• Data Access
  • Your Email  
  • Your Email  
Keep me signed in.
Forgot your password?
Close
  • Forgot Your Password?
  • Enter the email you signed up with and we'll email it to you.
  • Your Email  
Close
Back
MDO
Mining Data Solutions
  • Home
  • Database
  • Subscribe
  • Sign In
  • Sign In
United States
Back Forty Project

This page is not tailored to
devices with screen width under 750 px.
 Location:
17 km W from Stephenson, Michigan, United States

  Project Contacts:
E807 Gerue Street
Stephenson
Michigan, United States
49887
Phone  ...  Subscription required
EmailEmail
WebsiteWeb
Additional Resources for Suppliers & Investors
Drill results over 30 g/t Au
Stay on top of recent discoveries.
Search drill results by commodity and grade.
Largest mines in the Americas
Mining and mill throughput capaciites.
Full profiles of select mines and projects.
Deepest underground mines
Shaft depth and mill throughput data.
Full profiles of select mines and projects.
Heavy mobile equipment
HME type, model, size and quantity.
Full profiles of select mines and projects.
Permitting and construction projects
Projects at the permitting or construction stage. Full profiles of select projects.
Mines with remote camps
Camp size, mine location and contacts.
Full profiles of select mines and projects.
Mines & projects in United States
A list of country's mines and projects.
Full profiles of select mines and projects.
  • Overview
  • Owners
  • Geology
  • Mining
  • Processing
  • Production
  • Reserves
  • Costs & Financials
  • Fleet
  • Personnel
  • Filings & News

Thank you for browsing through mine profiles compiled by the Mining Data Online team.

Would you like to subcribe or schedule a Demo?
  • Name:
     
  • Company:
     
  • Position:
     
  • Phone:
  • Email:
  • Message:

Overview

StagePermitting
Mine TypeOpen Pit & Underground
Commodities
  • Gold
  • Silver
  • Copper
  • Lead
  • Zinc
Mining Method
  • Truck & Shovel / Loader
  • Mechanized Cut & Fill
  • Longhole stoping
  • Paste backfill
Mine Life12 years (as of Jan 1, 2019)
The Company is currently advancing a definitive feasibility study and preparing permit applications.


Owners

Source: p. 6
CompanyInterestOwnership
Gold Resource Corp. 100 % Indirect
On December 10, 2021, the Company successfully completed the acquisition of all the issued and outstanding common shares of Aquila Resources Inc. Aquila’s principal asset is its 100% interest in the Back Forty Project located in Menominee County, Michigan, USA.

Contractors

Subscription required - Subscription is required.


Deposit Type

  • VMS


Summary:

Deposit Types
The zinc-copper-gold-silver bearing sulphide mineralization identified on the Back Forty Property exhibits typical characteristics of VMS mineralization. This deposit type has been well documented in the literature since the early 1970s (Franklin et al. 1981) and the exploration model for the PVB was refined after the discovery of Flambeau (DeMatties et al. 1996).

Mineralized Zones
Mineralization at the Back Forty Deposit consists of discrete zones of: 1) zinc or copper-rich massive sulphide (±lead), which may contain significant amounts of gold and silver, 2) stockwork stringer and peripheral sulphide, which can be gold, zinc, and copper-bearing (±lead/silver), 3) precious metal-only, low-sulphide mineralization, and 4) oxide-rich, precious metal-bearing gossan.

Massive Sulphide Mineralization
The Main Zone massive sulphide, which accounts for the vast majority of massive sulphide mineralization lies at the statigraphic boundary of these two rhyolite units. Rhyolite 1 lies stratigraphically below this sulphide horizon (footwall) while rhyolite 2 lies above the horizon (hanging wall). Another massive sulphide horizon, the Tuff Zone, is located at or near the upper contact of rhyolite 2 and the lower contact of an overlying package of tuffaceous and siliceous sediments. A possible third massive sulphide horizon, the Deep Zone, may represent a lower mineralized zone.

