Mullite-Fibers-Reinforced Bagasse Cellulose Aerogels with Excellent Mechanical, Flame Retardant, and Thermal Insulation Properties.

Cellulose aerogels are considered as ideal thermal insulation materials owing to their excellent properties such as a low density, high porosity, and low thermal conductivity. However, they still suffer from poor mechanical properties and low flame retardancy. In this study, mullite-fibers-reinforced bagasse cellulose (Mubce) aerogels are designed using bagasse cellulose as the raw material, mullite fibers as the reinforcing agent, glutaraldehyde as the cross-linking agent, and chitosan as the additive. The resulted Mubce aerogels exhibit a low density of 0.085 g/cm3, a high porosity of 93.2%, a low thermal conductivity of 0.0276 W/(m∙K), superior mechanical performances, and an enhanced flame retardancy. The present work offers a novel and straightforward strategy for creating high-performance aerogels, aiming to broaden the application of cellulose aerogels in thermal insulation.

Mullite-like SmMn2O5-Derived Composite Oxide-Supported Ni-Based Catalysts for Hydrogen Production by Auto-Thermal Reforming of Acetic Acid.

The x%Ni/Sm2O3-MnO (x = 0, 10, 15, 20) catalysts derived from SmMn2O5 mullite were prepared by solution combustion and impregnation method; auto-thermal reforming (ATR) of acetic acid (HAc) for hydrogen production was used to explore the metal-support effect induced by Ni loadings on the catalytic reforming activity and product distribution. The 15%Ni/Sm2O3-MnO catalyst exhibited optimal catalytic performance, which can be due to the appropriate Ni loading inducing a strong metal-support interaction to form a stable Ni/Sm2O3-MnO active center, while side reactions, such as methanation and ketonization, were well suppressed. According to characterizations, Sm2O3-MnO mixed oxides derived from SmMn2O5 mullite were formed with oxygen vacancies; nevertheless, loading of Ni metal further promoted the formation of oxygen vacancies, thus enhancing adsorption and activation of oxygen-containing intermediate species and resulting in higher reactivity with HAc conversion near 100% and hydrogen yield at 2.62 mol-H2/mol-HAc.

Analysis of Factors Affecting the Preparation of Mullite Whiskers from Silica-Rich Slag and Application Studies.

This paper presents an in-depth comparative study of the effects of different molten salt systems, catalyst additions, preparation temperatures, temperature rise rates, and holding times on the properties of mullite whiskers during their preparation process, as well as exploring the enhancement of the toughening effect of mullite whiskers on ceramics. The morphology, crystal structure, and composition of the whiskers were analyzed via SEM, XRD, TG, strength tests, etc. The results show that the best-performing mullite whisker was prepared with an aluminum sulfate molten salt system, with the addition of aluminum fluoride catalyst at 4%, a temperature increase rate of 5 °C, a temperature increase up to 850 °C, and a holding time of 5 h, and its aspect ratio reached 20.64. By adding different contents of mullite whiskers and comparing the toughness strengths and wear rates of the silicon carbide ceramics, it was found that the toughness strength of the ceramics was improved by more than 16.5% and the wear rate was lower than 0.4% when the addition of mullite whisker was more than 3%.

Characterization of Silicate Glass/Mullite Composites Based on Coal Fly Ash Cenospheres as Effective Gas Separation Membranes.

Membrane technology is a promising method for gas separation. Due to its low energy consumption, environmental safety, and ease of operation, membrane separation has a distinct advantage over the cryogenic distillation conventionally used to capture light inert gases. For efficient gas recovery and purification, membrane materials should be highly selective, highly permeable, thermally stable, and low-cost. Currently, many studies are focused on the development of high-tech materials with specific properties using industrial waste. One of the promising waste products that can be recycled into membrane materials with improved microstructure is cenospheres-hollow aluminosilicate spherical particles that are formed in fly ash from coal combustion during power generation. For this purpose, based on narrow fractions of fly ash cenospheres containing single-ring and network structure globules, silicate glass/mullite composites were prepared, characterized, and tested for helium-neon mixture separation. The results indicate that the fragmented structure of the cenosphere shells with areas enriched in SiO2 without modifier oxides, formed due to the crystallization of defective phases of mullite, quartz, cristobalite, and anorthite, significantly facilitates the gas transport process. The permeability coefficients He and Ne exceed similar values for silicate glasses; the selectivity corresponds to a high level even at a high temperature: αHe/Ne-22 and 174 at 280 °C.

