MINERAL PROCESSING: Leach results positive on polymetallic black shale

ALBERTA - Dumont Nickel of Toronto reports that the polymetallic black shale is amenable to sulphuric acid leaching for the recovery of several metals. After a 36-hour cycle at 30°C in a 1% H₂SO₄ solution (or 24-hours at 50°C, in brackets), recoveries were Mo 28% (51%); Ni 89% (70%); U 84% (67%); V 34% (51%); Zn 88% (70%); Cu 53% (57%); Co 86% (69%); Cd 93% (71%); and Li 45% (58%).

The company says the tests are significant because they demonstrate that metals can be extracted from the black shales, recoveries are good enough to warrant further work, and optimized test conditions might recover other metals as well.

Dumont has a 253,624-ha land position 120 km north of Fort McMurray. Six polymetallic systems have been identified on the property. Two flat-lying, near-surface shale units are of particular interest. Both are mid-Cretaceous formations which outcrop in river valleys on the eastern part of the property but can be under 150 metres of overburden in other parts.

The company says that milestone advances during the past decade in bioleaching are responsible for bringing the potential of black shale deposits to light. Bioleaching offers low environmental impact as well as favourable capital and operating costs compared to traditional smelting and refining.

Please visit www.DumontNickel.com to learn more about black shale, which may become a source of metals in the future.