Liquid Phase Content Research Articles

Effect of Sintering Parameters and Liquid Phase Content on the Properties of Fe-Rich Based Impregnated Diamond Bit Matrix

Effect of Sintering Parameters and Liquid Phase Content on the Properties of Fe-Rich Based Impregnated Diamond Bit Matrix

The soft overcoming the hard-an erosion control method for elbow: Experiments and numerical simulations

A novel approach to alleviate erosion by adding water, based on the principle of the soft overcoming the hard, was investigated through self-designed erosion experiments and computational fluid dynamics (CFD) simulations. The results demonstrate that adding a liquid phase to the elbow significantly reduces the erosion rate. The erosion inhibition efficiency is positively correlated with the liquid phase content, reaching 81.56 % in the most severe erosion zone during the experiments. The liquid film can increase the drag force and reduce the particles' impact velocity. Rather than exacerbating erosion, the liquid film enables easier particle accumulation and mitigates erosion instead.

Near-zero thermal expansion ZrW2O8/SiO2f wave-transparent composites: Interfacial anti-debonding structures based on polymeric films

The thermal stability of fiber-optic gyroscopes (FOGs) limits their application in harsh environments. This work utilized the unique water-retention properties of hyaluronic acid and the low-temperature cold sintering process combined to fabricate near-zero thermal expansion ZrW2O8/SiO2f composites with thermal resistance. Based on this novel process, the interface debonding of the composites is effectively suppressed and the mechanical and thermal properties of the composites are significantly improved (flexural strength increased by 69.47 %). Moreover, the interface anti-debonding structure reduces the interfacial polarization and reflection loss of the composites, and enhances the wave-transparent properties in the 2–18 GHz frequency range, with a minimum reflection loss of −0.21 dB. Furthermore, the interface anti-debonding structure of the composite provides creep resistance with enhanced sintering densities (increased by 13.61 %). Simultaneously, the composites achieve a controllable coefficient of thermal expansion (CTE) by regulating the liquid phase content and reach near-zero CTE (−0.246 × 10−6 °C−1 [30–300 °C]). Finally, finite element analysis and thermal shock experiments show that the anti-debonding interfacial structure has excellent thermal resistance, and the densest ZrW2O8/SiO2f composites exhibit the best thermal resistance due to minimal thermal strain during thermal shock, which is expected to meet the requirements of FOGs applications.

Phase Evolution Behavior during the Reduction Process of Medium‐Silica Fluxed Pellets

To enhance the proportion of domestically manufactured Chinese pellets in the furnace, it is crucial to investigate the impact of calcium flux on the metallurgical characteristics of pellets and analyze the phase evolution behavior during the reduction process of medium‐silica fluxed pellets. This study examines the metallurgical properties of medium‐silica acid pellets and low‐basicity medium‐silica fluxed pellets produced in China. The results indicate that incorporating a small amount of calcium flux significantly enhances reducibility index (RI), reduces reduction swelling index, and lowers reductive degradation index (RDI+3.15 mm) for fluxed pellets. At a basicity level of 0.6, RI for medium‐silica fluxed pellets reaches 66.86%, while RDI−0.5 mm increases to 1.62% with increasing basicity levels. As pellet basicity increases, charge pressure drop (APmax) decreases, CaO content in silicate liquid phase within slag phase increases, and softening–melting zone widens, consequently leading to reduced solid‐phase particle content within pellets and increased fluidity within slag phase.

Investigation on ash fusion characteristics and mineral transformation mechanism of sorghum straw by paper-making sludge addition

The co-combustion of sorghum straw and paper-making sludge (PMS) is beneficial to alleviate the ash-related problem in sorghum straw combustion process. In this paper, the mineral migration and transformation behavior in sorghum straw ashes with the addition of PMS ashes under an oxidizing atmosphere were investigated using an X-ray diffractometer, thermogravimetric-derivative thermogravimetric, scanning electron microscopy-energy dispersive X-ray detector, and FactSage software. The results demonstrated that the increase in the PMS ash mass ratio led to an increase in ash fusion temperature (AFT) of sorghum straw mixtures. The generations of high melting-point (MP) calcium feldspar (e.g., Ca2MgSi2O7, Ca2Al2SiO7, Ca3MgSi2O8, and Ca7Mg (SiO4)4) and phosphates (e.g., Ca3P2O8, Ca5P2SiO12, and Ca7P2Si2O16) caused the increases in the AFT. The maximum weight loss of sorghum straw ashes decreased with the increasing PMS ash mass ratio, and the surface of the ashes underwent the transition from smooth to a whole loose and rough, which alleviated the ash-related problems of sorghum straw. The addition of PMS ashes decreasing the liquid-phase content calculated by FactSage at the same temperature also explained the sorghum straw AFT increase. The changes of AFT and its corresponding mechanisms in the sorghum straw with PMS ash addition under an oxidizing atmosphere provided the support for large-scale combustion of biomass.

