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Spontaneous separation of charged grains
Amit Mehrotra1, Fernando J Muzzio, Troy Shinbrot
1Department of Chemical & Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08816, USA.
Physical Review Letters
|October 13, 2007
Summary
Researchers discovered a new effect in flowing grains that separates mixed grains into two charged streams. This phenomenon has significant implications for industrial and natural processes involving granular materials.
Area of Science:
- Physics
- Granular Materials Science
Background:
- Lord Kelvin described an experiment in 1867 involving charged water droplet streams.
- Electrostatic interactions in flowing granular media are complex and not fully understood.
Purpose of the Study:
- To present a complementary effect to Kelvin's experiment in flowing grains.
- To demonstrate spontaneous demixing and charging of similar, well-mixed grains.
Main Methods:
- Observation of flowing granular materials under specific conditions.
- Analysis of charge separation and grain demixing.
Main Results:
- Flowing grains spontaneously separate into two distinct charged streams.
- Similar and well-mixed grains become demixed and oppositely charged.
Conclusions:
- The observed effect offers a novel mechanism for granular separation.
- This phenomenon has potential applications in industrial separation processes and understanding natural granular flows.
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