resumo
Four industrial wastes, namely, tionite (T), iron grit (IG), electroplating sludge (ES), and mill scale (MS), are typically disposed of in controlled hazardous landfills because of their toxic content, posing potential harm to human health and to the environment. At the same time, the chemical composition of these wastes, specifically the nature and content of transition metals, makes them potentially attractive for reuse in pigments manufacturing. This work details the study of these residues for producing coloured perovskites to be tested as inorganic pigments. The residues were mixed, in different proportions, and subsequently calcined to produce the required structures. The colouring potential was then assessed in a ceramic paste and in a transparent glaze. Leaching tests were carried out to verify the effective immobilisation of the hazardous species. Dark pigments were successfully obtained from the mixtures of T: ES: Co3O4, T: MS and T: IG. The crystalline phases present in T: ES: Co3O4 are nickel-chromium iron oxide spinel-Fe1.5Cr0.5NiO4 (without Co) or trevorite-Fe2NiO4 (with Co), titanium nickel oxide-TiNiO3 and titanite-CaTiSiO5. The mixtures T: MS and T: IG presented hematite (Fe2O3) and pseudobrookite (Fe2TiO5). Leaching tests confirmed the non-hazardous or inert character of the synthesized pigments. Products showed brownish or greyish hues, depending on the pigment added. T:75ES_1100, T:73ES:2Co_1100, T:75MS_1000, T:75MS_1100 and T:75IG_1000 pigments can effectively and safely be used to colour ceramic paste replacing partially or totally the commercial pigments.
palavras-chave
RED MUD; OPTICAL-PROPERTIES; CRYSTAL-STRUCTURE; CERAMIC PIGMENTS; COPPER SLAG; HEMATITE; TIO2; TRANSFORMATION; PERFORMANCE; SHRINKAGE
categoria
Environmental Sciences & Ecology
autores
Paz-Gómez, DC; Vilarinho, IS; Carvalheiras, J; Pérez-Moreno, SM; Seabra, MP; Labrincha, JA; Bolívar, JP
nossos autores
Inês Lousada Silveirinha Borges Vilarinho
Investigador Júnior
João António de Sousa Carvalheiras
Estudante de doutoramento
João António Labrincha Baptista
Professor Catedrático
Maria Paula Seabra
Professor AuxiliarProjectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC) and it has been also funded by the project ENFRIMA (UHU-202020).Open access funding provided by FCT|FCCN (b-on).