Metallurgical testing was first performed on the NZ and SZ in 1973 by INCO Ltd, and in the mid-1990’s by Teck-Cominco Corporation. Further tests were performed in 2009 and 2010 to support a historic Preliminary Assessment (PA), following the NI 43-101 guidelines, done by SRK Consulting Inc. (SRK) on October 8, 2010 which was updated in another NI 43-101 report on April 29, 2011 with an increase in throughput from 25,000 to 25,000 t/d. These historic reports are not considered current and are only discussed here as part of the previous work completed on the property.
Data from the locked cycle flotation tests performed in 2010, and used in the PA and PEA reports, were used in the current PEA report. Only the NZ and SZ oxide feed had cyanide leach column tests performed for the April 2011 PEA report. Additional tests carried out since April 2011 included leach column tests and cyanide bottle roll tests on the Tizate oxide feed and variability sampling and flotation tests on the NZ, SZ, and Tizate sulphides.
Flotation Concentrate & Tails Cyanidation Recovery Estimates
Flotation | Tails Cyanidation | Combined Recovery | |
Tepal Recovery | |||
Copper | 88.2% | 88.2% | |
Gold | 62.4% | 16.5% | 78.9% |
Silver | 27.4% | 15.5% | 40.2% |
Tizate Recovery | |||
Copper | 85.9% | 85.9% | |
Gold | 55.0% | 16.0% | 74.0% |
Silver | 59.6% | 18.5% | 78.1% |
Oxide Leach Recovery Estimates
Tepal Recovery | |
Gold | 83.2% |
Silver | 63.3% |
Tizate Recovery | |
Gold | 75.3% |
Silver | 55.9% |