Aggregate production from burnt oil shale and CO2 – an Estonian perspective

Estonia's main calcareous industrial waste output, such as burnt oil shale (BOS) from Narva Power Plants (PPs), cement kiln dust (CKD) from AS Kunda Nordic Tsement and municipal solid waste incineration (MSWI) residues from Iru Power Plant (PP), were all tested in a novel mixer-type granulator-carbonator for the production of constructional aggregates, with a focus being placed on the mechanical properties, the CO2 binding ability, and leaching behaviour. The mixtures of wastes after the addition of cement and quarry fines gave aggregates which exhibited satisfactory mechanical and leaching properties for further utilisation. The results of this study could serve as a basic research step towards closing the waste cycle in Estonian energy and cement sectors.