Fiber Sedimentation and Layer-By-Layer Assembly Strategy for Designing Biomimetic Quasi-Ordered Mullite Fiber Aerogels as Extreme Conditions Thermal Insulators.

Ceramic fiber aerogels are attractive thermal insulating materials. In a thermomechanical coupling environment, however, they often show limited mechanical strength and considerably increased heat transfer which can lead to thermal runaway. In this paper, inspired by bird's nest and nacre, we demonstrate a sample strategy combining fiber sedimentation and layer-by-layer assembly to fabricate ultrastrong mullite fiber aerogels (MFAs) with quasi-ordered structures. The fibrous layers and fiber bridges are constructed in a fiber sedimentation self-assembly process. The fiber sedimentation technique optimizes the structure of the MFAs by regulating the fiber orientation. Owing to the quasi-ordered structure, the fabricated MFAs exhibit the integrated properties of high compression fatigue resistance, temperature-invariant compression resilience from -196 to 1300 °C, and low thermal conductivity (0.034 W·m-1·K-1). By deliberately pressing multilayer MFAs into a thin paper, we substantially enhance the load-bearing capacity of the MFAs and achieve large temperature differences (563 °C) between the cold and hot surfaces by using a thin layer of MFAs (3-5 mm) under the simulated high-temperature (685 °C) and high-pressure (0.9 MPa) environment test. The combination of compression resistance, mechanical flexibility, and excellent thermal insulation provides an appealing material for efficient thermal insulation in extreme environments.

Study of the Mineralogical Composition of an Alumina-Silica Binder System Formed by the Sol-Gel Method.

Colloidal bonds are realized by sol-gel technology. The binder system of the refractory castable belongs to the Al2O3-SiO2 binary diagram. Mullite is the most thermally stable mineral in this system. This work was motivated by an attempt to maximize the mullite content in the NCC binder system, because a high content of mullite is a guarantee of the long service life of refractories. Initially, the mineralogical composition of the pure gel was tested after drying and firing at temperatures between 1000 °C and 1600 °C. The behavior of the gel during drying was described. Subsequently, a method of minimizing gel shrinkage during drying was sought. To this aim, fine fillers (microfillers) of alumina and silica were tested. In particular, the reactivity of the microfillers, the ability of the microfillers to react with the sol to form mullite, and the drying shrinkage of the microfiller-doped gel were evaluated. The study showed that the least suitable source of Al2O3 in terms of its reactivity is tabular corundum, which produces the lowest amount of mullite. The internal structure of the prepared binder system when using different microfillers was described. Based on the results from the second stage of the work, several complete matrixes of the binder system were designed and the degree of their mullitization at different firing temperatures was studied. During this stage, it was shown that the degree of mullitization of the binder system depends mainly on the microsilica content. In the binder system, the maximum mullite content recorded was 76%. The effect of amorphous SiO2 on the bulk density and internal structure of the binder system was also described.

Porous Mullite Ceramic Modification with Nano-WO3.

Mullite and mullite-alumina ceramics materials with dominance of the mullite phase are used in different areas of technology and materials science. Porous mullite ceramics materials can be used simultaneously as refractory heat insulators and also as materials for constructional elements. The purpose of this work was to investigate the WO3 nanoparticle influence on the evolution of the aluminum tungstate and zircon crystalline phases in mullite ceramics due to stabilization effects caused by different microsize ZrO2 and WO3. The use of nano-WO3 prevented the dissociation of zircon in the ceramic samples with magnesia-stabilized zirconia (MSZ), increased porosity by approximately 60 ± 1%, increased the intensity of the aluminum tungstate phase, decreased bulk density by approximately 1.32 ± 0.01 g/cm3, and increased thermal shock resistance by ensuring a loss of less than 5% of the elastic modulus after 10 cycles of thermal shock.

Catalytic Oxidation Activity of NO over Mullite-Supported Amorphous Manganese Oxide Catalyst.

