Genesis and possible applications of Lwamondo and Zebediela Kaolins, Limpopo Province, South Africa

ABSTRACT

The genesis and potential industrial applications of Lwamondo and Zebediela Kaolins in South Africa were determined. Selected physico-chemical characteristics were determined. Mineralogical characteristics were determined using XRD and SEM; and geochemical characteristics were determined using XRF and LA-ICP-MS. Kaolin colours were generally light (Lwamondo) and brown (Zebediela). Both kaolins had low pH (<6.5) and EC (<50 µS/cm). The texture of Lwamondo Kaolin was generally loam and clay loam, whereas that of Zebediela was clayey, silty and loamy. Major mineral phases were kaolinite, smectite and plagioclase in Lwamondo Kaolin, and kaolinite in Zebediela Kaolin. The morphology of the kaolins consisted mainly of stacks of kaolinite flakes. The most dominant major oxides were SiO₂, Al₂O₃ and Fe₂O₃, and the kaolins were slightly depleted in light rare earth elements. The studied characteristics indicated that the kaolins (i) formed in a supergene environment and (ii) are suitable for hollow bricks.

KEYWORDS:

• Genesis
• applications
• kaolin grade
• supergene

Acknowledgements

The authors are grateful to the management of Lwamondo Vhavenda Bricks and Zebediela Bricks for allowing the field component of the study to take place in their premises. The authors also acknowledge Mr Rivers Nkuna for drawing the maps in Figure 1.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was funded by the National Research Foundation (South Africa), [grant number UID 95472], and the University of Venda’s Research and Publications Committee [grant number RI/14/RI/01].