The development of cost-effective and high-performance heat-absorption and thermal-storage media from industrial solid waste represents a crucial pathway for the large-scale utilization of renewable energy. However, conventional iron-rich metallurgical slags often suffer from poor phase and structural stability at elevated temperatures. In this study, an efficient phase reconstruction strategy is proposed to fabricate magnesium-ferrite/forsterite multiphase ceramics with both broad-band photon-trapping capabilities and superior thermo-mechanical reliability through the introduction of an optimal amount of magnesium oxide (MgO). Microstructural evolution analysis reveals that the addition of appropriate MgO converts the low-melting-point silicate glass phase into a dense dual-crystalline framework, which simultaneously locks high concentrations of low-valence iron (Fe²⁺) and oxygen vacancies (Ov) within the spinel lattice. The enrichment of these micro-active defects significantly enhances intervalence charge transfer (IVCT) between Fe²⁺ and Fe3+ ions, leading to a substantial contraction of the optical bandgap to 1.77 eV. Consequently, the SM-30 ceramic, prepared at a baseline sintering temperature of 1250 °C, achieves a solar spectrum-weighted absorptivity of 92.71%, a specific heat capacity of 0.90 J/(g·K), and a high thermal conductivity of approximately 5 W/(m·K). Furthermore, this multiphase ceramic demonstrates exceptional anti-wear performance under high-temperature dry sliding friction conditions, which is primarily attributed to the subtle viscous flow of the residual glass phase at grain boundaries under service temperatures. This behavior not only effectively dissipates local thermal expansion mismatch stress at the interface but also facilitates the in-situ formation of a dense, continuous liquid-phase lubrication film on the friction surface. Ultimately, this work provides a promising, environmentally friendly approach and a robust theoretical foundation for the design of low-cost, integrated heat-absorption and thermal-storage materials for next-generation Concentrating Solar Power (CSP) systems.

In this work, the densification behavior of black AlN/B4C composites was examined with the aim of developing high-performance materials suitable for solar receiver applications. Hence, key processing parameters, including phase composition, sintering temperature, sintering time, and sintering additives were investigated. Black AlN/B4C ceramics with different B4C content (0-50 wt.

Cr-containing perovskite ceramics (ABO3) have been regarded as energy-saving infrared radiation (IR) material for thermal equipments. However, toxic Cr6+ formation generally occurred in material, leading to environmental and health risks. Herein, environment-friendly Ca2+/Co2+ co-doped LaAlO3 ceramics (La1-xCaxAl1-xCoxO3-delta, x = 0, 0.05, 0.10, 0.15 and 0.20) were designed via solid-phase reaction technology. The influence of Ca2+/Co2+ doping concentration on IR performance and energy-saving efficiency were systematically investigated. Part of original La and Al elements were respectively replaced by Ca and Co, generating lattice distortion, "Co2+-* Co3+-* Co4+" transformation and oxygen vacancy. The infrared emissivity (epsilon) was effectively improved by increasing Ca2+/Co2+ concentration, due to enhanced free carrier absorption, impurity level absorption and lattice vibration absorption. The La0.8Ca0.2Co0.2Al0.8O3-delta (CC20) exhibited the highest average emissivity (epsilon 0.76-2.5 mu m = 0.90, epsilon 2.5-14 mu m= 0.95). Additionally, the CC20 coating significantly increased the surface temperature (from 712.5 degrees C to 956.2 degrees C) of porous burner, with energy-saving efficiency of 13.8% during water heating. This IR ceramic with high emissivity has great energy-saving potential in high-temperature industry.

The increasing global demand for alternative energy sources and the environmental consequences of climate change necessitate research into renewable energy sources and energy conversion processes. Thermoelectric technology, which converts heat directly to electricity, can solve the energy issue and provide greener energy sources. The effects of yttria-stabilized zirconia (YSZ) on thermoelectric properties, such as electrical resistivity and Seebeck coefficients, of YSZ/ZnO composite have been investigated in this research. The study investigates the influence of sintering ZnO ceramics in an argon atmosphere at 1450 degrees C with various quantities of YSZ addition to the microstructure and thermoelectric properties. The solid-state reaction method was used to synthesize all ZnO ceramic samples without YSZ and with YSZ of 0.5, 2 and 3 wt%. The Seebeck coefficient of the sintered samples increased 44-92% with YSZ additions at 800 degrees C. At 800 degrees C, the nominal composition of 0.5 wt% YSZ had power factor 1505 mu W.m-1.K-2