Effect of Basicity and MgO/Al2O3 Ratio on Viscosity and Crystallization Behavior of HIsmelt Titanium‐Containing Slag

Numerous challenges persist in the smelting of vanadium–titanium magnetite using the blast furnace process. These challenges can be overcome by adopting the HIsmelt process, without the need for additional ore or enhanced slag operations. In this study, the effects of basicity and the MgO/Al2O3 ratio on slag viscosity and crystallization behavior are investigated through thermodynamic calculations and experiments. In the results, a decrease in slag viscosity with an increase in basicity and MgO/Al2O3 ratio is demonstrated. Notably, MgO/Al2O3 ratios have a minor impact on the viscosity and break temperature of the slag. With a TiO2 content of 40 wt% in the slag, perovskite phases are identified as the main equilibrium solid precipitates during the crystallization process under various basicity and MgO/Al2O3 ratios. As the slag temperature decreases further, the liquid phase content in the slag progressively decreases, reaching complete crystallization at 1159.0 °C. For industrial production, it is advisable to maintain the binary basicity of the slag within the range of 1.0–1.1, with the MgO/Al2O3 ratio around 0.6. Herein, the research findings contribute to a deeper understanding of the viscosity and crystallization behavior of HIsmelt titanium‐containing slag.

Contrasting effects of various factors upon the properties of foam ceramics and the mechanisms of crystalline phase reconstruction and microstructure regulation

The application prospects of foam ceramics are closely linked to their properties; however, the influence mechanism of the raw material composition and sintering parameters on the properties of foam ceramics remains obscure. In this study, the properties of SiO2–Al2O3–Na2O–K2O-based foam ceramics at various sintering temperatures and sintering times, and with different SiC contents, ratios of Al2O3 to SiO2, and fluxing agent contents were determined. Significant discrepancies in the variation trends and strengths of different influencing factors were observed. To interpret these phenomena, the crystalline phases and microstructure of the foam ceramics were analyzed, and the results indicated that their compressive strength was jointly controlled by their crystal phases and microstructure; however, other properties depended only on the microstructure. Furthermore, analysis of the phase diagram and sintering process revealed that the chemical reactions between the basic materials varied, as the ratio of Al2O3 to SiO2 and the fluxing agent contents were varied, resulting in differences in the phase transition temperature, liquid phase content, and crystalline phases. Moreover, the sintering temperature, sintering time, and SiC content affected the microstructure of the foam ceramics by changing the liquid viscosity, reaction time, and foaming amount, respectively. Overall, our findings provide a theoretical basis for preparing foam ceramics with excellent properties.

Effect of TiO2 on the Microstructure and Flexural Strength of Lunar Regolith Simulant

Lunar regolith is the preferred material for lunar base construction using in situ resource utilization technology. The TiO2 variations in lunar regolith collected from different locations significantly impact its suitability as a construction material. Therefore, it is crucial to investigate the effects of TiO2 on the properties of lunar regolith. This study aims to evaluate the influence of TiO2 content and sintering temperature on phase transformation, microstructure, and macroscopic properties (e.g., the shrinkage rate, mechanical properties, and relative density) of lunar regolith simulant samples (CUG-1A). The flexural strength and relative density of the sample with a TiO2 content of 6 wt% sintered at 1100 °C reached 136.66 ± 4.92 MPa and 91.06%, which were 65% and 12.28% higher than those of the sample not doped with TiO2, respectively. The experiment demonstrated that the doped TiO2 not only reacted with Fe to form pseudobrookite (Fe2TiO5) but also effectively reduced the viscosity of the glass phase during heat treatment. As the sintering temperature increased, the particles underwent a gradual melting process, leading to a higher proportion of the liquid phase. The higher liquid-phase content had a positive impact on the diffusion of mass transfer, causing the voids and gaps between particles to shrink. This shrinkage resulted in greater density and, ultimately, improved the mechanical properties of the material.

