Firing Behaviour of a Clayey Ceramic Body for Rustic Floor Tiles

2012 ◽  
Vol 727-728 ◽  
pp. 959-964 ◽  
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Sérgio Neves Monteiro

This work had as its objective to evaluate the firing behavior and microstructure of a typical clayey ceramic body from Campos dos Goytacazes, Brazil, used to fabricate extruded rustic floor tiles. The firing behavior of samples fired at 650, 850 and 1050°C was studied by thermal analysis (DTA/TG) and their microstructural characteristics were evaluated by mercury porosimetry and X-ray diffraction. Technological properties such as water absorption, linear shrinkage and flexural strength were also evaluated. The results showed that the clayey body presents a relatively high weight loss during firing due to a significant amount of clay mineral associated with aluminum hydroxide decomposition. After firing the clayey body developed an elevated amount of porosity and low mechanical strength. Quartz was detected as the only crystalline phase originated from the unfired body. By contrast, mullite, plagioclase feldspar and hematite appeared during the firing.

Cerâmica ◽  
2006 ◽  
Vol 52 (322) ◽  
pp. 138-145 ◽  
Author(s):  
C. M. F. Vieira ◽  
L. A. Peçanha Jr. ◽  
S. N. Monteiro

This work presents an investigation that was undertaken for three types of kaolinitic clays from the State of Rio de Janeiro, Brazil, with a potential use in whiteware floor tiles bodies. Different compositions prepared by mixing the three clays with other materials such as kaolin, quartz, philite, potash feldspar and talc, were investigated and compared with an industrial ceramic body for whiteware floor tiles (group BIIa). Physical and mechanical properties such as linear shrinkage, water absorption and flexural strength were evaluated in pressed specimens fired at temperatures varying from 1025 to 1225 ºC. The microstructure of the specimens was studied by X-ray diffraction, scanning electron microscopy and mercury porosimetry. The results indicated that the prepared compositions presented microstructural characteristics, specially the pore size distribution, and technological properties that are compatible with low-porosity ceramic tiles. However, they also display characteristics, such as an excessive plasticity and high loss on ignition, that could generate problems during the industrial processing.


2014 ◽  
Vol 87 ◽  
pp. 162-168
Author(s):  
Paula Cipriano da Silva ◽  
Roberto de Oliveira Magnago ◽  
Camila Aparecida Araujo da Silva ◽  
Bianca de Almeida Fortes ◽  
Claudinei dos Santos

ZrO2(Y2O3)-based ceramics with coloring gradient can facilitate the development of dental prosthesis by the improvement of esthetic properties. In this work, ZrO2 powders with different particle sizes were investigated. White and yellow zirconia powders (TOSOH Corporation-Japan) were characterized by particles size distribution using nanoSight-LM20 analyzer. Furthermore, samples were characterized by X-Ray diffraction, Scanning Electron Microscopy and relative density. Compacts with two layers, one white and one yellow were uniaxially pressed at 80MPa and sintered at 1530°C-120min. The yellow-powder presented average particles size of 180±66nm, while the white-powder presented particles size of 198±73nm. After sintering, full dense ceramics with tetragonal phase were obtained. The linear shrinkage of the yellow and white-layer was 22.75% and 22.05% respectively. This difference in shrinkage is important in the machining of prostheses in ceramic CAD/CAM systems, because they lead to difficulties in adapting this customized prosthesis in patients.


2020 ◽  
Vol 12 (22) ◽  
pp. 9417
Author(s):  
Jucielle Veras Fernandes ◽  
Danyelle Garcia Guedes ◽  
Fabiana Pereira da Costa ◽  
Alisson Mendes Rodrigues ◽  
Gelmires de Araújo Neves ◽  
...  

In this study, we develop ceramic formulations based on quartzite and scheelite tailings collected from mining companies in the northeast of Brazil (Rio Grande do Norte State). New ceramic samples (27 wt% of kaolin, 29 wt% of plastic clay, 11 wt% of quartzite tailing, and 0–8 wt% scheelite tailing) were uniaxially pressed in two steps (20 MPa and 50 Mpa for 20 s); dried at 110 °C for 24 h; and sintered at 1150 °C, 1200 °C, and 1250 °C. The main mineralogical phases (mullite, quartz, calcite, and anorthite) of the sintered samples were identified using X-ray diffraction (XRD). After evaluation of the physical-mechanical properties (water absorption, linear shrinkage, apparent porosity, and flexural strength), it was observed that the incorporation of scheelite tailing by up to 8 wt% did not significantly alter the properties of samples sintered at all temperatures. Our results indicate that the new ceramics formulations developed have strong potentials in manufacturing sustainable materials such as ceramic tiles and porcelain stoneware.


