Heating Stage Research Articles

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.

Interfacial failure induced by dynamic evolutional stress of NiCoCrAlY-4YSZ TBCs during gradient thermal cycling: Effect of 4YSZ top coat thickness

As the continuation of the previous work, the dynamic evolution of stress field of NiCoCrAlY-4YSZ TBCs with the top coat thickness of 100 and 200 μm at 1000 cycle is constructed based on the real interfacial morphologies of the TC/BC. Results indicated that interfacial stress usually exhibits higher value at the heating stage than cooling stage, which is completely different from the previous results during isothermal cyclic oxidation. Furthermore, the formed (Ni,Co)(Cr,Al)2O4 spinel oxide is unable to promote the high stress level at the TC/BC interface. The relationship between the stress state and formed (Ni,Co)(Cr,Al)2O4 spinel oxide as well as relative roughness was discussed.

BUBBLE DEFECTS AND CONTROL OF THERMAL CURING OF WATERBORNE RESIN COATINGS

To solve the problem of bubble retention leading to a decrease in the performance of waterborne resin coatings during thermal curing, a rapid thermal curing coating based on an aqueous epoxy-modified acrylic resin containing an amino resin cross linker was synthesized through solution copolymerization. Using a synchronous thermal analyzer, the mass loss and heat flow during the thermal curing process of the coating was measured. In addition, an in situ thermal curing visualization system was used to observe the curing behavior at the easy-open end notches under different heating rates. The results indicated that the curing process is divided into an initial rapid heating stage and a subsequent slower heating stage by the boiling point of water, with a critical temperature range of 126-150°C. The visualization experiments showed that when the temperature reached 100°C, the water quickly evaporated to form bubbles. Increasing the heating rate before this temperature caused the bubbles to rapidly escape. Therefore, an optimal heating profile with a rapid initial heating rate of 3.13°C/s, followed by a slower heating rate of 0.52°C/s in the next stage, is proposed. This discovery is of great significance for optimizing the thermal curing process of waterborne coatings on metal substrates, including those used for easy-open ends.

Research and application of heat recovery and automation monitoring system for new energy vehicle motor equipment

In order to improve the energy efficiency of pure electric vehicles, the author proposes a thermal energy recovery and automation monitoring system for motor equipment based on new energy vehicles. Based on the analysis of the battery thermal management model, a series heat exchange model between the motor and the battery was established. An integrated thermal management system control strategy based on motor waste heat recovery was proposed for electric vehicles in low temperature environments, and simulation and validation were conducted at different environmental temperatures (-10~0 ?). The simulation results show that this configuration can shorten the heating time by 111-343 seconds compared to traditional battery thermal management systems during the heating stage. During the insulation stage, frequent activation of positive temperature coefficient thermistor can be avoided and the battery temperature can be maintained around 20?C, which is not only conducive to extending the battery life but also reduces the comprehensive energy consumption by 4.39-7.70%. On the other hand, this configuration can reduce the impact of low temperature on comprehensive energy consumption from 9.77-2.07%. It is proved that heat recovery can effectively alleviate the range anxiety caused by ambient temperature.

Effect of full melt temperature sintering and semi-melt heat preservation sintering on microstructure and mechanical properties of Ti3SiC2/Cu composites

The influence of sintering parameters on the microstructure, phase composition and mechanical property of the Ti3SiC2/Cu composites sintered by spark plasma sintering technique was investigated and the related sintering mechanism was clarified in detail. Results indicated that during the heating process, one part of the high energy adsorbed by the composites let Cu melt and fill the gaps inside the composites. Meanwhile, there’s different molten condition about Cu duel to different heating temperature that cause Cu fill in the most space between Ti3SiC2 particles. The other part of the energy caused to the local high temperature, contributing for the chemical reaction and the formation of TiCx and Cu3Si. Therefore, at the same heating rate, the composites showed better mechanical property and higher density with a longer heating time. The heating stage played an important role in the change of the mechanical property, microstructure and volume of the composites. During the holding stage, because the amount of the reactants significantly decreased, the related chemical reaction got slow and the energy needed during this stage was lower than that during the heating stage. And the particle of Ti3SiC2 need more time for moving to the space of Cu. Therefore, the higher the holding temperature, the more significant was the diffusion of the phases. The more uniform the phases, the higher was the density. When heating temperature (higher than holding temperature) cause Cu complete melt and holding temperature keep the Cu in semi-melt, there will be a more effective sintering method.

