Name of the Project
Jacobina mine – Phase 2 expansion.

Location
In Bahia state, north-east Brazil.

Project Owner/s
Canadian-based precious metals producer Yamana Gold.

Project Description
The Jacobina operation comprises a complex of underground gold mines and a 6 500 t/d carbon-in-pulp processing plant.

The operation has total proven and probable reserves of 34.18-million tonnes grading 2.27 g/t.

Total measured and indicated resources are esti­mated at 42.47-million tonnes grading 2.26 g/t gold, with inferred resources estimated at 18.53-million tonnes grading 2.36 g/t gold.

The prefeasibility study (PFS) on the Phase 2 expan­sion project envisages an increase in the processing plant’s throughput to 8 500 t/d, which is expected to be achieved through the installation of an additional grinding line and incremental upgrades to the crushing and gravity circuits.

The Phase 2 expansion will ramp up gold production to 230 000 oz/y by 2023, at average feed grades of 2.4 g/t of gold.

The current mining equipment fleet and under­ground infrastructure at Jacobina is able to sup­port most of the additional production requirements for the Phase 2 expansion, including electrical substations and pumpstations. However, the acquisition of certain infrastructure will be moved to an earlier date to support the increased production rate.

Ventilation infrastructure will be upgraded to pro­vide adequate airflow for the additional working areas and increased equipment fleet. Total underground development is unchanged from the Phase 1 case, but the peak development rate is planned to increase from about 16 km a year to 19 km a year to support the higher production rate.

At the plant, crushing capacity will be increased by replacing an HP 500 tertiary crusher with a larger HP 800 crusher. In addition, a third ball mill, with a nominal capacity of 195 t/h, will be added to the plant to bring grinding capacity to required levels. Further, a new 6 000 t capacity silo, similar in size to the operation’s existing silos, will be installed to serve the new ball mill. The new grinding line will also have a new gravimetric concentration system.

The project has a mine life of 11.5 years.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The PFS case scenario, which is based on current mineral reserves only, delivers an after-tax net present value, at a 5% discount rate, of $777-million over an 11.5-year mine life using a conservative gold price assumption of $1 250/oz.

Capital Expenditure
The project has a total capital cost estimated at $57-million, of which $35-million pertains to the processing plant, including a 35% contingency, $14-million for underground mining and $8-million for infrastructure.

Planned Start/End Date
Phase 2 is expected to be completed in early 2023; the timeline depends on the feasi­bility study.

Latest Developments
The company is advancing the Phase 2 expansion at Jacobina.

Yamana expects to provide an update regarding capital expenditure and development schedule in mid-2021 once studies are finalised to facilitate permitting.

The company has also begun a conceptual study on a Phase 3 expansion, which will increase throughput to 10 000 t/d at modest additional capital requirements.

Yamana has also adopted a comprehensive Jacobina life-of-mine (LoM) tailings management strategy that reduces the surface disposition of tailings, with underground tailings disposal as backfill.

The company has initiated several studies to ensure long-term sustainability and reduce the environmental footprint of the operation.

Work conducted in 2020 confirmed that paste backfill and hydraulic backfill are technically feasible options for disposal of tailings into underground voids, thereby minimising the quantity of tailings stored on surface.

In March 2021, a feasibility study was completed at Jacobina for the installation of a hydraulic backfill plant. The initial capital cost for establishing the backfill system is estimated at $8-million.  

Plans are in place to advance the hydraulic backfill plant project, which is in the permitting phase.

A conceptual study is under way to evaluate further opportunities for a dry stack tailings facility and/or a paste backfill plant in parallel to the hydraulic backfill plant, which could provide opportunities in the future for the additional storage of tailings to support future mineral reserve development.

Existing surface tailings capacity and backfill will be sufficient for LoM production at Jacobina at the planned increased processing rates.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Yamana Gold, tel +1416815 0220 or email investor@yamana.com.