MRS Advances ◽  
2018 ◽  
Vol 3 (61) ◽  
pp. 3575-3579
Author(s):  
Francine M. Nunes ◽  
Eduarda M. Rangel ◽  
Fernando M. Machado ◽  
Rubens Camaratta ◽  
Letícia P. Cardoso ◽  
...  

AbstractThe food processing industry highlights the daily generation of large amounts of eggshell solid residue. In this way, this residue becomes a non renewable raw material to be reused as an additive in red ceramics, in order to reduce the volume of disposal to the environment and improve the physical properties of the product. The objective of this work was to evaluate the forming moisture, linear shrinkage of drying and shrinkage of drying burning of ceramic test pieces (CS’s) with formulations with 2% and 3% of white eggshell residue (ER) incorporated in clay. The clay and ER were collected in the city of Pelotas-RS. The ER sample was analyzed by X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD). After pressing, natural and artificial drying was carried out and the CS’s were burned. These were evaluated through normative parameters C-020/95, C-021/95 and C-026/95. The values obtained for the forming moisture were between 5.82 and 8.78%, for the linear shrinkage of drying between 0.10 and 0.43% and, for the linear contraction burning between -0.29 and 0.08%. The results showed that the addition of ER to the ceramic mass helped in the reduction of the forming moisture and the linear shrinkage of the ceramic test pieces.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
L. M. Romero-Guerrero ◽  
R. Moreno-Tovar ◽  
A. Arenas-Flores ◽  
Y. Marmolejo Santillán ◽  
F. Pérez-Moreno

In the present work, the chemical, mineralogical, refractory, and microstructural characterizations of kaolinites from the Huayacocotla-Alumbres region, which is between Veracruz and Hidalgo border, by X-ray diffraction (XRD), polarization optical microscopy (POM), scanning electron microscopy (SEM), refractoriness proof (pyrometric cone equivalent), and thermogravimetric analysis (TGA) were carried out. The analysis by POM showed that the kaolinization degree in this region is variable due to the presence of primary minerals, such as plagioclase, feldspar, and quartz. Additionally, hydrothermal alteration of the epithermal type was determined by oxidation of sulfides (pyrite and galena) and chlorite association. With the X-ray diffraction technique, andalusite and kaolinite were identified as the majority phases in Huayacocotla and quartz was identified as the majority phase in Alumbres. The minority phases, such as dickite, kaolinite, and cristobalite, were observed in both zones. The SEM technique was useful in the determination of the morphology of kaolinite and impurities of Na, Mg, K, and Fe of the complex clay illite-andalusite-dickite group. Thermogravimetric analysis was useful to discover the decomposition temperature and reveal the significant difference between 400 and 800°C, which showcases the greatest mass loss due to dehydration and carbonates decomposition. The mullite phase was detected at approximately 1000°C in the kaolin samples. The refractoriness tests were important to determine the stability temperature of kaolin, which is between 1300 and 1600°C. This stability temperature makes it feasible to use the kaolin as a refractory material for both low and high temperatures. The variables that affect the kaolin stability temperature were determined by principal components with the XLSTAT free program.


1994 ◽  
Vol 358 ◽  
Author(s):  
K. Dovidenko ◽  
S. Oktyabrsky ◽  
J. Narayan ◽  
M. Razeghi

ABSTRACTThe microstructural characteristics of wide band gap semiconductor, hexagonal A1N thin films on Si(100), (111), and sapphire (0001) and (10ī2) were studied by transmission electron microscopy (TEM) and x-ray diffraction. The films were grown by MOCVD from TMA1 + NH3 + N2 gas mixtures. Different degrees of film crystallinity were observed for films grown on α-A12O3 and Si substrates in different orientations. The epitaxial growth of high quality single crystalline A1N film on (0001) α-Al2O3 was demonstrated with a dislocation density of about 2*10 10cm−2 . The films on Si(111) and Si(100) substrates were textured with the c-axis of A1N being perpendicular to the substrate surface.


