Mechanical properties of anorthite based ceramics prepared from kaolin DD2 and calcite

Abstract

Anorthite is widely spread in nature and belongs to the plagioclase group of rock forming minerals. Plagioclases represent a continuous series of solid solutions between anorthite (CaO.Al 2 O 3 .2SiO 2 ) and albite (Na 2 O.Al 2 O 3 .6SiO 2 ) and form an enormous group of triclinic minerals. harabi52@gmail.com, Zaiou_21@yahoo.fr, guechia@yahoo.fr, semouni84@gmail.com, kanour17@yahoo.fr, foughali_lazhar@yahoo.fr, zouaisouheila@yahoo.fr, mezahif@yahoo.fr, guerfatiha@gmail.com Mineralogically, anorthite is reported as a chemically weak mineral, resulting in a basic reaction when dissolved into boiling water, while strong acidic and basic solutions dissolve it. Glass-ceramics and ceramics with crystalline anorthite are mainly used in electrical, thermo-mechanical and water resistance applications [1][2][3][4]. Anorthite is an important technical ceramic material that has good physical properties, such as very low thermal expansion coefficient, low dielectric constant and loss, good thermal shock resistance, and high creep resistance at high AbstractGood quality ceramics costs a lot that has limited their use in developing countries. This work was devoted to prepare low-cost and good quality anorthite based ceramics. The proposed composition was 80 wt% kaolin (DD2 type) and 20 wt% calcium oxide (CaO). The choice of these raw materials was dictated by their natural abundance coupled with a modified milling system, as another interesting advantage. Previous studies have shown that a simple vibratory multidirectional milling system using bimodal distribution of highly resistant ceramic milling elements has been successfully applied for obtaining fine powders. The influence of the relatively lower sintering temperature, ranging from 800 to 1100 °C, on the porosity and the average pore size (APS) have been investigated. The APS and the porosity values of samples sintered at 950 °C were about 1 μm and 4%, respectively. The best Vickers microhardness and 3-point bending strength values for these sintered samples, using this proposed milling system, were 7.1 GPa and 203 MPa, respectively. Finally, the crystalline phase evolution during heat treatment was investigated by X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy techniques.

Development and Characterization of Glass-Ceramics from Combinations of Slag, Fly Ash, and Glass Cullet without Adding Nucleating Agents

“…According to TGA-DSC analysis (Figure 8, Figure 9 and Figure 10), we can observe that Mixture 1 had a small endothermic signal at 930 °C and an exothermic signal at 1100 °C; and Mixture 2 showed an endothermic signal around 580 °C, which was likely related to a nucleation process, together with an exothermic peak at 800 °C. In the Mixture 3, it is possible to observe a slight endothermic signal at 850 °C and an exothermic peak at 1100 °C, as well as weak thermal events (observed in the DTA analysis) up to 1200 °C, in accordance with other research [37,38,39]. The endothermic signal before the exothermic signal was due to heat absorption accompanied by the softening and rearrangement of the microstructure of the samples during the thermal treatment.…”

Sintering of anorthite based ceramics prepared from kaolin DD2 and calcite

“…Many works have already been published in three main interesting research topics for the valorization of these native raw materials. These topics are bioceramics [3][4][5][6][7][8][9][10][11][12][13][14], advanced ceramics [15][16][17][18][19][20][21][22][23] and ceramic membranes [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Most of these publications are closely related to this work and clearly highlight their possible applications.…”

Characterization and application of ceramic membranes prepared from Algerian kaolin

“…After sintering at 1200 °C, peaks of mullite appeared due to the transformation of metakaolinite. The main phases detected in the membrane support sintered at 1200 °C [54] were mullite and spinel phases as illustrated in Fig. 6.…”