Waste-containing clinkers: Valorization of alternative mineral sources from pulp and paper mills

Waste streams generated from pulp and paper mills show high potential to be used as alternatives raw materials for production of clinker. In this context, this work aims to evaluate the use of such materials to obtain hydraulic binders, which are referred to as Ecoclinkers and Ecocements. Lime mud, wastewater treatment process sludge and biomass ashes were characterized, and five formulations (F1-F5) were developed by applying the Bogue equations. These compositions were processed at three different clinkering temperatures (1350, 1440 and 1455 °C). The formulated Ecoclinkers and a reference hydraulic binder were characterized by X-ray diffractometry to identify the crystalline phases, which were subsequently quantified by the Rietveld method. The results showed that crystalline phase characteristics of clinkers and cements, and compression strengths of ∼20 MPa after 28 days curing time were obtained, confirming the potential use of the investigated waste as alternative materials for production of clinker.