INDUSTRIAL MINERALS
56 E&MJ; • JUNE 2016 www.e-mj.com
applies to "mines in which noncombus-
tible ore is extracted and which liberate
a concentration of methane that is ex-
plosive, or is capable of forming explo-
sive mixtures with air, or have the po-
tential to do so based on the history of
the mine or the geological area in which
the mine is located." Methane sources
are shale deposits above and below the
trona beds.
How It's Mined
Ore is extracted by room-and-pillar meth-
ods, using both Sandvik 780 borer min-
ers and Joy 12HM12 drum-type continu-
ous miners. Roughly 80% of ore produc-
Clockwise from top: Most of the mine's trona production comes from its three Sandvik
borer miners, which cut oval, smooth-walled rooms and entries as they extract ore
from the 9- to 12-ft-thick seam. Each of the borer miners is coupled with a Joy Flexible
Conveyor Train, which moves in concert with the miner and feeds broken ore to the
mine's main conveyor system. The multisegment main conveyor line dumps ore into
a 1,200-ton-capacity storage bunker located almost 13 miles away at the mine's
main shaft complex, where it is loaded into 22-ton skips for transport to the surface.