Heat and Mass Transfer Characteristics of Oily Sludge Thermal Desorption

Oily sludge is a loose material containing solid and multiple liquid components. Thermal desorption is an efficient method of disposing of liquids from oily sludge. Most existing studies have mainly discussed the effect of some external process parameters on thermal desorption, with little discussion on the heat transfer characteristics and the variation in the wet component mass of oily sludge under heating. Small-scale experiments have been performed to measure the rise in temperature and liquid phase content change of the sludge during heating. The temperature rise rate increases with material density and increases faster during the initial heating stage, while it slows down as the liquid phase evaporates. The adhesive shear stress is determined by measuring the pulling force of the test rod, which decreases with decreasing water content and increases significantly with decreasing oil phase content. Heat transfer and energy distribution models have been developed to calculate the rise in the temperature of materials and the evaporation of contained liquids. The heat and mass transfer processes are obtained from simulation calculations by taking the initial material with a mass content of 25% water and 10% oil under a heating temperature of 500 °C. When the heating time reaches 135 min, the drying region reaches the boundary of the test container, at which the material temperature exceeds 350 °C. During the evaporation of different liquid-phase components, there are multiple segments in the corresponding temperature curves. The processing time and heat source temperature can be reasonably determined by analyzing the temperature rise of the material, and the effect of the disposal of liquids from oily sludge can be predicted by analyzing the changes in liquid content. The results may guide the formulation of process parameters for engineering project schemes for oily sludge disposal.

Effective disposal of hazardous waste from non-ferrous waste recycling through thermal treatment

Hazardous wastes containing non-ferrous metals have significant value in recycling. However, the recycling process generates leaching residues (HWLR) with high levels of heavy metals, posing a risk to the environment. Based on the component characteristics of HWLR, silica residue (SR), and silicon tetrachloride cracking slag (STCS), the feasibility of co-thermal treatment for the efficient disposal of HWLR, SR and STCS was verified in this study. According to the SiO2–Na2O–CaO ternary system diagram, the melting point of the system decreases gradually with the appropriate increase in SiO2 content when the CaO/Na2O ratio in the system was determined to be about 2.33. When the theoretical liquid phase content of the mixed system of 100%, the thermal treatment temperature could be lowered to 1100 °C, which is significantly below the melting points of HWLR, SR, and STCS individually. The experimental results confirmed that thermal treatment at temperatures above 1000 °C effectively eliminated the leaching toxicity of Cu, Ni, Zn, Cr, Cd, and Pb in the mixed samples of HWLR, SR, and STCS, which can mainly be attributed to the formation of a glass network structure during the thermal treatment process. This study demonstrated that low-temperature melting treatments could efficiently and thoroughly solidify heavy metals in HWLR, SR, and STCS.

In operando characterization of the ionic conductivity dependence on liquid transient phase and microstructure of cold-sintered Bi2O3-doped Li1.3Al0.3Ti1.7(PO4)3 solid-state electrolyte

A disruptive sintering technique, Cold Sintering Process (CSP), has been used to produce cold-sintered samples of Bi2O3-doped Li1.3Al0.3Ti1.7(PO4)3 (LATP) as solid-state electrolyte (SSE). An in operando impedance study has been performed to shed light on this sintering process. In this work, Bi2O3 and 3 m acetic acid solution sintering aids were synergistically added to LATP powders to sinter at low temperature. Effects of Transient Liquid Phase (TLP) content on the sintering behavior, phase composition, microstructure, and electrochemical properties were all investigated for a LATP doped with 2 wt% Bi2O3 (optimal content) solid-state electrolyte (SSE). The data revealed that the final electrical properties, which are the key parameter decisive for their application, are defined by the following sintering parameters: Transient Liquid Phase (TLP) content, temperature, pressure, and dwell time. Using acetic acid 3 m as TLP, LATP-based samples can be cold-sintered at optimized sintering conditions of 150 °C and 700 MPa of uniaxial pressure for 90 min. The resultant SSE shows a high ionic conductivity (4.5·10−5 S cm−1) at room temperature (RT) and relative density (∼95%), which demonstrates the effectiveness of the low-temperature sintering process by optimizing the ionic conductivity of LATP-based SSE, also reducing preparation costs and CO2 emissions.

Introducing an ionic conductive matrix to the cold-sintered Li1.3Al0.3Ti1.7(PO4)3-based composite solid electrolyte to enhance the electrical properties

