Articles on the cement industry from Global Cement

With nearly 82 million inhabitants and a GDP of Euro2.5tn in 2010, Germany is both the most populous and richest nation in Europe.^1,2 Although its cement production industry has been muted in recent years due to the global economic downturn, the country has a strong industrial background and is a leader in many industrial sectors, including the manufacture of cement production equipment, which has enabled strong exports to developing regions of the world.

This article, based on a paper presented at the 13th International Congress on the Chemistry of Cement at Madrid in July 2011, describes a radical, step-change approach to reducing CO₂ emissions from cement manufacture.

A cement is any substance which binds together other materials by a combination of chemical processes known collectively as setting.¹ Cements are dry powders and should not be confused with concretes or mortars, but they are an important constituent of both of these materials, in which they act as the 'glue' that gives strength to structures. Mortar is a mixture of cement and sand whereas concrete also includes rough aggregates.

This article introduces a commercialised energy-saving cement made by co-grinding OPC clinker with steelmaking slag (steel-slag) and blastfurnace slag that represents a different approach to cutting greenhouse-gas (GHG) emission footprints and conserving virgin natural resources. The cement uses only 15-30% of OPC clinker, 30-40% of steel-slag and 40-50% of blastfurnace slag (BFS), allowing for great reductions in GHG emissions, consumption of virgin natural resources and energy use by between 70% and 85%. The characteristics of steel-slag as a supplementary cementitious material are also discussed.

The energy intensive cement industry faces high and rising energy costs and must meet requirements for reducing CO₂ emissions. One remedy for these challenges is to increase energy efficiency by recovering waste heat and converting it to electricity.