Fortaleza de Minas Nickel Project

 

This USD 192 million project includes a grassroots open‑pit and underground mining operation with concentrating and smelting facilities.  The plant was designed to process 550,000 metric tons per year of high‑grade nickel sulfide ore to produce an intermediate (matte) product with 10,000 tpy of contained nickel.

The concentrator consists of primary crushing, semi-autogenous grinding (SAG), ball milling, and flotation.  The smelter employs Outokumpu Direct Nickel technology to produce matte for sale on the international market.

Prior to the beginning of engineering, Aker Solutions's mine planning and plant engineering specialists completed a feasibility study and ±15% capital cost estimate.  The study included a review of the geological and geotechnical work and the establishment of design criteria to be used in the development of the mine plan.  The plan established all key infrastructure, including the mine accesses, ore and waste handling systems, ventilation, backfilling, and surface and underground services.

Design of the open pit was completed using state-of-the-art computer software to establish the full pit limits and assist in development of a production schedule that will defer waste stripping and optimize production.  Working closely with the client’s technical specialists, Aker Solutions developed a cut-and-fill underground mining plan and schedule that minimizes dilution and maximizes recovery.

For the process plant, Aker Solutions revised the smelting process from a conventional roaster/furnace/converter circuit to the Outokumpu Direct Nickel process and also simplified the refining circuit.  Based on these changes and increased production levels, the financial viability of the project was improved.