Zelica Project

Exterra acquired the Zelica project during 2011, located only 20km to the north west of the Linden project, and has identified mineralisation over a strike length of 900m with the deepest drilling intercepts at approximately 65 metres below surface and appearing to be open at depth.

Metallurgical test work in 2006 indicated that recoveries in excess of 90% could be obtained by vat leaching, with fast leach times and low reagent consumption. Plans were made to establish a 600,000 tpa Vat Leach operation, however the project was not commissioned. Three vat ponds were built and remain on site for potential use.

A Scoping Study into development of the Zelica vat leach project using estimated industry-relevant OPEX costs was completed on the basis of using the current vat leach infrastructure on site to complete a bulk trial mining exercise to confirm the fundamentals for an ongoing operation.

The pit optimisation study was carried out at a benchmark gold price of $1,500/oz and at recoveries from 80% to 90% (based on prior metallurgical column leach test work). 

Optimisations were run from $800/oz to $2,000/oz in $20 increments. At the benchmark gold price positive cash flow was indicated for all recovery factors for the trial pit study, with recovered gold varying from 3,000 ozs to 15,000 ozs and with the optimum pit, cash cost per ounce at between $800 and $900. Exterra is still reviewing the capital expenditure requirements based on second hand plant.

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A review of the Zelica Resource by Ravensgate, taking a more conservative view with respect to the Inferred Resource, has resulted in a combined Indicated and Inferred Resource of 576,800 Tonnes at 1.63 g/t Au for 30,170 ozs. This represents a 35% increase in the Measured/Indicated category, however, with a reduction in Inferred ounces. It is believed this reviewed Inferred resource is more in line with a vat leach project economics. The resource, however, is open at depth and along strike and it is believed that with further systematic drilling the resource base will be extended.

A summary of the Zelica Resources are tabulated below at a 0.5 g/t Au lower cut off:

Table 2 – Zelica Resource

Resource Estimation completed by Ravensgate using Minesight Software
Resource was estimated using Ordinary Kriging reported above a 0.5 g/t Au block model grade with a 12.0 g/t Au top cut.

JORC ClassificationJORC Classificationg/t AuOunces
Indicated358,2001.6519,036
Inferred216,6001.5811,134
TOTAL576,8001.6330,170

Exterra believes, in the current economic environment and with the development of the Second Fortune underground mine, the Zelica project will be best developed in parallel with the Second Fortune underground mine.  Both projects will use common facilities, located at Linden, and management teams, which will add economic benefits to both projects. A Pre-Feasibility study into development of the Second Fortune deposit at Linden is currently in progress and expected to be complete by the end of the December quarter.

Zelica Site Layout

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