slurry probably would keep the entire surface of the tailings beach moist.
If the tailings parti,
the surface of the beach are kept damp, dusting potential would be minimal.
The tailings surfj
however, may dry during brief periods of mill process interruptions, hot
weather, or may not lb
continuously wetted if the flow paths of the slurry water are channelized.
A natural crust ma!
develop on the tailing surface upon drying but this crusting would not eliminate
dusting. Exxoq
proposes to control dusting by adding slurry discharge outlets as needed.
Alternative method
controlling tailings dust include:

1. A sprinkler system on the confining banks could supplement the tailings
discharge points
    keeping the tailing surface moist. This method requires a continuous
input of energy and'
    attention, and is less suitable over extended periods of time. An extreme
example wouldi
    flood the entire tailings beach. This method would control dust effectively
but continuou
    of water would be needed to maintain the pool. This technique would require
additional iw
    rock riprap on the sideslopes to prevent wave erosion and potentially
increase leachate
    generation.

2.  Chemical dust control agents could be sprayed on the tailings surface.
The maximum  IC
    effectiveness of the best agents is approximately one year. Used effectively,
chemical di
    control agents would cause a crust to develop on the tailing surface
which should be strop
    more resistant to destructive forces than a natural crust. Chemical dust
control agents a
    have little or no effect on tailings compressibility, permeability, or
leaching characterist

3. Mulches and erosion control mats could be used to minimize wind erosion
on the tailings
    Erosion control matting is likely to be extremely expensive, especially
when compared ,
    chemical dust control agents or spray-on mulches.

4. A layer of soil placed over the tailings and then revegetated should be
regarded as a pos
    only for a planned, long-term shutdown rather than an immediate response
to a short-te
    dusting problem. When full, the tailings ponds would have unprotected
surface areas ran
    between 40 and 100 acres. If a long-term shutdown of the mine/mill is
anticipated and A
    more than 2/3 full, closing the pond in accordance with the closure and
reclamation pl1
    more advantageous than attempting to stabilize the tailings surface.
Stabilization, how
    would preserve some pond capacity during mine/mill startup but would
require maintena
    during shutdown.

CONCENTRATE TRANSPORT

The zinc, copper, and lead concentrates may be sent to three different locations.
There are
of smelters being considered in the Pacific Northwest, the south (Tennessee),
and the northe
(Canada). The concentrates would be shipped out of Wisconsin via rail car
on the Soo Line r
Concentrate transportation by truck rather than rail would not be advantageous
given the p,
of the Soo Line track and the lower cost of rail shipments. Truck shipment
might be feasibl
destinations were limited to nearby areas, such as the White Pine, Michigan
smelter or local4
Lakes ports. All other United States and Canadian smelters considered as
concentrate dest
are served directly by rail. The same situation is generally true for shipment
to export har
especially if the railroad bridge at Sault Ste. Marie, Michigan were upgraded
to carry heavie
railcars.

High-pressure pipeline transport of metal concentrates was considered but
was determined
infeasible. Such systems are very expensive and are most advantageous in
remote locations.
roads or rail networks are inconvenient or non-existent. Another problem
with pipeline tr
concentrates is that the ultimate destination of the concentrates could change
over the proj

Combinations of rail-water shipment exist for U.S. and Canadian smelters
and export harbor
most cases, however, handling and storage charges at transfer points would
make such combi
more expensive than direct rail shipments. Such options would include use
of the St. Lawren
Seaway to east coast destinations and use of the Mississippi River to New
Orleans. The use
local to Crandon, such as Green Bay, are limited to a 8-9 months shipping
season, making s4



choice less desirable.                                                  
                :<



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