Main Zone Massive Sulphide
The Main Zone i ........


Mining Methods

  • Truck & Shovel / Loader
  • Mechanized Cut & Fill
  • Longhole stoping
  • Paste backfill


Summary:

The mine plan consists of a combined open pit and underground mining operation. Open pit mining will take place from Year 1 to Year 5. Underground development will be initiated in Year 5 and underground production mining will continue to Year 11.

A number of stockpiles, by material type, will facilitate the accelerated processing of higher-grade material and also manage fluctuations in process plant feed delivery from the two mining operations.

The Back Forty Project area consists of very subdued terrain and topography. The area, topography and climate are amenable to the conventional open pit mining operations proposed for the Project. The open pit mining operation will encompass a single open pit that will be mined with conventional mining equipment in three pushback phases. The underground mine will be developed beneath the open pit with a single decline access point located part way down the open pit ramp.

The open pit design is based on the 2018 Feasibility Study. Minor modifications were made to standardize on 5 m high benches with a quadruple (4) bench configuration, resulting in a 20 m vertical distance between catch berms. For scheduling purposes, the Back Forty pit was subdivided into three phases. Mining commences in a small higher-grade pit and then expands outwards by pushing back the pit wall. This enables annual waste stripping quantities to be distributed to avoid high and low annual tonnage fluctuations.

Open pit ........


Crushing and Grinding
Source: Subscription required

- subscription is required.


Processing

Flow Sheet: Subscription required

Summary:

- subscription is required.


Projected Production:

CommodityProductUnitsAvg. AnnualLOM
Gold Payable metal koz 692
Silver Payable metal koz  ......  Subscription required
Copper Payable metal M lbs  ......  Subscription required
Copper Concentrate kt  ......  Subscription required
Lead Payable metal M lbs  ......  Subscription required
Lead Concentrate kt  ......  Subscription required
Zinc Concentrate kt  ......  Subscription required
Zinc Payable metal M lbs  ......  Subscription required
Gold Equivalent Payable metal koz  ......  Subscription required  ......  Subscription required

Operational Metrics:

Metrics
Waste tonnes, LOM 53,069 kt *
Ore tonnes mined, LOM 15,849 kt *
Total tonnes mined, LOM 68,918 kt *
Tonnes processed, LOM 15,858 kt *
* According to 2019 study.

Reserves at October 14, 2019:
The Mineral Resource Estimate was based on metal prices of US$1,375/oz gold, US$22.27/oz silver, US$1.10/lb zinc, US$3.19/lb copper and US$1.15/lb lead.

CategoryTonnage CommodityGradeContained Metal
Measured 8,444 kt Gold 1.98 g/t 538.1 koz
Measured 8,444 kt Silver 20 g/t 5,430 koz
Measured 8,444 kt Copper 0.34 % 62.6 M lbs
Measured 8,444 kt Lead 0.17 % 31.8 M lbs
Measured 8,444 kt Zinc 3.25 % 605 M lbs
Indicated 9,827 kt Gold 1.81 g/t 572.4 koz
Indicated 9,827 kt Silver 27.61 g/t 8,723 koz
Indicated 9,827 kt Copper 0.3 % 64.7 M lbs
Indicated 9,827 kt Lead 0.33 % 72 M lbs
Indicated 9,827 kt Zinc 2.84 % 615.4 M lbs
Measured & Indicated 18,271 kt Gold 1.89 g/t 1,110 koz
Measured & Indicated 18,271 kt Silver 24.09 g/t 14,153 koz
Measured & Indicated 18,271 kt Copper 0.32 % 127.3 M lbs
Measured & Indicated 18,271 kt Lead 0.26 % 103.8 M lbs
Measured & Indicated 18,271 kt Zinc 3.03 % 1,221 M lbs
Inferred 1,194 kt Gold 3.71 g/t 142.5 koz
Inferred 1,194 kt Silver 49.24 g/t 1,891 koz
Inferred 1,194 kt Copper 0.38 % 10.1 M lbs
Inferred 1,194 kt Lead 0.47 % 12.5 M lbs
Inferred 1,194 kt Zinc 1.23 % 32.3 M lbs

