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The manufacture of products from refractory ceramics requires high temperatures due to the high activation energies of the sintering process of refractory oxides. Processing temperatures for ceramics made of ZrO 2 , Al 2 O 3 , MgO can be reduced if a flux or glass-forming component is selected. Furthermore, in multicomponent ceramics it is possible to create more favorable thermoresistive properties. This study examines the synthesis, structural, phase and mechanical properties of multicomponent porous ZrO 2 -WO 3 -Al 2 O 3 -MgO ceramics with varying weight concentrations of components. Experimental samples were obtained by standard solid state reaction method. The analysis of fabricated samples was carried out using X-ray phase analysis, scanning electron microscopy and the Vickers microhardness test. In this work, a new approach to increasing the microhardness of porous refractory ceramics is presented, in which WO 3 -based flux forms a matrix composed of glass-like formations that "attach" particles of ZrO 2 and MgAl 2 O 4 phases. The obtained ceramics demonstrates high microhardness values HV0.05 for porous materials ranging from 500 to 600. Studies have shown that the selected composition of multicomponent ceramics (x = 0.10–0.25) can be used as a refractory material up to temperatures of ∼1300 °C. The fabricated refractory ceramics potentially possess chemical stability and optimal microhardness properties, which makes these materials promising as a heat insulating lining in the metals, ceramics and glass manufacturing, as well as for components in the chemical industry. [ABSTRACT FROM AUTHOR]

The (Al 1-x Cr x) 2 O 3 solid solution (ACS) is expected to be an low pollution chromium source for high-performance alumina-chromium oxide refractory materials. In this work, the effects of Cr 2 O 3 content and reaction conditions on the solid solution behavior in the Al 2 O 3 -Cr 2 O 3 system were explored and the mechanism was revealed. The relationship between the lattice parameters of the formed ACS phase and the content of Cr 2 O 3 was closer to a linear one as the temperature rose, serving as an indicator for a higher degree of reaction. The solid solution reaction between Al 2 O 3 and Cr 2 O 3 was governed by the diffusion processes of Al3+ and Cr3+ at 1300–1500 °C and 1200 °C, respectively, and thus the increase of Cr 2 O 3 content slowed the solid solution reaction at a low temperature whereas promoted it at elevated temperatures. The diffusion process of solid solution reaction within the Al 2 O 3 -Cr 2 O 3 system was consistent with the Cater model; The diffusion activation energy (E a) decreased as the content of Cr 2 O 3 increased at 1300–1500 °C. When the content of Cr 2 O 3 increased from 25 to 60 mol%, the diffusion activation energy decreased from 92.48 to 86.49 kJ/mol−1, which was attributed to the augmentation in the diffusion rate of Cr3+ caused by the increase of Cr 2 O 3 content and its vapor-phase transport mechanism at high temperatures. [ABSTRACT FROM AUTHOR]

MgO-SiC-C refractories demonstrate distinguished thermal shock resistance and slag resistance, making them a promising alternative to magnesia-chrome refractories in matte smelting furnaces. Herein, we propose a novel approach to enhance both oxidation resistance and slag penetration resistance of such refractories by incorporating Si 3 N 4 -Fe powder. The results demonstrated that adding Si 3 N 4 -Fe powder effectively enhanced their overall performance. The oxidation resistance of the specimen with 6 wt% Si 3 N 4 -Fe was greatly improved because Si 3 N 4 in Si 3 N 4 -Fe could promote in-situ reactions to form more forsterite, and the FeO formed by iron oxidation could react with SiC to form Fe-Si alloys; the formed forsterite and Fe-Si alloys worked together to prevent oxygen intrusion. Meanwhile, Si 3 N 4 in Si 3 N 4 -Fe promoted the formation of forsterite layer in the corrosion area of refractories, and the reaction of Si 3 N 4 and Fe in Si 3 N 4 -Fe formed Fe-Si alloys to prevent slag penetration, which greatly improved the resistance to matte slag penetration of the refractories. [ABSTRACT FROM AUTHOR]

This study investigated the degradation mechanisms of SiC-MgAl 2 O 4 refractory materials in a bench-scale entrained flow gasifier. Layered degradation and protective SiO 2 formation on SiC aggregates were observed by macroscopic, microscopic, phase analysis, and thermodynamic calculations. A comparative investigation of erosion rates revealed that SiC-MgAl 2 O 4 materials located away from the burner had an unusually low erosion rate of 0.0017 mm/h, which was significantly lower than that reported in their counterparts situated near the burner (0.0167 mm/h). This performance surpassed even that of high-chrome refractory materials positioned at a similar distance from the burner. The findings underscore the remarkable durability of SiC-MgAl 2 O 4 , demonstrating its significant potential as a sustainable and chrome-free alternative for application in harsh gasification conditions. The environment-specific degradation patterns, characterized by the formation of mullite and cordierite, revealed the complex interaction between refractory materials and gasification environments. This understanding offers valuable insights that can inform the development and implementation of chrome-free refractory materials under industrial gasification conditions. [ABSTRACT FROM AUTHOR]

Pyrometallurgical recycling of lithium-ion batteries (LIB) has emerged as the go-to approach in industrial recycling solutions, yet it encounters significant challenges, such as lithium (Li) slagging. This study explores a reactor for pyrometallurgical recycling, that offers the potential to overcome this bottleneck by simultaneously recovering lithium and phosphorous (P) via the gas stream, more noble elements including cobalt (Co), nickel (Ni) and copper (Cu) as an alloy and less noble elements like aluminum (Al), calcium (Ca) and silicium (Si) as a slag. However, to enhance the efficiency and performance of this reactor, a critical focus is placed on evaluating refractory materials with reduced corrosion and diffusion characteristics. Already explored refractory materials, including aluminum oxide (Al 2 O 3) or magnesium oxide (MgO), have exhibited severe issues, such as accelerated corrosion and diffusion rates, leading to diminished performance and compromised efficiency. To evaluate a more suitable refractory material for pyrometallurgical recycling of LIB, tests using silicon carbide (SiC), chromium(III)-oxide (Cr 2 O 3) and zirconium dioxide (ZrO 2) were performed up to 1600 °C. The test results indicate that the investigated refractory materials offer distinct advantages and disadvantages. While SiC shows minimal to no wear by corrosion, Cr 2 O 3 exhibits higher resistance to Li diffusion. Contrary, ZrO 2 experienced severe corrosion and crack formation, showing unsuitability for LIB recycling. Based on these findings, a continuously operated reactor could use different refractory materials in specific zones. While the degasification zone could benefit from Cr 2 O 3 's minimal diffusion properties, areas with intense contact between the crucible and melt could utilize SiC's corrosion resistance. However, partial oxidation at the outer surface of the SiC crucible led to the formation of SiO 2 , another critical point to consider for scale-up plans, as it might influence the mechanical integrity long-term. [ABSTRACT FROM AUTHOR]

Protein Ser/Thr phosphatase PP1 is always associated with one or two regulatory subunits or RIPPOs. One of the earliest evolved RIPPOs is PPP1R2, also known as Inhibitor-2. Since its discovery nearly 5 decades ago, PPP1R2 has been variously described as an inhibitor, activator or (metal) chaperone of PP1, but it is still unknown how PPP1R2 affects the function of PP1 in intact cells. Here, using specific research tools, we demonstrate that PPP1R2 stabilises a subgroup of PP1 holoenzymes, exemplified by PP1:RepoMan, thereby promoting the dephosphorylation of their substrates. Mechanistically, the recruitment of PPP1R2 disrupts an inhibitory, fuzzy interaction between the C-terminal tail and catalytic domain of PP1, and generates an additional C-terminal RepoMan-interaction site. The resulting holoenzyme is further stabilized by a direct PPP1R2:RepoMan interaction, which renders it refractory to competitive disruption by RIPPOs that do not interact with PPP1R2. Our data demonstrate that PPP1R2 modulates the function of PP1 by altering the balance between holoenzymes through stabilisation of specific subunit interactions. PPP1R2, also known as Inhibitor-2, is a regulator of PP1 with an elusive function. Here, the authors show that PPP1R2 functions as an additional subunit of a subset of PP1 holoenzymes, thereby promoting the dephosphorylation of their substrates through stabilization of subunit interactions. [ABSTRACT FROM AUTHOR]

