NC0000361_Discharge Authorization_19911203

unimin
UNIMIN CORPORATION
Corporate Geology
Environmental Affairs
Mine Planning December 3, 1991
Mr. Mike Parker
North Carolina Department of Natural Resource
and Community Development
59 Woodfin Place
Asheville, NC 213902
Dear Mr. Parker:
UNIMIN Corporation's Mica plant is authorized to discharge
fluoride-bearing waters through Outfall 002. UNIMIN is aware that
this discharge could only occur following notification to the other
Spruce Pine feldspar operations and the North Carolina Division of
Environmental Management. A subsequent letter from the Division
would notify UNIMIN of the configuration (effluent limitation) which
is applicable, and the date UNIMIN could begin discharging.
UNIMIN's operation would like to keep Outfall 002 and its
fluoride allocation in its pending renewal for the following reasons:
1 ) UNIMIN is considering a rough quartz float to remove feldspar
prior to shipping this partially beneficated material to the
Crystal or Quartz plant for further processing.
2) Additionally, UNIMIN is investigating the use of a float cell
in the Mica processing circuit to improve the purity of the
final product shipped from this plant.
3) Lastly, UNIMIN desires to keep the discharge of fluoride from
its existing pilot plant a viable option.
If you have any questions, please call me.
Sincerely,
, L4 • a
Susan M. Armentrout
Sr. Environmental Specialist
SMA:SPM11-91:kap
CC: John Edney
Andy Regis
Roy Riddle
Hill Shalter
Charlie Stover
402 Mill Street • P.(Q Box 297 • Utica,IL 61373 • [phone]-Fax[phone]