A Heating and Cooling Stage With Fast Temporal Control for Biological Applications.

The study of biological processes involving live microscopy techniques requires adequate temperature control to respect the physiology of the organism under study. We present here a design strategy for a microscope temperature stage based on thermoelectric elements. The design allows the user to access a range of temperatures below and above room temperature and can accommodate samples of different geometries. In addition, by cooling simultaneously the sample insert and the objective, we minimize the temperature gradients along the sample for large magnification objectives requiring immersion oil. We illustrate how this design can be used to study the physiology of the zebrafish embryo over the temperature tolerance of this species. We envision that this device could benefit the communities using model and non-model organisms with physiological temperatures different from typical mammalian cell culture incubation in biomedical research.

Compaction pressure effect on the dielectric, DC and AC conductivity of C-130 porcelain

Porcelain insulators can be prepared in a variety of compositions using several different preparation techniques. In the frame of the present work the effect of the applied compaction pressures on the C-130 grade electroporcelain was studied in terms of electrical and dielectric properties. Compaction is a widely used preparation process, nevertheless, a little is known about the effect of the compaction pressure on the final electrical properties of the material. Samples prepared with different compaction pressures (from 70 MPa to 110 MPa; 10 MPa step size) were subjected to a measurement of DC conductivity up to 1200 °C, and a measurement of dielectric properties at room temperature after different firing temperatures. The DC conductivity of the raw samples ranged from ∼10−10 S/m at room temperature to <10−3 S/m at 1100 °C. Temperature dependence of the DC conductivity revealed that the dominant charge carriers were H+ and OH− ions (initial stages of heating) and alkali ions (at high temperatures and during second heating). The DC conductivity of the previously fired samples (at 1100 °C) ranged from ∼10−12 S/m (room temperature) to ∼10−3 S/m (1200 °C). The AC conductivity of the samples ranged from ∼10−7 S/m (samples fired at 1300 °C, measured at low frequencies) to ∼10−3 (raw sample, measured at high frequencies). AC conductivity measurements and dielectric analysis confirmed that the conduction occurred through ion hopping and the bulk boundary conductivity was dominant. The relative permittivity reached 7–8 after firing at 1300 °C at frequencies above 2 MHz.

Porous and heat analysis for foam block used in building wall restoration

Using COMSOL Multiphysics software, a thorough porosity and heat analysis is performed to examine the thermal performance and insulating qualities of foam blocks used in building wall restoration. The main goal is to comprehend how the foam block's temperature changes over time, emphasizing both its usefulness as an insulator and its heat transmission properties. The investigation showed that the foam block's exterior layer quickly absorbed heat during the early heating stages, indicating its effectiveness in storing thermal energy. Heat progressively moved within as the heating process went on, demonstrating the material's capacity to efficiently transfer thermal energy from the exterior to the interior. A consistent temperature distribution was seen during the advanced heating phases, highlighting the foam block's superior thermal conductivity and stability.

The influence of cyclic temperature and humidity effects on the compressive strength of heavy concrete

The paper presents the results of experimental studies of the effect of cyclic exposure to elevated temperatures up to 90оС and 150оС and moistening to full water saturation on the strength of heavy concrete. Quantitative data on the change of concrete strength properties depending on the influence factors are obtained. Proposals are formulated to take into account in calculations the influence of heating and moistening modes on the strength of concrete in axial compression. Under cyclic exposure to elevated temperatures and subsequent moistening at normal temperature, there are significant changes in the compressive strength of concrete at different stages of each cycle. At the short-term heating stage, the reduction in the prismatic strength of the concrete amounted to 15 - 22% of the concrete strength before heating. Prolonged isothermal heating results in a 13 - 25% increase in concrete strength. At the stage of subsequent moistening of concrete after heating, there is a decrease in strength by 25 - 27%, while the relative magnitude of strength reduction does not significantly depend on the number of previous cycles. In the investigated interval of up to twenty-five cycles of exposure to elevated temperatures and moistening, the greatest reduction in concrete strength was observed in the first and last cycles. For cycles with heating temperature up to 90⁰C at short-term heating at the beginning of the second cycle the concrete strength drop was 45.5%, and the concrete strength drop at short-term heating for the 25th cycle was 9.7%. For cycles with heating temperature of 150⁰C the strength drop was 45.9% and 52.5%, respectively. The accepted experimental mode according to the formula of cycle (6+1) + (6+1) is the most unfavorable for the strength of concrete under cyclic effects of elevated temperatures and subsequent moistening.

