In its third quarter report Silver Standard Resources noted good overall performance of its new Pirquitas silver-tin-zinc mine in Argentina, but once again revised down its estimate of 2010 tin-in-concentrate production. Although the tin circuit at the mine is now operating, problems with recoveries mean that contained tin output this year is now expected to be only 45 tonnes. Theoretical annual capacity of the mine is 2,500 tpy tin.
In a statement the company said: “The tin circuit is commissioned and despite it producing a high-grade saleable gravity tin concentrate, tin recovery is poor. Testwork is being conducted at a number of laboratories globally with the dual objectives of improving tin recovery while maintaining a good tin grade in the final concentrate. As a result of the low tin recovery, tin production is now estimated at less than 100,000 pounds for 2010 compared to the previous estimate of 600,000 pounds.”
The mine produced 1.9 million ounces of silver and the operation became cash positive in Q3. Silver production for the full year of 2010 is estimated at 6.3 to 6.5 million ounces of silver at an average cash production cost of between $11.50 to $12.00 per ounce of silver (net of by-product credits).
