Particle recovery in froth. Development of a novel coarse particle flotation device
Thesis event information
Date and time of the thesis defence
Place of the thesis defence
OP auditorium (L10), Linnanmaa Campus
Topic of the dissertation
Particle recovery in froth. Development of a novel coarse particle flotation device
Doctoral candidate
Master of Science (Mining and Mineral Engineering) Marly de Avila Carvalho
Faculty and unit
University of Oulu Graduate School, Faculty of Technology, Oulu Mining School
Subject of study
Mineral processing, coarse particle flotation
Opponent
Associate Professor Pablo R. Brito-Parada, Imperial College London
Custos
Professor Saija Luukkanen, University of Oulu
A new flotation technology for recovering valuable minerals from coarse particles
Minerals such as copper are essential for our everyday lives and for technologies like electric vehicles and renewable energy. However, as mineral deposits become poorer in quality, mining companies need to process more rock to produce the same amount of metal. This requires large amounts of energy and water, making it increasingly important to find more efficient ways to recover valuable minerals.
My research focused on developing and testing a new technology to recover valuable minerals from larger rock particles. Today, minerals are usually separated from unwanted rock using a process called flotation, where air bubbles carry valuable minerals to the surface. However, larger particles are difficult to recover because they can easily detach from the bubbles.
The new technology uses a different approach. Instead of introducing the particles into a tank where water and air are mixed, they are fed directly onto a layer of foam. This creates a calmer environment where larger particles can remain attached to air bubbles and be recovered more easily.
The technology was tested using copper and copper-gold ores in laboratory and pilot-scale studies. The results showed that it could recover valuable minerals from much larger particles than traditional flotation methods. It could also remove unwanted rock earlier in the process and recover valuable minerals that would otherwise be lost in the waste. Another important finding was that particles could be recovered even when only 1% of their surface contained exposed valuable minerals.
The research also showed that the technology can operate without the large amounts of additional water required by some other technologies designed for larger particles, making the process potentially simpler and more efficient.
Overall, the findings show that this new approach could help mining companies recover more valuable minerals while reducing the amount of material that needs further processing. This creates opportunities to reduce energy and water consumption and make mineral processing more sustainable.
My research focused on developing and testing a new technology to recover valuable minerals from larger rock particles. Today, minerals are usually separated from unwanted rock using a process called flotation, where air bubbles carry valuable minerals to the surface. However, larger particles are difficult to recover because they can easily detach from the bubbles.
The new technology uses a different approach. Instead of introducing the particles into a tank where water and air are mixed, they are fed directly onto a layer of foam. This creates a calmer environment where larger particles can remain attached to air bubbles and be recovered more easily.
The technology was tested using copper and copper-gold ores in laboratory and pilot-scale studies. The results showed that it could recover valuable minerals from much larger particles than traditional flotation methods. It could also remove unwanted rock earlier in the process and recover valuable minerals that would otherwise be lost in the waste. Another important finding was that particles could be recovered even when only 1% of their surface contained exposed valuable minerals.
The research also showed that the technology can operate without the large amounts of additional water required by some other technologies designed for larger particles, making the process potentially simpler and more efficient.
Overall, the findings show that this new approach could help mining companies recover more valuable minerals while reducing the amount of material that needs further processing. This creates opportunities to reduce energy and water consumption and make mineral processing more sustainable.
Created 24.10.2026 | Updated 26.10.2026