This paper is a study of porous ceramics from a mixture of clay (kaolinite), silica (silicon dioxide), and feldspar by adding the carbon black (CB) with different contents. The results were presented in terms of apparent porosity, relative density, microstructure and porous characteristic, flexural strength and phase formation. As observed, the sintering at 1200 ℃ is the optimum temperature in this work. In comparison to the samples without CB content, the apparent porosity and relative density of ceramics are highly dependent on the CB contents. This might be attributed to the presence of porous structure as seen in SEM images on the fracture surface of ceramics. It also revealed that the addition of CB resulted in smaller pore sizes and a more uniform pore distribution. The creation of pores in porous ceramics was mainly attributed to the loss of shape of CB microspheres at high temperatures, as observed from SEM. The flexural strength of the sintered samples exhibited an average decrease from 60 to 55 MPa due to the presence of CB, which is typically known to reduce the mechanical properties with high porosity. In XRD results, the muscovite phase is represented by a few of peaks with significant intensities, while the rest peaks are of undetermined phase. The strongest peak at a 26° of 2θ angle, suggesting the presence of potassium and aluminium in the form of silicate minerals.

This study explored the impact of sintering temperature variations on the synthesis and characteristics of mullite ceramics derived from a composite blend of kaolinite clay, silica (silicon dioxide), and feldspar. Sintering temperatures ranging from 1100 to 1200 ℃ were systematically examined to analyze alterations in shrinkage, density, microstructure, elemental composition, and phase formation. The study revealed that an increase in sintering temperature led to decreased shrinkage due to improved particle packing and reduced porosity. Ceramic density showed a direct relation with sintering temperature, reaching the optimal density at 1175 ℃ and indicating efficient particle packing and compaction. Analysis through field emission scanning electron microscopy (FESEM) provided insights into microstructural changes, including alterations in grain morphology, porosity, and connectivity. Energy dispersive X-ray spectroscopy (EDS) clarified element distribution within the microstructure, offering valuable information on compositional variations. X-ray diffraction (XRD) examinations unveiled temperature-dependent phase transformations, which confirmed the successful formation of mullite during the sintering process. A sintering temperature of 1175 ℃ yielded the optimal ceramic quality and cost-effectiveness for high-temperature heating processes.

This review article provided a thorough examination of porous ceramic materials, concentrating on production, characteristics, and the involvement of pore-forming agents. The primary objective of this research was to evaluate the effects of various ceramic materials and pore-forming agents on the structure, porosity, and mechanical characteristics of porous ceramics. The study's scope included a thorough investigation of key sources of literature, such as academic publications, review articles, and industry reports, to provide a comprehensive understanding of porous ceramic technology. According to the literature review, the selection of ceramic material and pore-forming agents has a significant influence on the pore size distribution, porosity, and mechanical strength of porous ceramics. Various manufacturing methods, including foaming, sintering, and sol-gel procedures, were explored in terms of their influence on porous ceramic microstructure and characteristics. Furthermore, the study emphasized the need to optimize processing settings and select pore-forming agents to obtain the necessary qualities in porous ceramic materials. Overall, this review is useful for researchers, engineers, and practitioners who desire to learn more about porous ceramic manufacturing, characteristics, and applications.