One of the most important of all building materials, cement is also one of the most polluting, with significant amounts of greenhouse gases released during production.
Cement manufacturing begins with mining limestone and burning it in gas and coal fired kilns at extremely high temperatures (approx. 1450°C) to transform it into a lumpy grey material known as clinker. This clinker is then crushed into cement powder in grinding mills.
Cement is the ‘glue’ that binds sand and aggregate to make concrete in construction work. Concrete’s ready availability, durability, versatility and relative cost ensure its continued (and growing) use in the building industry.
However, cement is highly polluting due to the significant levels of greenhouse gas emissions, which occur primarily during the chemical reaction when limestone is burned releasing CO2-e. The mining of limestone and transport of cement together with the energy required add further to the CO2-e output. With 900 kilograms of CO2-e estimated to be emitted for every tonne of cement manufactured, the cement industry alone generates approximately 5 per cent of global CO2-e emissions.
Having recognised the severity of the environmental issues associated with cement manufacturing some years ago, Independent Cement and Lime invested heavily in the development and production of a more environmentally sustainable alternative to cement - Ecoblend.