Abstract

USUGA-MANCO, Liliana M.; LOPEZ-VALDIVIESO, Alejandro  and  BUSTAMANTE-RUA, Moisés O.. Hydrophobicity study of kaolinite from La Unión, Antioquia. TecnoL. [online]. 2015, vol.18, n.35, pp.71-81. ISSN 0123-7799.

In this research three methodologies to convert the hydrophilic surface of kaolinite into a hydrophobic surface are proposed, this condition is required to recover this mineral by means of froth flotation. Taking into account the anisotropy, zeta potential and complex surface electrical properties of the kaolinite, three surface chemical treatments based on the interacting and absorption of anionic collectors onto the mineral surface, causing an increase in the contact angle and thus increased hydrophobicity of kaolinite were applied. The methodologies proposed were interactions of kaolinite particles with: sodium dodecyl sulfate solutions with concentration 1x10^-3M, 1x10^-4M, 1x10^-5M; sodium dodecyl sulfate solutions 1x10^-3M, 1x10^-4M, 1x10^-5M with further interaction with kerosene solutions 127000 ppm; and oleic acid solutions 1x10^-3M, 1x10^-4M, 1x10^-5M, each one with a five minutes of interaction. The experimental results obtained by zeta potential and contact angle of the kaolinite before and after applying chemical treatments indicate that larger the chain length of the collector and its concentration, bigger the contact angle and so, more hydrophobic the surface (edge or face). In order to optimize, control and understand this solid-liquid interaction phenomenon is suggested to find out about the hydrophobization mechanism of kaolinite with oleic acid and its percentage of hydrophobization.

Keywords : Contact angle; kaolinite; oleic acid; sodium dodecyl sulfate; hydrophobic.

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