2014 ◽  
Vol 805 ◽  
pp. 272-278 ◽  
Author(s):  
Antonielly dos S. Barbosa ◽  
Antusia dos S. Barbosa ◽  
Meiry Glaucia F. Rodrigues

Much interest has been aroused in the application in industrial processes using zeolite membrane, due to its crystalline structure, and narrow pore diameters. These features enable the continuous separation of mixtures based on differences in molecular size and shape and also based on different adsorption properties. This paper reports the synthesis of MCM-22 zeolite membrane, using the method of secondary growth. The MCM-22 zeolite was synthesized by the hydrothermal method and characterized by spectroscopy Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM).The ceramic support (α-alumina) was prepared using the technique of forming powder and then subjected to the sintering temperature of 1400 °C/1h and characterized by XRD. The zeolite membrane preparation was performed by the method of secondary growth and characterized by XRD, SEM and mercury porosimetry. The obtained zeolite membrane could be confirmed by X-ray diffraction. From, the obtained SEM pictures it was possible to observe the formation of a homogeneous film on the zeolite surface of the ceramic support (α-alumina).


2019 ◽  
Vol 9 (13) ◽  
pp. 2598 ◽  
Author(s):  
M. J. Hernández-Rodríguez ◽  
R. Santana Rodríguez ◽  
R. Darias ◽  
O. González Díaz ◽  
J. M. Pérez Luzardo ◽  
...  

In this study, mortar specimens were prepared with a cement:sand:water ratio of 1:3:0.5, in accordance with standard EN196-1. Portland CEM I 52.5 R grey (G) and white (W) cements were used, together with normalised sand and distilled water. Different amounts of TiO2 photocatalyst were incorporated in the preparation of the mortar samples. The effect of the addition of TiO2 was studied on mechanical properties of the mortar and cement including compressive and flexural strength, consistency (the flow table test), setting time and carbonation. Characterization techniques, including thermogravimetry, mercury porosimetry and X-ray diffraction spectroscopy (XRD), were applied to study the physico-chemical properties of the mortars. It was shown that adding the photocatalyst to the mortar had no negative effect on its properties and could be used to accelerate the setting process. Specimen photoactivity with the incorporated photocatalyst was tested for NOx oxidation in different conditions of humidity (0% RH and 65% RH) and illumination (Vis or Vis/UV), with the results showing an important activity even under Vis radiation.


2012 ◽  
Vol 727-728 ◽  
pp. 951-956 ◽  
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Mônica Manhães Ribeiro ◽  
Sérgio Neves Monteiro

Steel making in integrated plants involves several stages from the feeds tock preparation, by sintering or pelleting of the iron ore, to the rolling of the steel sheets. In any of these stages wastes are generated and unless recycled or used as by product, they will cause serious environmental problems. Therefore, this work has as its objective to evaluate the effect of incorporation of 20 wt.% of the powder waste, particulate material, retained in the eletrostatic precipitator equipment of the sintering stage from an integrated steel making plant on the microstructure a clayey ceramic fired at 1050°C. The microstructure of the fired ceramics was evaluated by scanning electron microscopy, X-ray diffraction and mercury porosimetry. The results showed that in the investigated temperature the waste increased the porosity of the clayey ceramic as well as introduced defects in the microstructure of the ceramic.


2003 ◽  
Vol 788 ◽  
Author(s):  
Predrag Kisa ◽  
Patrick Fisher ◽  
Al Olszewski ◽  
Ian Nettleship ◽  
Nicholas G. Eror

ABSTRACTThis study investigated the microstructural characteristics of directionally solidified freeze-dried silica sols. Porous structures were formed by depositing silica sol on silicon (100) single crystals. The deposited sols were unidirectionaly solidified by placing the silicon substrate on a copper block immersed in liquid nitrogen and then subsequently freeze-dried. Freeze drying removal of ice crystals created three-dimensional pore channels ranging from 3 to10 micrometers in diameter aggregated in grain like colonies 50–100 micrometers in diameter. Pore size, spacing, colony size and microstructure were determined using optical microscopy (OM) and scanning electron microscopy (SEM) while the structure of the amorphous SiO2 was characterized by X-ray diffraction (XRD). The microstructure results are compared and contrasted with silica aerogel obtained through conventional processing using supercritical CO2.


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