Elaboration and characterization of mullite-anorthite-albite porous ceramics prepared from Algerian kaolin

Abstract

Mullite-anorthite-albite porous ceramic materials were successfully prepared by a solid-state reaction between kaolin clay and two different additives (CaCO 3 and Na 2 CO 3 ). The starting raw material was characterized by X-ray fluorescence, X-ray diffraction (XRD) and dynamic light scattering techniques. The effect of CaCO 3 and Na 2 CO 3 concentration (10 to 70 wt%) on structure, morphology and thermal properties of the obtained ceramics was investigated by XRD, scanning electron microscopy and differential scanning calorimetry (DSC) techniques. The XRD patterns showed that mullite (3Al 2 O 3 .2SiO 2 ), anorthite (CaO.Al 2 O 3 .2SiO 2 ) and albite (Na 2 O.Al 2 O 3 .6SiO 2 ) were the main crystalline phases present in the materials. The morphology investigation revealed the porous texture of obtained ceramics characterized by the presence of sponge-like structure mainly due to the additive decomposition at high temperatures. The DSC results confirm the presence of four temperature regions related to the kaolin thermal transformations and the formation of minerals. The temperature and enthalpy of mineral formation are additive concentration dependent. As a result, the optimal content of additives which allowed the coexistence of the three phases, a spongelike morphology, and high porosity without cracks corresponded to 15 wt% CaCO 3 , 15 wt% Na 2 CO 3 , and 70 wt% kaolin.

Microstructure and properties of porous anorthite/mullite whiskers ceramics with high porosity

“…The addition reinforced materials were usually adopted to improving strength. [9][10][11] Compared with mullite particles, mullite whiskers (mullite w ) showed better reinforcement effect and have been successfully used in many porous ceramics. [12][13][14][15] For example, porous Al 2 TiO 5 ceramics reinforced by in situ formation of mullite whiskers has been prepared by Xu et al 13 and the results showed that the interlocking structure formed in the pores of the prepared materials was beneficial to improve the strength.…”

“…But the relatively low strength and low melting point restrict its application. The addition reinforced materials were usually adopted to improving strength 9‐11 …”

Characterization and application of ceramic membranes prepared from Algerian kaolin

“…The analysis of the powder showed the main crystalline phases present in kaolin KT2 and confirmed that its structure was essentially formed by a mixture of two crystalline phases identified as kaolinite and quartz. These crystalline phases were expected in such a type of kaolin [34,35]. The quantity of other crystalline phases (estimated from the height of the peaks) was in trace amounts, as in the case of free muscovite, which has also been detected [35].…”

“…These crystalline phases were expected in such a type of kaolin [34,35]. The quantity of other crystalline phases (estimated from the height of the peaks) was in trace amounts, as in the case of free muscovite, which has also been detected [35]. The normative calculation of the mineral compositions of kaolin KT2 gave a percentage of 16% for muscovite, 56% for kaolinite and 23% for quartz.…”

Open‐cell porous sound‐absorbing ceramics prepared by a new procedure that combines foamed and templated methods

“…Anorthite and albite are important ceramic billet ingredients, which can promote ceramic sintering. 30 According to the information of PDF # 31-0966, orthoclase phase and impurity phases have also been observed in Figure 2. Carborundum (CP) and carbon powders (VR) were purchased from Sinopharm Chemical Reagent Co., Ltd.…”