Azuay Gold Project, Ecuador




Key Data


The Azuay gold project is located in the Azuay Region of south-west Ecuador. The project is owned by EnviroGold, which has entered into agreements with two privately held mining companies to progressively earn 65% of the ownership by August 2012 for $6.5m. EnviroGold was renamed PanTerra Gold in September 2011.

The property includes two adjacent underground mines named Pinglio and Papercorp that occupy 700ha and have been mined on a small scale for over a decade.

The $92m project will involve expanding these two mines to produce 100,000oz of gold a year for ten to 12 years. The development will be carried over two phases.

Construction will commence in mid 2012 and annual production of 50,000oz is expected to begin from mid 2013.

The mine is estimated to have a 12-year life.

Reserves

The two deposits are estimated to host a combined resource of approximately 4Mt at grades of 10g/t to 12g/t of gold.

Geology

The deposit lies within the centre of a highly mineralised gold belt. Papercorp and Pinglio deposits host a network of veins. Within the Papercorp deposit, the veins are segmented into two groups, lower Papercorp and upper Papercorp, which are distanced 400m laterally west and 150m in elevation. Veins are either flat-lying with a less than 20° dip or moderately dipping between 20° and 65°.

"The property includes two adjacent underground mines named Pinglio and Papercorp that occupy 700ha."

Five tunnels - Cascada, Reina Rosario, Reina Cisne, Nueva Union and Fortuna - access the veins in the lower Papercorp zone. Access to the upper Papercorp veins is provided via three tunnels, namely 12 de Abril, Condor Oro and Bellavista.

The lower Papercorp contains mostly flat-lying veins (-25°). Few steep veins with a dip of -49° to -58° are hosted much closer to the surface.

"Two bazooka-style diamond drills will be used."

Mineralisation

At the Pinglio deposit, mineralisation is grouped into two zones, namely Ponderosa and Perez / S&S. The mineralisation is similar in style to that at Papercorp and includes narrow sheeted veins within flat-lying faults or gouge zones. A diatreme breccia litho that hosts most of the Pinglio veins differentiates the two deposits.

The Perez / S&S zone hosts the Perez 2 structure, a flat-lying, prominent structure with moderate grades and average width of 1.01m. The other two structures, namely Perez 1 and S&S, are not very extensive and are believed to be splays or extensions of the Perez 2 structure.

The Ponderosa zone hosts the bulk of the mineralisation at Pinglio. It includes five different veins that are related as splays or appear as stacked sequences. Named San Antonio, El Dorado 1 and 2, La Ponderosa 1 and 2, and La Palmas, the veins range in width between 0.62m and 0.93m and have spectacular grades varying between 8.88g/t and 39.4g/t.

Mine development

Phase one of the mine development will involve construction of a relatively low cost gravity plant. The $35m plant will extract free milling gold from a 260,000t/year underground mining operation. Phase one will also include construction and annual production of up to 50,000oz. The first phase is expected to be commissioned in June 2013.

During phase two, Albion and CIL circuits will be installed in 2014 and 2015. The circuits will cost $50m and will recover gold from refractory ore. The mining rate will be increased to 300,000t/year and gold production will reach 100,000oz/year during phase 2. The second phase is planned for commissioning in late 2014.

Processing

Approximately 60% of gold will be recovered through crushing and gravity separation. The remaining will be returned to carbon in leach circuit to produce the gold doré bars.

Multiple underground mines will feed a centralised crushing and milling plant. The milled ore will be delivered via a 10km slurry pipeline to the gravity and CIL circuits.

Drilling

"A $92m expansion will result in the mines producing 100,000oz of gold a year from mid 2014 onwards."

Historical drilling at Azuay was conducted between 1989 and 1993 by Placer Dome. It involved approximately 9,000m of RC drilling and extensive chip sampling and mapping of surface mineralisation.

To confirm the proposed mining target for the Papercorp and Pinglio mines, EnviroGold commenced an underground drilling programme in February 2011. The drilling programme will be carried out in two phases. During phase one, the deposits will be drilled out at 100m centres. If the results are positive, the deposits will be drilled to 50m centres in phase two. To test all the vein structures, a series of 100m to 300m holes will be completed across both the deposits.

Surface drilling to define the deeper underground targets will begin in December 2011 upon the receipt of environmental approvals. Most of the veins of upper Papercorp and all veins of the Pinglio deposit will be surface-drilled. The total cost of the exploration has been estimated at $4.5m.

Two bazooka-style diamond drills will be used to drill core holes of small diameter within limited space. By January 2011, the rigs and related equipment had arrived at the site. An exploration camp was constructed at the Papercorp mine site to house the drilling crews, field helpers, geologists and office facilities for the management of the resource definition drilling.

Financing

The project will be funded using cash generated by the Las Lagunas project in the Dominican Republic. The trial mining on the Las Lagunas project was completed in August 2011 and it is expected to begin gold and silver production by January 2012.

Bellavista shear zone
Diatreme Breccia – Ponderosa tunnel
San Antonio Vein – Pinglio
Fortuna-Nueva Union vein 1
Ponderosa tunnel entrance – Pinglio
Visible gold - La Ponderosa vein – Pinglio
The exploration camp for the project
Ponderosa surface stock pile – Pinglio