Name of the Project
Empire copper project.

Location
The project is located in Custer County, Idaho, in the US.

Project Owner
Phoenix Global Mining.

Project Description
The project comprises a skarn-hosted, openpit, heap-leach solvent extraction-electrowinning copper resource and a deeper-rooted and past-producing high-grade copper, gold, silver and tungsten vein system.

The project has measured and indicated resources of 11.49-billion tons, grading 0.52% copper above a cutoff grade of 0.184%, and 9.8-billion tons of inferred material above the same cutoff grading 0.41% copper.

The subject of the preliminary economic assessment (PEA) is the openpit copper oxide resource, and excludes any potential revenue from gold, silver or zinc. The PEA envisages average copper cathode production of 8 124 t/y from a two-million-tonne-a-year mine.

The PEA plan has been designed as a series of four phased push-backs to achieve a balanced production of ore and waste rock over the eight-year life-of-mine.

The mine preproduction requirements at the project are minimal, given the presence of mineable mineralisation near the bedrock surface. The first pit phases are planned near the crusher area to minimise haulage distances at the beginning of the mine life. Waste material from the pit areas will be used for construction of the heap-leach pad, crusher area and other infrastructure.

Run-of-mine (RoM) ore will be delivered to a modular crushing/screening plant at 350 short tons an hour. This throughput is based on 75% plant availability on a 24-hour basis. RoM material is expected to have a P100 of 24ʺ. The leach pad is being designed for crushed material having a P80 of three quarters.

The crushing/screening plant will comprise a dump hopper, a vibrating grizzly feeder, a jaw crusher, a secondary screen and cone crusher, and a tertiary screen and cone crusher. These components are connected by 30ʺ-wide conveyors. Ore grade material from the openpit will be crushed to 6.35 mm and then agglomerated with cement being loaded on the heap-leach pad in 10 m lifts. Agglomerated ore will be conveyed to the leach pad through a series of grasshopper conveyors feeding a radial stacker.

The PEA provides for a preliminary layout for a 20-million-tonne heap-leach pad. The leach pad is located in an east–west valley located to the north of the Empire openpit in an area known as North Gulch. The layout includes perimeter roads and anchor trenches.

The pregnant leach solution (PLS) pond will receive the aggregate flow of PLS from the leach pad and has a pond capacity of 5.6-million litres. The contingency pond is designed to capture any overflow of the PLS pond in the event of a 24-hour, 100-year storm event that saturates the leach pad. The design capacity is 31.72-million litres.

The leach pad is set to be built in stages to minimise initial capital. Phase 1 will allow for three years of operation before Phase 2 will need to be constructed.

Copper-bearing PLS will be pumped to the solvent extraction (SX) area for processing to extract the copper from solution. The SX stripping circuit consists of two stripping mixer-settlers in a series arrangement. Each SX stripper has two mix tanks and a settler which will mix the copper-rich organic from the extraction settlers with strongly acidic lean electrolyte to transfer copper from the organic liquid to the electrolyte. Rich electrolyte loaded with copper leaving the stripping settlers will report to the loaded organic tanks in the tank farm. The tank farm will be located below the SX facility and contains tanks, pumps, heat exchangers and filters that service the SX-electrowinning (EW) facilities. The tank farm will store and transfer organic, electrolyte, reagents and crud, as well as provide storage for a five-day supply of fresh reagents. The tank farm is designed with secondary containment capable of holding 110% of the contents of the largest tank.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at a 7.5% discount rate, of 53.66-million and an internal rate of return of 23.5%.

Capital Expenditure
Preproduction capital has been estimated at $61.21-million.

Planned Start/End Date
Production is expected to start in 2021.

Latest Developments
Phoenix Copper has appointed mining finance advisory firm Medea Natural Resources as lead financial adviser to arrange up to $70-million for the construction of the Empire mine project.

The funding will be used to construct the openpit, heap-leach, solvent extraction and electrowinning project at Empire.

Included in the $70-million financing that Medea has to arrange is $10-million of advance mezzanine debt financing, which will enable the company to complete the feasibility study quickly, while at the same time carry undertake exploration on the newly discovered Red Star high-grade lead/silver zone, as well on the underground sulphides, and on the two Idaho Cobaltbelt properties.

Key Contracts and Suppliers
Hard Rock Consulting (PEA mine plan); Call & Nicholas (openpit slope stability); Golder Associates (heap-leach pad and pond designs); Minerals Technology (metallurgical testwork); M3 Engineering & Technology Corp (process plant and infrastructure) and CES (environmental baseline and permits).

On Budget and on Time?
Not stated.

Contact Details for Project Information
Phoenix Global Mining, Dennis Thomas/Richard Wilkins, tel +44 20 7236 1177.