Universidad de Sevilla. Escuela Técnica Superior de Arquitectura.
Abstract
The objective of this work is to valorise the discharges (rejections) of
the Boukhedra iron ore mine (east of Algeria) as raw materials for the elaboration
of the cement raw. The study concerns the development of different types of low
impact environmental belite cements whose raw are exclusively mine rejections.
The use of a low CaO / SiO2 ratio and the combination of quick cooling of clinker
with adequate NaF and LiF mineralization in association with CaSO4, has led to
the production of belite cement with high hydraulic reactivity comparable to that
of ordinary Portland cements. The used mineralization plays also a positive role in
improving performance in terms of firing of the raw, by lowering the clinker
process temperatures of these cements, thus, enabling an additional gain in terms
of environmental impact and energy consumption. This mineralization and the low
LSF of these cements allows obtaining them at low burning temperatures 1150 °C
and 1100 °C for the cement with 2%LiF. This is 350 °C lower to ordinary
Portland cement. The addition of CaSO4, NaF and LiF to the clinkers makes the
improvement of its clinkering possible. The effect of LiF seems to be the most
significant followed by NaF and finally, CaSO
