Characterization of phlogopite for processing porous ceramic filters using the replica method

Abstract

The characterization of the raw material phlogopite [KMg₃(AlSi₃O₁₀)(OH)₂] and the process of manufacturing porous ceramic filters (PCFs) from it, using the polymeric sponge method in a simple and effective way, are described. Phlogopite was characterized by X-ray diffraction (XRD), attenuated total reflection Fourier-transform infrared spectroscopy, UV-vis spectroscopy, thermogravimetry, differential thermal analysis, and dilatometry, and PCFs by scanning electron microscopy coupled by energy dispersive spectroscopy and the immersion method to determine apparent porosity (PA), water absorption (AA), and bulk density (DA). XRD indicated, in addition to the phlogopite phase, the kaolinite, biotite, and goethite phases for the sample without heat-treatment. The band gap energy of 3.10 eV was determined by UV-vis. From the thermal analysis, the firing temperature between 1000 and 1200 °C was found. PA in the range of 92% to 95%, AA from 84% to 89%, and DA from 0.12 to 0.25 g.cm^-3 were determined. The PCFs presented high contents of oxygen, aluminum, silicon, iron, and magnesium, besides regular cellular structures with interconnectivity, and pore size distribution in the range of 250 to 400 µm.

Keywords:
characterization; porous ceramic filters; phlogopite; polymeric sponge method