The temperature and pressure conditions experienced by rocks during an impact event can be constrained using petrologic and microstructural analysis and is crucial to providing ground truth to the impact cratering process. Suevite is a polymict, impact melt‐bearing breccia, specific to Ries crater in Germany. There are competing models for suevite formation and emplacement, such as clastic flows pushed out of the crater rim or ejecta plume fallback. Knowledge of the temperature and pressure pathways recorded by grains within the suevite can help distinguish between these and other models. The accessory phase zircon (ZrSiO4) and its high‐pressure polymorph reidite are particularly useful in such circumstances as they are highly refractory minerals that can record the high‐temperature and/or high‐pressure conditions of an impact event. Here, we present evidence for a wide array of temperature and pressure conditions recorded in zircon grains within a single thin section of suevite. Zircons in this study range from unshocked to highly shocked (>53 GPa), and record temperatures more than 1673°C. These findings confirm previous studies concluding that suevites contain material exposed to very diverse pressure and temperature conditions during initial shock compression and excavation but do not, as a whole, experience extreme temperatures (>1673°C) or pressures (>30 GPa). [ABSTRACT FROM AUTHOR]

High-purity magnesia refractories were fabricated by brine magnesium hydroxide from the salt-lake brine (Qinghai Salt Lake) and Y 2 O 3 as an additive at 1780 °C. It avoided the substantial CO 2 emissions and ultra high temperature sintering process (＞1900 °C) when compared with the conventional magnesite-calcination technical approach. The results confirmed that Y 2 O 3 was dispersed on the MgO grains boundaries in the fabricated MgO aggregates, resulting in a decrease in apparent porosity and enhancing the grains' boundaries. With 3 wt% addition of Y 2 O 3 , the apparent porosity and bulk density of the sample reached to 15.9 % and 3.10 g/cm3 from 37.9 % to 2.30 g/cm3 of blank control group, respectively. Compared to the blank control without Y 2 O 3 -adding, the sample with 5 wt% Y 2 O 3 exhibited a 54.17 % increase in the resistance to molten slag. SEM results indicated that the incorporation of Y 2 O 3 in samples increased the porosity of small pores and enhanced grains boundaries, thereby suppressing slag's penetration. Furthermore, the Y 2 O 3 -adding was employed to disperse the MgO grains boundaries and existed as separate phases for grains boundaries enhancement. The slag attack of the fabricated MgO–Y 2 O 3 refractory raw materials were controlled by an inter-crystalline corrosion process. [ABSTRACT FROM AUTHOR]

Chromium–corundum, as a common refractory material, is broadly applied in high‐temperature kilns due to its superior thermal stability and high melting point. Unfortunately, this refractory is susceptible to corrosion and destruction under extreme furnace conditions by chemical erosion, mechanical wear, and thermal shock, which significantly shortens its useful life. Accordingly, in recent years, the issue of how to improve the slag corrosion resistance, mechanical, and sintering properties of chromium–corundum refractories has aroused widespread attention. In this work, the corrosion behavior and application status of chromium–corundum refractories in Ausmelt furnace, waste incinerator, coal water slurry gasifier, and HImelt melting reduction furnace are analyzed and discussed. To improve the service life of chromium–corundum refractories, the enhancement method and mechanism of sintering performance, mechanical properties, slag corrosion resistance, and thermal shock resistance are also summarized. Finally, some suggestions and prospects are made for the enhancement and longevity of chromium–corundum refractories. [ABSTRACT FROM AUTHOR]

The corrosion of slag on refractories usually starts from the matrix, so improving the slag resistance of the matrix is of great significance for the slag resistance of the refractories. To clarify the influence of matrix on the slag resistance of magnesia–carbon refractories, the slag corrosion experiments were conducted at 1873 K on MgO–C refractories, low‐carbon MgO–C refractories, and MgO–SiC–C refractories. The results showed that the slag resistance of MgO–C refractories was higher than that of low‐carbon MgO–C refractories, and the slag resistance of MgO–SiC–C refractories was superior to that of low‐carbon MgO–C refractories. The interaction between MgO–SiC–C refractories and slag generated high melting point phases such as forsterite and spinel, reducing the routes for the slag to infiltrate the inside of the refractories. MgO–SiC–C refractories reacted with slag to increase the viscosity of the slag, the viscosity being 86.3% and 51.9% higher than in the case of low‐carbon MgO–C and MgO–C refractories, respectively. Compared with MgO–SiC–C refractories, MgO–C refractories did not exhibit overwhelming advantages in slag resistance. Due to the low‐carbon content and good slag resistance, MgO–SiC–C refractories were promising low‐carbon magnesia‐based refractories for high‐temperature industries. [ABSTRACT FROM AUTHOR]

This study deals with the design and development of a new generation of MgO–C refractory material implementing spent MgO–C recyclate as a partial replacement of fresh raw materials, and a non-hazardous environment-friendly lactose- and tannin-based binder system. Throughout the experimental campaign the used MgO–C recyclate, which was received in three size fractions, was analysed, and building on the obtained results, multiple batches of various compositions of next-generation MgO–C bulks were prepared. These bulks varied in the ratio between the individual size fractions of the MgO–C recyclate, the ratio between the individual binder components and the amount of water used during the preparation of the raw material batches. The bulk samples were prepared in the form of cylinders through uniaxial pressing, cured and coked, and studied in terms of their cold crushing strength, microstructural parameters, thermal behaviour, residual carbon content, and microstructure. The proposed next generation of MgO–C composites represents a potential eco-friendly alternative to MgO–C refractories prepared from traditional raw materials while utilizing waste material which would otherwise end up landfilled. [ABSTRACT FROM AUTHOR]

Oxygen produced through in‐situ resource utilization (ISRU) is critical to maintaining a permanent human presence on the lunar surface. Molten regolith electrolysis and carbothermal reduction are two promising ISRU techniques for generating oxygen directly from lunar regolith, which is primarily a mixture of oxide minerals; however, both processes require operating temperatures of 1600°C to melt lunar regolith and dissociate the molten oxides. These conditions limit the use of many oxide refractory materials, such as Al2O3 and MgO, due to rapid degradation resulting from reactions between the refractory materials and molten lunar regolith. Yttria‐stabilized zirconia (YSZ) is shown here to be a promising refractory oxide to provide containment of molten regolith while demonstrating limited reactivity. This work focuses on corrosion studies of YSZ powders and dense YSZ crucibles in contact with molten lunar maria and highlands regolith simulants at 1600°C. The interactions between YSZ and molten regolith were characterized using scanning electron microscopy/energy dispersive spectroscopy, X‐ray diffraction, and electron backscatter diffraction. A FactSage thermochemical model was created for comparison with the experimental results. These combined analyses suggest that lunar maria regolith will degrade the YSZ faster than the lunar highlands regolith due to the lower viscosity of the maria regolith. The feasibility of long‐term molten regolith containment with YSZ is discussed based on the YSZ powder and crucible results. [ABSTRACT FROM AUTHOR]

