ClearFlow: a European project to purify mining water

Water Challenge is leading a new European initiative aimed at improving sustainable water management in the mining industry. The project, called ClearFlow, will run for 30 months and is co-funded by the European Union through the Eurostars/Eureka programme, with a budget exceeding €400,000.

ClearFlow seeks to develop an innovative hybrid system capable of producing high-purity water and recovering valuable solid materials from mining process fluids. The solution combines electrocoagulation, implemented by the Slovak partner Hofitech, with ASEC technology (Adiabatic Sonic Evaporation & Crystallization), patented by Water Challenge.

The system will deliver reusable water and dry solids with less than 2% humidity, achieving higher efficiency and lower energy consumption than conventional methods. Its modular, container-based design allows for easy deployment across different industrial settings, minimizing fluid transport and operational costs.

ClearFlow will be tested in three strategic locations in southern Spain —the Tinto River, the Odiel River near Tharsis, and the Port of Huelva— chosen for their complex composition and abundance of strategic metals. A functional prototype capable of treating up to 10 m³ of water per day will be validated under real industrial conditions.

Beyond its technical scope, ClearFlow supports the circular use of resources by enabling the recovery of materials such as copper, zinc, and rare earth elements. This contributes to Europe’s resource autonomy and to a more sustainable industrial model aligned with the goals of the green transition.

The project will also deliver technical and economic feasibility studies, scientific publications, and a roadmap for international commercialization.