ONTARIO – There may be new life yet for the former Magino gold mine 40 km west of Wawa. At least owner Argonaut Gold hopes so. The Toronto-based company recently concluded metallurgical testing that showed up to 70% gold recovery in column leach tests of historic stockpiled material.
The tests, conducted in December 2014, compared conventionally crushed material and that reduced in a high pressure grinding roll set at 9.5 mm. Recoveries from the crushed material were between 62% and 66%. Material that passed through the HPGR had recoveries of between 68% and 71%.
Tests aimed at optimizing cyanide use in the leach were also conducted. Three sample composites were prepared to represent shallow, mid level and deep mineralization. Testing revealed a 30% decrease in cyanide consumption from earlier work. Such a reduction would cut operating costs because cyanide accounted for 23% of processing costs, according to the January 2014 pre-feasibility study.
For additional information, the complete tables and explanation of methodologies of leach column and cyanide optimization test work can be found at ArgonautGold.com.