Electrochemical devices based on proton conducting ceramic oxides have shown a high potential for conversion processes at intermediate temperatures. In these cells, perovskite ceramics like BaZr 0.7 Ce 0.2 Y 0.1 O 3-δ (BZCY), which are based on the solid solution of BaZrO 3 and BaCeO 3 doped with Y, have proven to be a good compromise between chemical stability and proton conductivity. However, the refractory nature of this material system requires high sintering temperatures to enable dense ceramic membrane layers. Recently, a novel processing route, which applies the cold sintering process (CSP) as a pre-densification step has been developed allowing to lower the sintering temperatures while maintaining excellent electrochemical properties. In this study, we further improved this method by implementing a BZCY/NiO support layer for BZCY. After final thermal treatment under reducing conditions, a dense BZCY membrane supported by a porous BZCY/Ni electrode support resulted. We show that using powder processing techniques, it is possible to sinter thick layered structures, consisting of an almost dense, phase pure perovskite BZCY layer and a porous BZCY/NiO layer. Furthermore , the NiO phase was successfully reduced to Ni by an additional thermal treatment at 900 °C in Ar/H 2. The focus of this study was to generally prove the feasibility of applying co-cold sintering for the processing of layered ceramic architectures, which can be used – after further optimization of the processing – as electrode supported fuel or electrolysis cells. [ABSTRACT FROM AUTHOR]

The viability of synergistic preparing refractory material from ferronickel slag (FNS) and ferrochromium slag (FCS) has been confirmed based on the phase and microstructural transformation behavior of FNS and FCS during the sintering process in this research. The thermodynamic analysis results have shown that increasing magnesia additions at varying FCS/(FCS+FNS) ratios can result in the development of high‐melting‐point phases. The thermogravimetric‐differential thermal analysis, thermal expansion tester, X‐ray diffraction, and scanning electron microscope and energy‐dispersive X‐ray spectrometer analysis indicated that both the FCS/(FCS+FNS) ratio and magnesia addition have a significant impact on the transformation behavior of FNS and FCS during the sintering process. Specifically, as the FCS/(FCS+FNS) ratio increased, the temperature for generating the liquid phase decreased. By controlling the FCS/(FCS+FNS) ratio of 0.3 and magnesia addition of 30 wt.%, the expansion ratio of the FCS/(FCS+FNS) system during the sintering process was noticeably lower compared to that of the FCS and FNS demonstrating excellent densification. [ABSTRACT FROM AUTHOR]

High-temperature furnaces and coal-fired boilers are widely employed in the petrochemical and metal-smelting sectors. Over time, the deterioration, corrosion, and wear of pipelines can lead to equipment malfunctions and safety incidents. Nevertheless, effective real-time monitoring of equipment conditions remains insufficient, primarily due to the interference caused by flames generated from fuel combustion. To address this issue, in this study, a through-flame infrared imager is developed based on the mid-wave infrared (MWIR) radiation characteristics of the flame. The imager incorporates a narrowband filter that operates within the wavelength range of 3.80 μm to 4.05 μm, which is integrated into conventional thermal imagers to perform flame filtering. This configuration enables the radiation from the background to pass through the flame and reach the detector, thereby allowing the infrared imager to visualize objects obscured by the flame and measure their temperatures directly. Our experimental findings indicate that the imager is capable of through-flame imaging; specifically, when the temperature of the target exceeds 50 °C, the imager can effectively penetrate the outer flame of an alcohol lamp and distinctly capture the target's outline. Importantly, as the temperature of the target increases, the clarity of the target's contour in the images improves. The MWIR through-flame imager presents considerable potential for the real-time monitoring and preventive maintenance of high-temperature furnaces and similar equipment, such as detecting the degradation of refractory materials and damage to pipelines. [ABSTRACT FROM AUTHOR]

Hydrogen metallurgy technology reduces the energy consumption and CO 2 emissions of the ironmaking systems. With the development and promotion of hydrogen metallurgy technology, the reducing gases have affected the refractory materials of metallurgical equipment, placing new demands on the refractories. Si 3 N 4 –SiC ceramic is a type of refractory material with a wide range of applications in blast furnace linings, aluminium reduction cell linings and ceramic kiln furniture, etc. In this study, Si 3 N 4 –SiC ceramic samples were used to conduct gas corrosion experiments for 6 h at different reducing atmospheres (H 2 , CO and 50 vol%H 2 -50 vol%CO) and temperatures (600, 800, 1000 and 1200 °C). The corrosion mechanism was mainly assessed via thermodynamic calculations and analyses of the change in mass, changes in the phase composition and micro-morphological evolution. The results indicated that the reducing gas penetrated the interior of the material and underwent a series of chemical reactions with the sample. Solid products accumulated on the surface of the sample and the gaseous products were released from the surface of the sample. The Si 3 N 4 –SiC ceramic was stable in pure H 2 atmosphere, and a solid product film was generated on the surface in pure CO atmosphere. However, under the mixed H 2 –CO atmosphere, the reduction of the solid product, SiO 2 , by H 2 formed gaseous products, which were released from the sample and degraded the solid film, increasing sample corrosion. This study aims to provide a basis for the selection of refractories for different hydrogen metallurgy technologies and to improve the lifetime and operational efficiency of high-temperature equipment for hydrogen metallurgy. [ABSTRACT FROM AUTHOR]

LiCoO2 has become the most widely used cathode material in lithium‐ion batteries because of its high capacity and excellent stability. The high‐temperature solid‐state method is commonly used for the preparation of LiCoO2. However, this method will produce highly penetrating Li2O, which causes spall or fracture of the insulating refractory materials in the kiln. In this study, the corrosion resistance of bubble alumina, mullite, and calcium hexaaluminate (CA6) insulating refractories to LiCoO2 has been thoroughly investigated. Combining the laboratory‐scale interfacial reaction experiments with post‐experimental life cycle analysis of industrial insulating refractories, the interaction between the insulating refractory materials and LiCoO2 after calcination at 900°C for 5 h and the corrosion behavior of LiCoO2 on different insulating refractory materials following heat treatment at 900°C for 5 h every time and repeated seven times are investigated. The corrosion mechanisms are concluded by analyzing the physicochemical composition and macro‐ and micromorphology of the three insulating refractory materials before and after corrosion. The results can provide a basis for the use of insulating refractories in the development of lithium batteries. [ABSTRACT FROM AUTHOR]

The study involved measurements of surface tension of liquid binary copper-titanium alloys with respect to their chemical composition and temperature as well as investigations of the liquid alloy–refractory material-gaseous phase system wettability using usual refractory materials, i.e., graphite, aluminum oxide and magnesium oxide. The experiments were performed with the use of the sessile drop method and a high-temperature microscope coupled with a camera and a computer. The aim of this study was to determine the influence of titanium content in the Cu-Ti alloy on the surface tension and contact angle at the interface between the liquid alloy and the refractory material. The influence of temperature on these parameters was also examined. The tests were carried out for copper-titanium alloys with a maximum content of 1.5% wt. Ti, in the temperature range of 1373 to 1573 K. The test results indicate that as the titanium content in the alloy increases, its surface tension increases slightly. However, an increase in temperature causes a decrease in the surface tension of the alloys. In the case of an alloy containing 1.5% wt. Ti, surface tension at a temperature of 1373 K reaches 1351 mN∙m−1, and at a temperature of 1573 K, it decreases to 1315 mN∙m−1. As the temperature and titanium content in the alloy increase, a decrease in the contact angle is observed. The highest values of contact angles were recorded in the case of contact of the liquid alloy with graphite. For an alloy containing 0.1% wt. Ti at a temperature of 1373 K, the contact angle reaches 132°, while at a temperature of 1573 K, it decreases to 128°. For an alloy containing 1.5% wt. Ti, the values of contact angles are 100° and 96°, respectively. However, the contact angles have the lowest values for magnesium oxide. In the case of a temperature of 1573 K and an alloy containing 1.5% wt. Ti, the contact angle reaches 49°. Such a significant impact of titanium content on the contact angles may be due to its high affinity for oxygen (contact with a substrate made of Al2O3 and MgO and its reactivity with carbon (contact with graphite). [ABSTRACT FROM AUTHOR]

