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GEOLOGICAL SURVEY
OF NAMIBIA


Earth Sciences for Namibia's sustainable development

Industrial Minerals Group

The GSN Industrial Minerals Group was established in 1995 to provide a high-quality information service, laboratory analyses and advise to potential and existing investors in this sector of the Namibian economy. This group was set up with the assistance of the SYSMIN Programme of the European Development Fund. The British Geological Survey acted as a technical assistance provider until the final visit by the two advisors in December 1999.

Following the conclusion of the project the GSN is left with sustainable capability after the return of two Namibian counterparts from their studies at the end of September 1999.

The main tasks of the Industrial Minerals Group are:

  • To undertake local and regional market surveys to identify opportunities and constraints within the Namibian economy
  • To enhance the existing information on Namibia’s Industrial Mineral resources by undertaking field and laboratory investigations
  • The Industrial Minerals Group is now capable of providing laboratory and technical assistance to investors
  • Commodity reports are in progress and will contain information on the geology, mineralogy, chemistry, occurrences, mining methods used, markets, producers of industrial minerals available in Namibia. This information will also be put into a global context and will illustrate Namibia’s Industrial Mineral’s potential.

Laboratory facilities include:

  • A thermogravimeter for the quantitative determination of carbonates, kaolin, gypsum, talc, etc.  This is a technique that measures the changes in weight of a substance as a function of temperature, whilst the substance is subjected to a controlled heating programme (Figure 1, right above).
  • An X-ray sedigraph (Figure 2, right middle) for the automated sub-sieve particle size analysis of mineral powders. This is an important property, specifically in clays where stringent specifications in terms of particle size apply. Particle size is important in ceramics because it influences properties of unfired and fired ware.
  • The laboratory is also equipped with a hydrocyclone test rig (Figure 3, right below), which supplements the existing Wifley shaking table, and magnetic separator for mineral separation and beneficiation trials.
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  • A Reflectance Spectrophotometer, for quantitative color measurements of powders and pigments. Color is specified by manufacturers and the supply of products of consistent color is demanded by customers. Color is influenced by the overall particle size of a powder and changes in particle size distribution.
  • A Bruker axs D8 Advance diffractometer system was acquired as an extension of the Industrial Minerals Project and was installed in June 1999. A short familiarization course was held during August/ September 1999.

The associated GSN laboratory facilities that are available to the Industrial Minerals Group are:

  • Integrated sample preparation, and
  • Major and trace chemistry (X-ray fluorescence, ICP) analyses.
Current Projects

Extensive clay research has been initiated by geologists from the British Geological Survey-Geological Survey of Namibia Industrial Minerals Project funded by the European Development Fund (SYSMIN) since 1997, on the Mariental Clay body.

A preliminary assessment proved resources of 2 million tonnes of workable clay to a depth of 3.5m. The accompanying laboratory investigation showed clays of acceptable forming properties with moderate to high shrinkage on drying.

Bricks are currently produced from these clays (Figure 4, right) and have been sold to the local community for building purposes (Figure 5, left). Further research and advice are provided to this brickmaking-operation to fully utilize the capability and available resources.

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Research is currently ongoing using these clays in glazing mixtures to establish a ”recipe” for glazes suitable for the composition of the Mariental clays.

The following reports are available:

  • EG 101 Ceramic Clay Resources, Mariental: Preliminary resource assessment and laboratory evaluation – D.Piper, A.Bloodworth and M.Siyambango.
  • EG 102 Ceramic Clay Resources, Mariental: Results of Forming and Firing Trials of Ceramic Bodies –; D.Piper and Y. Kyl.
Industrial Minerals Database

The population of the database is currently in progress is aimed to be completed by July/August 2000. The database will include information on individual commodities, production and resource data, physical and chemical data, occurrence locations on almost 900 farms in Namibia. 

 

Last updated on 12 November 2002
Published by the Geological Survey of Namibia, Windhoek, Namibia
Copyright Geological Survey of Namibia 1997, 1998, 1999, 2000

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