Study on heat transfer of waxy crude oil melting phase change based on a novel model

The study of phase change heat transfer of crude oil melting is important for pre-heating and restarting of pipelines. Combining the characteristics of waxy crude oil characteristics of waxy crude oil melting, a novel mathematical model was established, which can accurately describe the non-linear release of latent heat, liquid-solid interface changes, natural convection, and other key heat transfer problems. In the process of heating and melting, the variation law of the solid-phase interface position in the pipe at different initial solidification states was analyzed. The results showed that in the partially solidified pipeline, the liquid crude oil in the pipeline has a higher temperature at the initial heating stage, and continuously loses heat to the low temperature crude oil, resulting in a decline in the liquid-phase ratio at the initial stage. Because crude oil was affected by different degrees of radial thermal resistance, latent heat release and porous medium characteristics at different positions of the pipeline, the temperature drop curves of the crude oil varies greatly.

Investigation of the temperature effect on the formation of a two-dimensional self-assembled network at the liquid/solid interface.

In this work, we investigate the temperature effect on the formation of self-assembled molecular networks (SAMNs) at the liquid/solid interface, focusing on an alkylated achiral glycine derivative at the 1-phenyloctane/HOPG interface. Using STM with an in situ heating stage, we comprehensively examine the concentration-temperature phase space for 2D network formation. This study allows us to determine the enthalpic and entropic contributions to the Gibbs free energy (ΔG) of monolayer formation, revealing that the process is enthalpically driven. Moreover, we further develop our previously established Ising code by incorporating temperature dependence, which provides valuable insights into the interplay of enthalpic and entropic factors. Our findings, supported by both experimental and theoretical analyses, demonstrate a strong agreement in thermodynamic parameters, validating our model as a proof of concept for studying temperature effects in SAMN formation. This research underscores the importance of understanding enthalpic and entropic contributions for the successful utilization of 2D molecular self-assembly.

Influence of pore-crack environment on heat propagation of underground coalfield fire: A case study in Daquanhu, Xinjiang, China

The development of pores and cracks in coalfield fire area promote the abnormal temperature, the greenhouse effect, and the release of toxic gases. It is of great significance to study the dynamic distribution characteristics of temperature field and concentration field of typical gas products in a coalfield fire area under different pore-crack environments for revealing the spreading law of underground coalfield fire. In this paper, the combined effect of coal combustion chemical reaction, heat energy transmission, flue gas seepage and pore-crack environment were considered. Taking Daquanhu coalfield fire area as an example, an optimized multi-field coupling model, which included the chemical reaction of coal combustion, convection heat transfer in cracks, heat transfer in porous media, gas seepage and improved partial differential equation of pore-crack evolution was constructed. The coalfield fires area was divided into combustion zone, caving zone, sagging subsidence zone, crack zone. The evolution law of temperature field, CO2 concentration field in the coalfield fire area under different air leakage and geological crack conditions was analysed. The results showed that the temperature development of coalfield fire is divided into rapid heating stage and stable development stage. At the rapid heating stage, the greater the air leakage flow was, the faster the maximum temperature rise in the combustion zone. At the stable development stage, with the air leakage decreased, the thermal buoyancy increased. The greater the number of cracks was, the greater the area of the drying zone (673.15 K < T < 1073.15 K) closed to the crack zone. The influence of crack environment on heat flux in the sagging subsidence zone and crack zone was obvious. The total heat flow in the crack zone was about 25 times that in the caving zone. The relationship between the maximum temperature in the combustion zone and the CO2 concentration at the crack outlet showed an exponential model (ExpGro1 exponential model). The area spread by coalfield fire increased linearly with the rang of surface temperature abnormal. The research results provided a basis for judging the spread trend of coalfield fire and extracting coalfield fire of heat energy.

