Tube Furnace Research Articles

Microwave Pyrolysis of Automotive Polypropylene Based on a Microwave Atmosphere Tube Furnace

Plastics have light weight and excellent performance, which are widely used in all kinds of automobiles. Polypropylene (PP) and its reinforcing materials are used in automotive components, where the surfaces of bumpers and fenders are coated with paint. Traditional recycling can frequently generate various pollutants, such as paint sludge. Microwave pyrolysis is a more environmentally friendly pyrolysis method with a higher heating coefficient than traditional electric pyrolysis. This study first explores the elemental composition of two types of automotive PP plastics and uses thermo-gravimetric analysis and the Kissinger-Akahira-Sunose method to preliminarily calculate the activation energy of automotive PP. The calculation results show that the activation energy of PP containing paint ranges from 189.145 kJ/mol- 199.513 kJ/mol, with an average value of 193.903 kJ/mol. The activation energy of PP without paint is between 215.506 kJ/mol-265.794 kJ/mol, with an average value of 242.425kJ/mol. Then, pyrolysis experiments on PP for vehicles without paint are conducted using a microwave atmosphere tube furnace at different temperatures and microwave powers. The experimental results showed that, when the pyrolysis temperature increased from 500oC to 620 oC, the total proportion of gas products rose from 0.75 wt.% to 4.81 wt.%, and the content of alkanes in the liquid products improved from 26.21 wt.% to 34.37 wt.%; when the microwave power increased from 900 W to 1100 W, the gas product rose to 20.77 wt.%, and the content of aromatic compounds in the liquid product improved to 17.78 wt.%. In addition, the pyrolysis experiment of automotive PP containing paint showed that paint had a relatively minor effect on the pyrolysis products of automotive PP. This study shows that using microwave pyrolysis to treat automotive PP and PP with paint is feasible, which provides a reference for the clean treatment of automotive polymers.

Oxygen vacancy-engineered P-doped MoO3/Ce2Mo4O15 bimetallic heterojunction nanosheet array for enhanced oxygen evolution reaction

Surface oxygen vacancies in defective metals have the capacity to enhance oxygen evolution reaction (OER) activity but easily suffer from instability and deactivation in continuous electrocatalysts. Heterojunction engineering is important for achieving effective catalysis, but its simultaneous engineering remains a challenge. Therefore, it is necessary to develop an effective heterojunction catalyst to improve the electrocatalytic stability of defective metallic oxygen vacancies. In this work, we report a Ce, Mo bimetallic defective heterojunction P-MoO3/Ce2Mo4O15@NF-1 via a facile one-step hydrothermal method and annealing in a tube furnace. Bimetallic oxide heterojunctions offer several advantages over conventional single-metal heterojunctions, including stable structure, more active sites, faster rates of electron transfer, and less pollution of the environment. Meanwhile, P-doped catalyst could enhance the metallicity significantly. In addition, the prepared catalyst P-MoO3/Ce2Mo4O15@NF-1 showed extraordinary catalytic activity for OER in alkaline media. The overpotential and Tafel slope of the catalyst at a current density of 50 mA cm-2 were 270 mV and 87.27 mV dec‑1, respectively. It maintains an impressive balance between electrocatalytic activity and stability. This research explores the co-effects of Ce and Mo bimetallic oxide in defective electrocatalysts and also provides ideas for designing OER catalysts with defective metal heterojunctions.

Multi-scale thermal degradation of wood pellets under low heating rates: Experiments and modeling

Pyrolysis and combustion experiments were carried out on a single wood pellet in a drop tube furnace, under a heating rate of 5 °C/min. Kinetic modeling was done using the Extended Independent Parallel Reaction model. Three reactions were considered in the pyrolysis case and only one in the combustion case. In the pyrolysis case, a thermal model was proposed which is coupled with the kinetic model to correct the temperature inside the pellet. In the combustion case, the mass rate curve was compared to that of the main gaseous emissions. The mass and mass rate curves between the combustions of a pellet in the drop tube furnace and of pellet sawdust in a thermobalance under the same heating rate were compared.

Analysis of Flow-induced Noise Characteristics of Ethylene Cracking Furnace Tubes before and after Coking

Analysis of Flow-induced Noise Characteristics of Ethylene Cracking Furnace Tubes before and after Coking

Study on pyrolysis of ultra-high-quality oil shale: product characterization and a utilization process

ABSTRACT Nantun (NT) oil shale of ultra-high oil yield (>30%) is rare in the world, while the characteristics of this kind of oil shale are not widely reported. An oil shale pyrolysis experiment has been conducted in a tube furnace. The products of gas, oil and char are collected and analyzed on their yield and properties in the range of 450 to 650°C. The oil yield remained above 30% in the range of 450 to 550°C and decreased rapidly from 30.84% to 9.35% at 550 to 650°C. The char yield drops from 66.14% to 57.94% as the pyrolysis temperature increases, and aliphatic hydrocarbon components in char have been cracked completely at 450°C. The yield of pyrolysis gas rises as the pyrolysis temperature increases. CO accounts for the largest proportion of pyrolysis gas, with a volume fraction of over 70%. Based on the characteristics of pyrolysis products, an ultra-high-quality oil shale pyrolysis and utilization process and an Aspen Plus simulation model have been developed that provides estimated material and energy equilibriums for an industrial self-sustaining pyrolysis process to produce char and shale oil. This process can produce 0.61 kg oil and 0.29 kg char per kilogram of oil shale under self-sustaining conditions at 500°C. In practical applications, the pyrolysis temperature is recommended to be 500°C.

