Pulacayo Project Feasibility Study - Apogee Silver
Pulacayo Project Feasibility Study - Apogee Silver
Pulacayo Project Feasibility Study - Apogee Silver
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<strong>Pulacayo</strong> 1 000 t/d Phase I <strong>Feasibility</strong> <strong>Study</strong> - NI 43-101 Technical Report<br />
090644-3-0000-20-IFI-100<br />
The zinc cleaner concentrate recovered 7.8% of weight, 1.3% of lead, 84.7% of zinc and<br />
38.8% Ag. The concentrate assayed 0.324% Pb, 41.2% Zn and 2 463 g/t Ag.<br />
13.1.6.3 Locked Circuit Flotation Tests<br />
Large scale two cycle locked cycle flotation tests were performed using the process<br />
flowsheet similar to that developed for San Cristobal deposit.<br />
The lead concentrate assaying 62.2% Pb, 4.46% Zn and 10,891 g/t Ag, recovered 3.1%<br />
weight, 88.8% of lead, 3.9% of zinc and 63.4% of silver. The zinc concentrate assaying<br />
61.5% Zn, 0.9% Pb and 3,303 g/t Ag, recovered 5% weight, 87.6% of zinc, 2.1% of lead and<br />
31.3% of silver.<br />
The tailings were very difficult to settle due to high proportions of clay in the ore, which will<br />
impact the process flow sheet and overall plant design.<br />
The lead and zinc third cleaner concentrates were analyzed for impurities. The results<br />
indicate that penalties may be incurred on the concentrates for several impurities, as they are<br />
higher than the norm for smelter contracts.<br />
13.2 UTO Metallurgical Test Program (Stage 2)<br />
UTO conducted a metallurgical test work program on these three samples comprising<br />
comminution (only Bond Ball Work Index), open circuit flotation tests (OCT), locked cycle<br />
flotation tests (LCT), OCT tailings (non-float) size by size analyses and OCT tailings (nonfloat)<br />
sedimentation tests.<br />
Clays mineralogy studies were not carried out to determine the presence of shrinkingswelling<br />
clays (Smectites) and other type of clays that may produce very fine slimes.<br />
However, during the course of the metallurgical test work, slimes were produced affecting the<br />
flotation performance. The host rock contained significant amount of clay material, which<br />
resulted in problems in settling of tailings and flotation pulp rheology.<br />
13.2.1 Second Set of Samples<br />
In 2009, the laboratory facility of Universidad Nacional de Oruro (UTO) in Bolivia, received<br />
material from the <strong>Pulacayo</strong> <strong>Project</strong>. Individual drill intervals were combined by UTO as<br />
specified by Micon and ASL to generate three (3) composite samples.<br />
These three composites represent a higher grade, a medium grade and a lower grade<br />
composite sample (roughly 100 kg each). All the samples were metallurgical tested by UTO<br />
and the products were assayed by ALS Chemex in Lima, Peru. <strong>Silver</strong>, zinc, lead and copper<br />
concentrations were determined using an aqua regia digestion followed by spectroscopy. For<br />
samples with silver value exceeding 300 ppm the fire assays (ALS code AA26) method was<br />
used.<br />
A summary of the estimated core grades and assay values for all three composites (first<br />
sample composite set) is shown in Table 13.2. Core intervals were chosen that would result<br />
in low, medium and high grade composites. The spatial distribution of the intercepts used to<br />
prepare the bulk samples is well documented.<br />
TWP Sudamérica S.A. Av. Encalada 1257 Of. 801, Santiago de Surco Lima 33, Perú (51-1) 4377473<br />
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