Characterization of elaborated Moroccan mullite to improving porous refractories quality

Abstract

Production of porous and light-weight bricks with acceptable flexural strength is accomplished. Sawdust was used as an additive to an earthenware brick to produce the pores. SEM-EDS, XRD and XRF analysis of the raw materials and the elaborated refractory were performed. Mixtures containing sawdust were prepared at different proportions (up to 30%). Apparent porosity at 1600 °C was investigated with the bulk density, water absorption, firing shrinkage and flexural strength. Microstructural investigation was carried out by both natural light microscopy and polarized light microscopy. The results obtained showed that the samples tested here maintained their shape without undergoing any deformation up to 1600 °C. The use of sawdust decreased the fired density of the bricks down to 1.24 g/cm³.

Catalytic complete oxidation of acetylene and propene over clay versus cordierite honeycomb monoliths without and with chemical vapor deposited cobalt oxide

“…It should be noted that the observed dull reddish color of the studied clay is associated with its high content of Fe 2 O 3 which is typical of not only Moroccan clays [31,32], but also several clays worldwide [33][34][35][36]. …”

Preparation and Spectroscopic Characterization of Iron Doped Mullite

“…Two grams of powdered material (Fe-mullite + amorphous SiO2 obtained by thermal treatment of NH4,Fe-gel) dried at 378 K for 24 h was poured into a stainless-steel reaction vessel containing 100 ml of 2 M NaOH solution preheated at 343 K (concentration of the suspension was 20 g/dm 3 ). The reaction vessel was equipped with a thermostated jacket and fitted with a water-cooled reflux condenser and a thermometer.…”

“…2 Mullite can usually be formed by heating mixtures of silica-and alumina-containing appropriate precursors (minerals, oxihydroxides, etc.). 3 Properties of mullite can be modified by insertion of a transition metal ion, such as iron, into the structure. Iron may occupy both octahedral and tetrahedral sites in the lattice.…”

Effect of andalusite rich schist grain size and the addition of metallic aluminum powder on the properties of silica–alumina refractory

“…Mullite has been produced by a variety of high-tech processing methods, including sol-gel technology, chemical syntheses, co-precipitation and hydrolysis [7]. Syntheses based on natural minerals such as kaolinite, or the sillimanite group (kyanite, andalusite, sillimanite), and simple alumina-silica mixtures, lead to synthesized ceramics with high quality of mullite by conventional processing-sintering methods [1,[8][9][10][11][12][13][14][15][16][17][18]. Mullite derived from alumina-silicate minerals has been studied for many different reasons including microstructural development [6,[13][14][15]17], its structure [5], methods of synthesis [2][3][4]7,11,16], thermal evolution and the mechanical properties [3,19].…”

“…Different types of refractory can be synthesized according to the nature of the raw materials and the used process [2][3][4][5][6][7][8][9][10]. The application fields of refractory are multiple and depend on the properties of each type.…”