The process plant contemplated in the Preliminary Economic Assessment is a standard copper treatment facility, consisting of primary crushing, a SAG/ball mill circuit followed by copper flotation, thickening and filtering, and magnetite concentration of the copper tailings. The process plant design criteria were based on metallurgical testwork completed to August 2009.
Aura Minerals has completed metallurgical testwork during 2007 to 2009 in Brazil. The testwork carried out to date has covered all aspects of metallurgy: grinding, sulfide copper recovery, oxide copper recovery, magnetite recovery, assessment of gold, nickel and gallium recovery, and mineralogical examinations. The programs have been conducted at several facilities in Brazil, Peru, and Canada.
The results of the testwork programs conducted to date show expected metallurgy from a primary grind of 80 microns of:
- copper recovery of at least 85% to a minimum 30% copper concentrate;
- gold recovery is projected to be approximately 65% from a 0.1 g/t Au head grade; and
- magnetite recovery of approximately 92% to a 67% iron concentrate grade, relative to an approximate 11% mass yield of total Fe content.
Arapiraca Overall Process Flowsheet