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White cement is a building material for which demand
is very high. Compared to grey cement, it has
the same advantages regarding construction but at
the same time provides avariety of possibilities that
allow more creativity in construction. Thanks to its
high colour purity, surfaces are bright and look elegant.
It is therefore especially popular in the sunny
countries of the Middle East and the Mediterranean
region. As white cement can be easily coloured with
colouring pigments, it is also used for producing
coloured products such as terrazzo plates.
Owing to these demands, the production of white
cement is extremely complex. Furthermore, it is far
more expensive than grey cement because product
output is lower, while more energy is needed to produce
it.
To produce white cement, rather colourless raw
materials with a very low content of iron oxide are
needed. They are calcined in a rotary kiln at approx.
1,400 °C to produce cement clinker. The decisive
factor for the whiteness of the cement is the
clinker cooling process. Only by means of cooling
systems that have been designed especially for
white cement production, high quality can be obtained.
Thanks to its vast experience concerning white
cement production, in March 2007 Polysius was
awarded a contract to supply a company in the
west of Tunisia with a 1,000-tpd turnkey white cement
production line. The new line is being built in
the Feriana plant of the SOciete Tuniso-Andalouse
de Ciment Blanc (SOTACIB). Production is planned
to start at the beginning of the year 2009.
From the raw material preparation to the cement grinding, including
the quality assurance system, the new line is equipped with
state-of-the-art components from Polysius.
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