Worthless previously untreatable waste dump sulphide ore with a grade of only about 0.5% nickel was being converted into a high grade very saleable product of about 4% nickel as shown in Figure 1.

It is clear that this ore sorter appears to have the potential to completely revolutionise the production of nickel sulphide ore.

The A$1.5m ore sorter was developed applying an electro-magnetic concept that apparently Western Mining unsuccessfully tried some years ago (in the 1990s ?) on waste mullock when it was operating the Long nickel mine, but also apparently never tried their sorter on ROM ore. Reliance recognised that with expected average grades of ~2.8%Ni ore from the Beta mine that they needed to upgrade the ore. (The mine’s recently opened East Alpha has the nice golden yellow nickel lode of hangingwall ore at 17%Ni in the face we saw underground, of which the highest specimen from development to-date is about 33%Ni).

Consequently, the current electro-magnetic technique was developed with lab scale testing (when we referred to it in our ERA (Eagle Research Advisory) report on Consolidated Minerals dated 5 August 2005) achieving about a 30% upgrade in the product (eg from 3% Ni to 3.9%Ni), while reducing the tonnage by 25% to 30%. The process consists of rock being crushed to result in a 20mm to 70mm target fraction which passes at a particular speed through the electromagnetic sensors that identify a nickel-ore-bearing rock specimen and notify a laser to direct one of the up to 20 air jets to blast the nickel rock specimen out of the rock “stream” passing over the edge of a belt.

Currently almost 1,000tpd appears to be capable of being treated, resulting from the ~0.5%Ni commissioning feed in about 300t of fines (<20mm, at ~1%Ni to 1.5%Ni), 300t of oversize (>70mm), 300t of waste, and 100t of ~4% Ni ore. A secondary circuit was being constructed to re-crush the oversize and feed it back through the circuit. ROM trials were expected to commence from about 6 May.

Consolidated Nickel and Ultrasort have understandably patented the ore sorter and Consolidated Nickel has the rights to use the ore sorter within a 100km radius of Kambalda (which hence includes the Kambalda, Widgiemooltha and Lanfranchi nickel fields).

Suddenly all those low grade dumps and low grade orebodies potentially become capable of being converted into saleable nickel ore. In addition, because the waste being rejected is often ultramafic serpentinite, theoretically the Fe:MgO ratio could be higher, further enhancing the saleability of the ore.

Although the BHP Billiton Nickel West (formerly Western Mining) deals with the individual nickel sulphide producers are shrouded in secrecy, we have partly referred to them in the ERA research and in this column before. Basically, the producers receive a recovery according to the grade of nickel that they deliver, such that for 1% Ni ore they get about 70% and for >3.5% Ni they get about 90% (<1%Ni ore is usually rejected as are ores that fail to meet minimum Fe:MgO ratios and other specifications). The producers also pay to truck their ore to the WMC concentrator in Kambalda, and pay to process the ore through the concentrator.

It is easy to see the significance of the impact of the ore sorter, especially when the treatment and trucking costs are factored in, resulting in higher recoveries and lower costs, yet alone the conversion from a sometimes unsaleable to saleable Ni ore product.

As a further cost saving, as the Beta-Hunt mine develops, Consolidated Nickel expect to install an ore sorter underground to separate the waste for use in CAF (cut-and-fill), and truck more ore (and less waste) out of the mine.

The ore sorter can apparently be set to “air-blast” out the ore or the waste, so if the waste component is expected to be lower than the ore component, then the waste rock component can be targeted for air-blasting out of the way.

Whether the ore sorter can be applied to other minerals besides nickel has yet to be tested, however, it is clear that this new ore sorter appears capable of giving the current nickel sulphide producers a MAJOR shake up, potentially resulting in lower costs, higher profitability and higher nickel production.

Disclosure and Disclaimer : This article has been written by Keith Goode, the Managing Director of Eagle Research Advisory Pty Ltd, (an independent research company) who is an Authorised Representative with Taylor Collison Ltd, and with his associates, may hold interests in some of the stocks mentioned in this article. The opinions expressed in this article should not be taken as investment advice, but are based on observations by the author. The author does not warrant the accuracy or completeness of any information and is not liable for any loss or damage suffered through any reliance on its contents.

Figure 1. The new Consolidated Nickel-Ultrasort Ore Sorter at Beta-Hunt in Kambalda