There are both Red Iron Ore (Hematite) and Brown Iron Ore (Limonite) deposits in the
vicinity of Birmingham. These deposits are the southeastern continuation of the Silurian
Clinton Iron Formation which extends from New York State along the Appalachian
Mountains. Red Mountain on the east side of the city was the location for most of the
iron mines. Many antebellum charcoal furnaces utilized the Brown Limonite Ore;
however, after the Civil War, the mainstay of the iron and steel industry was the Red
Mountain Hematite Ore. The hematite ore beds were in the Red Mountain Formation
with a dip of about 16°. The greatest production came from the “Big Seam.“ This seam
was 15-22 feet thick and divided into parts by a small bed of slate. Smaller amounts of
production came from the thinner Ida and Irondale Seams located above and below the
Big Seam respectively.
Early surface mining took place along the outcrop on Red Mountain but subsequently
moved underground following the dip of the ore beds. Over the years, many variations
of stope and pillar mining were used. Inclined slopes for ore hoisting were driven down
dip in ore from the outcrop. Manways were driven parallel to and at some distance
away from the slopes. These were used by the miners to access the workings.
Headings (levels) were driven in the ore from the slopes and perpendicular to them.
Stopes were mined between the headings.
The two parts of the Big Seam were frequently mined as separate benches in the
stopes. Barren slate was discarded underground. Rails were laid in the headings for
transporting cars to the slope. Timber supports were used in areas of weaker ground.
Some iron mines used leased convict labor to keep costs down.
Early hand loading gave way to the use of “automated” mining using slushers and, later
still, Joy loaders. Hand tramming and mule haulage gave way to the use of mine
locomotives. (See W. R. Crane, 1924, for a more complete description of iron mining
methods in the early 1900s.)
The ore grade in the Red Mountain mines was around 36% iron and, while the ore
contained no sulfur, it was relatively high in phosphorous. The phosphorous content
and metallurgical practice in the late-1800s caused it to be used to make pig iron rather
than steel. Later, the availability of improved technology permitted its use in steel
making.
Iron ore mining in the Birmingham District followed the ups and downs of iron and steel
production. Active mining stopped in 1975. After that, cheaper imported ores were
used until the iron and steel industry was mostly shut down. It is estimated that from
1840 to 1975, 375 million short tons of iron ore were produced in the Birmingham
District
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