COPY OF FINAL PROSPECTUS - Mirabela Nickel

Metallurgy
The Santa Rita deposit contains nickel sulphide as well as lesser amounts of nickel oxides. A comprehensive
testwork program has been undertaken on the nickel sulphides to determine the mineralogical, comminution
and metallurgical properties of the various mineralised zones within the deposit.
The key results of the metallurgical testwork program are as follows:
• the Santa Rita deposit can be categorized into two major mineralogical types; peridotite, which
represents approximately 65% of the deposit and has approximately 20% of the nickel associated with
silicates and hence has a maximum recovery of approximately 70%; and pyroxenite, which represents the
remainder of the deposit and has an increased component of nickel sulphide and as a consequence, an
improved nickel recovery of between 75% and 80%;
• the samples are in the medium range in terms of competency for crushing and grinding. The
comminution results also indicated that SAG milling would be appropriate for these samples;
• a nickel concentrate grade of 13% to 14% can be achieved via conventional flotation at a recovery of
between 66% and 68%;
• there is potential for improvements in both nickel grade and nickel recovery. This would most likely be
achieved through further optimisation of the flotation parameters and concentrate regrind options. It
should be noted that the overall nickel recovery will remain limited to a large extent by the percentage of
nickel associated with sulphides in the deposit;
• the settling properties of the flotation tail are acceptable in terms of flocculent consumption, thickener
capacity, underflow density and overflow liquor clarity; and
• additional testwork is to be completed on samples of the flotation concentrate. The lack of completed
testwork in this area would be considered to be a low risk.
Mining Operations
Mining Methods
The current mining plan is based on exploiting the Santa Rita disseminated nickel sulphide deposit by
conventional open pit mining techniques using backhoe excavators and off-road dump truck equipment. These
mining methods are common in Brazil. Included in these operations will be normal drilling, blasting, loading,
hauling activities, as well as the supporting functions of dewatering, grade control and equipment maintenance.
Appropriate personnel training and development of the workforce will be undertaken to ensure that all
operators and supervisors have the necessary skills base and experience to carry out the various mining activities
in a safe, efficient and effective manner.
Process Plant Design
The proposed process plant to treat the Santa Rita deposit consists of primary crushing, conventional SAG
and ball milling, followed by a flotation circuit. It is proposed that material be delivered to a primary crusher by
a front end loader and/or 100 tonne dump trucks. The primary crusher would reduce the ROM feed to P 80 size
of 120mm. This material will then be conveyed to a coarse ‘ore’ stockpile where it could be fed at a steady rate to
the milling circuit.
A comprehensive study has been undertaken in respect of the milling circuit, which would have a 8 MW
SAG mill in open circuit with a 5.8 MW ball mill to produce a rougher feed at a P 80 grind size of 125m. The
capacity and configuration of the comminution circuit is considered acceptable by RSG Global, particularly with
the provision to include a pebble crusher and a regrind mill if necessary later in the project.
The comminution properties of potential mining dilution was not tested, however the geological assessment
indicated that there is unlikely to be any material difference in the competency of the mineralised zones as
opposed to the waste zones.
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