The current study investigates the effect of adding a low-cost biomaterial (sawdust biomass) to kaolinite clay on the properties of insulating refractory materials. Natural kaolinite clay from NW Tunisia has been selected for porous ceramic preparation due to its high alumina content (23.64%) with low impurities, especially iron and alkaline oxides. For this study, a set of cylindrical samples were prepared from mixtures of Tabarka clay with different proportions of sawdust (10, 15 and 20%). Those green specimens were pressed and sintered to 1350 °C for 2h. Experimental data showed that the increase in sawdust proportion increased the open porosity from 24 to 35%. SEM images showed higher important porosity with higher biomass addition. Similarly, bulk density and compressive strength decreased to 1.65 g/cm³ and 17 MPa, respectively. Mullite phase was also generated by the abundant alumina and silica in the raw feed. Several ceramic specimens were also manufactured under optimal conditions: sawdust (20%), pressure (10 kN), and sintering at 1200, 1250 and 1300 °C. The obtained ceramics showed higher porosity (57%), but lower bulk density (1.13 g/cm³). These are the required standards for silica-alumina insulating materials, confirming the possible valorization of kaolinite clay from Tunisia for refractory insulating ceramic. [ABSTRACT FROM AUTHOR]

Utilizing spent refractory material (SRM), generated after the overhaul of aluminum electrolytic cells, as a raw material for producing Al-Si alloys presents an efficient approach towards achieving full resource utilization of SRM. However, a bottleneck restricting this technology has become the dissolution of SRM. Based on the heat and mass transfer mechanism, the shrinkage core model of SRM particle dissolution was established. The effects of alumina concentration, silica concentration, electrolyte superheat, particle temperature, and turbulent kinetic energy dissipation rate on the mass dissolution rate and dissolution time of SRM particles were investigated. Calculation results and experimental data were compared to confirm the accuracy of the established model. The results show that by maintaining low alumina and silica concentrations, increasing the electrolyte superheat and particle preheating temperature, and increasing the electrolyte turbulent kinetic energy dissipation rate, SRM particles can dissolve faster. The dissolution of agglomerated particles is greatly influenced by the turbulent kinetic energy dissipation rate and superheat. The present research provides promising guidance for practical application in predicting particle dissolution time, controlling process parameters, and accelerating the dissolution of SRM particles. [ABSTRACT FROM AUTHOR]

Semi‐rebonded periclase‐chromite refractories are commonly utilized in the working lining section of the molten pool in oxygen‐enriched top‐blowing furnaces for nickel production. Its resistance to nickel slag corrosion determines the safety and service life of the melting furnace. The composition of nickel slag influences the corrosion resistance of semi‐rebonded periclase‐chromite refractories. By comparing and analyzing specimens corroded by primary and modified nickel slag, the influence mechanism of w(CaO)/w(SiO2) variations on corrosion resistance of semi‐rebonded periclase‐chromite refractories was clarified. The results show that a spinel isolation layer is preferred to form at a lower w(CaO)/w(SiO2) ratio (< 0.576) and enhance the corrosion resistance of semi‐rebonded periclase‐chromite refractories. As the ratio increases, the slag viscosity falls and the corrosion products contain larger levels of Ca3Cr2Si3O12 and Ca3MgSi2O8, which prevent the creation of the isolation layer and establish a conduit for Ca2+ and Si4+ transport and reaction into the interior of the refractory. [ABSTRACT FROM AUTHOR]

The interaction between refractories and molten steel in tundish has significant influence on quality of steel. The calcined dolomite and fused magnesia were adopted as raw materials to prepare MgO–CaO based refractories for tundish. Then the reaction behavior between refractories with different contents of calcined dolomite and molten steel was investigated. After reaction with different refractories at 1550 °C for 90 min, the total O and P in steels reduced by 33.9 % and 77 % respectively when increasing calcined dolomite from 0 to 60 wt%, the average size and area proportion of inclusions decreased from 4.92 μm and 9.98 ‰ to 2.47 μm and 4.73 ‰ respectively. Inclusions of FeO wrapped by FeO–P 2 O 5 –MnS translated to FeO coated by FeO–MnS. The CaO introduced by calcined dolomite could reduce the increase of oxygen to molten steel owing to better thermodynamic stability compared with MgO. Meanwhile, CaO could absorb [P] to form Ca 3 (PO 4) 2 on the surface of calcined dolomite particles, which was beneficial for dephosphorization of molten steel. [ABSTRACT FROM AUTHOR]

This study investigated the local corrosion of alumina and magnesia refractory in CaO–Al 2 O 3 –SiO 2 –MgO slag due to the Marangoni effect, which is a key factor for localized wear in different industrial processes, using experimental, analytical, and numerical approaches. The objective is to explore the Marangoni effect using computational fluid dynamics simulation aiming to provide insights into the dominant slag flow patterns influencing refractory corrosion and to determine whether the observed corrosion groove can be attributed solely to the Marangoni effect. Static finger tests were conducted at temperatures of 1500 and 1550 °C employing a continuous wear testing device. A two-dimensional axisymmetrical section model of the test assembly was created, incorporating concentration-dependent surface tension gradients and surface tension forces to replicate the Marangoni flow. As the surface-tension simulation required time steps in the order of 10−5 s, modeling up to the experimental time scale cannot be realized. Consequently, the simulation outcomes were extrapolated to anticipate the groove radii of the experimental corrosion steps. Corrosion rates were derived from measurements and analytical methodologies. Established analytical equations for corrosion under surface-tension-flows were adapted to enhance the accuracy of corrosion rate estimation. However, the analytical considerations yielded poor estimates. Meanwhile, the employed simulation model successfully generated plausible predictions of the Marangoni flow. Drawing from the extrapolated simulation outcomes, the projected groove radii exhibited a close correspondence to the measured values, demonstrating a relative error of approximately 3 %, 11 %, and 15 % for the magnesia system at 1500 °C and alumina systems at 1500 and 1550 °C, respectively. Taking into account the uncertainties inherent in the methodological approach, the disparities in the alumina values suggest the involvement of mechanisms beyond the Marangoni effect in the localized wear. Consequently, this study effectively clarifies the impact of the Marangoni effect on the local wear of the examined material systems. [ABSTRACT FROM AUTHOR]

