Challenge the practice is addressing: This practice addresses adding value to waste while removing a source of environmental impact from a closed mine and purifying the water with a cutting-edge facility. The Holmtjärn Mine in Västerbotten, Sweden, was reclaimed in accordance with the standard at the time, but due to the environmental impact, Boliden decided to take new measures.
Concrete practice to achieve the expected goal: at many of Boliden’s former mines there are heaps of material containing sulphides. This material affects local adjacent watercourses leading to a low pH, when it oxidises and produces acid. To investigate, conduct and prioritize actions for this effect is an ongoing responsibility for Boliden. They took a fairly extensive sample of the rock at Holmtjärn and discovered that it contains enough gold to make concentration viable. The goal is to transport all of the waste rock from Holmtjärn to the concentrator in Boliden, removing a major source of environmental impact while also making a financial profit rather than a loss.
Expected impact/goal of the practice: Once the waste rock has been removed, any residual metals at the site will gradually be washed out of the soil and water. In order to prevent these from spreading, an ultramodern water treatment plant will be used. In summary, the plant provides high levels of purification and efficient chemical use, is remote controlled and regulated, mobile, and partially self-sufficient in terms of power supply. They will be able to precipitate 99.9% of the metals present in the water. When the levels at Holmtjärn reach a safe level, the plant will be relocated to the closed mine where it can do the most good.
Who is the target user group of the practice/intervention or implementing the practice/intervention? This practice is relevant for industry