Feasibility Study Results

Highlights ($1,200/oz Au; 3.1:1 Real:USD)

  • Average annual gold production of 205,000 oz over a 17.2 year mine life
  • Average annual gold production of 260,000 oz in years 1-10
  • Proven & Probable Mineral Reserves of 3.8 million oz at 1.02 g/t Au
  • Pre-Tax IRR of 37%; Post-Tax IRR of 26% ($1,200/oz Au)
  • Pre-Tax NPV of $942 million; Post-Tax NPV of $665 million (5% discount rate)
  • Average cash operating costs of $618/oz gold
  • All-in sustaining cash costs of $779/oz gold
  • Initial capital costs of $298 million (after tax) including pre-production costs and taxes
  • Life-of-mine strip ratio of 4.3:1
  • Average 93% gold recovery over life of mine

Estimated Project Schedule

Completed Milestones & Upcoming Catalysts


The Feasibility Study considers open pit mining using a 100% owner-operated equipment fleet including trucks, loaders and drills. The mine has been designed to deliver an initial 3.5 million tonnes per year (10,000 tonnes per day) of mill feed, expanding to full production of 7 million tonnes per year (20,000 tonnes per day) in Year 3. The study contemplates a mine that will extract ore over a 17 year period not including eight months of pre-production stripping. The Feasibility Study optimizes the mine plan for the first eleven years with a delivered head grade of 1.30 g/t.  Material from the last three months of pre-production stripping will be used to commission the process plant.

The average strip ratio for the life of the mine is estimated at 4.3:1.  Open pit bench heights of 10 meters will be mined and ore hauled with 136-tonne haul trucks and matching loading equipment.  Best practice grade control drilling will be done with reverse circulation drilling and rock sampling on mine benches prior to blasting. This provides the greatest flexibility for grade control during operations while maintaining reasonable mine operating costs and production capability. 

During the mining operation, a stockpile will be maintained adjacent to the primary crushing plant to meet production targets in the event of weather related mining interruptions and as mill feed in the later years of the operation. Waste rock will be hauled to dedicated waste management facilities near the open pits. 


Extensive feasibility level test work was completed by SGS, using representative run-of-mine composites, that confirmed the material from the Volta Grande mineral deposits is amenable to a conventional crush, grind, gravity concentration, leach and carbon-in-pulp (CIP) flow sheet. 

Test work results indicated that 40% to 50% of the gold will be recovered in a gravity concentrate. The overall estimated gold recovery based on all ore types being processed during the life of mine is 93%.

The Company also completed feasibility-level test work of bond work indices, JK drop weight and SMC tests. These results were used to model the crushing and grinding circuits that confirmed the run-of-mine material is amenable to semi-autogenous (SAG) and ball mill grinding circuit configuration.

Mineral Reserves

The mineral reserves for the Volta Grande Project are based on the conversion of measured and indicated mineral resources (see Mineral Resources section below) within the current Feasibility Study mine plan.  Measured mineral resources are converted directly to Proven mineral reserves and Indicated mineral resources to Probable reserves. The total fully diluted mineral reserves for the Volta Grande Project are as follows:

Classification Tonnes(t) Gold Grade g/t) Contained Gold(oz)
Proven 41,757,000 1.07 1,442,000
Probable 74,212,000 0.98 2,346,000
Proven + Probable 115,969,000 1.02 3,788,000
*This mineral reserve calculation was completed as part of the feasibility study dated March 25, 2015 (download report here), and was completed under the supervision of Gordon Zurowski, P.Eng of AGP Mining Consultants Inc, who is a Qualified Person as defined by NI 43-101. Mineral reserves are stated within the final design pit based on a $1,020 gold price pit shell with a $1,200 gold price for revenue. The cut-off grade was 0.37 g/t for Ouro Verde and 0.40 g/t for Grota Seca. The mining cost averaged $10.90/tonne milled, processing was $7.25/tonne milled and G&A was $0.84/tonne milled. The process recovery was assumed to average 93%. The exchange rate assumption applied was R$3.10 equal to US$1.00 The Feasibility Study only considers the Volta Grande open pit mineralized zones. The Feasibility Study does not include the South Block. Mineral resources that were part of the March 2015 mineral resource associated with South Block and underground mineral resources were left outside of the scope of the Feasibility Study.

**The above information was obtained from the Feasibility Study report for the Volta Grande Gold Project, which can be downloaded here. Please see cautionary notes and Qualified Person statement related to these results here.
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