A new kaolin deposit in western Africa: mineralogical and compositional features of kaolinite from Caluquembe (Angola)



Export to

Please use this identifier to cite or link to this item: http://hdl.handle.net/11703/120655
Title: A new kaolin deposit in western Africa: mineralogical and compositional features of kaolinite from Caluquembe (Angola)
Authors: Consorci del Museu de Ciències Naturals de Barcelona
Tauler, Esperança
Xu, Jingyao
Melgarejo, Joan Carles
Gonçalves, Antonio Olimpio
Campeny, Marc
Issue Date: 3-Jul-2019
Keywords: Caolí
Terres rares
Spatial coverage: Angola
Access to document: http://hdl.handle.net/2072/358307
Citation: Clays and clay minerals, 2019
Extent: 50 p.
Abstract: Large kaolin deposits developed by weathering on Precambrian granitic rocks have been discovered in the Caluquembe area, Huíla province, Angola. To determine accuracy of analysis and to evaluate the samples kaolinite grade, it was used full profile Rietveld refinement by X-­‐Ray Powder Diffraction (XRPD) and Gravimetric Thermal Analysis (TGA). Caluquembe kaolin is mainly comprised of kaolinite (44 to 93 wt.%), quartz (0 to 23 wt.%) and feldspar (4 to 14 wt. %). AGFI Crystallinity Index, calculated by XRPD profile refinement, indicates low and medium defect kaolinite. Kaolinite particles show a platy habit and they are stacked together forming ‘booklets’ or radial aggregates, also occurring as fine anhedral particles in a finer-­‐grained mass. Muscovite-­‐kaolinite intergrowths have also been found. Whole-­‐rock chemical composition was analyzed, including major, trace, and Rare Earth Elements (REE). Chondrite and Upper Continental Crust normalized REE patterns show the same tendency for all samples, with a significant enrichment in Light Rare Earth Elements (LREE). Mineralogical and compositional features of the Caluquembe kaolin indicate that it is a suitable material in the manufacture of structural products, such as bricks, pavers and roofing tiles. In addition, REE significant contents of the Caluquembe kaolin can be considered as a potential future target of mining exploration. Caluquembe; Angola; kaolinite; AGFI; REE.
Appears in Collections:Mineralogia / Articles

Files in This Item:
There are no files associated with this item.

All rights reserved
Metadata ruled by