Commodity Production Costs:

CommodityUnitsAverage
All-in sustaining costs (AISC) Gold Equivalent USD  ......  Subscription required&nbs
All-in sustaining costs (AISC) Gold USD  ......  Subscription required *†
C1 cash costs Gold Equivalent USD  ......  Subscription required&nbs
C1 cash costs Gold USD  ......  Subscription required *†
Assumed price Lead USD  ......  Subscription required&nbs
Assumed price Zinc USD  ......  Subscription required&nbs
Assumed price Copper USD  ......  Subscription required&nbs
Assumed price Silver USD  ......  Subscription required&nbs
Assumed price Gold USD  ......  Subscription required&nbs
* According to 2019 study / presentation.
† Net of By-Product.

Operating Costs:

Units2019
OP mining costs ($/t mined) USD 3.03 *
UG mining costs ($/t mined) USD  ......  Subscription required
OP mining costs ($/t milled) USD  ......  Subscription required
UG mining costs ($/t milled) USD  ......  Subscription required
Processing costs ($/t milled) USD  ......  Subscription required
G&A ($/t milled) USD  ......  Subscription required
Total operating costs ($/t milled) USD  ......  Subscription required
* According to 2019 study.
Subscription required - Subscription is required.

2019 Study Costs and Valuation Metrics :

MetricsUnitsLOM Total
Initial CapEx $M USD  ......  Subscription required
Sustaining CapEx $M USD  ......  Subscription required
Closure costs $M USD  ......  Subscription required
OP OpEx $M USD  ......  Subscription required
UG OpEx $M USD  ......  Subscription required
Processing OpEx $M USD 310
G&A costs $M USD 46
Total OpEx $M USD  ......  Subscription required
Mining Taxes $M USD  ......  Subscription required
Income Taxes $M USD  ......  Subscription required
Royalty payments $M USD  ......  Subscription required
Gross revenue (LOM) $M USD  ......  Subscription required
Pre-tax Cash Flow (LOM) $M USD  ......  Subscription required
After-tax Cash Flow (LOM) $M USD  ......  Subscription required
Pre-tax NPV @ 6% $M USD  ......  Subscription required
After-tax NPV @ 6% $M USD  ......  Subscription required
Pre-tax IRR, %  ......  Subscription required
After-tax IRR, %  ......  Subscription required
After-tax payback period, years  ......  Subscription required
Subscription required - Subscription is required.


Proposed Heavy Mobile Equipment as of October 14, 2019:
HME TypeModelSizeQuantityLeased or
Contractor
Alimak climber ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
....................... Subscription required ....................... Subscription required ....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required
....................... Subscription required ....................... Subscription required ....................... Subscription required Leased
Subscription required - Subscription is required.

Mine Management:

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 23, 2022
....................... Subscription required ....................... Subscription required Subscription required Oct 14, 2019
....................... Subscription required ....................... Subscription required Subscription required Oct 14, 2019
....................... Subscription required ....................... Subscription required Subscription required Oct 14, 2019
Subscription required - Subscription is required.

Staff:

Total WorkforceYear
Subscription required 2019

Corporate Filings & Presentations:

DocumentYear
................................... Subscription required 2021
................................... Subscription required 2021
................................... Subscription required 2020
................................... Subscription required 2020
Feasibility Study Report 2018
Press Release 2018
Year-end Mineral Reserves 2018
Preliminary Economic Assessment 2014
Subscription required - Subscription is required.

Subscription required - Subscription is required.

Terms of Use Privacy Policy © 2017-2023 MDO Data Online Inc.