In this investigation, we extensively studied the effect of various parameters on the processing, microstructure, sintering and thermoelectric characteristics of ZnO ceramics. Different Nb-doped ZnO-based ceramics, ranging from 0 to 0.25 wt %, were fabricated and sintered at the temperature of 1450 degree celsius for 2 h in an inert atmosphere of argon (Ar). Various characterizations were employed to discern the performance attributes of these ceramics, encompassing phase analysis, densification, and microstructure evaluations. Thermal conductivity properties were studied from room temperature up to the temperature of 800 degree celsius. Thermoelectric properties and efficiency of the sintered ceramics were evaluated across the temperature range of 100-800 degree celsius. Results indicated that the incorporation of Nb into ZnO ceramics resulted in a harmonious structure due to the attained homogeneous and complete solid solution diffusion reaction. It was found that the optimal values for thermal conductivity, electrical resistivity, and thermoelectric properties were achieved at 0.15 wt % Nb doping. ZnO doped ceramics exhibited typical behavior of n-type semiconductors, showcasing exceptional thermoelectric properties at elevated temperatures. Our findings indicate that native defects, such as oxygen vacancies (OV), contribute to decreased band gap energy values and increased carrier concentration, thereby enhancing electrical conductivity and power factor. Hence, this study underscores the viability and practicality of Nb-doping ZnO sintered in an argon atmosphere as an effective approach to enhance its thermoelectric performance.

Locally found Egyptian dolomite, commercial zirconia, and alumina were used to fabricate calcium zirconate-based refractory with improved thermal shock damage resistance. CaZrO3/MgO (CZM) and CaZrO3/MgAl2O4 (CZS) green compacts were obtained by mixing dolomite, commercial zirconia, and alumina with molar ratios of 1:1.23:0 and 1:1.23:0.59, respectively, and then ball milled for 1 h and uniaxially pressed at 150 MPa. The obtained green compacts were sintered at 1200, 1300, 1500, and 1650 °C for 2 h with a heating rate of 5 °C/min. The phase composition, microstructure, densification parameters, and thermal shock damage resistance of the prepared refractory were investigated. The results showed that CaZrO3 was present as the predominant phase and c-ZrO2 as a secondary phase due to the solubility of calcium and magnesium ions in the zirconia lattice structure. CZM1500 and CZS1500 showed a bulk density of 4.05 and 3.8 g/cm3 respectively. Thermal shock damage resistance of CZM samples was greatly improved with the in situ spinel synthesis where CZS1500 was able to withstand 16 cycles before fracturing compared to 10 cycles recorded for CZM1500.

Refractories are characterized by their ability to withstand high temperatures that reach 2800°C, their ability to withstand sudden changes in temperature, resist mechanical shocks, due to the formation of glass at a temperature of 1050-1100°C, it is required that the molds manufactured from refractories withstand that temperature. This is in addition to the ability of the refractory material to show the fine details and the prominent and recessed sculptural surfaces (smooth - rough) in the glass product, and to achieve the uniqueness and excellence of the glass product.This is due to the requirements of refractory mold in its manufacture and assortment with manual blowing in terms of its ability to withstand pressures, non-fragmentation, thermal endurance that reaches (1500 - 1750°C), and a low rate of expansion and contraction that reaches ± 0.05 mm, as well as its flat smoothness, which is considered as a mirror of a model formation.Since the glass material is acidic, it requires that the components of the refractory composition of the mold be acidic or neutral as well. To prevent the adhesion with the glass components thus, some refractories were selected that enter into the work of refractory formulations that can achieve chemical and natural properties suitable in the manufacture of glass forming molds by manual blowing. (16) Refractory compositions were made, and the research reached to find new refractories that meet the requirements. Thus, it is recommended to use refractories for producing the prototype of the glass products which are characterized by aesthetic products.

