When manufacturing our core products – aggregates and cement – we mainly utilise raw materials from our own quarries and sand and gravel pits in the direct vicinity of the production locations. When producing aggregates, we process the raw materials from such sites without the use of additives.
Alternative raw materials for cement manufacturing
Our production of clinker — the most important intermediate product for cement manufacturing — involves the utilisation of alternative raw materials. These include old foundry sand, potter’s plaster from the porcelain industry and sludge from drinking water purification systems.
Through the use of additives in the cement grinding process, we have been able to reduce the proportion of clinker, which is very expensive to burn, in the final product. We primarily utilise blast furnace slag from steel production operations, as well as fly ash that remains as a byproduct in coal-fired power plants. The sharp decline in steel production following the global financial crisis led to a shortage of blast furnace slag in 2009. This development forced us to adjust our cement portfolio.
Our Eastern European and Indian plants have traditionally been the leaders in the use of blast furnace slag. In fact, cement plants in Ukraine and Russia are often built directly next to steelworks in order to generate synergy effects. The expertise we have gained in this area is gradually being transferred to other regions. All in all, the share of alternative raw materials in clinker and cement production operations decreased from 13.0% in 2008 to 11.6% in 2010. During the period under review we did not achieve our goal of further reducing the proportion of clinker in our cement. This proportion currently amounts to 76.1%.
Alternative fuels replace natural resources
An even more important goal for HeidelbergCement is to replace fossil fuels with alternative fuels wherever possible. The utilisation of waste materials and byproducts from other industrial sectors not only enables us to contribute to natural resource conservation but also creates potential new solutions for sustainable waste management. The type of material used depends on such factors as availability and calorific values.
We also take into consideration the chemical composition of the substances we employ in order to avoid harmful emissions and a negative impact on the environmental compatibility of the product in question. Our selection and use of alternative materials are in accordance with the guidelines developed by the World Business Council for Sustainable Development.
Our alternative fuels strategy focuses on three globally available waste material flows:
- sorted fractions of domestic and municipal waste with high calorific values
- sewage sludge
- hazardous waste.
The share of alternative fuels (incl. biomass) in the total fuel mix was 20.5% in 2010. As a result, HeidelbergCement remains the global leader in the cement manufacturing industry.
Innovative use of alternative fuels
We substantially increased the processing and utilisation of hazardous waste in 2010. For example, we successfully inaugurated the state-of-the-art Recyfuel processing platform in Belgium. We are also utilising more and more of this type of waste in our German and Indonesian plants, whereby the focus is on old paints and varnishes, used oil filters and roofing felt. An internal workshop held in 2010 once again offered experts from various Group units the opportunity to share experience and best-practice examples of the use of such waste.
We expanded the utilisation of sewage sludge in 2010 — particularly in North America and Turkey. We also successfully conducted practical tests with sludge at various plants in Belgium and Germany. And despite market difficulties in Hungary and northern Europe, we significantly increased the use of plastic fractions from municipal waste there as well.
Our criteria for the use of alternative raw materials and fuels
When utilising alternative raw materials, we place a high priority on the quality of our products; the health and safety of our employees, neighbours and customers; and environmental protection. Regulations and criteria governing the safe handling and use of alternative raw materials and fuels are therefore contained in a Group-wide guideline. We also have specialists for alternative materials who supervise procedures each time a new alternative material or fuel is used at a plant. We conduct training sessions twice a year that also address the handling of particularly hazardous wastes. In addition, our employees can obtain information and share knowledge related to this issue on an extensive knowledge and information platform on the Group intranet.