Nitric oxide (NO) can pose a severe threat to human health and the environment. Many catalytic materials that contain noble metals can oxidize NO into NO2. Therefore, the development of a low-cost, earth-abundant, and high-performance catalytic material is essential for NO removal. In this study, mullite whiskers on a micro-scale spherical aggregate support were obtained from high-alumina coal fly ash using an acid-alkali combined extraction method. Microspherical aggregates and Mn(NO3)2 were used as the catalyst support and the precursor, respectively. A mullite-supported amorphous manganese oxide (MSAMO) catalyst was prepared by impregnation and calcination at low temperatures, in which amorphous MnOx is evenly dispersed on the surface and inside of aggregated microsphere support. The MSAMO catalyst, with a hierarchical porous structure, exhibits high catalytic performance for the oxidation of NO. The MSAMO catalyst, with a 5 wt% MnOx loading, presented satisfactory NO catalytic oxidation activity at 250 °C, with an NO conversion rate as high as 88%. Manganese exists in a mixed-valence state in amorphous MnOx, and Mn4+ provides the main active sites. The lattice oxygen and chemisorbed oxygen in amorphous MnOx participate in the catalytic oxidation of NO into NO2. This study provides insights into the effectiveness of catalytic NO removal in practical industrial coal-fired boiler flue gas. The development of high-performance MSAMO catalysts represents an important step towards the production of low-cost, earth-abundant, and easily synthesized catalytic oxidation materials.

Catalytic Ozonation of Polluter Benzene from -20 to >50 °C with High Conversion Efficiency and Selectivity on Mullite YMn2O5.

Catalytic decomposition of aromatic polluters at room temperature represents a green route for air purification but is currently challenged by the difficulty of generating reactive oxygen species (ROS) on catalysts. Herein, we develop a mullite catalyst YMn2O5 (YMO) with dual active sites of Mn3+ and Mn4+ and use ozone to produce a highly reactive O* upon YMO. Such a strong oxidant species on YMO shows complete removal of benzene from -20 to >50 °C with a high COx selectivity (>90%) through the generated reactive species O* on the catalyst surface (60 000 mL g-1 h-1). Although the accumulation of water and intermediates gradually lowers the reaction rate after 8 h at 25 °C, a simple treatment by ozone purging or drying in the ambient environment regenerates the catalyst. Importantly, when the temperature increases to 50 °C, the catalytic performance remains 100% conversion without any degradation for 30 h. Experiments and theoretical calculations show that such a superior performance stems from the unique coordination environment, which ensures high generation of ROS and adsorption of aromatics. Mullite's catalytic ozonation degradation of total volatile organic compounds (TVOC) is applied in a home-developed air cleaner, resulting in high efficiency of benzene removal. This work provides insights into the design of catalysts to decompose highly stable organic polluters.

Analysis of Influencing Factors in the Preparation of Mullite Whiskers from Recovering Silicon-Rich Waste under Low-Temperature Conditions.

A large amount of catalyst waste containing silicon is deposited or buried every year, resulting in serious environmental pollution and a waste of resources. In this paper, a method to prepare mullite whiskers by recycling silica-rich waste under low-temperature conditions was investigated. The effects of raw materials, sintering temperature, catalyst addition, holding time and co-solvent addition on the structure, morphology and phase transition of the synthesized whiskers were investigated and characterized with SEM, XRD, TEM, TG and DTA. The results show that the addition of 10% Na2SO4 as the liquid-phase mass transfer medium could effectively improve the crystallization efficiency of mullite whiskers, while providing an ideal living environment for the growth of whiskers. The crystallinity and uniformity of mullite were positively correlated with the addition of aluminum fluoride trihydrate and the holding time, respectively. The growth law and conditions of mullite whiskers are discussed, and the optimal growth process conditions of mullite whiskers were optimized. The optimal conditions for mullite whiskers were determined as follows: the addition of aluminum fluoride is 5 wt%, the sintering temperature is 825 °C, and the holding time is 5 h at the time of sintering. This work offers new prospects for the industrial production of mullite whiskers from recycled silica-rich waste.

Room temperature fabrication of cobalt mullite for the snappy adsorption of cationic and anionic dyes.

Cobalt mullite adsorbent for the robust adsorption performance toward Victoria Blue (VB) and Metanil Yellow (MY) is fabricated by the sol-gel method at room temperature using dipropylamine as a structure-directing agent. The synthesized adsorbent is characterized by XRD, FT-IR, and HRTEM. From these analyses, it is found that dipropylamine binds with the alumina and cobalt oxide, which makes it into tetrahedral to octahedral form. This interaction causes the formation of cobalt mullite. It is observed that trigonal alumina and orthorhombic cobalt mullite are interlinked to form a hybrid network. The special feature of adopting this adsorbent for the adsorption of VB and MY is that it has a large amount of Brønsted acid site because of the octahedral coordination of Al and Co. The large availability of acid sites in the framework and hybridization of two different network systems favors robust adsorption. The rate of adsorption (K2 = 0.00402 g/mg.min for VB and K2 = 0.004 g/mg.min for MY) and adsorption capacity (Qe = 102.041 mg/g for VB and Qe = 19.0406 mg/g for MY) are greater for VB than MY. This may be due to the more steric factor involved in MY than VB. Thermodynamic parameter indicated that the adsorption of VB and MY is spontaneous, endothermic, and increased randomness in the adsorbent-adsorbate interface. The results from the enthalpy value (ΔH° = 65.43 kJ/mol for VB and ΔH° = 44.729 kJ/mol for MY) revealed that the chemisorption is involved in the adsorption process.

