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In recent years, regenerative thermal oxidizer (RTO) has been widely used in the petroleum industry, chemical industry, etc. The massive storage required by solid waste has become a serious problem. Due to their chemical composition, bauxite tailings as raw materials for high-temperature thermal storage ceramics show enormous potential in the fields of research and application. In this study, we propose a method for preparing ferric-rich and high specific storage capacity by adding Fe2O3 powder to bauxite tailings. Based on a 7:3 mass ratio of bauxite tailings to lepidolite, Fe2O3 powder with different mass fractions (7 wt%, 15 wt%, 20 wt%, 30 wt%, and 40 wt%) was added to the ceramic material to improve the physical properties and thermal storage capacity of thermal storage ceramics. The results showed that ferric-rich thermal storage ceramics with optimal performance were obtained by holding them at a sintering temperature of 1000 °C for 2 h. When the Fe2O3 content was 15 wt%, the bulk density of the thermal storage ceramic reached 2.53 g/cm3, the compressive strength was 120.81 MPa, and the specific heat capacity was 1.06 J/(g·K). This study has practical guidance significance in the preparation of high thermal storage ceramics at low temperatures and low costs. [ABSTRACT FROM AUTHOR]

A large amount of metallurgical solid waste accumulation poses a serious threat to the environment. Study on synergistic reinforcement of synthetic process of metallurgical solid waste‐based ceramics with fly ash is of great significance in reducing environmental pollution and resource utilization. A metallurgical solid waste‐based ceramic used as building ceramic was developed with the erosion part of used MgO–C bricks and fly ash as main raw materials, and the amount of solid waste added to the prepared ceramics was at least 60 wt% and up to 90 wt%. The effects of fly ash content and sintering temperature on the crystalline phase transitions, morphologies, and the main physical and mechanical properties of ceramics were investigated by X‐ray diffraction, scanning electron microscopy, and mechanical testing. The results show that the obtained ceramics presented maximum bending strength and minimum water absorption, 80.14 MPa and 5.04%, respectively, when the raw material proportions were the erosion part of used refractories accounted for 60 wt%, fly ash 20 wt%, pyrophyllite 10 wt%, and quartz sands 10 wt%, and the process parameters were the sintering temperature 1150°C, sintering time 120 min, and molding pressure 15 MPa. [ABSTRACT FROM AUTHOR]

Novel and stringent automotive exhaust gas emissions standards are urgently needed to counter the problems posed by the worsening global climate and environment. However, the traditional cordierite‐based honeycomb ceramics substrates with ultimate pore density have seriously restricted the establishment of new emission standards. Herein, we introduce a novel robust substrate with tailored volume‐specific surface area and low heat capacity. This substrate employs the synergy of high‐strength ceramic fibers and ultrathin TiO2 nanosheets. The micro‐sized fibers provide support to ensure structural strength during the catalytic reaction, while the nanosheets play the dual role of connecting the fibers and providing a high surface area for catalyst immobilization. The new three‐dimensional (3D) microarchitecture exhibits a high volume‐specific surface area of 3.59×104 cm2/cm3, a compressive strength of 2.01 MPa, and remarkable stability after high‐speed air erosion at 800 °C. The honeycomb‐like structure exhibit low resistance to gas flow. Furthermore, after loading with Pt and Pd nanoparticles, the composite 3D microarchitecture delivered an excellent catalytic performance and prominent structural stability, with a super low light‐off temperature of 150 °C. The outstanding mechanical and thermal stability and the high surface area and light‐off temperature of the new substrate indicate its potential for use as a highly efficient catalytic carrier to meet the next‐generation auto emissions standards. [ABSTRACT FROM AUTHOR]

In order to realize the large-scale and high-value utilization of waste architectural ceramics, high-temperature resistant materials based on waste architectural ceramics were prepared with sodium silicate as the binder, clay/bauxite and metakaolin/bauxite as coating materials, and the cold strength obtaining mechanism was explored. The phase composition, the microstructure and the mechanical properties of the high temperature resistant materials based on waste architectural ceramics were tested and analyzed. The results showed that when the heat treatment temperature was between 110-1 000, the strength of the samples mainly came from the physical adhesion of sodium silicate and fine powder. When the temperature rose to 1 100, the strength of the sample was improved since the internal low-melting-point components melted and promoted sintering. The addition of clay and bauxite can effectively enhance the flexural strength of the samples when the heat treatment temperature is 1 000. When the heat treatment temperature rises from 900 to 1 000, the flexural strength of the samples will be enhanced owing to the formation of silica alumina spinel and mullite from metakaolin. [ABSTRACT FROM AUTHOR]

