Arctic Mineral Resources has designed a modern and sustainable development plan for an underground mining operation that minimises footprint and impact to the surroundings. This plan includes utilisation of all extracted volumes, resulting in a mine with no waste and hence with no need for deposits on- or offshore. Please see further details on our key operating principles.
Our mine in Vevring will yield large quantities of valuable garnet in addition to semi-finished rutile concentrate and by-products. We can fully avoid the need for permanent landfills and sea deposits as we will maximise recovery and commercial utilisation of all sellable minerals and either backfill and/or find alternative uses for the residual tailings. Our deposit has high grade garnet ore from fjord level inwards. This enables us to develop our mine adit directly from barges situated in the fjord. An agreement with a developer of a large industrial site nearby for area to stockpile ore, place our recovery plant and offtake tailings as building material during our initial operating phase yields time to develop necessary space and infrastructure underground whilst recovering and selling garnet from the industrial site. At the end of this phase, we will move the entire operation underground with only a minor quayside visible outside the mine entrance. Upon reaching the end of our mining operation, all infrastructure will be removed and tunnel openings blocked with local rock, supplemented by planting natural vegetation to ensure that the landscape will appear close to identical to what it did prior to commencing mining.
KEY DESIGN PRINCIPLES
In-house experience and collaboration with Norwegian and international industry experts in the design phase, has led to the following key design principles:
Maximise income / profit per tonne of rock, minimise pre-production time and investments
- Liberation (crushing/milling) that preserves grain sizes (higher income per tonne)
- Focus on Europe as primary market due to favourable supply-demand fundamentals
- Mine at an extraction rate enabling 100% sale of all recoverable products
- Minimise pre-production capital requirement
- Outsource operating tasks to partners who already possess necessary equipment
- Establish time and cost- efficient mass dispatch through a fjord-facing entry point
- Utilise an existing industrial site to commence production concurrently with infrastructure developments
- Focus capital investments on mineral recovery and product quality
- Avoid expensive / complex solutions (e.g., constructing a long pipeline to obtain supply of process water)
Minimise operational risk / increase ability to meet goals and targets
- Moderate annual extraction rates to yield manageable volumes
- Mine inwards and upwards before mining at depth
- Outsource operating tasks to competent partners with skills, know-how and experienced personnel
Minimise / avoid regulatory obstacles
- Plan operations within a minimal environmental footprint
- Plan operations within a minimal physical footprint
- Utilise already regulated areas to the extent possible to avoid regulatory delays
- Avoid surface and seabed deposits that carry potential for conflicts to remain in control
Underground mining with roadless access straight from the fjord
The favourable geotechnical conditions of the Vevring deposit allows for resource- and cost-efficient underground mining. Our properties contain high grade ore surfacing at fjord level. By commencing mining with equipment on barges we are able to establish production at a fairly moderate level of pre-production investments.
Mineral recovery without using chemicals
Garnet is a fairly heavy and fairly magnetic mineral compared to most other minerals in our deposit. Recovering garnet from our Vevring-Engebo is done in a 4-step process:
- Comminution: Extracted rocks are crushed down to +/- 5mm using normal comminution equipment
- Liberation: Single mineral grains, typically smaller than 0.5mm are liberated by use of a conventional rod mill
- Gravimetric separation: Minerals are separated based on density using conventional gravimetric spirals
- Magnetic separation: Minerals are separated based on magnetic susceptibility using high intensity magnets
The above steps are carried out using conventional / well-known technology. Recovered garnet is dried and sampled for quality control prior to being stored in silos. Industrial-scale mineral recovery is one of our core competences. Mineral recovery will not involve toxic chemicals and tailings are hence free of pollutants.
A more advanced sketch can be found here.
The mineral recovery yields different grain sizes of garnet:
and different by-products with their own markets and customers:
Mass flows without permanent deposits
Our mining operation will yield significant garnet volumes per ore tonne as well as by-products (rutile, coarse and fine aggregates) that will be dispatched externally on a continuous basis and / or backfilled in completed stopes.
To avoid waste and to maximise resource utilisation by use of underground mining, we focus on optimising tailings utilisation for each operating phase. Tailings post mineral recovery feature a particle size distribution from fine sand to clay. Due both to the mineralisation in the deposit as well as the mineral recovery process, tailings tend to feature inert minerals, limited content of mica and pyrite (minerals with water absorbing properties), and neutral to slightly basic pH-values. Lab-scale tests to-date have documented strength-inducive properties when used in concrete aggregate applications. During the initial operating phase, the most efficient use is as fine-grained aggregates in further development of the industrial site at which we will carry out our mineral recovery. This is effectuated through an offtake agreement with the site developer. Offtake in this phase enables mass balance whilst developing underground infrastructure and completing initial mine stopes.
Upon moving the operation underground, a significant part of tailings will be backfilled in completed stopes to alleviate stress imposed on vertical pillars. This enables us to design a mine plan that reduces resources left as permanent pillars to a minimum, thereby optimising resource utilisation. Tailings will be backfilled in a dewatered state (with similar humidity as natural soil). This limits excess volume and loss of process water whilst retaining flexibility in tailings for transport and handling with ordinary mobile and fixed equipment, e.g., dump trucks and conveyor belts. Some tailings fractions will also be stored temporarily in silos for dispatch to external clients via a centrally located mass dispatch infrastructure system consisting of silos with automated dischargers, conveyor belts, and ship loaders. Garnet concentrates and semi-finished rutile concentrates will similarly be temporarily stored in silos prior to dispatch. Waste rock will be crushed and screened to market specifications prior to storage in silos and dispatch as aggregate products.
Mineral recovery site for the initial operating phase
To minimise pre-production infrastructure investments and obtain mass balance during the initial operating phase, we have signed an agreement for area lease and 100% tailings offtake with the developer of the industrial site, Lutelandet, located some 55 km of sailing distance away from Vevring. During this phase mining and first step crushing will take place at Vevring and thereafter dispatched to Lutelandet in bulk vessels. All residual tasks are performed onshore at Lutelandet with mineral products stored in silos prior to dispatch and tailings stored in stockpiles prior to offtake by the site developer.
INITIAL OPERATING PHASE
Mass logistics during underground development
Mass logistics during the initial operating phase:
Product storage – initial operating phase
Mineral products will be store in silos, aggregates and tailings will be stored in onshore stockpiles.
Mass flow in the permanent phase
After the initial operating phase at Lutelandet, all equipment and infrastructure will be transported to Vevring and moved underground to its permanent location, with only the quayside and product dispatch equipment visible from the fjord.
Storage and intermediate storage – permanent phase
Mineral products, aggregates and tailings will be stored in silos from which mineral concentrates, aggregates, and some tailings will be dispatched onto bulk vessels whilst fines from aggregates crushing and a majority of mineral tailings will be loaded onto dump trucks and transported for storage in completed stopes.
A high-level illustration of equipment and machinery for processing and intermediate storage logistics can be found here.
Minimal footprint – during and after operations
Our landowners are located directly above the mine entrance. The local community in which they reside is located directly west of the landowners. It is hence of vital importance to minimise the visible and audible footprint of the mine to preserve the locals’ quality of life. Roadless access to the mine from the fjord combined with underground mining allows for a minimal permanent footprint. The physical footprint above ground will include a 200m2 quayside developed in the mountainside, two tunnel openings, as well as required ventilation shafts and emergency exits. At the end of the mine life, the quayside is easily reclaimed with local rock supplemented by replanting of natural vegetation. The physical footprint above ground can practically be erased at the end of our mining operation.