The highly active heterogeneous iron oxide@graphene oxide (alpha-Fe2O3/Fe3O4@GO) composite was produced using a simple assembly method to incorporate into the electroless Ni-P thin film to enhance its performance. It was thoroughly characterized using X-ray diffraction (XRD), Raman Spectroscopy, Fourier transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and N2 adsorption-desorption tests. The outcomes showed that the alpha-Fe2O3/Fe3O4 nanoparticles were uniformly and densely distributed on the GO sheets, with a tiny diameter of about 160 nm.Ni-P/alpha-Fe2O3/Fe3O4@GO composite coatings were created on low-carbon steel using an acidic electroless plating bath containing various alpha-Fe2O3/Fe3O4@GO nanosheets. The protective effect of co-deposited nanosheets on the corrosion behavior of the coatings was examined in a 3.5 % NaCl solution. Electrochemical techniques, including electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization investigations, were used to evaluate the layers' corrosion resistance. The outcomes demonstrate that adding alpha-Fe2O3/Fe3O4@GO significantly increases the coatings' ability to resist corrosion. Maximum corrosion resistance was achieved at a dosage of 50 mgl- 1 alpha-Fe2O3/Fe3O4@GO nanosheets in the plating bath. According to the SEM images the alpha-Fe2O3/Fe3O4@GO were implanted in the Ni-P matrix and were evenly disseminated over the coated surface. Moreover, the incorporation of alpha-Fe2O3/Fe3O4@GO enhances the mechanical properties of Ni-P thin film.Because of its improved performance, ease of synthesis, and low cost, this coating layer warrants more consideration as a good option for possible application to safeguard carbon steel utilized in the atmosphere.

In solar thermal technology, solar receiver materials with high solar absorptivity and photocatalytic efficiency have recently become a mandatory requirement for promoting and maximizing the released thermal and elec-trical energy. This paper presents a detailed study of the optical performance and thermal stress durability of the promising solar receiver material, black Al2O3/CuO ceramics. Different Al2O3/CuO ceramics with different CuO content (10-40 wt%) were obtained by the pressureless sintering method. Optical properties such as solar absorbance and reflectance, band gap energy and photoluminescence are inclusively investigated. The thermal stress resistance of the obtained ceramic receivers is simulated using the finite element modeling (FEM) method at different temperatures. Results indicated that adding and increasing the content of CuO to Al2O3 has a sig-nificant role in transforming alumina from a non-solar light-absorbed material to a solar absorber material with high absorptivity in the Ultraviolet-Visible-Near Infrared (UV-VIS-NIR) spectrum. Composite with 40 wt% CuO has recorded the maximum absorbance of 75% in the visible light region. Moreover, Al2O3/CuO ceramics gave multiple graded band-gaps in the range of (1.6-5 eV). Composites with high wt% of CuO have the most increased photocatalytic activity and light emissivity efficiency. Thermal stress analysis of the different ceramics showed outstanding stress durability with uniform heat distribution. Hence, black Al2O3/CuO ceramics can be considered ideal solar absorber materials with high sustainability and durability at high temperatures.

High-strength low-cement castables have been produced for the first time from waste of demolished glass furnaces. Adispersant of long-chain ionizable sodium tripolyphosphate (STPP, 0.2 wt.%) had a positive effect on electrostatic stabilization and improvement of the rheological characteristics of alumina-zirconia-silica (AZS) castable. Four castable mixes of various packing moduli (n = 0.22, 0.23, 0.24, and 0.25) have been formulated using the Andreasen equation. The castable of Andreasen packing modulus n = 0.25 demonstrated an outstanding compressive strength (1118.15 kg/cm(2)) and a moderate bulk density (2.65 g/cm(3)) when fired at 1375 degrees C. It showed the highest dimensional stability and a permanent linear change of less than 0.6% at 1300 degrees C. It displayed high thermal shock resistance (30 cycles) and high abrasion resistance (abrasion loss similar to 2.05% after 280 abrasion test cycles) when fired at 1300 degrees C. Therefore, this castable can be used in high wear-rate sections of cement kilns and is an excellent choice in case of kiln instability. The results indicated that the castable with n = 0.25 is highly recommended for lining the inlet of rotary cement kilns at 1000 - 1300 degrees C. The results open the door for the use of waste from demolished glass kilns to produce high-strength low-cement refractory castable for lining cement kiln inlets.

This research presents the possibility of producing durable foam glasses from glass cullet using SiC/AlN foaming agent. The foaming agent generated by the SiC and AlN couple results in a more homogeneous microstructure and thus the emergence of foam glasses with better properties compared to the nitride foaming agent used alone in our previous work. The fabricated foam had a crack-free, 3-D cellular structure with macropores whose geometries varied between elliptical-, pentagonal-, and hexagonal-shaped constructions. It also had a lightweight (≥ 0.18 g/cm 3 ), high cold crushing strength (≤ 4.5 MPa), low thermal conductivity (0.09–0.16 W/m K), and contained more than ~ 89 vol.% gas bubbles enclosed between 11 vol.% impervious glass walls. The properties accomplished by the foam prepared in this work conform with the requirements of international standard for commercial glass foams, demonstrating its strong capability to be utilized in potential applications in sustainable buildings and energy efficiency in industry.

