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
Should levels significantly exceed any of the thresholds certain smelters may choose not to
consider such concentrates for their feed mix.
19.3.2.2 Lead Concentrates
At around 48% Pb, the Pulacayo concentrates can be considered medium-grade with several
internationally traded qualities running both higher and lower than these levels. The silver level in
the concentrates can be considered relatively high, which will likely make these, concentrates
less attractive to Chinese smelters because of the prevailing negative arbitrage between the
LBMA and Shanghai prices.
Elements commonly found in lead concentrates, which are typically subject to penalties, and their
thresholds are:
Table 19.9: Elements Commonly Found in Lead Concentrates Which are Typically Subject to
Penalties and their Thresholds
Element
Typical Penalty Thresholds
As 0.2 to 0.5%
Sb 0.2 to 0.5%
Zn 5 to 7%
F+Cl
500 to 800 ppm
Based on the information available, arsenic and antimony levels are both seen to be well above
typical penalty thresholds and, on a standalone basis, might make these concentrates less
attractive to certain buyers for, at a combined 2.6 to 2.8% arsenic +antimony, the level is quite
high. While Chinese smelters can typically handle antimony at these levels - in fact, many
smelters in southern China like antimony unfortunately, this is not the case at many Western
plants, as the overall load of arsenic and antimony will affect product and by-product quality. As
such, although most plants in theory could handle the concentrate the quantity that each plant
might accept will vary dramatically.
In addition to the arsenic and antimony, the silver content may determine the final homes for this
material for, as highlighted in this report; high silver-bearing concentrates are a very difficult fit for
the Chinese market. This can be expected to lead to additional charges being incurred via higher
silver refining charges, higher treatment charges, or both.
In addition to these elements, other potential quality issues with the lead concentrates include:
The lead grade at 46 to 50% is acceptable for China and in many cases preferable,
although this is not the case in the West where most plants generally look for higher grade
concentrates;
Zinc at 3.5% would be attractive to the Chinese however, it is generally an undesirable
element at most Western plants, and although at these levels, it is unlikely to be a
significant issue.
Despite the above, it is not believed that quality issues would preclude sales of these
concentrates, as there are other means of managing the impurities. Accordingly, regardless of
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