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Influence of very small bubbles on particle/bubble heterocoagulation
N Mishchuk1, J Ralston, D Fornasiero
1Institute of Colloid Chemistry and Chemistry of Water, The National Academy of Sciences, pr. Vernadskogo 42, Kyiv 03142, Ukraine.
Journal of Colloid and Interface Science
|May 27, 2006
Summary
Very small bubbles on particle surfaces significantly impact particle-bubble interactions in flotation. These bubbles decrease the critical particle size needed for heterocoagulation, improving mineral recovery.
Area of Science:
- Surface chemistry
- Colloid science
- Mineral processing
Background:
- Heterocoagulation between particles and bubbles is crucial in flotation processes.
- The role of sub-micron bubbles on particle surfaces in controlling these interactions is not fully understood.
Purpose of the Study:
- To investigate the influence of sub-micron bubbles on particle-bubble heterocoagulation.
- To quantify the effect of bubble size and distribution on interaction forces and flotation behavior.
Main Methods:
- Calculated electrostatic and van der Waals forces between particles and bubbles.
- Varied parameters including electrolyte concentration, particle size, and bubble size/distribution.
- Compared surface force barrier height with hydrodynamic pressing forces during flotation simulations.
Main Results:
- Sub-micron bubbles on particle surfaces profoundly affect particle-bubble interactions.
- The presence of these bubbles significantly reduces the critical particle radius required for heterocoagulation.
- Force barrier height is sensitive to bubble size, distribution, and electrolyte concentration.
Conclusions:
- Surface-bound sub-micron bubbles are key determinants of heterocoagulation efficiency.
- Optimizing bubble characteristics on particle surfaces can enhance flotation selectivity and recovery.
- This finding has implications for designing advanced flotation reagents and processes.
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