IMX Resources' (ASX: IXR) initial metallurgical testwork has identified that high grade nickel concentrates with high recoveries can be produced from the multiple Ntaka Hill ore zones at the Nachingwea Ni-Cu joint venture in Tanzania.
By using conventional processing technology the high grade nickel concentrates with high recoveries will greatly reduce technical and start-up risk, boosting confidence that the JV will be able to advance development of the project into a potential world class mine operation.
High grade composite concentrate results were returned from the initial ‘sighter’ flotation tests at the various Ntaka Hill deposits.
- 16.7% nickel (Ni) to 18.6% Ni concentrate at Sleeping Giant with between 84.2% and 90.2% recovery;
- an M zone composite concentrate of 17.2% Ni with 88.1% recovery; and
- 15.0% Ni concentrate with 88.1% recovery from H zone.
Of particular significance was that all the concentrates returned low contaminant levels of arsenic (As), antimony (Sb), antimony (Cr), lead (Pb), zinc (Zn) and in particular MgO (magnesium oxide) which reported between 1.5% and 3.9% MgO, which is low by global standards.
Importantly, the high grade nickel concentrate produced from Nachingwea will be highly marketable and compares favorably to the best nickel sulphide mines in the world.
The composite flotation tests were conducted at a moderately coarse grind size of 106 μm (P80) using a conventional concentrate processing technique for nickel sulphide ore.
The company said it is planning further testwork to optimise concentrate grade and recoveries through grind size determinations and reagent additions.
Comminution testwork has also been initiated with Bond Mill Work index rate tests completed on 3 ore zone composites.
An average work rate of 14.8 kWh/t was determined for the Ntaka ores, which is typical for hard rock sulphide ores, and confirms the suitability of a conventional comminution circuit with typical operating costs.
Additional metallurgical testwork will be conducted on 2011 core samples to provide definitive performance and engineering design data for the project.
The JV intends to undertake this test work program in the first half of 2012.
The joint venture is between IMX (25%) and Continental Nickel (TSXV: CNI) (75%), and a 2011 budget of C$8.775 million is designed to expand the current Mineral Resource at the Sleeping Giant deposit within Nachingwea.
Initial 2011 diamond drilling has confirmed a high grade core zone at the Sleeping Giant deposit, and in addition, new intersections of disseminated sulphide mineralisation have been discovered above the Sleeping Giant Zone.