Wonawinta Silver Project
Wonawinta snapshot:
- Largest 'pure' silver project in Australia
- 51Moz Ag indicated / inferred resource
- 14Moz Ag probable reserve
- High potential for reserve & resource increases
- Rapid progression from exploration to development with forecast production in Q4 2011.
CCR began work on the Wonawinta silver project silver project in 2008, which is now wholly owned by the company. The previous joint venture partner, CBH Resources has a royalty interest in the tenements.
After defining an attractive exploration targets in 2008, CCR undertook two campaigns of resource definition drilling to establish and inferred resource, which is more than doubled the initial estimates.
Preliminary mineralogical and metallurgical test work indicated good recoveries by a combination of cyanide leaching and gravity concentration. An independent mining study modelled ore production from a series of four shallow open pits.
Wonawinta geology plan showing CCR drillholes and inferred resource locations.
South pit area cross-section showing flat-lying secondary mineralisation. (view larger map)
Additional prospective ground covering extensions to the mineralisation was acquired. The second drilling campaign proved the existence of significant southern extensions to the mineralisation in this tenement, auguring well for future resource increases.
A scoping study indicated a robust and profitable project with modest capital requirements.
A feasibility study, confirming the project's viability was completed in June 2010. An optimisation study is expected to be completed by November 2010.
Key outcomes of the feasibility study were:
- High rates of conversion of inferred to indicated resources and resources to reserves.
- Developing a preliminary mining schedule based on the probable ore reserve.
- Obtaining firm mining cost estimates.
- Determining the process flowsheet.
- Confirming that high silver recoveries could be achieved by cyanide leaching.
- Obtaining engineering based capital and operating cost estimates for the processing plant.
- Determining the most cost effective infrastructure solutions.
- Confirming the project’s economic viability.
- Optimise the mining schedule, focusing on reducing the strip ratio and mining the higher grade ores as early as possible in the project life.
- Refine the capital cost estimate for the processing plant.
- Determine the lead recovery process route.
- Finalise the infrastructure arrangements.
Based on the outcomes of the optimisation study to date CCR revised the project economics and confirmed that the project was an attractive investment proposition and would be viable even in the unlikely event that no lead is recovered.
Key parameters include:
- Production: 12.8 Moz silver over 5 years
- Mining method: shallow open pit mining
- Cash cost of production: $10.20/Oz (no lead), $6.50/Oz with lead recovery
- Total capital expenditure: $32 million
- Payback: 2 years, strong cash flows.
High potential exists to further increase the mine life through additional resource conversions and discoveries. Future drilling will occur after the completion of soil sampling.
