Project

Additional Metallurgical Test Work in 2012

Positive metallurgical testing yielded gold recoveries of 93% and 94% within 24 hours for mineralization in the oxide zone and recoveries from 82% to 86% within 48-72 hours in the Transitional Zone at La Cumbre.

Click on map to view PDF

The following table summarizes the results of the metallurgical testing (bottle roll):

 2012 Cyanide Leach Tests – Summary Results
Batero-Quinchia Project

Preliminary Metallurgical Test Work in 2011

Preliminary metallurgical testing undertaken by G&T Metallurgical Services (“G&T”) on behalf of the Company was completed on six drill core composite samples to determine their response to gravity concentration, flotation and cyanidation.  The response to cyanidation via bottle roll tests was clearly superior and yielded gold recoveries ranging from 66% to 94% as determined by G&T. Test work on oxide mineralization returned up to 94% recovery.

Preliminary metallurgical tests indicate a relationship between gold and sulphur grades, and the gold recovery.   Cyanidation extraction (after 48 hours) averaged 73% recovery at a nominal P80 grind size of 100 microns, and 80% recovery at a finer nominal grind size of 70 microns. The best gold recovery was on the highest grade, with 91% recovery at the coarser grind size and 94% recovery at the finer grind size.  The lowest sulphur grade produced the highest recovery.

Recovery Increases with Flotation and Cyanidation

A second phase of metallurgical testing was completed on three of the samples representing the sulphide zone from the previous test work.  Three batch cleaner tests were carried out as well as cyanide bottle roll tests on the rougher and cleaner tails.  A 5% to 10% increase in gold recovery using flotation and cyanidation of the rougher and cleaner tails was achieved on a nominal 100 micron grind and a 4% increase in gold recovery was achieved on a nominal grind of 70 microns.