (some plants)
Layering yard (some plants).
(2) Iron processing flow (Figure 2-62):
Coke is transported from the coke screening tower to the
blast furnace area where it may be stored in bins in the stock trestle or
stockpiled on the ground- (Annotation 2).
Limestone and iron ore are transported
from mines and unloaded into raw material stockpiles (Annotation 1).
(b) Roasting and sintering plant.
If the iron ore has a high sulfur
content, it goes to a roasting and sintering plant (Annotation 16). The iron ore
is first roasted to remove sulfur and sintered to fuse iron ore particles so they
will not be blown out of the blast furnace and lost.
(c) Layering yard.
quality are used, they must be combined to assure a uniform charge for the blast
This mixing of ores takes place in the layering yard (Annotation 17).
Thin layers of different ores are laid atop one another in established proportions
by a gantry crane or special layering machinery.
(d) Stock trestle.
Ore is taken, as needed, from the layering yard (or
stockpile if no treatment is necessary) and placed in bins in the stock trestle.
Limestone usually does not need any special treatment beyond crushing.
some plants powderize their raw limestone to increase its quality. This operation
can be recognized by the presence in the stock trestle alongside the coke and iron
(e) Blast furnace. From the stock trestle, the charge
(measured amount of
iron ore, limestone, and coke) is carried up and into the blast
5) via a conveyor device called a skip hoist (Annotation 3).
The tall, tapering
shape of the blast furnace may be hard to recognize because of
obscuring pipes and