Name of the Project
Pebble copper/gold/molybdenum/silver/rhenium project.

Location
South-west Alaska, in the US.

Project Owner/s
Pebble Limited Partnership, a subsidiary of Northern Dynasty Minerals.

Project Description
A new preliminary economic assessment (PEA) has provided updated production, financial and cost estimates for the proposed project.

In addition to the proposed project, the 2021 PEA examines three potential mine-expansion scenarios, and potential alternative strategies for gold recovery that could form the basis for future permit applications and reviews.

The proposed project envisages a 20-year openpit mining operation with a processing rate of 180 000 t/d. Life-of-mine (LoM) metal production for this scenario is estimated at 6.4-billion pounds of copper, 7.3-million ounces of gold, 300-million pounds of molybdenum, 37-million ounces of silver and 230 000 kg of rhenium.

Average metal production is forecast at 320-million pounds a year of copper, 363 000 oz/y of gold, 15-million pounds a year of molybdenum 1.8-million ounces a year of silver and 12 000 kg/y of rhenium.

The three expansion scenarios are modelled on a concept identified by Northern Dynasty’s Pebble Limited Partnership in a request for information submission to the US Army Corps of Engineers (USACE) during the federal permitting process.

The first expansion would expand the Pebble process plant from 180 000 t/d to 250 000 t/d, following the 20-year project life envisioned in the proposed project, with subsequent mining and processing of an additional 6.3-billion tons of mineralised material.

The second and third expansions would expand the Pebble process plant to 270 000 t/d in production Year 10 and production Year 5 of openpit production respectively under the proposed project.

All three expansion scenarios process the same volume of mineralised material over the LoM of 8.6-billion tons.

In all the examined development scenarios, an on-site gold plant could start operation in production Year 5 after the required permits have been acquired.

The plant could be expanded, with the process plant expansions undertaken in production years 10 and 21 for the corresponding expansion scenarios.

In the case of the production Year 5 expansion scenario, a permitted gold plant could be built to match the process plant expansion.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
At forecast long-term metal prices, the project has an after-tax net present value (NPV), at a 7% discount rate, of $2.3-billion and an internal rate of return (IRR) of 15.8%, with a payback of 4.7 years.

At prevailing metal prices, the project has an after-tax NPV, at a 7% discount rate, of $4.8-billion and an IRR of 23.8%.

The expansion studies have an IRR of between 18.2% and 21.5%, and an NPV of between $5.8-billion and $8.5-billion.

Capital Expenditure
Initial capital costs for the proposed project are estimated at $6.05-billion, and do not include the projected costs of any of the expansion scenarios.

Additional capital expenditures would be required to facilitate the addition of an on-site gold plant and development of the various expansion scenarios.

Planned Start/End Date
Not stated.

Latest Developments
None stated.

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Northern Dynasty Minerals, tel +1 604684 6365 or email info@northerndynasty.com.
Pebble Limited Partnership, tel +1 907339 2600 or email receptionist@pebblepartnership.com.