Neutron imaging of froth structure and particle motion. (April 2018)

• Record Type: Journal Article
• Authors: Heitkam, Sascha; Rudolph, Martin; Lappan, Tobias; Sarma, Martins; Eckert, Sven; Trtik, Pavel; Lehmann, Eberhard; Vontobel, Peter; Eckert, Kerstin
• Is Part Of: Minerals engineering. Volume 119(2018)
• Page Start: 126
• Page End: 129
• Publication Date: 2018-04
• Subjects: Neutron imaging -- Flotation -- Froth -- Particle tracking -- Foam drainage; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2018.01.021
• Languages: English
• ISSNs: 0892-6875

Abstract

Graphical abstract: Highlights: Neutron imaging is outstandingly applicable for dynamic froth investigation. At PSI, neutron imaging of froth with 10 fps and 200 μ m resolution is feasible. Liquid content distribution can be evaluated quantitatively. Gadolinium particle larger than 200 μ m can be tracked. Abstract: This article reports on the simultaneous measurement of foam structure and attached particles employing neutron imaging. An aqueous foam sample is placed in the NEUTRA beamline at the Paul Scherrer Institut, enabling a spatial resolution of less than 200 μ m to be achieved at a frame rate of more than 1 Hz. A forced drainage setup allows the liquid content of the foam to be controlled. The averaged attenuation of the neutrons is demonstrated to yield the liquid fraction of the foam. Hydrophobized gadolinium particles with a diameter of 200 μ m are added to the foam. Using two surfactants, different levels of hydrophobicity are achieved. Depending on the drainage flow and the hydrophobicity, the particles are washed out of the foam at different rates. An avalanche-like motion of particle clusters is observed. Neutron radiography is demonstrated to yield unique insights into the unsteady froth flotation process.