Flyashes (CFP)

Standardisation of flyashes for use in concrete

Flyashes of coalfired powerplants are used amongst other purposes for the production of concrete.

Since 2005 exists an European harmonised standard (EN-450-1 and 2) on flyash for this special purpose, which is under revision actually in CEN TC 104.

As coal fired power plants are one important potential user of such solid recovered fuels, this revison is also of importance for ERFO, and is followed by its working group.

In the existing standard thre are restrictions for types of co-combustion materials and the use of SRF is excluded if the flyashes from those plants should be used for the production of concrete.

For the use of SRF as co-combustion material, there is the possibility to be subject for an ETA.

While ERFO has no problem to define parameters, which have to be fullfilled by flyashes, whether they are from use of primary fuels or SRF, ERFO disagrees with a concept, where maximum percentages for the use of only certain types of secondary fuels are made, which are even exclusive.

The approval of the two standards is expected for 2011.

Flyashes is also mixed with the clinker produced in cement kilns, for the production of certain types of cements.