Slag piled high
If you've traveled through East Helena,
you probably noticed the huge pile of black
material at the ASARCO Smelter along the
highway. The material, called
"slag", is waste product produced as ASARCO
removed lead from the ore.
Getting the lead out . . .
than a century, crushed ores
containing galena (PbS) were brought to East
Helena from as far away as Chile and Korea.
Once at the smelter, the ores were "roasted"
in order to remove the sulfur. The sulfur combined with oxygen to form a gas called sulfur dioxide, a pollutant that contributes to acid rain. A law called the Clean Air Act, which went into effect in the early 1970s, required that industries like the smelter remove this emission. A pollution-control device called a "scrubber" had to be installed to do this.
formed a material called "sinter," which was a
mixture of lead oxide (PbO) and other rock
the sinter had to be melted. Crushed
limestone and quartz were added to make it
easier to melt the mixture. Once the material
was melted, the heaviest stuff (lead) would
sink to the bottom of the tank. The molten
lead was then drained out through openings
in the bottom into molds where it
Separation by melting . . .
separation by melting is called
smelting. The rest of the molten material,
which had been floating above the layer of
also solidified, forming the black waste
product called slag. For years the slag was
disposed of by dumping it along the
edge of the smelter property.
Other metals too . . .
closure in the spring of 2001, the
ASARCO Smelter shipped 10-ton pieces of
lead by rail to a refinery back east. The
refinery was able to separate trace amounts of
other valuable metals such as gold and silver.
In a typical year (early 1990s) the smelter's
bullion yielded the following:
69,000 tons of lead
3,500 tons of copper
690 tons of arsenic
150 tons of
20,000,000 oz. of
200,000 oz. of
has piles of slag . . .
The smelter in
Anaconda was designed to extract copper
from the ores mined in Butte. The texture of
Anaconda's slag (CLICK HERE to see aerial photo.) is much different than the
slag in East Helena. East Helena's slag is
very "blocky," with pieces varying from
fist-size to much larger. In Anaconda the
slag is more like sand because the molten
slag was spilled into water, causing it to
harden and shatter into sand-sized pieces. In
fact Anaconda's slag has been used in sand
traps at the famous Old Works Golf
Trivia . . . Below: A closer view of
the slag (looking toward Helena)
Country Music Hall of Fame singer, Charlie Pride, once worked at East Helena's smelter and starred on the Smelterite baseball team.
Below: A view from
the south (looking over the Helena
Terms: ore, flux