During the operation of the waste liquid incinerator, the alkali metal slag might adhere to the surface of the refractory material to form an inhomogeneous solid slag layer, causing the furnace lining to be simultaneously corroded by three phases of alkali metals: vapor, molten salt, and slag. This phenomenon intensifies the damage to the refractory material. Therefore, this paper investigates the mass transfer and permeation process, phase change process and corrosion rate of Na 2 CO 3 inside corundum refractory materials in three phases: Na vapor, molten Na 2 CO 3 and Na-slag. The results showed that alkali vapor penetrated the interior through the pores, and the NaAlO 2 and β-Al 2 O 3 generated by the reaction led to the volume expansion and microcracks. Na vapor continued to penetrate the interior along the cracks and eroded the sample, and the higher the temperature the greater Na vapor penetration. In vapor phase corrosion, the effect of corrosion time on the erosion resistance of corundum refractories is less than that of temperature, and the increase in corrosion time does not lead to the formation of additional new phases. In the molten salt corrosion experiments, it was found that the molten salt corrosion was accompanied by vapor phase corrosion at 1100 °C, and the amount of Na 2 CO 3 has a greater effect on the corroded mass than the temperature. Comparing the corrosion of refractory materials by the three phases of Na 2 CO 3 , the molten salt corrosion rate was the highest, followed by the vapor phase corrosion, and finally the slag corrosion. It is concluded that the slag layer can effectively prevent the corrosion of the refractory material by alkali metal molten salts and vapors, thus prolonging the service life of refractories. [ABSTRACT FROM AUTHOR]

The oxidation of six NbTi-i refractory medium- and high-entropy alloys (NbTi + Ta, NbTi + CrTa, NbTi + AlTa, NbTi + AlMo, NbTi + AlMoTa and NbTi + AlCrMo) were investigated at 1000 °C for 20 h. According to our observation, increased Cr content promoted the formation of protective CrNbO4 and Cr2O3 oxides in NbTi + CrTa and NbTi + AlCrMo, enhancing oxidation resistance. The addition of Al resulted in the formation of AlTi-rich oxide in NbTi + AlTa. Ta addition resulted in the formation of complex oxides (MoTiTa8O25 and TiTaO4) and decreased oxidation resistance. Meanwhile, Mo's low oxygen solubility could be beneficial for oxidation resistance while protective Cr2O3/CrNbO4 layers were formed. In NbTi + Ta, NbTi + AlTa and NbTi + CrTa, a considerable quantity of Ti-rich oxide was observed at the interdendritic region. In NbTi + AlCrMo, the enrichment of Cr and Ti at the interdendritic region could fasten the rate of oxidation. Compared to the recent research, NbTi + AlCrMo alloy is a light-weight oxidation-resistant alloy (weight gain of 1.29 mg/cm2 at 1000 °C for 20 h and low density (7.2 g/cm3)). [ABSTRACT FROM AUTHOR]

High-temperature adhesives find extensive application in diverse domains, encompassing repairs, production processes, and material joining. However, achieving their curing at ambient temperatures remains a formidable challenge due to the inherent requirement of elevated temperatures, typically exceeding 500 °C, for the curing reaction. To overcome this limitation, in this study, we developed a distinctive inorganic phosphate-based composite adhesive by incorporating dual-functional calcium monoaluminate (CA) into a traditional adhesive blend comprising Al(H2PO4)3 and MgO. This distinctive approach significantly diminishes the curing temperature, enabling it to occur at room temperature. Firstly, CA's facile hydration reaction effectively scavenges surrounding water molecules, thereby accelerating the dehydration curing process of Al(H2PO4)3. Secondly, as hydration is an exothermic process, it locally generates heat around the Al(H2PO4)3, fostering optimal conditions for its curing reaction. Moreover, the adhesive's strength is substantially bolstered through the strategic inclusion of Nano-Al2O3 (enhancing the availability of reaction sites) and Nano-SiO2 (improving overall stability). As a demonstration, the adhesive formulation with added CA containing 2% Nano-Al2O3 and 2% Nano-SiO2 achieved a remarkable tensile strength of 32.48 MPa at room temperature, underscoring its potential as an efficient solution for various practical adhesive applications. The adhesive prepared in this study harnesses the hydration properties of CA to absorb moisture and release substantial heat, introducing a novel method for ambient temperature curing. This development promises to broaden its applications in refractory materials, coatings, and equipment repair. [ABSTRACT FROM AUTHOR]

Carbon fibers (C f) were incorporated into Al 2 O 3 –C refractories to enhance their toughness in this work. The results indicated the 0.3 wt% C f -adding improved the high-temperature bending strength to 1.93 MPa from 1.07 MPa, and led to a 55 % enhancement in thermal shock resistance. The above enhancement could attributed to the in-situ formed SiC coating which was observed on the carbon fiber's surface and strengthened the interface bonding between the carbon fiber and refractory matrix. A solid-liquid diffusion reaction was employed to describe the formation process of in-situ SiC layer on the carbon fibers. Furthermore, the wedge-splitting test with digital images was carried out to investigate the crack-growth trajectory during the splitting process. It was confirmed that C f -adding could enhance the strength and reduce brittleness with the crack-bridging, pullout, and interlock behaviors of carbon fibers in the refractory matrix. [ABSTRACT FROM AUTHOR]

We investigated interactions between Ti6Al4V alloys and strontium zirconate (SrZrO3) ceramic to assess its potential as a refractory mold material in investment casting. We developed a robust yet simple procedure to examine both the liquid–solid and solid–solid interactions using pellets in drop casting and diffusion couple methods. Reaction layers were characterized using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD). The results were compared to alumina (Al2O3) which is still a common refractory ceramic for molds in investment casting. Our findings indicate that Ti6Al4V surfaces in contact with SrZrO3 had no apparent changes in surface chemistry nor microstructure. On the other hand, Ti6Al4V surfaces in contact with Al2O3 developed γ-TiAl and α2-Ti3Al intermetallics with thicknesses of ~ 100 μm in diffusion couples and ~ 10 μm in drop-casting experiments. Nanoindentation results showed that the surface of Ti6Al4V in contact with Al2O3 was significantly harder compared to SrZrO3, confirming our conclusion. Given the time and costs associated with mechanical and chemical removal of reaction layers on Ti6Al4V castings, SrZrO3 can be a better choice for a mold material in the investment casting of titanium alloys. [ABSTRACT FROM AUTHOR]

The reactions of rare earth elements (REEs) with refractory materials significantly affect their effective concentrations and inclusion modifications in molten steel. This study investigated the influence of steel-refractory reactions on the modification of inclusions in lanthanum-, cerium-, and yttrium-added steels utilizing three types of commonly used crucibles as smelting vessels. Steel-refractory reactions were found to strongly affect inclusions with different outcomes for smelting in MgO, Al 2 O 3 , and MgO·Al 2 O 3 crucibles. The RE-crucible reactions affected the evolution and size of inclusions in molten steel by influencing the content of [Mg] and [Al]. The RE-MgO crucible reactions increased [Mg] content, leading to more MgO inclusions and a smaller average size. The RE-Al 2 O 3 crucible reactions increased [Al] content, resulting in more REAlO 3 inclusions and a bigger average size. The reactions of La, Ce, and Y with MgO·Al 2 O 3 crucibles had varying effects on the evolution of inclusions. La and Ce selectively eroded the crucible, mostly reacting with the Al 2 O 3 component and generating REAlO 3 inclusions. In contrast, the slow reaction rate of Y with the crucible and the formation of the dense Y 2 O 3 layer at the steel/crucible interface made it react almost simultaneously with both MgO and Al 2 O 3 components, and the modification of inclusions was dominated by [Mg] rather than [Al]. The above conclusions provided more information on how the reactions between rare earth elements and refractory materials affected inclusions in rare earth steels during smelting. They also enriched the theory of inclusion control in steel and offered new controlling strategies. [ABSTRACT FROM AUTHOR]

