ECuFlot – Efficient Copper Flotation in Water-Scarce Regions through Innovative Use of Process Water

ECuFlot is an international junior research group dedicated to the development of a new generation of water-efficient flotation technologies for copper recovery. The project addresses one of the most pressing challenges in the raw-materials sector: how to secure copper supply for the energy transition while ore grades decline, fine-particle losses increase and mining regions face growing water scarcity.

ECuFlot responds to this combined challenge by developing an integrated flotation concept that treats process water not merely as a constraint, but as a controllable process variable. The project investigates how specific ions, salinity, reagent residues and changing water compositions affect the fundamental mechanisms of fine-particle flotation. This knowledge will be translated into models, sensor concepts and digital tools that support robust flotation operation under realistic industrial conditions.

Rather than relying on purely empirical process optimisation, ECuFlot combines hydrodynamics, interfacial chemistry, particle–bubble attachment, bubble–bubble coalescence, froth behaviour, reagent performance and digital process monitoring. This enables a step change from trial-and-error operation toward model-informed, sensor-supported and ultimately digitally assisted flotation control.

ECuFlot is established as an international junior research group at the Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics. The project brings together expertise in multiphase flow, flotation, interface science, water chemistry, sensor technology, numerical simulation, mineral processing, recycling and industrial process integration. Its partner network connects German research and industry with leading institutions and companies in raw-material-rich and technology-relevant regions, including Chile, South Africa, Australia, Finland, France and Germany.

ECuFlot is funded within the EGARoh_Junior funding framework, announced under the Strategy for Research for Sustainability (FONA). The call is implemented through the specialist programme “Geoscience for Sustainability” (GEO:N), which forms part of the Federal Ministry of Research, Technology and Space programme “Research for Sustainable Development” (FONA), and supports international junior research groups addressing the demand for skilled personnel in the exploration, extraction and processing of primary raw materials.

Within this framework, ECuFlot contributes to the development of innovative technologies for sustainable copper ore processing in water-scarce regions. The focus lies on ion-sensitive and water-efficient flotation concepts that improve the recovery of fine copper particles, enable the use of recycled and saline process waters, reduce freshwater demand and strengthen resource efficiency and sustainability in the copper value chain.

Scientific and Technological Approach

ECuFlot is based on the idea that flotation performance in recycled and saline process waters can only be improved if the underlying physical and chemical mechanisms are understood across scales. The project therefore connects four levels of investigation: microscale mechanisms, cell-scale hydrodynamics, process-scale validation and digital process support.

At the microscale, ECuFlot studies how specific ions, reagent–ion interactions and salinity influence particle–bubble attachment, particle detachment, thin-film drainage and bubble–bubble coalescence. These mechanisms determine whether fine copper minerals can attach to bubbles, remain attached during turbulent transport and report to the froth phase as concentrate.

At the cell scale, the project investigates multiphase hydrodynamics in high-intensity, high-turbulence flotation systems. Turbulence, gas dispersion, bubble-size distribution, residence time and solids transport are quantified under relevant operating conditions. This allows the group to identify how hydrodynamic conditions interact with water and reagent chemistry to influence flotation selectivity and recovery.

At the process scale, laboratory and pilot flotation experiments link mechanistic observations to metallurgical performance indicators such as copper recovery, concentrate grade, selectivity, water demand and reagent consumption. Representative ores, secondary material streams and process-water compositions are used to test whether the developed concepts remain robust under industrially relevant variability.

At the digital scale, ECuFlot integrates experimental data, sensor information and simulation results into models and digital tools for process monitoring and future online optimisation. The aim is not simply to simulate flotation, but to create implementable digital components that can guide water recycling, process interpretation and operating strategy in variable process-water environments.

Research Objectives

The main objective of ECuFlot is to develop a sustainable, ion-sensitive and salt-tolerant flotation concept for the recovery of fine copper particles under water-scarce operating conditions.

• Develop sustainable and water-efficient flotation concepts for copper recovery under water-scarce operating conditions.
• Improve the recovery of fine and ultrafine copper-bearing particles from low-grade primary ores and secondary resources.
• Establish a better understanding of how recycled, saline and compositionally variable process waters influence flotation performance.
• Investigate the interaction between water chemistry, flotation reagents, mineral surfaces, bubbles and froth stability.
• Characterise the hydrodynamic behaviour of advanced flotation systems under realistic process conditions.
• Link fundamental flotation mechanisms to measurable process indicators such as recovery, selectivity, water demand and reagent consumption.
• Develop modelling approaches that describe key flotation mechanisms and support process interpretation across laboratory and pilot scales.
• Integrate experimental data, sensors and simulation results into digital tools for process monitoring, prediction and optimisation.
• Validate the developed concepts using representative ores, process waters and industrially relevant material streams in cooperation with international and industrial partners.
• Contribute to resource-efficient and more sustainable copper production by reducing freshwater use, improving raw-material recovery and supporting circular-economy strategies. 

Project Vision

The long-term vision of ECuFlot is to move copper flotation from conventional water-tolerant operation toward truly water-aware and ion-sensitive process engineering. In future flotation plants, the composition of process water should not be treated as an unpredictable disturbance measured only by bulk indicators such as pH or conductivity. Instead, water chemistry should become an integrated part of process design, process monitoring and process optimisation.

In doing so, ECuFlot aims to establish a new basis for sustainable copper recovery: higher recovery from increasingly complex resources, lower freshwater demand, improved resilience under variable water chemistry and stronger integration of primary and secondary raw-material streams.

By connecting German research excellence with international raw-material partners and industrial technology providers, ECuFlot contributes to a more secure, efficient and sustainable copper value chain. The project supports the transition toward resource-efficient mining and processing, strengthens circular-economy approaches and helps prepare the next generation of experts needed for Europe’s raw-material future.