Comparison of Thermal Behaviors of Carbon and Stainless Steel Billets during the Heating Process.

The effect of thermal properties on the thermal behavior of a steel billet was investigated during the heating process to understand each effect and to provide process engineers with sufficient data to choose the optimal design conditions in reheating the furnace for hot rolling. Carbon steel and austenitic stainless steel (STS) were compared based on numerical simulations owing to the completely different thermal properties of these two steels: carbon steel having a phase transformation with a relatively high thermal conductivity and STS having no phase transformation with a relatively low thermal conductivity. The thermal conductivity affected the thermal behavior of the billet in the initial stage of heating owing to the high temperature difference between the surface of the billet and the gas in the furnace, i.e., the high Biot number. Accordingly, a non-firing zone and/or a preheating zone with a low gas temperature are necessary for high-alloyed steels including STS because the thermal conductivity of these steels is relatively low. The phase transformation of the carbon steels needs to occur in the primary heating zone, and this zone needs to have a relatively low gas temperature to reduce the temperature deviation or thermal stress in the billet. The heating pattern of the carbon steels and STSs in the reheating furnace should be designed differently considering the thermal conductivity and latent heat by the phase transformation of steels to obtain a high heating quality for the billet.

Deterioration of equivalent thermal conductivity of granite subjected to heating-cooling treatment

Understanding the thermal conductivity of granite is critical for many geological and deep engineering applications. The heated granite was subjected to air-, water-, and liquid nitrogen (LN2-) coolings in this context. The transient hot-wire technique was used to determine the equivalent thermal conductivity (ETC) of the granite before and after treatment. The deterioration mechanism of ETC is analyzed from the meso-perspective. Finally, the numerical model is used to quantitatively study the impact of cooling rate on the microcrack propagation and heat conduction characteristics of granite. The results show that the ETC of granite is not only related to the heating temperature, but also affected by the cooling rate. The ETC of granite decreases nonlinearly with increasing heating temperature. A faster cooling rate causes a greater decrease in ETC at the same heating temperature. The higher the heating temperature, the stronger the influence of cooling rate on ETC. The main explanation for the decrease in ETC of granite is the increase in porosity and microcrack density produced by the formation and propagation of pore structure and microcracks during heating and cooling. Further analysis displays that the damage of granite at the heating stage is induced by the difference in thermal expansion and elastic properties of mineral particles. At the cooling stage, the faster cooling rate causes a higher temperature gradient, which in turn produces greater thermal stress. As a result, it not only causes new cracks in the granite, but also aggravates the damage at the heating stage, which induces a further decrease in the heat conduction performance of granite, and this scenario is more obvious at higher temperatures.

Advantages of Friction Welding of Fittings with Small Diameter Conical Contact Form

Introduction. As numerous production tests show, the use of manual arc welding (MAW) of thick-walled fittings of small diameter (up to 80 mm) does not provide a high-quality weld joint that meets the requirements of regulatory and technical documents of nuclear power plants (NPP). The solution to this problem is possible on the basis of research and development of welding technology with optimal heat input instead of MAW. Existing fusion welding technologies do not allow for optimal regulated heat input. However, this can be realized during the development and further use of the friction welding (FW) method. Therefore, this work aimed at developing a technology based on an automated technique of friction welding, which could provide the enhancing of the quality of weld joints of small diameter fittings of power equipment to the level of regulatory requirements.Materials and Methods. Small diameter fittings with a conical contact surface made of low-alloy steel 10GN2MFA were used. The experimental study was performed on a friction welding machine MST–41. Methods of non-destructive and destructive quality control were used in accordance with the regulatory and technical documentation of nuclear power engineering.Results. A methodology was developed, and the optimal dimensions of the conical contacting surface under welding were determined. It was shown that optimal heat input during friction welding was achieved by preparing a conical contacting surface in the angle range α = 30º–40º. The methodology and parameters of the friction welding mode for models of small diameter fittings were experimentally tested. In the course of the research, a cyclogram of the friction welding process was obtained and described, which confirmed the stage-by-stage formation of the weld joint due to the sequential inclusion of annular sections of the conical surface of the connected parts in the heating stage. The results of non-destructive and destructive testing were obtained, confirming the presence of a high-quality weld joint at the level of the requirements of the regulatory and technical documents of the NPP.Discussion and Conclusion. The obtained research results can be used to develop the technology of friction welding of pipes, as well as products made of carbon and low-alloy steels.