To enhance the ionic conductivity of lithium garnets, a co-doping strategy was adopted with both strontium and zirconium for Li 6 + y La 3 − y Sr y NbZrO 1 2 (y = 0 , 0.25, 0.5, 0.75 and 1.0) (LLSNZO). By increasing the content of Sr, lithium garnet ceramics maintain cubic structure when y is in the range of 0–0.75. A secondary phase of SrZrO 3 appeared in the ceramic when y = 1. 0. We also studied the cross-section of lithium garnets with silver electrode. Results showed that the density of LLSNZO ceramics increased continuously against the increase of Sr content, while their total ionic conductivity enhanced initially and then reduced, with the maximum reached when y = 0. 5. It is indicated that ionic conductivity of lithium garnets is not only decided by the density but also decided by the concentration and the mobility of Li + . [ABSTRACT FROM AUTHOR]

In this paper, ZrO 2 -SiC-Al 2 O 3 ceramic was fabricated by as-prepared ZrO 2 -SiC powders and commercial α-Al 2 O 3 powders, sintered at 1450 °C for 1 h. ZrO 2 -SiC composite powders were synthesized through carbothermal reduction with zircon as raw material and carbon black as the reductant. Through ZrO 2 -SiC-Al 2 O 3 ceramic mechanical properties measurements it was indicated that this ceramic had excellent properties in both bending strength and hardness. In addition, ZrO 2 -SiC-Al 2 O 3 ceramic abrasive wear property was measured. ZrO 2 -SiC-Al 2 O 3 ceramic mass loss increased along with the increase in both wheel rate and applied load. The type of wear particles had an important effect on abrasive wear resistance. ZrO 2 -SiC-Al 2 O 3 ceramic displayed excellent abrasive wear resistance in bentonite and quartz slurries in comparison with SiC slurry. [ABSTRACT FROM AUTHOR]

TiO 2 is an ideal substitute to ZrSiO 4 ceramic opacifier, yet it is limited to application because of the undesirable yellowing resulting from rutile formation. Herein, the SiO 2 -CaCO 3 -TiO 2 composite opacifier (Si-Ca-Ti) was constructed. The glaze used Si-Ca-Ti presents a superior opacification performance than ZrSiO 4 opacified glaze without causing yellowing, showing L*, a*, b* values of 94.81, -0.67 and 3.23. By comparison, the glaze using SiO 2 , CaCO 3 , and TiO 2 mixture shows lower opacification and yellowish surface with L* and b* values of 92.99 and 5.36. It is revealed that there is a close interface bonding among SiO 2 , CaCO 3 and TiO 2 in Si-Ca-Ti, which promotes their combination reaction to generate opacification phase titanite and inhibit rutile formation when sintering, resulting in the white surface and opacification improvement of the glaze. This study proposes a green and efficient strategy to achieve white and highly opacified glaze for sanitary ceramics, exhibiting good application prospect. [ABSTRACT FROM AUTHOR]

The corrosion behavior of plasma-sprayed Ni/Al–Al2O3 and Ni/Al–Al2O3+13 wt.% TiO2 graded ceramic coatings in 5%HCl solution was investigated. It was shown that the corrosion resistance of a Ni/Al–Al2O3 graded coating was 130 times that of a single Al2O3 coating. The corrosion resistance of Ni/Al–Al2O3+13%TiO2 graded coatings was increased by 39.2% compared to a Ni/Al–Al2O3 graded coating with the same compositional gradient. The improvement in corrosion resistance of graded ceramic coatings mainly resulted from the change of corrosion behavior due to the change in structure of the coating. The bond layer alloy particles in the transition layers were distributed isolated in the ceramic matrix. Thus, the connected pores in the working layer were actually pseudo-connected pores. As a result, the electrochemical corrosion between the bond layer and the matrix was restrained. In addition, the pseudo-connected porosity in graded coatings lay on not only the open porosity but also the structure of the graded coating. [Copyright &y& Elsevier]