abstract
This work reports the development of inorganic pigments based on chromium doped titanite (CaTiSiO(5)). For economical and environmental reasons, wastes were used as raw materials but similar formulations from pure reagents were also prepared to assess the effect of impurities contained in wastes. Pigments were characterised by XRD, SEM + EDS microprobe analysis, and UV-vis-NIR spectroscopy. The colouring mechanism (the pigment is reddish brown) seems to result from the combined contribution of octahedral Cr(III) and tetrahedral Cr(IV)species replacing Ti(4+) and Si(4+), respectively. In both pure reagents and waste-based pigments, colorimetric parameters were evaluated and their colouring performance was tested in transparent and opaque ceramic glazes. Intense and stable brown hues were developed with optimized formulations, i.e. containing 0.044Cr at 1300 degrees C. (C) 2009 Elsevier B.V. All rights reserved.
keywords
MALAYAITE CERAMIC PIGMENTS; TECHNOLOGICAL PROPERTIES; OPTICAL SPECTROSCOPY; CRYSTAL-CHEMISTRY; OXIDATION-STATES; PHASE-TRANSITION; IONS; LUMINESCENCE; CASSITERITE; CATIOSIO4
subject category
Engineering
authors
Hajjaji, W; Zanelli, C; Seabra, MP; Dondi, M; Labrincha, JA
our authors
João António Labrincha Batista
Associate Professor with Aggregation
Maria Paula Seabra
Assistant Professoracknowledgements
The work was supported by FCT (Project PTDC/CTM/72318/2006).