Carlos Maurício Fontes Vieira

Incorporation of solid wastes in red ceramics: an updated review

A review on the fundamentals and technological advances in the incorporation of industrial solid wastes into red ceramics was updated since 1997, when the first overview on this subject was published by Dondi, Marsigli and Fabbri. Other works conducted before this period, but not covered by that overview were also reviewed. Modifications were introduced in the original categories of wastes to permit a wider variety to be considered. In addition to fuel and fluxing wastes, a category of property affecting wastes substituted the originally proposed fly-ash and plasticity reducing/ plastifying wastes categories. In order to be more comprehensive, this updated review considered industrially relevant subdivisions within each category. Accordingly, fuel wastes encompass: oily residues, blast furnace sludge, and paper industry residues. Fluxing wastes encompass: rejects from ornamental rocks, glassy residues and fluxing ashes. Property affecting wastes encompass: grog, water treatment sludge, steel-refining sludge/slag, non-fluxing ashes, mineral processing tails, galvanic sludge, spent catalyst reject, textile slurry, foundry reject sands, tannery sludge and construction and demolition leftovers.

Characterization of red ceramic body used in the production of bricks in the region of Campos dos Goytacazes - RJ

The objective of this paper is to characterize a mixture of clays in the area of Campos dos Goytacazes-RJ used in the fabrication of bricks. It makes possible to evaluate the possibility of application of this body in the production of others products with greater aggregate value, as roof tiles, wall and floor tiles. In this work were realized the following tests: chemical composition, differential thermal analysis(DTA), thermogravimetric analysis(TGA), particle size distribution analysis and determination of physical-mechanical properties in function of the temperature of it burns. The results demonstrated that the ceramic body studied is appropriate for the production of massive and walled bricks. However to manufacture roof tiles, floor and wall tiles it is necessary to manipulate the body formulation to obtain the of properties in agreement with technical norms in use.

Ballistic Efficiency of an Individual Epoxy Composite Reinforced with Sisal Fibers in Multilayered Armor

Sisal fibers are among the natural lignocellulosic ones with great impact resistance for potential use in polymer composites. This work evaluates the ballistic efficiency of the distinct individual components of a multilayered armor. These include the front ceramic, the back metallic sheet and the intermediate layer as either the conventional aramid fabric or a novel sisal fiber reinforced epoxy composite. Sisal fibers incorporated in epoxy resin plates with volume fraction of 30% were ballistic tested using the 7.62 caliber ammunition. The fibers were embedded under pressure in the epoxy resin matrix and cured at room temperature for 24 hours. The tested specimens were examined by scanning electron microscopy.

Massas cerâmicas para telhas: características e comportamento de queima

This work has for objective to study the characteristics and technological properties of a typical roofing tile ceramic body from the county of Campos of Goytacazes-RJ with other three ceramic bodies of recognized technical quality, coming from States of Santa Catarina and Piaui and of Portugal. The ceramic bodies were submitted to analysis of X-ray diffraction, chemical composition, DTA/TGA, particle size distribution and plasticity. Samples were made by uniaxial pressure at 20 MPa for firing in temperatures varying from 825 to 1075 oC. The firing technological properties evaluated were: lineal shrinkage, water absorption and flexural strength (3 points). The results indicated that the ceramic body from Campos presents significant differences in the evaluated characteristics in comparison with the other ceramic bodies. Consequently, the ceramic body from Campos showed a different firing behavior, with higher values of water absorption, flexural strength and lineal shrinkage.

Cinza da lenha para aplicação em cerâmica vermelha. parte I: características da cinza

The eucalyptus firewood is one of the main fuels used by the industries of red ceramic in the municipal area of Campos of Goytacazes, State of Rio de Janeiro. In principle this firewood has promising characteristics for addition into ceramics. Thus, the present work has for objective to characterize the ash generated from burning firewood aiming at its incorporation into red ceramic products. The ash was submitted to X-ray diffraction, chemical composition, particle size distribution, thermal analysis (ATD/TG), mercury porosimetry and scanning electron microscopy tests. The results showed that the ash of the firewood comes as agglomerates of particles, being constituted mainly by Ca, Si, Mg, K and S.

Alterações microestruturais de cerâmica argilosa incorporada com lodo de ETA

This work had as its objective to investigate the microstructural aspects of red ceramic incorporated with sludge from water treatment plant fired at 700°C. The sludge was collected at the filter stage in the water treatment plant of the county of Itaperuna, Rio de Janeiro State. The microstructure of the ceramics was analyzed with X-ray diffraction and scanning electron microscope with energy dispersive spectroscopy, EDS, facility. The results indicated that the incorporation of filter sludge change the fired phases and increases the microstructural defects of the ceramic.