Cuttlefish-Bone-Structure-like Lamellar Porous Fiber-Based Ceramics with Enhanced Mechanical Performances.

Porous fiber-based ceramics have been widely applied in various fields because of their excellent thermal insulation property and high thermal stability property. However, designing porous fibrous ceramics with enhanced comprehensive performances, such as low density, low thermal conductivity, and high mechanical properties at both room temperature and high temperature, is still a challenge and the future development trend. Hence, based on the lightweight cuttlefish bone that possesses a "wall-septa" structure with excellent mechanical performance, we design and fabricate a novel porous fibrous ceramic with the unique fiber-based dual structure of lamellas by the directional freeze-casting method and systematically investigate the effects of lamellar components on the microstructure and mechanical performances of the product. For the desired cuttlefish-bone-structure-like lamellar porous fiber-based ceramics (CLPFCs), the porous framework formed by the overlapping of transversely arranged fibers helps to reduce the density and thermal conductivity of the product, and the longitudinally arranged lamellar structure replaces traditional binders and plays an important role in improving the mechanical properties in the direction parallel to the X-Z plane. Compared with traditional porous fibrous materials reported in the literature, the CLPFCs with an Al2O3/SiO2 molar ratio of 1:2 in the lamellar component exhibits prominent comprehensive performances, such as low density, excellent thermal insulation property, and outstanding mechanical performances at both room temperature and high temperature (3.46 MPa at 1300 °C), indicating that the CLPFCs are a promising candidate for applications in high-temperature thermal insulation systems.

Preparation of Anorthite/Mullite In Situ and Phase Transformation in Porcelain.

A high sintering temperature is required to acquire excellent performance in the production of porcelain but results in high fuel consumption. To prepare the porcelain with outstanding performance at a lower temperature, a self-produced additive containing calcium (CaK) was added into a three-component system of kaolinite-feldspar-quartz. XRD and SEM were used to characterize the samples. The toughening mechanism and Gibbs free energy were investigated. After introducing the CaK, the bending strength of the porcelain fired at 1513 K increased from 56.32 ± 0.65 MPa to 95.31 ± 0.63 MPa, which was 21.83% higher than that of the porcelain without CaK at an optimal firing temperature of 1603 K. The main crystal phase of the sample comprised mullite and quartz in the raw materials at 1453~1603 K. The anorthite was observed at 1453 K and interlocked with needle-shaped mullite at 1513 K in the porcelain after adding CaK, which resulted in the higher bending strength. Quantitative analysis indicated that the amount of anorthite decreased at 1513 K and disappeared at 1543 K; the amount of mullite increased with temperature. The Gibbs free energy of the reaction (CaO•Al2O3•2SiO2 + 2(Al2O3•2SiO2) → 3Al2O3•2SiO2 + CaO + 4SiO2) at high temperature was negative, which suggested that the formation of mullite (3Al2O3•2SiO2) from anorthite (CaO•Al2O3•2SiO2) was possible. These findings implied that the addition of CaK contributed to the appropriate phase composition and microstructure, and the excellent performance of the porcelain at a lower temperature. In addition, the transformation between anorthite and mullite was possible in the special raw material system. The results are of interest in producing anorthite/mullite ceramics at reduced sintering temperatures and the conversion between anorthite and mullite.

Microstructure and Crystallization Kinetics of Silica-Based Ceramic Cores with Enhanced High-Temperature Property.

