Great Panther Silver Limited has updated its mineral resources at the company's 100%-owned Topia silver-gold-lead-Zinc mine in Durango, Mexico.
The 2011 mineral resource estimate, by Vancouver-based Roscoe Postle Associates (RPA), comprises measured & indicated ("M & I") mineral resources of 171,000 tonnes at 864g/t silver, 1.56g/t gold, 7.53% lead and 4.37% zinc (7.44 million silver equivalent ounces), a 36.3% increase over the 2009 resource estimate. In addition, RPA estimates 285,000 tonnes of 868g/t silver, 1.5g/t gold, 6.5% lead and 3.7% zinc (11.91 million silver equivalent ounces) in the Inferred category, a 109.3% increase over the previous estimate.
"The significant increase in our resource base at Topia is a validation of the longevity of this high grade silver-gold-lead-zinc mine," stated Robert Archer, President & CEO. "Considering there were no compliant resources when we bought the Topia Mine, we have consistently increased the resource base with every drill program, while increasing production at the same time. We have a lot of confidence in the future of the Topia operation."
The 2011 RPA mineral resource estimate provides updates for the Argentina vein (Argentina Mine), plus new mineral resource estimates for the Don Benito (north and south veins in the 1522 and Crucero 9N Mines), Recompensa (Recompensa and Rincon Mines), Cantarranas (Hormiguera Mine), San Jorge (San Miguel Mine), San Gregorio (San Gregorio, Mina 7, and Durangueno Mines), El Rosario, and La Prieta veins.
The estimate was based on a minimum NSR value of $US130 / tonne (corresponding to the 2010 direct mining and processing costs which are 77% of the total operating costs). This is applicable at Topia since the general and administrative ("G&A") costs are $US38 / tonne. Current operating costs for the Topia Mine veins are $US130 / tonne ore mined and processed, and any additional resources to the mining plan would require no increase in G&A costs and reduced unit mining costs. The 2011 RPA mineral resource estimate assumed (1) actual concentrate transport, and smelter treatment and refining charges in effect through 2009 and 2010; (2) RPA long term estimates of metal prices as of February 2011, and typical plant recoveries for 2010, in Table 1; and (3) minimum mining width of 0.3 metres. Capping was individually applied to each of the veins making up the summary in Table 1.
This estimate replaces those by Wardrop in 2009 and 2006 for the Argentina and various other veins on the property. The breakdown for the RPA mineral resource estimates on the Topia property is given in Table 1 below. The estimate has increased over that reported in 2009 (see Company news release July 21, 2009 and Tables 1 and 2), mainly due to inclusion of new veins that were being explored and mined but were unreported as mineral resource. A direct comparison of the Wardrop and RPA mineral resources is not relevant due to differing metal prices and minimum NSR values, as well as estimating methodologies; however, the overall percentage increase is shown in Table 3 below.
The production rate from the Topia mines is increasing each year and is planned at 36,000 tonnes in 2011. Additionally, there are other mineralized veins that are not included in this resource estimate. By applying reasonable estimates of 50% mining dilution and 80% mining recovery, management expects the current resources to support a mine life of at least fifteen years. It is anticipated that, with additional drilling, the resource will continue to increase. This "rolling resource" is typical for underground mines as it is often not cost-effective to define a large resource/reserve in advance of mining.
While most of the current resource base came from Great Panther Silver's diamond drilling and underground development, the resources estimated in certain veins (e.g. Argentina) on the property came largely from the verification of Peñoles' sampling, on levels that are planned for access later in 2011 and 2012 and are still intact. The majority of Great Panther Silver's mining to date has come from new mine development on veins reported in these estimates. There is lesser production from other veins that are not included in this update and these may be estimated in future resource updates.
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