Structural Refinement by the Rietveld Method on Clinkers Obtained from Waste from Pulp and Paper Mills

摘要

Pulp and paper mills have a process that generates waste with high levels of CaO and SiO_2, which can be valued as an alternative mineral source in the cement industry. In this work the lime mud, biomass ashes and WWTP sludge are used in the production of clinker. Analysis of X-ray diffraction (XRD) confirmed the crystalline phases calcite and quartz. Chemical analysis by X-ray fluorescence (XRF) identified Al_2O_3, CaO and SiO_2, providing support for the calculation of theoretical stages by applying the Bogue equations. Five formulations and three processing temperatures (1350, 1400, 1455 °C) were studied. The products obtained and an ordinary Portland cement (OPC) were characterized by XRD with quantification by the Rietveld method. The results showed that the processing conditions used produced beliticos (higher content of C2S) and Portland (C_3S content greater) ecoclinker.