Annual European production of incineration bottom ash (IBA) is about 20 mil. tons per year. IBA particles below 2 mm are often denoted as a fine fraction. They form 30-40 % of IBA, i.e. annual production 6-8 mil. tons. A significant amount of non-ferrous metals is present in IBA fine fraction (e.g. 1-2 % of Al, up to 1 % of Cu) and small part heavy NFe (HNFe) comprises of precious metals, rare earth elements, etc. Metals recovery from IBA fine fraction is up to now very rare, it means a wasted potential of about 70,000-140,000 tonnes Al and up to 70,000 tonnes Cu per year. Moreover, IBA fine fraction cannot be used in the construction industry, except road construction together with coarse fractions, because environmental quality does not meet legal requirements, mostly due to the elevated metal content and their leachability.

The ReFina project will develop an innovative and complex treatment for incineration bottom ash fine fraction. Physical separation methods will be used for efficient recovery of NFe metals with particular interest in HNFe. Hydrometallurgical treatment will be used for ultra-fine particles beyond the efficiency of physical separation for the recovery of metals and chemically bound metals. The remaining metals-depleted mineral fraction with enhanced environmental parameters will be used for advanced application in the construction industry, e.g. as a sand substitute. Hence, the ReFina project solution offers a complex treatment of IBA fine fraction for the exploitation of all valuable components. It is an innovative and original approach complementary to current bottom ash treatment methods focused on particle over 2 mm.