abstract
The perception of industrial waste has changed, in the last decades, from an economic and environmental problem to a potential raw material. In this work, the synthesis of a stable pigment was prepared by combining two hazardous and unexplored wastes: red mud (RM, rich in Fe) and electroplating sludge (ES, rich in Ni/Cr). The wastes were mixed in different proportions and calcined at 1200 degrees C. Black and brown pigments were obtained from the mixture of RM/ES in 1:3 and 1:1 wt proportions, respectively. The color was given by the chrome-iron-nickel spinels, based on Ni2+ T-3(1g)(F-3) transitions (approximate to 13,000 cm(-1)), Cr3+ (4)A(2g) -> T-4(1g)(F-4) transitions (approximate to 24,400 cm(-1)) and Fe3+ (approximate to 15,000-approximate to 122,500 cm(-1)). The achieved coloring strength and thermal stability on various ceramic glazes render excellent prospects for the industrial application of such waste-based pigments. (C) 2018 Elsevier Ltd. All rights reserved.
keywords
CHROMIUM
subject category
Engineering; Environmental Sciences & Ecology
authors
Carneiro, J; Tobaldi, DM; Capela, MN; Novais, RM; Seabra, MP; Labrincha, JA
our authors
David Maria Tobaldi
Researcher
João António Labrincha Baptista
Full professor
Jorge Augusto Oliveira Carneiro
Post-Doc Fellowship
Maria Paula Seabra
Assistant Professor
Marinélia Capela
Researcher
Rui Miguel Novais
Assistant Professoracknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.