Producing new technological materials with high performance from clean sources has become a global requirement. Alumina/aluminum titanate (Al 2 O 3 /Al 2 TiO 5 ) composites are high-temperature portentous materials used in various advanced applications. In this work, different Al 2 O 3 /Al 2 TiO 5 composites were obtained with high thermal and mechanical properties for high-temperature applications by a low-cost process. The targeted composites were produced from calcined alumina and, rutile ore extracted from the Egyptian black sands by pressureless sintering at a temperature of 1650 °C/2 h. Rutile was added to alumina with a different content (0–40 wt%) to promote its sinterability and thermo-mechanical response. Evaluation of the produced composites in terms of phase composition, densification, microstructural features, mechanical and thermal properties was investigated. The results indicated that the addition of small amounts of rutile (10 and 20 wt%) succeeded in forming a stable Al 2 O 3 /Al 2 TiO 5 composite structure. However, higher content of rutile led to the formation of Al 2 TiO 5 rich matrix composites. Moreover, highly dense composites with harmonic microstructure and enhanced mechanical strength were attained by increasing the rutile content. The composite with only 10 wt% rutile addition gave the highest density of 3.6 g/cm 3 and the highest cold crushing strength and modulus of rupture values of 488.73 MPa and 106.19 MPa, respectively. Notably, the addition of rutile has a substantial effect on promoting the thermal properties and thermal stability of the obtained composites up to a high temperature of 1400 °C. The present study shows that addition of rutile ore to alumina is one economical way of improving the densification and thermal expansion of Al 2 O 3 for high temperature applications. Using a clean source such as rutile ore that contains some thermal stabilizers as Fe 2 O 3 , Al 2 O 3 , SiO 2 , ZrO 2 , and MgO instead of pure TiO 2 has played a noticeable role in improving the reaction sintering and resulting in a highly qualified material. Thus, sintered Al 2 O 3 /Al 2 TiO 5 composites can be considered as a promising high-temperature material for advanced applications.

This research presents the possibility of producing durable foam glasses from soda-lime glass waste using SiC foaming agent via viscous flow sintering at 900 ℃.The use of SiC instead of the nitride foaming agent applied in a previous work results in a more homogeneous microstructure and thus the emergence of foamed glass with better mechanical properties.The fabricated foam had a crack-free, 3-D cellular structure with closed pores of various geometries.It also had a lightweight ( ~ 0.233 g/cm 3 ), high cold crushing strength (CCS) (3.37 MPa), low thermal conductivity (0.105 W/m-K), and contained more than ~ 92.7 vol.% gas bubbles enclosed between 7.3 vol.% impervious glass walls.The properties accomplished by the glass foam prepared in this work conform with the requirements of the international standard for commercial glass foams, demonstrating its strong capability to be utilized in potential applications in sustainable buildings and energy efficiency in the industry.

Hydroxyapatite (HA) crystals were synthesized from calcium acetate monohydrate and phosphoric acid using hydrothermal method. The various interactions of reactant concentrations (1 – 3 Molar), surfactant {aminotris (methylene phosphonic acid) [N(CH2PO3H2)3] (ATMP)} concentrations (0 - 100 ppm), and hydrothermal times (6 – 24 hours) were investigated and their effects on the mean diameter of the HA crystals were obtained using the Box-Behnken experimental statistical design. Results have shown that surfactant has no effect on the mean diameter of the crystals. On the other hand, the results revealed that time and reactant concentration are major parameters in changing the particle size of hydroxyapatite crystals. Without addition of the surfactant, well elongated crystals with high degree of crystallinity were synthesized. With addition of the surfactant, the agglomeration of HA particles as well as hardness of HA pressed discs are significantly increased. HA particles were ranged from 2.7 µm to 7.2 µm as crystal aggregates whereas the obtained crystallite sizes ranged from 17.3 nm to 30.3 nm.

This work proposes a new promised high temperature composite material based on black Al2O3/CuO ceramics with simple and low-cost production method. These ceramics will represent the solar receiver material responsible for absorbing the concentrated solar radiation in the solar tower technology. CuO is added to alumina with different content (10-40 wt%) in order to promote its sinterability, enhancing its properties and its performance toward solar energy absorption. A detailed study of the material processing is included. Evaluation of the produced composites in terms of phase composition, densification, and microstructural features is investigated. Moreover, thermal properties and mechanical durability are optimised to ensure the material's sustainability. Results indicated that addition of a small percentage of CuO to Al2O3 has drastically enhanced the different characteristics of alumina regarding its densification, microstructure, thermal and mechanical properties. Composite with 10 wt% CuO gave the highest thermal conductivity, the best thermal emissivity, the lowest thermal expansion, the most outstanding thermal shock resistance and mechanical durability. Hence, Al2O3/CuO composites can be strongly nominated as a promised high temperature solar receiver material.

