High-Tech Critical Elements in Historical Tailings
In historical tailings in Yxsjöberg, Sweden, researchers are studying the geochemical behavior of high-tech critical substances such as Be, Bi, Ge, Ga, In, W, in the terrestrial environment. It is of great importance to understand this since the flux of these elements will increase in society due to climate change.
The mine tailings contains both sulfides, carbonates and fluoride, and has been deposited oped to the atmosphere for more than 50y which has resulted in sulfide oxidation and mineral weathering. Mineralogical and geochemical analysis has been combined to understand the mobility, transport and adsorption to secondary minerals within the tailings, and how much that has leached out to downstream surface water. The project also elucidates the weathering state of the tailings and for how long weathering will continue. Groundwater in the tailings and surface water downstream the tailings has been sampled monthly and filtered for dissolved and particulate fractions. Both the dissolved and the particulate fraction has been screen for 71 elements at ALS Scandinavia, Luleå.
In the tailings, scheelite has been weathered and released W to the groundwater which has nott been seen berfore. The groundwater contains the highest concentrations of Be measured worldwide. Beryllium is released from the unusual mineral danalite which is unstable in an oxic environment. The results shows that high concentrations of potentially harmful elements exits in neutral mine drainage.
The results from this project will help to understand how mine waste should be stored to prevent negative impact on the environment and to get a sustainable society in a changing climate.