One of the biggest challenges industry must face is the treatment of metal-containing fine-grained materials. Novel, energy efficient and groundbreaking separation/benefication technologies are needed to shift the current mining paradigm towards the exploitation of natural mineral deposits that are very fine -grained (below 20 μm particle size).
To extract valuable minerals from mined ore, the latter must first be crushed and ground down to the micrometer range. This allows the valuable particles to be liberated from the gangue minerals. It is at this early stage of the raw materials cycle that flotation techniques are applied to separate the valuables into a concentrate that can be processed in subsequent pyrometallurgical steps. Froth flotation is the key process in this beneficiation for all classes of ores and already the separation process, which is capable of handling fine material, typically with particle sizes between 20 μm and 200 μm.
For the European raw materials industry, the ability to float particles < 20μm is “ground breaking” since no technology exists for the recovery of the fines at satisfying rates and qualities. Low-grade ore, frequently the only available primary or secondary raw material, needs to be ground to ultra-fine sizes in order to liberate the finely disseminated valuable minerals from the impurities. Only by such a fine liberation, the valuable can be enriched to the necessary level (typically >60%), and the impurities that deteriorate the product quality in the downstream process can be discarded to comply with the stringent grades requirements for downstream processing. The capability to separate impurities and concentrate valuable fines is thus essential for the EU to secure sustainable access to raw materials, particularly relevant in view of the dominating role of China in the production of CRMs.
FineFuture will develop innovative process intensification strategies and, based on the fundamental knowledge gained and supported by state-of-the-art modelling. The different parts of the project will deliver optimized fundamental flotation solutions, which will be tuned under industrial conditions to maximize recovery of fine mineral particles increasing resource efficiency at reduced consumption of energy and water. The knowledge-based technology for high fine particles recovery will be validated at the pilot scale under the leadership of the industry.
Using the concerted expertise, the FineFuture project will tackle the following key scientific challenges of fine particle flotation:
- Find a way to control the surface interactions between a bubble and fine particle to selectively enhance their attachment probability.
- Identify the proper tuning of the complex hydrodynamic conditions to enhance the efficiency of bubble-particle collisions.
- Drastically reducing the entrainment of fine gangue particles to the concentrate associated with high liquid recoveries.