Biomass ashes as secondary material in the cement industry

Aktivität: Gespräch oder VortragVortrag


For the generation of heat and electricity, biomass incineration is increasingly used in the last years as wood counts as CO2-neutral fuel. After the combustion process ashes remain as residues. Bottom ashes are the coarse fraction and contain valuable elements for soils and plants. Therefore they can be recycled to the earth and new plants can grow. Fly ashes, on the other hand, are collected in the gas cleaning system and contain often higher amounts of heavy metals which restricts their reuse on soils for agriculture and in forests. Usually these ashes have to be disposed. In this study an alternative way of recycling for fly ashes has been investigated. Additionally to literature data, fly ashes from several Upper Austrian biomass incinerators have been analyzed and the concentrations of heavy metals and alkaline metals have been evaluated. The chosen method for analysis was inductively coupled plasma – optical emission spectroscopy as this method has low limits of detection (in the ppb range) and gives good reproducible results. As biomass fly ashes contain high amounts of alkali and earth alkali metals, they are good substitutes for secondary material in the cement industry. On the other hand, components as for example chloride or heavy metals can cause problems in the production process like corrosion and sticking and decrease the quality of the product cement. It could be found that biomass ashes can be used in the cement industry to a certain percentage so as to make sure that certain limit concentrations of elements are not exceeded. Especially the limit for chloride limits the utilization of biomass ashes if polymers (e.g. PVC) are used as substitute fuel in the cement kiln.
Zeitraum7 Okt. 2011
EreignistitelHungarian Italian Symposium on Spectrochemistry
OrtSümeg, UngarnAuf Karte anzeigen