Name and Location
Sonora lithium project, Mexico.

Client
Bacanora Minerals.

Project Description
Sonora is one of the world’s larger known clay lithium deposits.

It has an indicated mineral resource estimate of five-million tonnes of lithium carbonate equivalent (LCE) and an inferred mineral resource of 3.9-million tonnes of LCE.

The project involves the development of a mine and lithium carbonate (Li₂CO₃) processing facility.

A prefeasibility study (PFS) has highlighted the strong economic potential of producing up to 35 000 t/y of battery-grade Li₂CO₃.

In addition, Sonora has the potential to produce up to 50 000 t/y of potassium sulphate for sale to the fertiliser industry. The PFS envisages an openpit operation using conventional truck-and-shovel mining methods.

Hydraulic excavators and haul trucks, as well as an ancillary fleet of dozers, graders and water trucks, will be used for the mine operation.

For the Stage 1 and Stage 2 mining design, 50-million tonnes of ore, at a grade of 3 525 parts per million (ppm) of lithium and 1.49% potassium, with a stripping ratio of 3.1:1, will be mined over the initial 20-year mine life.

The processing plant design comprises a preconcentration stage involving scrubbers, hydrocyclones and reverse flotation to produce an initial concentrate prior to roasting.

The integrated plant has been designed to initially process 1.4-million tonnes of ore a year during the first two years of the project, subsequently increasing to about 2.7-million tonnes a year after Year 3.

The plant design also includes a circuit to produce 50 000 t/y of commercial-grade potassium sulphate through a series of evaporation, precipitation, filtration and packaging stages.

Net Present Value/Internal Rate of Return
The PFS estimates a pretax internal rate of return of 29% (post-tax 25%) and an associated net present value, at an 8% discount rate, of $776-million (post-tax $542-million).

Value
Stage 1 has an initial capital cost of $240-million.

Stage 2 has a capital cost of $177.1-million.

Duration
The PFS estimates project commissioning to take place in the final quarter of the 2018 calendar year.

Latest Developments
Bacanora has reported that it is making substantial progress on its flagship Sonora lithium project as it works on completing a definitive feasibility study (DFS) by the first quarter of 2017.

The 3 000 m infill drilling programme is progressing well, with more than 2 000 m drilled to date, with a target of upgrading a portion of the current resource from the indicated to the higher-confidence measured category.

The latest drill intercepts are consistent with the average thickness of the deposit, and assay results are expected next month.

The pilot plant expansion is progressing in parallel with metallurgical testing. The company expects to deliver battery-grade lithium carbonate samples to offtakers in Asia and Europe during the third quarter. Negotiations regarding offtake agreements with these potential partners are ongoing and will continue in tandem with the preparation of the bankable feasibility study, the developer has said.

During the next 12 months, the company plans to employ engineers and operators to keep the plant in continuous operation and gain process expertise.

It has appointed Ausenco Engineers to undertake the process engineering for the DFS. SRK Consulting will undertake the mineral resource estimate, and International Mining Consultants will provide the reserve estimate and mine planning.

Key Contracts and Suppliers
Ausenco Engineers (process engineering for DFS), SRK Consulting (mineral resource estimate) and International Mining Consultants (reserve estimate and planning).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Bacanora Minerals, tel +1 403 237 6122, fax +1 403 237 6144 or email info@bacanoraminerals.com.