Pulacayo Project Feasibility Study - Apogee Silver

Pulacayo 1 000 t/d Phase I Feasibility Study - NI 43-101 Technical Report
090644-3-0000-20-IFI-100
1.4 Mining Methodology and Reserve Statement
Pulacayo is an existing mine with a long history of development, however in more recent
years on a much reduced scale. This project plans to increase production significantly and
exploit previously unmined material utilizing a combination of two methods. Shrinkage
stoping will be used on zero level and longhole open stoping will be used on all levels below
zero level. The stope widths vary from 1 m to 6 m, depending on the mining method and
width of mineralization.
The mine has an existing tunnel (San Leon Tunnel) located on zero level which starts in the
town of Pulacayo and exits on the northern side of the mountain that hosts the mineralized
rock. This tunnel will continue to be used but a new decline ramp system will be constructed
to allow access with trackless equipment and to exit closer to the mineral processing plant.
This decline ramp system will be developed from surface (at an inclination of 8 degrees from
the horizontal) using conventional drill and blast techniques.
For the shrinkage stoping planned or zero level, conventional drill and blast techniques will
be used to advance existing ore and waste drives, and to develop new shrinkage stopes. Air
loaders will be used to clean development faces. The broken rock will be loaded into
locomotives and trammed out of the mine. Development of the required tunnels for access to
the long hole stopes will be done with a drill jumbo and blasting using Anfex. These tunnels
are the main haulage, crosscuts and ore drives and are planned with dimensions 4.0 m high
and 4.0 m wide. An LHD will be used to muck out, and the broken rock will be hauled out of
the mine using the existing 15 tonne truck.
1.4.1 Backfill
Backfilling of mined out long hole stopes is planned to facilitate both safe mining and to
provide for better grade and dilution control. Cemented backfill will provide permanent
support to the stope excavation, particularly with regard to the mining of adjacent areas. A
backfill plant will be constructed on surface near an existing ventilation shaft and will be fed
with tailings from the concentrator plant. The backfill will be mixed on surface with cement
and pumped underground in a pump column and distributed to the stopes.
1.4.2 Mine Production
The mine has been designed for an ore production of 1,000 tons (t) per day. The mine plan
indicates a total of 3,557 Million tons of ore and 0.839 Million tons of waste. These will be
extracted over a planned 12.5 year Life of Mine (LOM). The average grades over the LOM
are 239 g/t for silver, 1.09% for lead and 1.91% for zinc.
TWP Sudamérica S.A. Av. Encalada 1257 Of. 801, Santiago de Surco Lima 33, Perú (51-1) 4377473
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