Due to the limitation of the subsequent process for producing V 2 O 5 , the converter of vanadium extraction needs to use the slag with high MgO content to splash slag. This paper focus on the corrosion behavior of vanadium slag with high MgO content on MgO–C refractory. Corrosion experiment, SEM-EDS analysis, XRF analysis, and theoretical calculation are utilized to study the interface and mass transfer between slags and refractory. The results indicate that the average width of the reaction interface decreases from 9.3 μm to 3 μm with the increase of MgO content from 2 wt % to 8 wt %. When the corrosion time increases from 15 min to 60 min, the average width of the reaction interface decreases from 9 μm to 5 μm, and stabilizes at 5 μm as the corrosion continues. The mass transfer coefficient of MgO rises to 0.663 × 10−2 cm s−1 in the first 60 min of corrosion time, and then falls to 0.592 × 10−2 cm s−1 as the corrosion continues to 120 min. The mass transfer coefficient of MgO also shows an increasing trend with the increase of temperature and rotation speed. When the temperature increases from 1445 °C to 1490 °C, the mass transfer coefficient of MgO increases from 0.1313 × 10−2 cm‧s−1 to 1.4556 × 10−2 cm‧s−1. When the rotation speed increases from 10 rpm to 30 rpm, the mass transfer coefficient of MgO increases from 0.411 × 10−2 cm s−1 to 0.818 × 10−2 cm s−1. [ABSTRACT FROM AUTHOR]

MgO–ZrO 2 refractories were produced by combining MgO refractories (with a CaO/SiO 2 ratio of 2.1) with monoclinic ZrO 2 powder using wet-bag cold isostatic pressing. The phase composition and mechano-physical properties of the MgO–ZrO 2 materials were influenced by the interaction between ZrO 2 and MgO refractories. ZrO 2 enhanced the cold modulus of fracture of MgO refractories but decreased the hot modulus of fracture due to changes in bonding phases. The addition of 1 wt% ZrO 2 transformed Ca 2 SiO 4 into CaMgSiO 4 and CaZrO 3. CaMgSiO 4 with a low melting point deteriorated the hot modulus of fracture of MgO–ZrO 2 refractories from 13.3 to 2.97 MPa. With an increase in ZrO 2 to 3–5 wt.%, CaMgSiO 4 remained while CaZrO 3 gradually transformed into the solid-solution Ca 0.2 Zr 0.8 O 1.8. This transformation occurred because ZrO 2 seized CaO from CaZrO 3 to stabilize itself. Based on thermodynamic equilibrium ZrO 2 preferentially reacts with CaO-containing phases in the MgO matrix in the following order: Ca 3 SiO 5 > Ca 2 SiO 4 > CaZrO 3 > CaMgSiO 4. The thermal shock resistance of MgO–ZrO 2 refractories with less than 5 wt% ZrO 2 was not significantly improved by assessing their strength loss and coefficient of thermal expansion. In conclusion, it is recommended to incorporate ZrO 2 into MgO refractories with low SiO 2 or CaO to develop high-performance MgO–ZrO 2 refractories. [ABSTRACT FROM AUTHOR]

Abundances, apparent sizes, and individual chemical compositions of chondrules, refractory inclusions, other objects, and surrounding matrix have been determined for Semarkona (LL3.00) and Renazzo (CR2) using consistent methods and criteria on X‐ray element intensity maps. These represent the non‐carbonaceous (NC, Semarkona) and carbonaceous chondrite (CC, Renazzo) superclans of chondrite types. We compare object and matrix abundances with similar data for CM, CO, K, and CV chondrites. We assess, pixel‐by‐pixel, the major element abundance in each object and in the entire matrix. We determine the abundance of "metallic chondrules" in LL chondrites. Chondrules with high Mg/Si and low Fe/Si and matrix carrying opposing ratios complement each other to make whole rocks with near‐solar major element ratios in Renazzo. Similar Mg/Si and Fe/Si chondrule–matrix relationships are seen in Semarkona, which is within 11% of solar Mg/Si but significantly Fe‐depleted. These results provide a robust constraint in support of single‐reservoir models for chondrule formation and accretion, ruling out whole classes of astrophysical models and constraining processes of chondrite component formation and accretion into chondrite parent bodies. [ABSTRACT FROM AUTHOR]

The authors have described a method for synthesis of the crystalline phases of chromium boride CrB and CrB2 at atmospheric pressure without introducing additional modifiers improving the reactivity of the original charge. The formation of chromium borides was implemented under the action of an arc discharge with the original vacuum free dc electric-arc reactor. The influence of the parameters of the reactor on the phase composition of the obtained samples has been investigated. It has been established that the impact of an arch discharge of strength 200 A and duration 60 s on a mixture of Cr and B powders in a 1.0:2.55 atomic ratio ensures the formation of chromium diboride CrB2. The properties of the obtained powders have been studied by the methods of x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Background: Chronic urticaria (CU) is a persistent condition characterized by recurrent hives and itching, often resistant to standard treatments. Subcutaneous Histaglobulin, an immunomodulatory agent, has emerged as a potential therapeutic option for refractory CU. This study aims to evaluate the efficacy and safety of SC Histaglobulin in managing patients with refractory chronic urticaria. Methods: A clinical evaluation was conducted with 50 patients diagnosed with refractory CU. Participants received SC Histaglobulin (2 mL weekly) for 8 weeks. Outcomes were assessed using the Urticaria Activity Score (UAS7), Dermatology Life Quality Index (DLQI), and visual analog scale (VAS) for pruritus. Data were collected at baseline, during treatment, and at 4 weeks post-treatment. Statistical analyses included paired t-tests and Wilcoxon signed-rank tests. Results: The mean UAS7 score decreased significantly from 31.4 ± 6.2 at baseline to 12.1 ± 5.4 at the end of the treatment (p < 0.001), with 40% of patients achieving complete symptom resolution. DLQI scores improved from 15.8 ± 4.3 to 6.4 ± 3.1 (p < 0.001), and VAS scores for pruritus reduced from 7.6 ± 1.4 to 2.5 ± 1.1 (p < 0.001). SC Histaglobulin was well-tolerated, with mild adverse events reported. Conclusion: SC Histaglobulin is an effective and well-tolerated treatment for refractory chronic urticaria, significantly improving symptoms and quality of life. The study supports the use of SC Histaglobulin as a viable therapeutic option in this challenging patient population, although further research is needed to confirm these findings and explore long-term outcomes. [ABSTRACT FROM AUTHOR]

Developing and designing carbon-free refractory materials is an effective alternative to MgO–C refractory materials to produce large-scale, high-quality, low-carbon special steels. Therefore, in this work, excessive MgO is introduced into MgAlON to prepare a series of MgO–MgAlON composite refractories. The enhancement mechanism of comprehensive performance is systematically evaluated, where MgO as a reinforcer features intergranular phase strengthening and grain boundary purification effects. Besides, the pore structure of MgO–MgAlON composite refractories is also optimized to regulate the molten slag wetting behavior. The results demonstrated that MgO–MgAlON composite refractories have apparent porosity of 13.86%–15.84 %, bulk density of 2.78–2.97 mg cm−3, and compressive strength of 204.17–253.97 MPa. When 42.8 % MgO is introduced, the sample strength retention ratio after thermal shock measurement and slag corrosion experiments are 64 % and 75 %, respectively. Consequently, a cost-effective and feasible reinforcement strategy for MgO–MgAlON composite refractories is proposed, paving the way for. [ABSTRACT FROM AUTHOR]