Recycling of Steel Sludge into Red Ceramic

The present paper has for objective to evaluate the effect of fine steel sludge waste incorporation on the properties and microstructure of a kaolinitic clayey body used to the fabrication of bricks and roofing tiles. Compositions were prepared with additions of waste of 0, 5 and 10 wt.% in a kaolinitic clay from the county of Campos dos Goytacazes, State of Rio de Janeiro, Brazil. To determine the technological properties such as bulk density, linear shrinkage, water absorption and flexural strength, specimens were prepared by uniaxial pressure at 20 MPa and then fired in a laboratory furnace at 700°C, 900°C and 1100°C. The microstructure of the fired specimen was evaluated by SEM. The results showed that the incorporation up to 10 wt. % of fine steel sludge does not change the ceramic properties, specially, at low temperatures. Hence, the recycling of steel sludge into red ceramic fabrication can be considered as an environmentally correct solution for the final disposal of this type of waste.

Reciclagem de resíduo proveniente da produção de papel em cerâmica vermelha

This work has for objective to evaluate the effect of the incorporation of waste from the paper production, in up to 10 wt % on the properties and microstructure of a clayey body used in the fabrication of bricks. The raw materials, the paper waste and the clayey body were, respectively, obtained from the area of Santo Antonio de Padua and Campos dos Goytacazes, north of the State of Rio de Janeiro. Specimens were prepared by uniaxial pressing at 20 MPa before firing at 750 °C. The evaluated physical and mechanical properties were: linear shrinkage, water absorption and flexural strength. The microstructure of the ceramics was evaluated by SEM. The results showed that the waste addition changes the physical and mechanical properties of the ceramic, generating a deleterious effect on the water absorption and flexural rupture strength for incorporations above 5 wt %. By contrast, incorporations of 3 wt % of the waste were found to be a viable alternative for the final disposal of waste from the paper production.

Effect of kaolinitic clays from the State of Rio de Janeiro in the composition of whiteware floor tile bodies

Este trabalho apresenta uma investigacao sobre tres tipos de argilas cauliniticas do Estado do Rio de Janeiro, Brasil, com potencial uso em massas de pavimentos cerâmicos de base clara. Diferentes composicoes, preparadas atraves da mistura das tres argilas com outros materiais, tais como quartzo, filito, feldspato potassico e talco, foram investigadas e comparadas com uma massa cerâmica industrial de pavimento de base clara (grupo BIIa). Propriedades fisicas e mecânicas tais como retracao linear, absorcao de agua e tensao de ruptura a flexao foram avaliadas em corpos de prova prensados e queimados em temperaturas variando de 1025 a 1225 oC. A microestrutura das amostras foi avaliada por difracao de raios X, microscopia eletronica de varredura e porosimetria de mercurio. Os resultados indicaram que as composicoes preparadas apresentam caracteristicas microestruturais, especialmente a distribuicao de tamanho de poro, e propriedades tecnologicas que sao compativeis com revestimentos cerâmicos de baixa porosidade. Entretanto, as composicoes tambem apresentam caracteristicas, tais como uma excessiva plasticidade e elevada perda de massa, que podem gerar problemas durante o processamento industrial.

Efeito da adição de fonolito na sinterização de argila caulinítica

This work had as its objective to evaluate the firing behavior of a kaolinitic clay incorporated with phonolite aiming at semiporous pressed ceramic tiles. Compositions were prepared with addition of 20 and 40 wt.% of phonolite to a kaolinitic clay. For comparison, an industrial ceramic body from Santa Gertrudes, State of S. Paulo, was also evaluated. Cylindrical specimens were prepared by uniaxial pressure at 25 MPa followed by firing at temperatures varying from 1050 to 1200 oC. The fired specimens were submitted to the following tests: linear shrinkage and water absorption as function of the firing temperature. The microstructural evaluation of the compositions was accomplished by X-ray diffraction and scanning electron microscopy. The results showed that the phonolite addition significantly improve the sintering of the clay, mainly, above 1150 oC with sharp decrease of the porosity. Although the clay/phonolite mixtures showed higher amount of alkaline oxides as compared with the industrial ceramic tile body, the required water absorption of 10% for semiporous tiles was only reached at temperatures around 80 oC higher than the industrial body.