Mineralogy, surface properties and electrokinetic behaviour of kaolin clays derived from naturally occurring pegmatite and granite deposits

Ivanić, Maja; Vdović, Neda; Barreto, Sandra de Brito; Bermanec, Vladimir; Sondi, Ivan (2015) Mineralogy, surface properties and electrokinetic behaviour of kaolin clays derived from naturally occurring pegmatite and granite deposits. Geologia Croatica, 68 (2). pp. 139-145. ISSN 1330-030X

Preview

PDF - Published Version - article Available under License Creative Commons Attribution. Download (1MB) | Preview

Abstract

This paper presents research on the surface characteristics, specific surface area (SSA), cation exchange capacity (CEC) and the electrophoretic mobility (EPM) of kaolin clays obtained from different naturally occurring pegmatite and granite deposits worldwide. Particular emphasis was placed on studying the influence of ancillary minerals on these properties, as well as the diversity in morphological and structural characteristics of kaolinite in samples. Mineral composition and the morphology of the kaolin samples were investigated using X-ray diffraction (XRD) and field emission scanning electron microscope (FE- SEM), respectively. The SSA was determined by the BET method, CEC by ammonium selective electrode and surface charge by EPM measurements. Results showed that the surface properties of the kaolin samples were strongly influenced by the presence of ancillary constituents, particularly smectite minerals. Their occurrence, even in trace amounts, significantly increased the SSA and CEC values of the investigated samples. Most importantly, EPM measurements revealed that the character of the amphoteric surfaces of the dominant kaolinite mineral in the samples was rescinded by the permanent pH-independent siloxane basal charge of smectite. The presence of ancillary smectites, characterized by higher surface reactivity, hindered the surface properties of the prevailing kaolinite mineral in the kaolin clay deposits.

Item Type:	Article
Uncontrolled Keywords:	kaolin clays; igneous deposits; ancillary minerals; surface properties
Subjects:	NATURAL SCIENCES > Geology
Divisions:	Division for Marine and Enviromental Research
Projects:	Project title Project leader Project code Project type Nanominerali u sedimentima i tlima: formiranje, značajke i uloga u biogeokemijskim procesima-NanoMin Ivan Sondi IP-11-2013-2504 HRZZ Međudjelovanje minerala i okoliša- Vladimir Bermanec 119-0000000-1158 MZOS
Depositing User:	Maja Ivanić
Date Deposited:	11 Jul 2016 10:42
URI:	http://fulir.irb.hr/id/eprint/2915
DOI:	10.4154/gc.2015.09

Actions (login required)

View Item