Name of the Project
Goliath gold project.

Location
North-west Ontario, Canada.

Client
Treasury Metals.

Project Description
A preliminary economic assessment (PEA) on the Goliath project has proposed an initial openpit mining plan to take advantage of mineralised material at surface. Revenues generated from openpit mining will be used in the development of underground (UG) operations. 

To optimise the mill head grade, the PEA envisages that UG mine development will start immediately in Year 1 to create UG mill feed by Year 2.  It has been proposed that once UG production is on line, the openpit production will decrease over an eight-year period to supplement the UG mill feed to nameplate capacity. As proposed, the openpit will operate over an eight-year mine life and will use no significant stockpile from the storage of low-grade material. This will have the additional benefit of reduced rehandling costs for the low-grade stockpile that was proposed in previous studies.  

Total production is estimated at 1.14-million ounces of gold and 2.08-million ounces of silver, 154 700 oz of which it is proposed will be from the openpit and 987 300 oz from UG. The PEA is based on an average milling rate of 875 000 t/y, or 2 500 t/d, with an average head grade of 3.81 g/t gold and 10.55 g/t silver. Metallurgical and optimisation studies continue to indicate high recoveries using a traditional carbon-in-leach (CIL) circuit and an estimated overall recovery of 95.5% for gold and 62.6% for silver.

A standard CIL circuit with gravity extraction is considered the base case for the proposed processing facility. An average of 2 500 t/d will be primary-crushed using a jaw crusher and then ground to the target leaching P80 of 106 µm using a single-stage semiautogenous mill and classifying cyclones.  A gravity circuit comprising a scalping screen and centrifugal concentrator will be fed from the cyclone feed distributor. The gravity concentrate will be batch-treated in an intensive leach reactor and the pregnant solution treated by electrowinning. Cyclone overflow will pass through a trash screen before entering the CIL circuit.

Jobs to Be Created
Not stated.

Net Present Value/Internal Rate of Return
The project has a post-tax net present value, at a 5% discount rate, of $306-million and an internal rate of return of 25%, with a payback of 4.1 years.

Value
Initial capital to fund construction is estimated at C$133.2-million, with an additional C$132.5-million in sustaining capital over the life-of-mine primarily to fund the underground expansion. The main increases in the capital costs since the 2012 PEA came from advanced engineering studies to support the mine permit process and the major cost changes were attributed to the tailings facility, closure costs and openpit preproduction costs. The total mill facility includes costs associated with a backfill plant for underground production and the company will use existing office, warehousing and electrical facilities on site to minimise capital costs needed for construction.

Duration
Not stated.

Latest Developments
None stated.

Key Contracts and Suppliers
None stated.

On Budget and on Time?
Not stated.

Contact Details for Project Information
Treasury Metals, tel +1 416 214 4654, fax +1 416 599 4959 or email info@treasurymetals.com.