Good recovery figures from Ungava

Metallurgical tests commissioned by Canadian Royalties (CZZ-T) on mineralization from its Ungava nickel-copper projects show high base metal and platinum-group recoveries.

Testing by SGS Lakefield Laboratories on drill core from the project established that conventional flotation works on sulphide mineralization from the Mesamax, Expo and Mequillon deposits. Mineralization from the different deposits had a wide range of characteristics, but all types behaved similarly in flotation cells. All the mineralization is a pyrrhotite-pentlandite-chalcopyrite assemblage. It is also acid-generating.

Bulk nickel-copper concentration was tested, but final work evaluated only separate nickel and copper concentrates, which would be an easier sell to smelters in any event.

Nickel recoveries ranged from 75% to 82% and copper recoveries, from 83% to 98%. Platinum and palladium were recovered in both concentrates, but mainly in the nickel concentrate. Total recoveries were 60-80% for platinum and 80-93% for palladium.

Canadian Royalties’ is considering building a mill where the two concentrates could be produced and filtered; they would then be stored until the shipping season.

Tests on material from the Expo deposit showed that optimum results came from grinding the material to 0.03-0.05 mm. Its copper concentrate graded 27% copper and recovered 64% of the copper. The nickel concentrate from the same material, which graded 10% nickel and 3% copper, recovered 74% of the nickel and 19% of the copper, as well as most of the platinum group elements.

The recoveries significantly exceeded those obtained in 1970 in flotation tests on Expo mineralization.

Flotation on net-textured mineralization from the Mesamax and Mequillon deposits recovered 87% of the copper and 3% of the nickel in a 28%-copper concentrate. Most of the palladium reported to the copper concentrate. A second concentrate grading 12% nickel recovered 72% of the nickel and 10% of the copper, plus a significant portion of the platinum. The best recoveries came at grinding sizes of 0.05-0.07 mm.

Massive sulphides from Mesamax yielded a 31% copper concentrate that recovered 71% of the copper, and a 15% nickel concentrate that retrieved 80% of the nickel, 27% of the copper, and most of the palladium and platinum.

The mineralization is only mildly abrasive. Grinding work index figures ran from 7.7 to 19.9 kWh per tonne for ball milling, and from 5.3 to 22.9 kWh per tonne for rod milling.