Structural and fluid dynamic characterization of calcium carbonate-based porous ceramics

Abstract

The aim of this work was to experimentally evaluate the use of calcium carbonate as a poregenerating agent in ceramic compositions. Compositions that contained 50% kaolin, 20% limestone, and different concentrations of quartz and feldspar were prepared by uniaxial pressing. Samples were heat-treated at a heating rate appropriate to induce calcium carbonate degassing, and they were then sintered at 800, 900, and 1050 °C. Tests of X-ray fluorescence, thermogravimetric analysis, porosimetry, and air permeation were performed. The composition (wt%) that contained 50% kaolin, 20% limestone, 20% feldspar, and 10% quartz and heat treated at 1050 °C (k 1 = 1.73×10 -13 m 2 and k 2 = 1.00×10 -8 m) showed the highest level of permeability among the investigated samples. Fluid dynamics simulations showed that the prepared samples would exhibit a pressure drop greater than the range desired for applications that involve the filtration of aerosols, but alternatively would be suitable as substrates for asymmetric membranes in microfiltration applications.

Bioactivity and Cell Compatibility of β-Wollastonite Derived from Rice Husk Ash and Limestone

“…The degradation rate of β-wollastonite was also influenced by the crystallinity, sintering period, microstructure, and porosity [ 39 , 40 ]. In this study, the main factor for the increasing degradation rate is the porosity of the material itself.…”

Mechanical property and gas filtration behavior of porous reaction bonded Si3N4 with monodispersed PMMA as pore former

“…The Darcy permeability k 1 and inertial permeability k 2 in this work and those obtained from recent literature on porous ceramics, such as porous SiC ceramics, 41,42 porous Si 3 N 4 ceramics, 11,43,44 porous SiC–Si 3 N 4 ceramics 45 and other porous ceramics, 46–48 are shown in Figure 13. It is worth mentioning that the porous Si 3 N 4 prepared this work has a k 1 ranging from 1.59 × 10 −15 to 1.91 × 10 −14 m 2 , falling in the microfiltration zone of the k 1 range of 1 × 10 −17 to 1 × 10 −13 m 2 , which indicates that the samples prepared in this work are suitable for microfiltration applications.…”

Obtainment of Porous Ceramic Structures: A Comparison among Different Compositions and Methods of Conformation

“…Three formulations (Table 1) were formed in three ways: pressing, slip casting and polymeric sponge method. The formulations were prepared based on previous work [18] being formed by kaolin, calcium carbonate (CaCO 3 ), potassium feldspar, albite, quartz and white clay (Colorminas Colorificio e Mineração, Brazil). The formulations were ground in a mill rotates jars with solids content of 33 wt% for 5 h rotation of 50 rpm, resulting in a powder passing the 200 mesh.…”