Name of the Project
Back Forty gold/zinc project.
Location
Michigan, in the US.
Project Owner/s
Aquila Resources.
Project Description
Back Forty has openpit proven and probable mineral reserves of 11.65-million tonnes grading 1.85 g/t gold, 21.7 g/t silver, 2.64% zinc, 0.21% lead and 0.28% copper.
Mining operations will encompass a large openpit that will be mined with conventional mining equipment in three pushback phases.
The mining fleet will comprise major equipment used directly in the rock-moving operation, including blast-hole drills, hydraulic excavators, and 91 t haul trucks. Various support equipment will be required, such as dozers, graders, water trucks, and light vehicles for maintenance, personnel transport and mine supervision.
The process plant design is based on a flexible metallurgical flowsheet designed for treating of a variety of ore types. The key project design criteria for the process plant are:
- a nominal throughput of 4 000 t/d sulphide ore and 800 t/d oxide ore.
- crushing circuit availability of 75%, which will be supported by surge bins and dedicated feeders for choke feeding cone crushers for optimum crushing performance and wear minimisation. The oxide and sulphide process plant will have availability of 91.3% using standby equipment in critical areas and reliable grid power supply.
- sufficient automated plant control to minimise the need for continuous operator interface and allow for manual override and control if and when required.
The project has an estimated mine life of seven years, with total payable gold production of 468 000 oz (or an average of 67 000 oz/y) and 135 000 oz in Year 1. Total payable gold equivalent production of 1.1- million ounces.
Total payable zinc production is estimated at 512-million pounds (or an average of 73-million pounds a year). Total payable zinc equivalent production of 1.2-billion pounds is estimated.
Aquila has also identified several opportunities to further enhance the overall economics of the project, including the possible addition of an underground expansion.
Potential Job Creation
Not stated.
Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at a 6% discount rate, of $208-million, and an internal rate of return 28.2%, with payback of 2.2-years.
Capital Expenditure
Initial project capital costs are estimated at $294-million.
Planned Start/End Date
The project has an estimated 24-month construction period.
Latest Developments
The Michigan Department of Environment, Great Lakes, and Energy (EGLE) has approved amendments to Aquila Resources' nonferrous metallic mineral mining permit and its Michigan air-use permit for its Back Forty project.
The amendments update the permits to align with the project design outlined in the August 2018 openpit feasibility study, as well as in its wetlands permit that was issued June last year.
The amendments follow the decision by the EGLE environmental review panel to uphold the mining permit. The contested challenge to the permit began in April 2018.
In May this year, an Administrative Law Judge upheld the final decision and order on the nonferrous metallic mineral mining permit for Back Forty. Following the judge’s ruling, the Menominee Indian Tribe of Wisconsin appealed the decision to the environmental review panel, which comprises technical experts from various fields.
The three-person panel adopted the judge's May 3 decision, which found "that the proposed mining operation will not pollute, impair, or destroy the air, water and other natural resources, or the public trust in those resources”, in compliance with Michigan's nonferrous metallic mining statute.
Key Contracts and Suppliers
Lycopodium Minerals Canada (feasibility study).
On Budget and on Time?
Too early to state.
Contact Details for Project Information
Aquila Resources director of corporate development and investor relations David Carew, tel +1 647 943 5677 or email dcarew@aquilaresources.com.