New solutions for mine closure and reclamation from the regional circular bioeconomy

We demonstrated how local organic side streams can be used to provide a viable cover solution for closed mine waste sites, while promoting local business based on circular bioeconomy.

Minerals are increasingly needed for the green transition. This will also increase mining activity in Finland. The closure and aftercare of mines is an essential part of their life cycle. The local biomass streams can be utilized in landscaping of mine waste areas, simultaneously providing circular bioeconomy-based business opportunities for companies in the region.

In Biopeitto 2 project, carried out in cooperation with the Geological Survey of Finland, we worked with a mining company and local companies in Lapland to create a network of actors and to demonstrate the implementation of a biocover solution for a mining site. The network of actors included a wastewater treatment plant, a demolition wood processing company as owners of the raw materials, a supplier of pyrolysis equipment, logistic operators, a local plant nursery and the mine as the end user of the solution.

In the value chain pilot, the demolition wood was pyrolysed into biochar, composted with the sewage sludge and the produced growing medium was used in the mine waste area. Vegetation of the cover solution was carried out using local Nordic plant species. The practical scale pilot demonstrated the agility of companies to quickly seize new business opportunities, which will accelerate the scaling up of operations as demand increases.

The project's research results showed that a biochar-based cover solution significantly improves plant growth in the harsh conditions of Lapland. Biochar increased the cost of the solution but made it carbon negative.

The experiences with the growing media and value chain pilot developed in the project were good. The same model has been applied to new experiments established at other mining sites in Central Lapland and Kainuu in new projects. The scientific and economic knowledge accumulated in the resulting set of projects has clearly boosted the development and implementation of biocover solutions.

Both mining operators and public authorities have incorporated the knowledge gained from the projects into their own work and are now paying more attention to cover solutions for mining waste areas, both during operation and during the planning and start-up phase of mining activities. In addition, the authorities have started to require studies on the use of local plant species in cover solutions.

For pyrolysis equipment manufacturers and biochar producers, the projects have opened up a new market perspective where the use of biochar offers significant benefits. Biocover solutions also offer new large-scale uses for sewage sludge.

”We have gained a lot of new knowledge from the Biopeitto projects, which we are now using in our mine closure planning. Biocover solutions have been scientifically proven to offer more environmentally friendly and potentially cost-effective solutions."

Tiina Ilo, environmental expert, Boliden Oy