2009 Montana Mining - Montana Mining Association

Barretts Minerals Inc.
uses an ancient resource
for modern applications
Early Native Americans discovered talc, commonly called soapstone,
in the Ruby Mountains of what is now southwest
Montana. Local tribes mined it for their own use, including trading
with other tribes; and, the Lewis and Clark journals even mention
smoking a peace pipe made from this easily carved rock when they
navigated the waters of the Beaverhead River in 1805 and camped by
Rattlesnake Cliffs.
The talc mining tradition in the Ruby Mountains started by the early
Native Americans is still carried on today, at Barretts Minerals Inc.
(BMI), which extracts the talc from two mines in the Ruby Mountain
Range and processes it along the banks of the Beaverhead River south
of Dillon, Montana. Although artists still produce carvings from this
talc, it is now also used in many industrial and consumer applications
such as paints, plastics, ceramics and health-care products. Though
talc (Magnesium Silicate Hydroxide) is the world’s softest mineral, it
has very little chemical reactivity – it is practically insoluble in water,
weak acids or alkalis, and has a melting point of 1,500o C. These char-
52 Montana Mining 2009
acteristics make the mineral ideal for ceramic applications, such as the
substrate used to encase precious metals like the platinum in catalytic
converters, which reduce automobile pollution; indeed, a good portion
of the talc mined at Barretts Minerals is sold for this purpose.
“The catalytic converters of the majority of automobiles manufactured
in North America – and a great deal of those worldwide – contain
talc from the Treasure and Regal Mines. So most of the people in
this country are driving around with talc from our mines,” says Jim
Daley, plant manager at Barretts.
The mineral is also an excellent filler and extender; used in paints
to improve coverage, in plastics for reinforcement, and for use in what
is known as an “antiblock” to reduce static cling in plastics wraps and
bags, it is also utilized in various products such as body powder, and
as a coating on tablets and chewing gum. Since the Montana talc has
a platy structure it does not have the health risks associated with other
minerals that could be used for these applications.
Electron Micrograph scan showing the platy structure of BMI talc.