Ceramic whiskers exhibit excellent performance due to their special structure, making them widely used in the field of refractories. In this work, a novel Al 4 SiC 4 whisker was designed to improve the mechanical properties and thermal shock resistance of Al 2 O 3 –SiC–C (ASC) refractories. By introducing nickel nitrate as a catalyst, the Al 4 SiC 4 whiskers with a special "stalactite" structure could be directly grown in situ at the operating temperature of ASC (1450 °C). Combining the experimental results and first-principles calculations, the AlNi 2 Si alloy formed during the heat treatment process acted as catalyst sites, AlO, SiO and CO were easily absorbed on the Ni 55 surface. Subsequently, the Al–O, Si–O and C–O bonds were broken and reacted with each other to grow Al 4 SiC 4 whiskers according to the vapor-liquid-solid mechanism. As expected, the incorporation of Al 4 SiC 4 whiskers resulted in a 57.4 % increase in cold compressive strength (CCS) and a 47.2 % increase in residual strength ratio (RSR) of the ASC refractories due to the strengthening mechanism of whisker bridging. This study presents a novel research strategy for enhancing the properties of refractories. [ABSTRACT FROM AUTHOR]

a new refractory microstructure with thermal stress buffering gap around aggregates was designed. PVA (Polyvinyl alcohol)-coated MgAl 2 O 4 (MA) aggregates were prepared by spray coating technology. The obtained PVA coated MA aggregates were adopted in MgAl 2 O 4 –C (MA-C) refractories to research its effect on properties of refractories. The results showed that a uniform PVA layer could be coated on the surface of MA aggregates by spraying coating technique. In the heat treatment process, the PVA around MA aggregates was decomposed and leaves gap between aggregates and matrix, which could offset the aggregates expansion. Due to the reducing thermal expansion coefficient, the thermal shock resistance of refractories was significantly improved. The COMR after thermal shock and the residual strength retention rate of the sample with stress buffering gap were 6.02 MPa and 77.87 %, while that of the sample without stress buffering gap were 5.26 MPa and of 60.32 %. [ABSTRACT FROM AUTHOR]

Refractory materials are used worldwide in process equipment. However, gaseous and liquid process products penetrate the surface layer and deep into the volume of refractories, destroying rather expensive constructions that are complicated to repair. To address this challenge, there is a need to develop protective coatings for refractory materials that can limit the penetration of working media and extend their operational lifespan. In this work, the application of gas-dynamic cold spraying (CGDS) to produce a coating on the refractory materials using fine titanium dioxide (TiO2) particles is explored. These particles are accelerated within a nitrogen flow, passing through a Laval nozzle, and then sprayed onto a fireclay surface. The mechanisms of particle deposition and layer formation on porous surfaces through experiments and numerical simulations were investigated. The geometry of a typical refractory pore was determined, which was then incorporated into computational fluid dynamics (CFD) simulations to model the cold spraying process of porous substrates. As a result, the influence of the particle size on its velocity and angle of penetration into pores was established. Experimental findings demonstrate the effective closure of pores and the formation of a particle layer on the refractory surface. Furthermore, the nanoindentation tests for the refractory samples showcase capabilities for checking coating thickness for porous materials. [ABSTRACT FROM AUTHOR]

Abstract Metasurface solar absorber serves as a kind of important component for green energy devices to convert solar electromagnetic waves into thermal energy. In this work, we design a new solar light absorber configuration that incorporates the titanium nitride substrate, aluminum oxide layer, titanium nitride layer, and the topmost refractory nanostructures. The metasurface absorber based on this configuration can achieve an average spectral absorption of over 91% and a total solar radiation absorption of 91.5% at ultra-wide wavelengths of 300–2500 nm. It is discovered that the excellent performance of the proposed metasurface absorber is attributed to the synergistic effects of surface plasmonic effect and Fabry–Pérot (FP) cavity resonance by comprehensive analysis of the simulated field distributions. Furthermore, the effect of geometrical parameter of the proposed configuration on absorber performance is studied, indicating the proposed configuration possesses a large fabrication tolerance. Moreover, the proposed configuration is not sensitive to the polarization direction and the angle of incident light. It is also found that the use of other refractory metal materials and other shapes as the topmost absorbent nanostructures also have good results with this configuration. This work can offer a universal platform for constructing and guiding the design of refractory metasurface solar absorbers.

MgO–C refractories are of paramount importance in the converter side blowing system, requiring outstanding oxidation resistance under harsh conditions including high temperature, oxygen atmosphere, and high‐speed airflow. In this study, MgSiN2 phase reconstruction was used to improve the oxidation resistance of MgO–C refractories, as well as the mechanical properties and oxidation resistance of MgO–C refractories were evaluated. The results indicated that the cold modulus of rupture of the sample with 9 wt% MgSiN2 was increased by 93.3% compared with the MgO–C refractories without MgSiN2. After oxidation tests, the oxidation index and rate constant (k) of the sample with 9 wt% MgSiN2 were reduced by 38.9% and 35.3%. Furthermore, incorporating MgSiN2 facilitated the formation of layered dense structures consisting of plate‐like Mg‐Sialon and MgO–Mg2SiO4–MgAl2O4. This structural optimization effectively inhibited oxygen diffusion and reaction within the material, resulting in gradual oxygen potential mitigation. [ABSTRACT FROM AUTHOR]

MgO–C refractories are of paramount importance in the converter side blowing system, requiring outstanding oxidation resistance under harsh conditions including high temperature, oxygen atmosphere, and high‐speed airflow. In this study, MgSiN2 phase reconstruction was used to improve the oxidation resistance of MgO–C refractories, as well as the mechanical properties and oxidation resistance of MgO–C refractories were evaluated. The results indicated that the cold modulus of rupture of the sample with 9 wt% MgSiN2 was increased by 93.3% compared with the MgO–C refractories without MgSiN2. After oxidation tests, the oxidation index and rate constant (k) of the sample with 9 wt% MgSiN2 were reduced by 38.9% and 35.3%. Furthermore, incorporating MgSiN2 facilitated the formation of layered dense structures consisting of plate‐like Mg‐Sialon and MgO–Mg2SiO4–MgAl2O4. This structural optimization effectively inhibited oxygen diffusion and reaction within the material, resulting in gradual oxygen potential mitigation. [ABSTRACT FROM AUTHOR]

Cost-effective decarbonization and structural strengthening of carbon-containing refractory materials are crucial for the development of low-carbon steel (LCS) and ultra-low-carbon steel (ULCS) technologies. In this study, a carbonaceous-ceramic reinforcement assembly structure composed of multilayer graphenes and silicon carbide whiskers/particles (MLGs-SiC w /SiC p) has been successfully designed and fabricated. By employing three-roll milling (TRM) for low-cost exfoliation of expanded graphite (EG) into MLGs in a phenolic resin (PF) medium, we optimized the exfoliation cycles to fine-tune the morphology of MLGs. Subsequently, the catalytical solid-state conversion of PF/MLGs reacting with Si into SiC w /SiC p at 1400 °C, under varying C/Si molar ratios and catalyst contents, not only retained the structural integrity of MLGs but also embedded them within a novel SiC w /SiC p composite matrix. Our research elucidates the catalytic conversion mechanism, underscoring the significant role of nickel catalysts in promoting efficient SiC conversion. This work offers a promising pathway for developing high-performance, economical, low-carbon refractories. [ABSTRACT FROM AUTHOR]

Alumina-silica based refractories have found vast applications in various industries due to their strong resistance to corrosion and price advantages. In this research work high temperature corrosion resistance of aluminosilicate refractories against silicate melt was investigated. Various refractory brick matrices based on bauxite, chamotte and andalusite were prepared. The microstructure and chemical characteristics before and after corrosion cup test, as well as physical and mechanical properties were evaluated. The results indicated that corrosion resistance is increased in the following order of chamotte < bauxite < andalusite. Chemical composition and porosity were considered as determinant factors influencing corrosion process and mechanical properties of the refractory bricks. Low porosity of the andalusite aggregates raised the corrosion resistance by making limitations for melt infiltration into refractory material. Low mullitization of andalusite reduced the density and mechanical strength in comparison with other aluminosilicates. [ABSTRACT FROM AUTHOR]

