Surface chemical and selective flocculation studies on iron oxide and silica suspensions in the presence of xanthan gum

Loganathan, S and Sankaran, S (2021) Surface chemical and selective flocculation studies on iron oxide and silica suspensions in the presence of xanthan gum. In: Minerals Engineering, 160 .

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Abstract

The changes in the surface chemical properties of iron oxide and silica suspensions consequent to the addition of xanthan gum were studied. The adsorption density of xanthan gum for iron oxide was found to be maximum at pH ~ 2, whereas almost nil adsorption was found for silica throughout the pH range investigated. The isoelectric points (i.e.p.) of iron oxide and silica were found to be located at pH ~ 8.4 and presumably less than pH 2 respectively. The addition of xanthan gum shifted the i.e.p. of iron oxide towards more acidic pH values, in proportion with the concentration of xanthan gum added, with a concomitant change in the zeta potentials to more electronegative or less electropositive values. The maximum flocculation of iron oxide (98) was observed in the wide pH regime of 2�9 with the optimum dosage of xanthan gum (20�50 ppm). The electrokinetic and flocculation characteristics of the silica were not altered much by the addition of xanthan gum, akin to the adsorption result. FTIR spectral investigations provide evidence in support of hydrogen bonding and chemical interaction forces between iron oxide and xanthan gum. Maximum separation efficiency of 65 for iron oxide-silica mixture was observed in selective flocculation tests. © 2020 Elsevier Ltd

Item Type:	Journal Article
Publication:	Minerals Engineering
Publisher:	Elsevier Ltd
Additional Information:	The copyright of this article belongs to Elsevier Ltd
Keywords:	Adsorption; Flocculation; Hydrogen bonds; Iron oxides; Ostwald ripening; pH; Silica, Adsorption densities; Chemical interactions; Iso-electric points; Selective flocculation; Separation efficiency; Silica suspensions; Surface chemical properties; Surface chemicals, Xanthan gum
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	27 Jan 2021 10:20
Last Modified:	27 Jan 2021 10:20
URI:	http://eprints.iisc.ac.in/id/eprint/67282

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