For the tendency toward cleaner production and safe conversion of undesired toxic wastes to highly priced advanced products, this work introduces new ceramics/glass composites of Cr2O3/Fe2O3/lead silicate glass (LSG) from industrial LSG wastes. Both chromia Cr2O3 and hematite Fe2O3 ceramics are added equally to the LSG wastes with different percentages (10, 20, and 30 wt.%) via the pressureless sintering method. The competitiveness of this work is dependent on the conversion of undesired waste materials into advanced/smart optical materials with a low cost and an environmentally friendly method. Hence, the influence of both Cr2O3 and Fe2O3 additions on the behavior and the different characteristics of the lead silicate wastes are comprehensively investigated. Evaluation of the final ceramics/glass composites was achieved through their phase composition, microstructure, optical, and magnetic characteristics. The results verified that the insertion of both chromia and hematite together into the glass waste had a key role in improving its morphological properties and optical and magnetic behaviors. Composite with 30% of Cr2O3/Fe2O3 gave the highest optical absorbance of 90%, the lowest and best band gap energy of 1.68 ev, and the highest refractive index of 2.85. Also, it recorded the best magnetic behavior with the highest saturation magnetization of 139.700 × 10-2A m2 kg-1 and the best coercivity of 190.0 Oe. These findings confirmed the successful clean conversion of the hazardous lead silicate waste into advanced products with promising optoelectronic characteristics.

Ceramic engineers have investigated the rheology of the refractory concrete to keep the balance between the desired characteristics of castables and its flow demeanor. The rheology of refractory concrete determines their application manner and a considerable fraction of its properties are largely affected by its flowability. This article gives a brief introduction to refractory concretes. It discusses the variable determinants of castables’ rheology according to their significance and their relation to each other. The measurements of rheology were examined by conventional techniques and the mathematical models of viscosity and rheometry approaches are also used for clarification. Insights into the rheology of alumina–silica containing castables were speculated through exploring submicron and nano-sized particles. The rheology of refractory concrete can be adapted properly according to the application manner and the specified requirements.

Herein low-cement alumina-zirconia-silica matrices with outstanding high-temperature strength have been successfully produced for the first time from the demolished industrial trash obtained from glass melting furnaces. Different fine matrix mixes with Al2O3/SiO2 ratios of 1 to 3 were formed from the fine powders with particle sizes of less than 500 μm of ZAC, calcined alumina, refractory cement, and silica fume. The formed batches were cast with water, demolded, dried, and fired at different sintering temperatures. The experimental mixture of formula Al2O3/SiO2 = 3 presented the maximum load capacity ( 132 MPa), the highest density (2.76 g/cm3), and the lowest porosity (1.42 vol.

Oxide ceramics are considered as promising high temperature solar absorber materials. The major aim of this work is the development of a new solar absorber material with promising characteristics, high efficiency and low-cost processing. Hence, this work provides a comparative and inclusive study of densification behavior, microstructure features, thermal emissivity and thermal conductivity values of the two new high temperature solar absorbers of ZrO2/Fe2O3 and Al2O3/CuO ceramics. Ceramic composites of ZrO2/(10-30 wt%) Fe2O3 and Al2O3/(10-30 wt%) CuO were prepared by pressureless sintering method at a temperature of 1700 degrees C/2hrs. Identification of the solar to thermal efficiency of the composites was evaluated in terms of their measured thermal emissivity. Thermal efficiency and heat transfer homogeneity were investigated in terms of thermal conductivity and diffusivity measurement. The results showed that both composites exhibited comparable densification behavior, homogenous and harmonious microstructure. However, Al2O3/10 wt% CuO composite showed higher thermal and solar to thermal efficiencies than ZrO2/Fe2O3 composites. It gave the lowest and the best thermal emissivity of 0.561 and the highest thermal conductivity of 15.4 W/m. K. These values proved to be the best amongst all those of the most known solar absorber materials made from the expensive SiC and AlN ceramics. Thus, Al2O3/CuO composites have succeeded in obtaining outstanding properties at a much lower price than its other competitive materials. These results may strongly identify Al2O3/CuO composites as promising high-temperature solar absorber materials instead of ZrO2 and the other carbide and nitride ceramics.