Physicochemical Properties of Aminated Butyl-Nanocrystals in Correlation to the Flotation
Response of Quartz
ABSTRACT
The increasing complexity of the ores composition worldwide calls for suitable collectors with specific
properties, such as selectivity, wettability, and in regard to environmental regulations, biodegradability.
Therefore, collectors have to satisfy many features to improve the efficiency of flotation processes. Cellulose
nanocrystals gain more and more interest due to the versatile preparation routes which enable the integration
of specific functional groups and components with different degrees of hydrophobicity within the molecular
structure. Consequently, cellulose nanocrystals can be employed in flotation processes as depressant or
collector molecules, respectively. Nonetheless, the usage of cellulose nanocrystals is still limited due to a
lack of the characterization of nanocrystal-mineral interactions and the change of the surface wetting
properties of minerals after adsorption phenomena between nanocrystals and minerals. In these studies,
butyl-amine cellulose nanocrystals (BAC) and quartz are used as standard model to investigate
physicochemical properties of both, BAC and quartz, and examine the applicability of BAC in flotation
processes. Therefore, the particle size and size distribution, surface charge distribution and electrophoretic
mobility of BAC and quartz are measured. Based on this, the adsorption isotherm of BAC on quartz is
established. For the determination of the surface free energy, the inverse gas chromatography (iGC)
technique as well as the contact angle method are applied and compared. Finally, flotation experiments in
bench-scale prove the efficiency of BAC to be used in flotation processes.
Robert Hartmann (Robert.Hartmann@oulu.fi), Mirja Illikainen (Mirja.Illikainen@oulu.fi)
KEYWORDS
Cellulose nanocrystals, quartz, surface charge distribution, electrophoretic mobility, adsorption, surface free
energy, flotation