THE BOURSE WHISPERER: IMX Resources (ASX:IXR) has announced good metallurgical results from initial flotation test work on samples of disseminated hanging wall mineralisation taken from the Sleeping Giant zone at the company’s Ntaka Hill nickel sulphide project.
The project is located west of the port town of Mtwara in Tanzania, and is part of the 100 per cent-owned Nachingwea property.
“These positive results demonstrate the potential to economically recover nickel from the large tonnage disseminated hanging wall nickel mineralisation included in the March 2012 mineral resource update,” IMX Resources managing director Neil Meadows said in the company’s announcement to the Australian Securities Exchange.
“This positive proof of concept is a big step forward on the path towards developing a mine at Ntaka Hill.
“This preliminary test work is the first phase of the definitive metallurgical program designed to fast track critical design decisions for development.
“Further test work is ongoing with 12 tonnes of samples currently being tested in Canada, with results expected to be available in the first quarter of 2013.”
IMX used test conditions these initial flotation tests that were identical to those developed for the main higher grade core of Sleeping Giant, in which high grade concentrates (up to 18 per cent nickel) were produced from a relatively coarse grind size (average: P80 of 100 micron1) with low reagent additions.
The company said this represents extremely simple conventional processing for nickel flotation.
By blending this disseminated hanging wall mineralisation with the main higher grade nickel from the Sleeping Giant Zone, or the other higher grade zones at Ntaka Hill, IMX claimed it expects a premium nickel concentrate to be produced, which it hopes would be highly sought after and potentially attract premium prices.
The flotation tests were carried out on ten disseminated nickel sulphide diamond core samples, eight of which returned good results with the remaining two samples returning ‘outlier‘ results that IMX said require further investigation.
Preliminary flotation results. Source: Company announcement
Head grades of between 0.25 per cent and 0.39 per cent nickel, and 0.03 per cent to 0.11 per cent copper were tested to produce nickel and copper concentrates averaging 11.2 per cent nickel and 3.2 per cent copper respectively, at average recoveries of 69.1 per cent for nickel and 83.2 per cent for copper with manganese oxide contaminant levels averaging 6.5 per cent (excluding ‘outlier’ tests).
IMX said further metallurgical test work, including mineralogical investigations, will now be carried out on the disseminated hanging wall mineralisation to:
– Understand the performance of the two ’outlier‘ tests with respect to lithology and volumes of material affected; and
– Optimise the flotation conditions, which should lead to improvements in concentrate grade and metal recoveries.
This test work is part of the large definitive test work program being carried out to provide the design basis for the processing facilities at Ntaka Hill.