Silica-based ceramic cores play key roles in the casting of aeroengine blades, but they are highly limited by the poor high-temperature mechanical property. Here, fused mullite (FM) and sintered mullite (SM) powders were modified in silica-based ceramic cores, and the microstructure evolution and crystallization kinetics of ceramic cores depending on mullite types were studied. The ceramic cores with FM showed a dense microstructure and superior mechanical properties compared to those with SM. The ceramic cores with 10 wt.% of FM showed a crystallization activation energy of 1119.5 kJ/mol and a crystallization exponent of 1.74, and the values of 938.4 kJ/mol and 1.86 as SM were employed; the decreased crystallization activation energy and the elevated crystallization exponent by SM suggested that the excess impurities of alkali oxides and alkaline-earth oxides significantly promoted the crystallization of cristobalite. Even though the ceramic cores with mullite powders decreased slightly in the room-temperature mechanical property, their high-temperature flexure strength and creep deformation resistance were enhanced. The ceramic cores with 10 wt.% of FM showed excellent comprehensive performance, with linear shrinkage of 0.69%, room-temperature strength of 18.9 MPa, and high-temperature strength of 15.5 MPa, which satisfied the demands for hollow-blade casting.

Alpha Al2O3 Nanosheet-Based Biphasic Aerogels with High-Temperature Resistance up to 1600 °C.

Alumina aerogels are desirable for lightweight and highly efficient thermal insulation. However, they are typically constrained by brittleness and structural collapse at high temperatures. The manufacture of alumina aerogels with ultralow thermal conductivity and excellent thermal stability at high temperatures beyond 1300 °C is still challenging. Herein, alumina aerogels with superior ultrahigh-temperature-resistant and thermal insulation were successfully prepared by assembling the α-Al2O3 nanosheets with silica sols as the high-temperature binders. Benefiting from the generation of the mullite-covered alumina biphasic structure, the α-Al2O3 nanosheet-based aerogels (ANSAs) exhibit excellent thermal and chemical stabilities even after calcination at as high as 1600 °C. The ANSAs had a low thermal conductivity (0.029 W·m-1·K-1 at room temperature), structural stability with a measured compressive strength of 0.6 MPa, and good thermal shock resistance. Furthermore, the 2D α-alumina@mullite core-shell sheets were also prepared as assembly units to construct aerogels (AMSAs). This core-shell structure can improve temperature resistance through inter-lattice suppression under continuous energy input at high temperatures. The AMSAs have a linear shrinkage of only 2.7% after calcination at 1600 °C for 30 min, further improving the temperature resistance, making them an ideal super-insulating material for applications at extremely high temperatures.

Effect of temperature and glass content on crystalline phases in porcelain sintered with recovered automotive glass.

In the pursuit of sustainable porcelain production, this research examines the potential of using recovered automotive glass as a substitute for traditional feldspar, specifically feldspar imported from Spain. Porcelain samples were sintered at different temperatures and with varied proportions of automotive glass. The crystalline phases formed post-sintering were determined through X-ray diffraction and quantified by dissolving the porcelain in concentrated hydrofluoric acid. Results revealed that the inclusion of automotive glass, owing to its dissolved oxide content, accelerated the porcelain melting process and led to an increase in the vitreous phase. Notably, anorthite phases became dominant and mullite formation was evident at 1100 °C, stabilizing in samples G00 and G10, and then increasing at 1200 °C due to the emergence of secondary mullite. This secondary mullite forms from the residual silica after the primary mullite formation and the aluminium in the feldspars, which is about 17 %. For samples G20 and G30, only primary mullite was observed due to the decreased aluminium content resultant from feldspar replacement by glass. These findings underscore the viability of automotive glass in porcelain production, providing a sustainable and effective alternative to feldspar.

Formaldehyde Decomposition from -20 °C to Room Temperature on a Mn-Mullite YMn2O5 Catalyst.

Large ambient temperature changes (-20->25 °C) bring great challenges to the purification of the indoor pollutant formaldehyde. Within such a large ambient temperature range, we herein report a manganese-based strategy, that is, a mullite catalyst (YMn2O5) + ozone, to efficiently remove the formaldehyde pollution. At -20 °C, the formaldehyde removal efficiency reaches 62% under the condition of 60,000 mL gcat-1 h-1. As the reaction temperature is increased to -5 °C, formaldehyde and ozone are completely converted into CO2, H2O, and O2, respectively. Such a remarkable performance was ascribed to the highly reactive oxygen species generated by ozone on the YMn2O5 surface based on the low temperature-programed desorption measurements. The in situ infrared spectra showed the intermediate product carboxyl group (-COOH) to be the key species. Based on the superior performance, we built a consumable-free air purifier equipped with mullite-coated ceramics. In the simulated indoor condition (25 °C and 30% relative humidity), the equipment can effectively decompose formaldehyde (150 m3 h-1) without producing secondary pollutants, rivaling a commercial removal efficiency. This work provides an air purification route based on the mullite catalyst + ozone to remove formaldehyde in an ambient temperature range (-20->25 °C).

