BRITISH COLUMBIA – As SHERWOOD COPPER of Vancouver prepares its Minto copper-gold mine for production, it is already testing new areas that may prolong the life of the project. The company said that independent metallurgical testing of the high-grade Area 2 resource recovered 90-95% of the copper, 60-75% of the gold and 80% of the silver in samples.
G&T METALLURGICAL of Kamloops, B.C., conducted variability testing on 22 composite samples from Area 2 with grades ranging from 0.3-3.5% Cu. All samples grading greater than 1.0% copper achieved 90-95% copper recovery in open circuit batch tests at a standard grind, slightly less for lower grade material.
Composites from six of the zones underwent locked cycle tests at target primary grind sizings of 150 microns and 270 microns. The P zone composite achieved average copper recoveries of about 90% at a 40% copper concentrate grade, regardless of grind size, in locked cycle tests. There was variation among zones, but the results are very encouraging, in the words of Sherwood president and CEO Stephen Quin.
No gravity work was carried out to determine what amount of free gold was being lost to tailings. Oxidation was not an issue in any of the samples tested, and the lower copper recoveries reported above were generally for the lower grade sample material provided.
Learn more about the Minto development at www.SherwoodCopper.com.