Several types of waste are generated in a mine, but three types stand out with the largest volume: waste rock, tailings and mine water.
Wastewater produced at a mine is also known as tailings. This water can come from a variety of sources, depending on whether it is an open-cast or underground mine, whether it has a positive or negative water balance, and according to the refining process used.
Mine water – a source of water and valuable materials for a sustainable future
At a time when the world is facing increasing water shortages and more frequent droughts, there is a growing focus on alternative water sources that could alleviate this critical problem. One such source is mine water, which was previously considered a waste product of the mining industry. Integrating mine water into a broader water management plan could be the key to creating a more sustainable and resilient water management system, especially in areas where water shortages are an urgent problem.
Fig. 1: Desalination of mine water on the laboratory electrodialysis unit by Silvie Heviánková (right) and Petra Malíková (left).
We are a team of researchers working at the VSB-Technical University of Ostrava (Czech Republic). We have been dealing with the problem of mine water for many years. Our goal is to develop technologies for the treatment and purification of all categories of mine water – acid, mine and saline. In the REWAISE project, we are pushing the boundaries of our understanding of mine water management even further. We see mine water as an important source of water that could help alleviate water shortages around the world. We also see mine water as a source of particularly critical raw materials, such as lithium.
Mine water – an environmental problem or an opportunity for sustainable development and economic growth?
Fig. 2: Jeremenko Water Pit, Czechia – localization
Within the REWAISE project we focus on mine water from the Jeremenko water pit, located in the very centre of Ostrava, Czech Republic. This mine water is often referred to as the Ostrava sea. The name is an accurate comparison, as the mine water, which is located almost 650 metres underground, has a composition close to that of seawater.
Fig. 3: Managed discharge of mine water Jeremenko
This water is currently pumped to the surface and discharged untreated into the river. As mentioned above, the mine water is located in the in the centre of the city of Ostrava, which is known for its dense industrial buildings. The use of mine water as a resource for industrial companies is therefore directly proposed.
Fig. 4: Laboratory ED unit Fig. 5: Analytical laboratory of our workplace
And what is our job? We monitor the quality of mine water on a long-term basis and test technologies for its purification and treatment in the laboratory. As with seawater, where membrane technologies such as reverse osmosis (RO) and electrodialysis (ED) are used for desalination, we are mainly testing these methods on mine water. It turns out that with the right combination of technologies we can obtain water that can be used as operational/technological water as well as drinking water. The magic lies in the right combination of technologies. This approach can inspire new projects around the world and contribute to a more sustainable future for us all.
Mine water as a source of lithium?
Fig. 6: Glass-laminate piping for pumped mine water Jeremenko
Mine water also contains very interesting concentrations of e.g. lithium. To give you an idea, the concentration of lithium in seawater ranges from 0.1 to 0.2 mg/l. In the Jeremenko mine water the concentration is almost 10 times higher, i.e. about 1 mg/l. With a properly selected membrane technology we can increase the concentration to 6 mg/l. Our goal is to find a suitable method to extract lithium from mine water into a suitable commercial product.
Turning mine water into a valuable source of water and raw materials is an innovative step towards a sustainable future that can have a significant positive impact on the environment and the economy.
Curious to read more REWAISE updates? Follow our accounts in LinkedIn and X.