In the present work, a Polymer-In-Ceramics (PIC) solid electrolyte based on Li1.3Al0.3Ti1.7(PO4)3 (LATP) and PEOn-LiTFSI (poly(ethylene oxide) - lithium bis(trifluoromethanesulfonyl)imide) is obtained via Cold Sintering Process (CSP), at a temperature of 150 °C without any post-heat treatment, this is 900 °C below the traditional sintering temperature. This novel study demonstrates the effect of the Transient Liquid Phase content (TLP) and the composition of the polymeric active filler on the final Composite Solid Electrolyte (CSE) properties, with the sintering process being monitored by in-operando Electrochemical Impedance Spectroscopy (EIS). Firstly, the 15 wt% of TLP is stated as the optimal liquid content based on the electrical answer and workability. Then, the (EO:Li+) molar ratio is studied from (1:1) to (8:1). The highest ionic conductivity of 1.04·10−4 S cm−1 and a relative density above 98% are achieved at room temperature when the TLP content is 15 wt% and the molar ratio (2:1), with the LATP content set in 90 wt%. Moreover, the activation energy (Ea) is drastically reduced, from 0.388 eV (LATP ceramic electrolyte) to 0.298 eV (PIC electrolyte), with a lithium transference number (tLi+) close to 1. Therefore, this research work proposes a potential solid electrolyte to substitute the traditional liquid electrolytes.

Method of Determining the Liquid Phase Content in the Pelletized Charge for Producing Compacts with the Maximum Strength II. Development of the Method

Method of Determining the Liquid Phase Content in the Pelletized Charge for Producing Compacts with the Maximum Strength II. Development of the Method

Synthesis of zirconium boride (ZrB2) rod crystals through salt-assisted boro/carbothermal reduction

High-aspect-ratio ZrB2 rod crystals were synthesized via a molten-salt-mediated boro/carbothermal reduction using ZrOCl2· 8H2O/B4C/C as the raw material and NaCl as the flux material. This synthesis may improve the poor fracture toughness of monolithic ZrB2 ceramics. X-ray diffraction and scanning electron microscopy confirmed that the heat-treatment temperature of 1550 °C and the addition of 50 wt% NaCl were the most effective in the preparation of ZrB2 grains with a high aspect ratio. Thermogravimetric and differential scanning calorimetry was used to study the influence of NaCl addition, which increased the liquid-phase content. Finally, the growth of ZrB2 grains along the c-axis into rod-like morphology at elevated temperatures was investigated by transmission electron microscopy. This work revealed that the addition of NaCl has a positive effect on the reducing of synthesis temperature and increasing of products particle size. The ZrB2 rod crystals synthesized have diameters and aspect ratios of approximately 1 μm and 30, respectively.

Effects of alloying ZrB<sub>2</sub>(HfB<sub>2</sub>)–SiC with tantalum on the structure and resistance to high-temperature oxidation and ablation: A review

This review presents a comprehensive analysis of the impact of tantalum alloying on the structure, heat resistance, and ablation resistance of ZrB2(HfB2)–SiC ultra-high-temperature composites. The influence of the primary phase content on the effects on the structural and morphological features of the oxide layers and their protective efficiency is analyzed. It is shown that alloying positively affects the composite's behavior by enhancing the viscosity and thermal stability of the glass phase, decreasing anionic conductivity, partially stabilizing the ZrO2(HfO2) lattice, and forming temperature-resistant complex oxides, such as Zr11Ta4O32 or Hf6Ta2O17 on the surface. It has been established that the alloying can have negative effects, including an increase in the liquid phase content, oxide film discontinuity, ZrO2(HfO2) grain damage due to TaB2 oxidation, or a significant amount of gas release due to TaC oxidation, as well as the formation of oxygen diffusion channels during the verticalization of Zr11Ta4O32 or Hf6Ta2O17 platelets. It is essential to note that the oxidation and ablation resistance, as well as the mechanisms driving composite behavior, differ depending on the alloying compounds and test conditions. Overall, this study sheds light on the role of tantalum alloying in enhancing the performance of ZrB2(HfB2)–SiC UHTC and highlights the importance of understanding the underlying mechanisms that govern their behavior.

Method of Determining the Liquid Phase Content in the Pelletized Charge for Producing Compacts with Maximum Strength I. Experimental Study

Method of Determining the Liquid Phase Content in the Pelletized Charge for Producing Compacts with Maximum Strength I. Experimental Study

Effects of sludge on the ash fusion behaviors of high ash-fusion-temperature coal and its ash viscosity predication

The co-gasification of sludge and coal is a promising way to regulate coal ash fusion characteristics and recover energy from sludge simultaneously. In this paper, the ash fusion behaviors of high ash-fusion-temperature (AFT) Datong coal, textile dyeing sludge (TDS), their mixtures, and the corresponding AFT modification mechanisms on laboratory scale were investigated by an AFT tester, X-ray diffractometer, Raman spectrometer, and FactSage software. The AFTs of Datong coal mixtures decreased slowly when TDS share was in the range of 0–6%, quickly (6–9%), and then nearly stable (>9%) because of its corresponding increasing basic oxide values (the total content of SO3, CaO, MgO, Fe2O3, Na2O, and K2O). The generations of low melting-point minerals of hercynite and anorthite with TDS additions resulted in the AFT decrease. The decreasing intensity of Si–O–Si peak and the increasing ratio bond of bridging oxygen and non-bridging oxygen led to the AFT decrease. Both the decreases in the temperature at which all minerals change into liquid-phase and the continuously increasing liquid-phase content (at the same relative high temperature) in Datong coal mixed ashes with increasing TDS mass ratio were contributed to the variations of AFT. The viscosity-temperature characteristics variation was also predicted using FactSage calculation. The 9.0–12.0% mass ratio of TDS might be suitable for Datong coal entrained-flow bed gasification.

