Canada Nickel has announced processing test results from its Crawford nickel-cobalt sulphide project in the Timmins-Cochrane mining district. The latest processing data suggests a 52% nickel recovery, with 46% of the recovered nickel splitting into a high-grade nickel concentrate, at 37% nickel. The remaining 54% of the nickel recovered would be destined towards a standard-grade nickel concentrate, at 13% nickel.
According to Mark Selby, the company’s chair and CEO, these latest results suggest that the ‘high-grade’ concentrate could be the highest-grade nickel sulphide con worldwide.
“The 52% recovery from a higher-grade core sample marks another excellent step forward for the Crawford project. Half of the recovered nickel is in a high grade concentrate at 37%; this result and other testwork demonstrates our ability to deliver 40-50% of the recovered nickel into a 35% nickel concentrate, which would be the highest grade nickel sulphide concentrate in the world, according to Wood Mackenzie. The standard grade concentrate delivered concentrate grade of 13%, in line with typical grades for most nickel sulphide projects.”
Selby added that given the range of mineralogy within the deposit, the next phase of work will be focused on flowsheet optimization and developing a wide range of test samples. The final flowsheet will be part of the feasibility study, which is expected by year-end (Canada Nickel is aiming to deliver a preliminary economic assessment of Crawford in the first quarter).
Previously, in December, the company announced locked cycle test results on Crawford samples, with nickel recoveries between 46% and 51%, reporting to a high-grade nickel concentrate at 28% nickel, and to a low-grade concentrate, at between 8% and 13% nickel. At the time, between 32% and 57% of the recovered nickel would report to the high-grade concentrate while an estimated 43% to 68% of the recovered nickel would show up in the low-grade concentrate.
In the latest testing, cobalt recoveries came in at approximately 35%. PGM assays are pending.
The high-grade concentrate includes an iron content of 18% and also features 7% of magnesium oxide. The standard-grade concentrate fraction is made up to 37% iron and 19% magnesium oxide. Although the magnetite recovery was not optimized, 44% of the iron reported to an iron concentrate grading 45% iron.
The latest flowsheet includes two stages of grinding, desliming and flotation. The company sees further potential for improved recoveries and concentrate grades with additional optimization.
Based on the release, Crawford is designed to deliver concentrates to local processing facilities; the high-grade nickel product would be aimed at battery metal consumers while the lower-nickel, higher-iron product could be used to make a ferronickel feed for stainless steel consumers.
This year’s metallurgical testing will have two areas of focus – the first is the optimization of recovery and concentrate grades and of the grinding and reagent inputs used. The second is ongoing lab work to evaluate the potential for improved recoveries from using coarser grind sizes and additional desliming.
Earlier this month, Canada Nickel entered into a non-binding memorandum of understanding with Glencore, to assess the potential use of the major’s Kidd concentrator and metallurgical site in Timmins for the processing of Crawford material.
Resources at Crawford, updated in October, feature 657 million measured and indicated tonnes at 0.26% nickel and 646 million inferred tonnes at 0.24% nickel.
(This article first appeared in the Canadian Mining Journal)