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
In-place densities
Feed characterization
Mineralogy
Leaching
Gravity concentration
Bench- scale open circuit and locked cycle tests (LCT’s)
13.1.1 First Set of Samples
Several pieces of rock from the composite were selected for in-place bulk density
determination and for mineralogical study. The remaining composite sample was crushed to
nominal 6 # (3.36 mm), blended and split into 2 kg and 10 kg charges for metallurgical test
work.
A representative portion of the composite sample was pulverized and submitted for chemical
XRF/XRD analyses. A summary of the estimated core grades and assay values for this
single composite (first sample composite set) is shown in Table 13.1. The head analyses of
the sample were significantly higher than the values calculated from drill core data.
Table 13.1 Sample Composite Grades and Head Assays
Sample ID Estimated Core Grades Head Assays
Ag, g/t Pb, % Zn, % Ag, g/t Pb, % Zn, % Cu, %
Bulk Composite 415 1.84 3.46 518.9 2.2 3.96 0.212
The sample contained 2,120 ppm (0.212%) Copper and 910 ppm (0.09%) Arsenic, which
may have detrimental effects on the concentrates.
13.1.2 Mineralogy
Mineralogical studies of pieces of drill core from drill holes PuD005 and PuD007 were
investigated microscopically in polished sections for characterization of sulphide minerals
with the highlights following:
The predominant sulfide mineral in the samples was pyrite with minor amounts of
galena, sphalerite and marcasite.
Sphalerite and galena was locked in pyrite-marcasite mineralization.
Native silver was not detected in the samples.
Replacement rimming of sphalerite by late galena and tennanite associated with
galena was observed in the drill core sample. This could result in product
contamination during froth flotation recovery (intertwined species).
The host rock contained significant amount of clay material which resulted in
problems in settling of tailings and flotation pulp rheology.
TWP Sudamérica S.A. Av. Encalada 1257 Of. 801, Santiago de Surco Lima 33, Perú (51-1) 4377473
Page 98