Influence of the use of secondary materials on the levels of heavy metals in Portland cement clinkers and cements

摘要

The cement industry is using increasing quantities of secondary fuels to cover the thermal energy requirement for the clinker burning process and as a replacement for natural raw materials in the production of raw meal. Ruedersdorfer Zement GmbH has been replacing natural raw materials and fuels with secondary feed materials for a number of years. The works operates an environmental laboratory with modern equipment for quality control. The levels of trace elements in the feed materials and products have been systematically analysed for seven years. So far it has not been possible to detect any critical increases in the levels of trace elements. Any detrimental effects on process behaviour and product quality can be dependably avoided by proper, controlled, use of the secondary materials.