SRK has been involved with several studies that are considering the use of dewatered tailings stacks in northern Europe. Tailings dewatering has become a popular option for mining projects in recent studies due to the increased pressure for tailings facilities to minimise the likelihood and consequences of failure. The main advantages of the dewatered stack include:
• improved landform stability
• enhanced water recovery
• reduced infiltration to tailings
• improved access to tailings surface
• progressive reclamation
• blending into existing natural landforms
Although dewatered tailings has significant advantages over traditional slurry tailings, there are only a few dewatered tailings stacks in northern Europe. One key challenge is the operation of facilities in cold climates. SRK draws on experience from Arctic projects in North America to identify appropriate measures for these conditions: operating plans must consider protecting tailings and return water infrastructure against cold climate/freezing conditions.
The permitting process in many countries in northern Europe is rigorous, and the permitting process often begins at the pre-feasibility study (PFS) level of design rather than feasibility or detailed design phase (as is the case in other jurisdictions). It is therefore critical to identify high quality solutions that are practical and achievable at an early stage of design. Critical independent review (i.e. from another practice or entity), typically reserved for feasibility-level studies, can greatly improve identification of potential gaps in scoping and PFS-level studies.
Since there are few examples of dewatered tailings stacks in northern Europe, regulators have a limited dataset for evaluating new projects. However, SRK considers that there are no significant barriers to permitting since dewatered tailings stacks have fewer risks, lower consequences of failure, improved water stewardship, and smaller footprints when compared to traditional slurry tailings strategies.
SRK has been working to provide confidence in switching to new tailings strategies that incorporate dewatered tailings in northern Europe where appropriate. An example of this is the construction of 3D renders showing various stages of dewatered tailings stack designs in support of PFS-level studies. These images help illustrate the life cycle of dewatered tailings facilities from early construction through to the post-closure phase. The aim is to provide clarity to regulators and other stakeholder groups on how the tailings will be managed and what the visibility and appearance of the final landform will be.
SRK has successfully delivered PFSlevel designs that give clients a route to permitting their projects and hopes to see more dewatered tailings projects in northern Europe in the coming years.