Solvent-assisted recrystallisation for the recovery of cannabinoids from Cannabis extraction by-products

A wax by-product removed from the initial stages of commercial Cannabis processing, which contains significant amounts (39–51% (w/w)) of cannabinoids, is currently underutilised due to a lack of information on wax composition and further processing options. Significant value might be generated from further recovery of the cannabinoids entrapped within the wax fraction, and from further processing of the wax into useable products. This study aimed to develop a method to recover the cannabinoids contained in the wax and to prepare the wax for further refinement into a valuable product. A method where the wax by-product was dissolved in ethyl acetate and then recrystalized was developed, which consisted of a heating and mixing stage followed by filtering and washing with additional solvent. The main variables for the experiments were the ratio of solvent to wax for dilution, and the ratio of solvent to wax for post-crystallisation washing. The recrystallisation method was successful in recovering the cannabinoids from the wax and the effectiveness of the recovery was significantly impacted by the solvent addition. The method was validated on two samples of industrial by-products sourced from the cannabinoid extraction industry, and the highest recovery over two consecutive dissolution-recrystallisation cycles was 68.3% and 96.3%, for wax A and B respectively. In both cases, maximum recoveries were achieved with the experiments corresponding with the highest solvent addition. It was therefore concluded that the use of more solvent during recrystallisation, especially for the washing step during filtering, was favourable as it resulted in a higher recovery of cannabinoids from the wax by-product. Furthermore, wax carry-over to the recovered filtrate was sufficiently low (< 3% (w/w)), and was easily removed by centrifugation. The majority of the carried-over lipophilic components were fatty acids, with a maximum concentration of 17.39 mg/g in the filtrate removed after the first stage of recrystallisation with wax A. The other components (n-alkanes, fatty alcohols) were in significantly lower abundance compared to the fatty acid fraction. The recovery when the wax was filtered without undergoing recrystallisation was 33.5%, significantly less than the recovery of the recrystallisation method. This work successfully demonstrated a methodology for simple cannabinoid recovery from Cannabis processing by-products, with the potential to create significant additional value from what is currently regarded as a waste in this industry.

Deformation law and bonding mechanism of 45 carbon steel/316L stainless steel cladding tubes fabricated by three-roll skew rolling bonding process

Realizing the continuous forming and metallurgical bonding in bimetallic cladding tubes with high-strength and corrosion-resistance is the key bottleneck to be solved urgently. In this study, 45 carbon steel/316L stainless steel (CS/SS) cladding tubes were fabricated by the three-roll skew rolling bonding process under different radial reduction rates. The deformation law, interfacial microstructure characteristics, and deformation mechanism were analyzed. With the increase of the radial reduction rates from 11.7 % to 19.3 %, the 45 CS/316L SS cladding tubes were elongated along with the diameter and wall thickness decrease. Besides, the wall thickness ratio between 45 CS and 316L SS was unchanged due to the coordinated deformation. Tensile shear fracture locations of CS/SS cladding tubes were on the 45 CS matrix, and the average diffusion distances in the longitudinal section and the cross section were consistent, proving that uniform metallurgical bonding was achieved. Besides, average decarburized layer thickness decreased and average diffusion distances increased with the increase of radial reduction rates. Furthermore, spherical and fibrous Mn-Si-Cr-O oxides, generated in the insulation heating process, were dispersed near the bonding interface. The refined grains were formed close to the interface, and deformation twins were formed away from the interface on the 316L SS side, whereas only elongated ferrite grains evolved due to the decarburization adjacent to the interface on the 45 CS side. Therefore, the interfacial bonding mechanism was illustrated as three stages, namely the insulation heating stage, the skew rolling bonding stage, and the air cooling stage. The three-roll skew rolling bonding process provides a high-efficiency method to prepare CS/SS cladding tubes with uniform metallurgical bonding, which adopts axial forming and contributes to breaking through the product length size limit.

