demonstrations:froth_flotation
Froth Flotation
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Separating Mixtures, Mining and Resources
Alternative titles: Ore Separation with Froth
Summary
Students simulate the froth flotation process used in mining to separate valuable minerals from waste rock. By adding water, kerosene, and detergent to a mixture of sand and iron filings, they observe how bubbles can help separate materials.
Procedure
- Place one spatula of a sand and iron filings mixture into a test tube.
- Add 5 ml of water, seal with a stopper, and shake for 10 seconds. Record observations.
- Add 5 ml of kerosene to the same mixture, reseal, and shake for 10 seconds. Record observations.
- Add one drop of detergent to the mixture, reseal, and shake again. Record observations.
- Compare results after each step, focusing on bubble formation, separation of materials, and movement of particles.
Links
📄 Floating Froth Experiment - Oresome Resources: https://www.oresomeresources.com/wp-content/uploads/2010/03/Experiment-Floating-Froth-1.pdf
Variations
- Try using different mineral mixtures, such as powdered chalk with sand, to model other ore separations.
- Test different detergents or frothing agents to see how they affect separation efficiency.
- Scale up the experiment using a beaker and stirrer for group demonstrations.
Safety Precautions
- Wear safety glasses and gloves throughout the experiment.
- Handle kerosene carefully; keep away from open flames and use in a well-ventilated area.
- Dispose of mixtures safely according to teacher or lab technician instructions; do not pour kerosene down sinks.
- Wash hands after handling chemicals and mixtures.
Questions to Consider
- What happened when only water was added to the mixture? (Sand and iron filings stayed mixed without separation.)
- Why was kerosene added? (It attaches preferentially to certain particles, helping them float with bubbles.)
- What role did the detergent play? (It acted as a frothing agent, stabilizing bubbles to carry particles to the surface.)
- Did all the iron filings separate out? Why or why not? (Not all may separate due to incomplete attachment to bubbles or mixing.)
- Why is froth flotation valuable in metal production? (It allows efficient separation of ores from waste, making extraction more economical.)
- How might modern techniques improve this process compared to early versions? (Use of more selective chemicals, better bubble control, and larger-scale machinery.)