Mine closure and reclamation

Our goal is to close the mine in a safe, sustainable and exemplary manner, ensuring that the mining area remains secure for both people and the environment.

The regulations given in the environmental permit for closure and rehabilitation are followed. Pyhäsalmi Mine Oy also promotes projects that secure the region’s vitality after the end of mining operations.

More information about closure and responsibility can be found in the following videos:

Pyhäsalmi Mine History & Closure

Pyhäsalmi Mine ESG in Closure

CLOSURE AND AFTER-CARE MEASURES BY REGION

Underground mine

All removable machinery, equipment, lighting, cables, pipes and other materials will be removed from the underground mine, as far as it is technically and safely possible. In addition, the machines and equipment that may remain in the underground will be emptied of substances that cause the risk of environmental pollution. Finnish Supervisory Agency together with Finnish Safety and Chemicals Agency will carry out the final inspection of the dismantling measures.

If there will not be any further use of the underground mine the mine will qradually fill with water. Before that shafts and passageways will be closed and ensured that there is no risk of collapse in the tunnels, which could cause subsidence of the ground surface. According to the groundwater modelling, it would take about 50 years for the mine to fill up naturally. Another option is to actively fill the underground mine.

The dismantling of the underground mine commenced in late 2022 and is expected to be completed in 2026.

Discover how the mine closure process is carried out in this video

Mine Site

Unnecessary buildings and structures will be demolished. Some of the buildings, such as the old hoist tower and the office building, are protected by Finnish Heritage Agency.

Some refurbishment work was carried out on the old hoist tower and the auxiliary shaft tower was demolished in 2022.

The old pump station (P6) was dismantled on the shore of Junttiselkä in Lake Pyhäjärvi in 2023, and the associated discharge pipeline was removed from the lake in 2025.

Open pit and quarry

The open pit and quarry will remained fenced. If the underground mine fills with water also the open pit and quarry will be filled and form small but deep lakes. The quality of the water discharging from the quarries will be monitored and treated if needed.

Tailings Management Facility

The tailings ponds will be covered the way that it minimizes the entry of water and oxygen into the tailings, in order to prevent the formation of acid mine drainage. Pond C, which currently serves as a water storage basin, will be transformed into a constructed wetland.

Moraine from the surrounding area is used for covering the tailings ponds, as its fine‑grained composition provides low water permeability. The moraine is sourced from two permitted extraction areas. Preparatory works at the extraction areas began in 2025, and actual material extraction will start in 2026. The construction of the cover layers will take several years.

Water treatment

In closure phase the seepage from the tailings ponds and surface water from the mine site are treated with lime precipitation in Actiflo® water treatment system. The waters are actively treated until the water quality requires it. The aim is to transition gradually to passive water treatment once water quality improves sufficiently over the coming decades.

The water treatment plant was built in 2022. Pilot runs and process adjustments were conducted between 2023 and 2025, and the plant was commissioned in 2026.

An overview of how water management is carried out at the mine is provided in this video