Tuning the Coefficient of Thermal Expansion of Transparent Lithium Aluminosilicate Glass-Ceramics by a Two-Stage Heat Treatment

Transparent glass-ceramics with a Li2O–Al2O3–SiO2 (LAS) system have been extensively utilized in optical systems in which thermal stability is of utmost importance. This study is aimed to develop thermal treatment routes that can effectively control the structure of transparent LAS glass-ceramics and tune its thermal expansion coefficient within a wide range for novel applications in photonics and integrated optics. The optimal conditions for the nucleation and crystallization of LAS glass were determined by means of differential scanning calorimetry and a polythermal analysis. XRD, Raman spectroscopy, and TEM microscopy were employed to examine the structural changes which occurred after heat treatments. It was found that the second stage of heat treatment promotes the formation of β-eucryptite-like solid solution nanocrystals, which enables effective control of the coefficient of thermal expansion of glass-ceramics in a wide temperature range of −120 to 500 °C. This work provides novel insights into structural rearrangement scenarios occurring in LAS glass, which are crucial for accurately predicting its crystallization behavior and ultimately achieving transparent glass-ceramics with desirable properties.

Precise control over gas-transporting channels in zeolitic imidazolate framework glasses

Porous metal–organic frameworks have emerged to resolve important challenges of our modern society, such as CO2 sequestration. Zeolitic imidazolate frameworks (ZIFs) can undergo a glass transition to form ZIF glasses; they combine the liquid handling of classical glasses with the tremendous potential for gas separation applications of ZIFs. Using millimetre-sized ZIF-62 single crystals and centimetre-sized ZIF-62 glass, we demonstrate the scalability and processability of our materials. Further, following the evolution of gas penetration into ZIF crystals and ZIF glasses by infrared microimaging techniques, we determine the diffusion coefficients and changes to the pore architecture on the ångström scale. The evolution of the material on melting and processing is observed in situ on different length scales by using a microscope-coupled heating stage and analysed microstructurally by transmission electron microscopy. Pore collapse during glass processing is further tracked by changes in the volume and density of the glasses. Mass spectrometry was utilized to investigate the crystal-to-glass transition and thermal-processing ability. The controllable tuning of the pore diameter in ZIF glass may enable liquid-processable ZIF glass membranes for challenging gas separations.

Effects of phosphorus on the fusion characteristics of synthetic ashes with different Al2O3/CaO ratios

In this paper, five series of synthetic ashes with different Al2O3/CaO ratio mass ratios were prepared, and the ash fusion temperatures (AFTs) of the samples with different percentages (5–20 wt%) of phosphorus pentoxide (P2O5) added were measured under a mild reducing atmosphere to study the effect of phosphorus on the fusion characteristics of the ashes in different compositions. X-ray diffraction (XRD), thermodynamic equilibrium calculations, and high-temperature heating stage microscopy (HHSM) were used to investigate the mechanism of phosphorus in changing the fusion characteristics of the ash. The results showed that the addition of P2O5 produced the least effect on AFTs of samples with an Al2O3/CaO ratio of 6:4. For lower Al2O3/CaO ratios (classified as peralkaline), the addition of P2O5 caused a decrease-increase-decrease trend in AFTs, while for higher Al2O3/CaO ratios (classified as peraluminous), the AFTs of samples were decreased by phosphorus. The stronger affinity of P2O5 for CaO and Al2O3, compared to that of SiO2, was noticed and led to a shift of main minerals in the slag from silicates to phosphates and to the isolation of SiO2. In addition, the phosphorus-bearing samples followed the same “melt-dissolution mechanism” as the phosphorus-free samples.