Concurrent calcination of clay and
phosphogypsum for cement manufacture: A pilot plant study
Osha, O. A.
Chemical Engineering Programme,
Abubakar Tafawa Balewa University,
Bauchi, Nigeria.
ABSTRACT
The
Nigerian cement industry today comprises of seven operating plants,
the majority of which are over twenty years old. The effects of the
aged plants and shortage of critical inputs has manifested in a
sharp decline in capacity utilization, recently estimated at less
than 50%. The industry is, therefore, in urgent need of innovative
technology to reduce its production cost and increase production
capacity. This paper reports a study in a pilot plant of a process
for the manufacture of multiple cement types for various
applications using a cement additive prepared by burning clay soil
and waste gypsum. The result indicates that two different categories
of cement could be obtained by varying the amounts of additive added
to clinker during grinding. The additive is ground with clinker
without the need for natural gypsum. Up to 40% of clinker mass is
replaced by additive and further processed to cement, thereby
increasing productivity. Since clinker is the most expensive
constituent of Portland cement, the economic implication is a
reduction in production cost, enhanced sales and greatly improved
cement availability.
Keywords:
Clay, Phosphogypsum, Additive, Portland cement,
Pilot plant.
