Following the successful completion of a preliminary economic assessment for Vista Gold’s Mt. Todd Gold project, Tetra Tech Proteus was engaged to provide a feasibility study for the project.

Mt. Todd, Vista Gold’s flagship and principal asset, is about 250 kilometers southeast of Darwin, in the Northern Territory of Australia. According to Vista Gold, Mt. Todd is the largest undeveloped gold resource in Australia.

Mt. Todd is a brownfield development project with significant existing infrastructure. Tetra Tech Proteus’s scope of work for the pre-feasibility study primarily included the process plant and non-process infrastructure. The study methodology included developing process design criteria and documentation, schematic drawings, general arrangement drawings, 3D models, design reviews, and calculations to support the capital and operating cost estimates.

The pre-feasibility study evaluated two development scenarios:

  • Base Case: 50,000 tonnes per day
  • Alternate Case: 33,000 tonnes per day

The study included the following elements:

  • Process design review
  • Preliminary design for process plant and infrastructure
  • Water supply
  • Tailings dam
  • Geology
  • Mine closure
  • Process plant closure
  • Project services closure
  • Project infrastructure closure
  • Surface water, hydrogeology, and acid and metalliferous drainage
  • Capital and operating cost estimation