On the rising demand for eco‐friendly refractories, reducing the use of likely toxic magnesia‐chromium aggregates remains a challenge. Previous studies by some of the authors have proposed Cr‐free alternative compositions, although the morphology of the spinel precipitates has varied across the different suggested systems. The mechanisms involved in the formation of these distinct morphologies were unclear and, therefore, are the focus of this work. In all compositions, SEM/electron backscatter diffraction revealed cube–cube orientation relationships between matrix and precipitates, indicating that their formation is influenced by the lattice parameter misfit (δ), which was measured using synchrotron X‐ray diffraction. It could be concluded that coarser and spherical precipitates form to minimize their surface‐to‐volume ratio in compositions with high absolute δ‐values. Conversely, low‐misfit systems enable the spinel to form a 3D‐network. The potential use of this knowledge to tailor the microstructure of novel compositions was demonstrated by a small Nb2O5 addition into one of the proposed compositions. [ABSTRACT FROM AUTHOR]

Fiberboard (FB) is extensively utilized in heat‐insulating refractory materials owing to its lightweight nature and excellent resistance to high temperatures. Nevertheless, the inadequate mechanical properties and limited dimensional stability of FB hinder its further application. The vacuum filtration was utilized in this study to manufacture inorganically modified insulation FB, incorporating plus fiber/1260 fiber and silica sol as the primary constituents and sepiolite powder (HS) as the modifier. The experimental results show that the fabricated samples exhibited extremely high porosity (75.3%–90.2%) and low thermal conductivity (.063–.15 W m−1 K−1, 200–800°C). The fibers were arranged in a three‐dimensional structure, overlapping with each other, and the silica sol adhered to the fibers, forming a spatial mesh structure through cross‐linking. Importantly, the incorporation of HS was effective in controlling the agglomeration of the silica sol, leading to a more uniform distribution within the fibers. Additionally, the study found that the mechanical properties (high hardness (64–72 HA)) and high‐temperature durability of the FBs were enhanced due to the flocculant modification. This study highlights promising prospects for industrial applications and offers a cost‐effective admixture for modifying and preparing high‐performance FBs, which is expected to see broad adoption in thermal insulation and energy conservation applications. [ABSTRACT FROM AUTHOR]

Background: Refractory exit-site infections (ESIs) and tunnel infections (TIs) are challenging complications for patients undergoing peritoneal dialysis (PD). This study compared the outcomes of surgical intervention, notably the cuff-shaving (CS) procedure coupled with negative-pressure wound therapy (NPWT), and conservative management strategies for patients with refractory ESI and TI. Methods: We retrospectively reviewed patients who underwent PD at our center, focusing on the incidence and management of ESI and TI. We evaluated and compared treatment outcomes, including ESI scores, frequency of ESI and/or TI, identification of causative microorganisms, and duration of catheter survival or time until removal. Results: We identified 97 episodes of catheter-related ESI and/or TI across 71 patients with an incidence rate of 0.15 episodes per patient-year. Of the 23 patients with refractory ESI and/or TI, surgical intervention was performed in 8, while 15 chose conservative management. In the one-month follow-up, patients who underwent CS combined with NPWT showed no complications such as leakage, and their local symptoms resolved completely. The mean PD catheter survival time was significantly longer in the surgical group (29.38 ± 7.25 months) than in the conservative group (7.86 ± 2.13 months). Surgical intervention demonstrated a significantly higher therapeutic efficacy and extended catheter survival. Conclusions: The combination of CS and NPWT as a surgical approach is crucial for eradicating infectious foci and significantly improving the longevity of PD catheter function. This integrated surgical strategy offers a promising solution for the management of refractory ESI and TI in patients undergoing PD. [ABSTRACT FROM AUTHOR]

Refractory materials are an important pillar for the stable development of the high-temperature industry. A large amount of waste refractories needs to be further disposed of every year, so it is of great significance to carry out research on the recycling of used refractories. In this work, lightweight composite aggregate was prepared by using discarded Al2O3-ZrO2-C refractories as the main raw material, and the performance of the prepared lightweight aggregate was improved by adjusting the calcination temperature and introducing light calcined magnesia additives. The results showed that the cold compressive strength and thermal shock resistance of the lightweight aggregates were significantly improved with increasing calcination temperature. Moreover, the introduction of light calcined magnesia can effectively improve the apparent porosity, cold compressive strength, and thermal shock resistance of the prepared lightweight aggregates at the calcination temperature of 1400 °C. Consequently, this work provides a useful reference for the resource utilization of used refractories, while the prepared lightweight aggregates are expected to be applied in the field of high-temperature insulation. [ABSTRACT FROM AUTHOR]

Complex geometries of mullite lightweight refractory materials with high strength and low thermal conductivity were successfully achieved through additive manufacturing using the direct ink writing technique and fly ash beads coated with alumina sol. In the refractory preparation process, printing ability of the ink was enhanced by adding additives (dispersant and binder). The adjustment of printing parameters, such as pressure, nozzle size, and printing speed, resulted in an enhancement of the refractory structure's accuracy. Compared to the ink with uncoated fly ash beads, the inks with coated fly ash beads show better stability and shear thinning behavior. The compressive strength of the refractories improved significantly. Meanwhile, the thermal conductivity of the refractories kept in a low level. The use of fly ash beads coated with alumina sol in the preparation of porous refractory resulted in the formation of mullite wishers within the pore walls. This created micron-size pores between the whiskers, greatly enhancing the thermal insulation and strength of the porous refractories. The Ashby-Glicksman model was particularly advantageous in predicting the thermal conductivity of the insulation refractories, especially when dealing with a complex pore structure. Therefore, utilizing the direct ink writing technique to produce lightweight refractory materials shows promise in addressing the challenge of creating intricate lightweight refractory parts. [ABSTRACT FROM AUTHOR]

The rapid development of the power industry has resulted in a significant amount of electric porcelain solid waste. To address the challenges of small‐scale utilization and low added value associated with the current utilization of porcelain solid waste, a new high‐temperature resistant material was successfully developed using waste electric porcelain with varying particle sizes as the primary raw material. The dependence of composition, structure, and mechanical properties on fine particle size and sintering temperature was explored. The research has determined that the most effective particle size for the synthesis of refractory materials using waste electric porcelain is 120 mesh, and the optimal temperature is 1600°C. When the temperature exceeds 1500°C, the expansion generated by the decomposition of sillimanite will counteract the shrinkage of the liquid phase reaction, thereby maintaining the morphology of the sample. This process forms a unique interwoven mullite morphology through the decomposition of sillimanite, thereby enhancing the strength of the material. As a result, the optimal bending strength of 74 MPa and the optimal compression strength of 207 MPa were obtained. The realization of high‐temperature resistant materials based on discarded electric porcelain has shown foreseeable potential in large‐scale high‐value utilization. [ABSTRACT FROM AUTHOR]

Thymic carcinoma (TC) is an uncommon type of thymic epithelial tumors. Patients with relapsed or refractory TCs have a poor prognosis. Immune checkpoint inhibitor monotherapy can be applied as a second-line treatment for such cases. This study reported a TC patient who did not respond to conventional chemotherapy and radiotherapy but achieved prolonged partial remission lasting 17 months following the third-line treatment with antiprogrammed cell death-1 inhibitor sintilimab. This patient did not experience any serious side effects associated with sintilimab treatment. The above results demonstrated that sintilimab could be a feasible therapeutic option for refractory TC patients. [ABSTRACT FROM AUTHOR]