Thermal Properties of Porous Mullite Ceramics Modified with Microsized ZrO2 and WO3.

Mullite ceramics are well known as materials with a high temperature stability, strength and creep resistance. In this research, the effect of a modification with magnesia-stabilized zirconia and yttria-stabilized zirconia, separately, as well as in a mixture with WO3, in 1:1 and 1:2 ratios on the thermal properties of porous mullite ceramics was investigated. The porous mullite-containing ceramics were prepared by a slip casting of the concentrated slurry of raw materials with the addition of a suspension of Al paste for the pore formation due to the H2 evolution as a result of the reaction of Al with water. The formed samples were sintered at 1600 °C and the holding time was 1 h. The materials were characterized using X-ray diffractometry, scanning electron microscopy, mercury porosimetry, the laser flash contactless method, thermal shock resistance testing and the non-destructive impulse excitation method for determining the elasticity modulus. The modification of the porous mullite ceramic with a mixture of ZrO2 and WO3 oxides had a positive effect by decreasing the thermal conductivity, due to the increased porosity, in comparison to the undoped samples and samples with only ZrO2. The doubling of the WO3 amount in the modifying oxide mixtures improved the ceramic thermal shock resistance. The porous mullite ceramics which were modified with magnesia-stabilized zirconia (2.8 mol% MgO) and WO3 had a lower thermal conductivity and improved thermal shock resistance than the samples with yttria-stabilized zirconia (8 mol% Y2O3) and WO3.

Effect of Silicon Source (Fly Ash, Silica Dust, Gangue) on the Preparation of Porous Mullite Ceramics from Aluminum Dross.

Aluminum dross (AD) is a waste product produced during aluminum processing and can be used to prepare mullite ceramic materials. However, the research on the preparation of mullite porous ceramics entirely from solid waste is still in the development stage. In this paper, porous mullite ceramics were successfully fabricated using a solid-phase sintering process with AD and different silicon sources (fly ash, silica dust, and gangue) as raw materials. The bulk density, apparent porosity, and compressive strength of the specimens were obtained, and the phase compositions and microstructures of the sintered specimens were measured using XRD and SEM, respectively. The average activation energy of the phase transition of fly ash, silica dust, and gangue as silicon sources were 984 kJ/mol, 1113 kJ/mol, and 741 kJ/mol, respectively. The microstructures of the mullite in the specimens were prisms, random aggregates, and needle-shaped, respectively. The formation of needle-shaped mullite combined with the substrate enhanced the mechanical strength of the porous mullite ceramics. The apparent porosity, density, and compressive strength of the specimens with gangue as the silicon source were 33.13%, 1.98 g/cm3, and 147.84 MPa, respectively, when sintered at 1300 °C for 2 h.

Corrosion-Resistant Plug Materials for Geothermal Well Fluid Control.

Conventional cements and plugs are challenged by corrosion in CO2-rich and extreme geothermal environments, due to the hostile chemistry and high temperatures. Thermite-based sealing and well intervention technologies are being applied in the oil and gas industry, combining the energy delivery capability of thermite materials with the sealing characteristics of low melt temperature alloys. The thermite reaction products (ceramics) and the sealing alloys used in these plugs both have very attractive corrosion properties, and their operating envelopes extend into geothermal conditions. Thermite plugs and platforms, without supplemental sealing materials, have been considered for nuclear waste isolation, carbon sequestration, and geothermal applications due to the geochemical stability of the ceramic product and its very high service temperature. This study addresses corrosion resistance of the thermite reaction products. A range of engineered thermite systems which yield thermite reaction products including pure aluminum oxide, feldspar, or aluminosilicate solid solutions (in addition to the iron produced in thermite reactions) was developed. These materials were evaluated for their strong acid resistance (pH 1), carbonate resistance (sodium carbonate) and thermal shock resistance (600 °C heating → cold water quenching repeated three times). Performance of different materials was evaluated based on the changes in mechanical properties, water-fillable porosity, phase changes under stress conditions. The aluminosilicate product exhibited very good corrosion resistance, both from material loss and strength perspectives, while the other products performed with varying degrees of stability. This paper presents the results of the thermite corrosion studies and describes the novel tools being deployed, and under development, to satisfy challenging barrier and intervention applications.