Comprehensive study of recycling municipal solid waste incineration fly ash in lightweight aggregate with bloating agent: Effects of water washing and bloating mechanism

Recycling into lightweight aggregate (LWA) by sintering is a promising technology for disposal of municipal solid waste incineration fly ash (FA). In this study, FA and washed FA (WFA) were combined with bentonite and SiC (bloating agent) to make LWA. The performance was comprehensively studied by hot-stage microscopy and laboratory preparation experiments. Water washing and increased FA/WFA improved LWA bloating extent, while shorten the bloating temperature range. Water washing also increased the 1 h-water absorption rate of LWA, making it harder to meet the standard. Excessive FA /WFA usage (70 wt%) will prevent LWA from bloating. For the goal of recycling more FA, mixture with 50 wt% WFA could prepare LWA that meet standard GB/T 17431 at 1140–1160 °C. After water washing, the ratio of Pb, Cd, Zn, and Cu stabilized in LWA increased by 279 %, 410 %, 458 %, and 109 % for 30 wt% FA/WFA addition, and 364 %, 554 %, 717 %, and 697 % for 50 wt% FA/WFA addition, respectively. The change of liquid phase content and viscosity at high temperature were determined using the thermodynamic calculations and chemical compositions. The bloating mechanism was further investigated by integrating these two properties. To obtain accurate results of the bloat viscosity range (2.75–4.44 log Pa·s) for high CaO systems, the composition of the liquid phase should be taken into account. The liquid phase viscosity required for bloating start was proportional to the liquid phase content. With temperature increasing, bloating would end when viscosity drops to 2.75 log Pa·s or liquid phase content reach 95 %. These findings provided further understanding of the heavy metal stabilization during LWA production and the bloating mechanism of high CaO content systems, and could contribute to the feasibility and sustainability of recycling FA and other CaO-rich solid wastes into LWA.

Self-foaming high strength artificial lightweight aggregates derived from solid wastes: Expansion mechanism and environmental impact

Expanded lightweight aggregates (LWAs) were produced using high content of solid waste (95 wt%) without foaming agent. The effects of sintering temperature and duration on LWA properties were studied. The optimal high-temperature liquid phase content and viscosity for producing LWAs with excellent properties were ∼70 % and 1.58 × 104 Pa·s, respectively. The LWA obtained at a sintering temperature of 1200 °C with a duration of 60 min had a water absorption of 1.03 %, a bulk density of 0.57 g/cm3, and a high compressive strength of 6.75 MPa. The leached concentrations of heavy metals from LWAs complied with the environmental standard.

Study on gasification dephosphorization of phosphorus magnetite reduced by SiC

The mechanism of reduction and dephosphorization of phosphorus-containing magnetite was studied using SiC as reducing agent. The thermodynamic conditions for the reduction of Ca3(PO4)2 and Fe3O4 by SiC were simulated by FactSage7.1 thermodynamics software, respectively, indicating that the reduction of Ca3(PO4)2 by SiC is thermodynamically feasible, but the kinetic conditions of the system are not good when no liquid phase is formed. The Fe2SiO4 liquid phase can be formed by reducing Fe3O4 by SiC at 1200 ℃. When the SiC ratio is 10 wt.%, the liquid phase content is the largest, which can reach more than 60 wt.%. Therefore, in this paper, the Fe2SiO4 liquid phase generated by the reduction of Fe3O4 by SiC is used to improve the kinetic conditions of the reduction of Ca3(PO4)2 by SiC at high temperature, and relevant experiments were carried out. The research results show that the system generates a suitable amount of liquid phase at 1250 °C, and the gasification dephosphorization rate is the highest, which is 39.89 wt.%, at 1200 °C, the reduction reaction was not fully carried out, and the dephosphorization rate by gasification was only 23.79 wt.%. At 1300 °C, Fe3O4 was completely reduced to metallic Fe, which combined with the reduced P4 gas to form Fe2P. Gasification dephosphorization rate is only 28.25 wt.%.