Mining’s old guard needs strong medicine
A new report details subpar investor returns in the mining industry over the last decade, particularly big cap diversified companies which have not adapted to new realities.
Amex Exploration (TSXV: AMX) reported gold recoveries over 95% from all samples and over 98% on high-grade samples from its Perron project. The Perron project is about 110 km north of Royun-Noranda in the Abitibi region of Quebec.
Samples from the Denise, Gratien, Grey Cat, and Team gold zones were tested by gravity, flotation and leaching. Gold and silver were recovered from a Knelson MD-3 concentrator at a coarse primary grind of 80% passing 184-416 μm. All samples were amenable to gravity recovery, ranging from 34% (in lower grades) and up to 72% in higher grades.
A single flotation test was performed on a 2-kg subsample of each of the gravity tailings. The samples were treated with potassium amyl xanthate and methyl isobutyl carbinol at a natural pH for 10 minutes. Under these conditions an additional 70.1% to 93.1% of the gold was recovered.
Amex said that direct cyanidation of the gravity tailings may recover gold and silver as well as does flotation.
The flotation test was performed on half the flotation tailings. The slurry was reground to 70% passing 90 μm and leached in a bottle roll for 48 hours at pH 10.5 to 11.0. Cyanidation as tested gave excellent results, recovering 79.0% to 96.7% of the gold in the tails.
Eldorado Gold (TSX: ELD; NYSE: EGO) recently spent C$15 million on charity flow-through shares of Amex and now holds a 9.9% interest in Amex.