Co-pyrolysis of cellulose and lignin: Effects of pyrolysis temperature, residence time, and lignin percentage on the properties of biochar using response surface methodology

Cellulose, hemicellulose, and lignin constitute the basic components of biomass. Knowledge of the interactions between cellulose and lignin during pyrolysis is crucial for unraveling the pyrolysis characteristics of biomass. In this study, for the co-pyrolysis of cellulose and lignin to produce biochar, three influencing factors were selected: pyrolysis temperature (400–800 °C), residence time (5–30 min), and lignin percentage (0–100 %). Pyrolysis experiments were conducted in a vertical tube furnace and the impact of these three factors on the characteristics of biochar was comprehensively explored employing response surface methodology. The results revealed obvious differences between actual values and theoretical values. Specifically, the results showed that the interaction between cellulose and lignin increased the biochar yield, oxygen content, volatile content, and ash content by 6.14 %, 22.85 %, 30.95 %, and 46.75 %, respectively. In contrast, the carbon content, fixed carbon content, and HHV of biochar were relatively reduced by 9.38 %, 11.80 %, and 3.3 %, respectively. Furthermore, Raman spectra of biochar showed that the actual value of graphitization degree of biochar was higher than the theoretical value. This was further corroborated by XPS analysis, wherein owing to the interactions between cellulose and lignin, the actual C-C bond content decreased in contrast to the theoretical value. However, the contents of C-O, CO, COOH functional groups, and aromatic rings increased. Finally, the summary of the co-pyrolysis rules of cellulose and lignin provided a reference for optimal pyrolysis conditions and understanding the mechanism of co-pyrolysis.

Effects of Oxygen Partial Pressure and slag Basicity on the Behavioral Characteristics of Ni in Slag Drying Smelting

This study was intended to investigate the effects of basicity and oxygen partial pressure on the distribution behavior of Ni in the nickel smelting process using nickel oxide ore, the raw material of nickel, among natural ores. Experiments were conducted in a vertical tube furnace using Fe-Ni metal and FeO-MgO-SiO2 ternary slag, which simulated the composition of natural ore. An equilibrium experiment was conducted to observe the distribution ratio of Ni, and thermodynamic data required for this experiment was calculated through Factsage. As a result, it was found that as the oxygen partial pressure increased, the Ni content in the slag increased linearly. The Ni content in the slag increased as the basicity moved away from 0.60.

The Tube Furnace with Online Mass Loss Measurement as a New Bench Scale Test for Pyrolysis

In this paper, a new gram scale experiment with well characterised boundary conditions is proposed for pyrolysis experiments. The set-up consists of a tube furnace, based on ISO19700, with a newly designed concept for a balance within the oven, allowing for online mass loss measurements. Samples with a length up to 50 cm can be investigated in this apparatus. The oven allows for experiments at fixed temperatures or at fixed heating rates, under controlled atmosphere, w.r.t. gas composition and flow rate. A thorough characterisation of the set-up is presented, including aspects like reproducibility of the heating rate or the precision of the balance. The functionality of the balance has been demonstrated with calcium carbonate (CaCO3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{3}$$\\end{document}) experiments. This material was chosen because it decomposes in a single reaction, which only releases CO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{2}$$\\end{document}. This allows for comparison between the mass loss rate of the balance and the CO2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_{2}$$\\end{document} production rate, measured by a gas analyser. Results for two different heating rates: 3 K/min and 5 K/min and for different masses (25 g and 8.5 g) are presented. The two measurement methods are in excellent agreement. Finally, the data obtained from the new experimental set-up is compared to results from thermogravimetric analyser (TGA) experiments.

Reduction behaviour of electric arc furnace dust (EAFD)-bituminous coal composite pellet in tube furnace

Reduction behaviour of electric arc furnace dust (EAFD)-bituminous coal composite pellet in tube furnace

Mitigation mechanisms of ash deposition and adhesion by different coatings on heated surfaces at macro and molecular scales

Research on the mitigation of ash deposition on coals rich in alkali and alkaline earth metals using coatings is limited. Existing research methods, mainly focusing on ash composition and melting characteristics, cannot fully elucidate the key mechanisms underlying ash adhesion properties on various coated surfaces. Therefore, this study explored the mitigation mechanisms of nickel and chromium coatings on ash deposition using a drop tube furnace, custom-made ash adhesion strength tester, and molecular dynamics. The results revealed that nickel and chromium coatings effectively mitigated ash deposition, with a more significant effect at temperature less than 1000 °C. Above 1000 °C, the ash melting led to a significant increase in ash adhesion strength, diminishing the inhibitory effect of coatings. The key minerals, Na2SO4, Ca2MgSi2O7, and Ca2Al2SiO7, mainly physically adsorbed onto the NiO(001) and Cr2O3(001) surfaces. The binding energy of these minerals with NiO(001) and Cr2O3(001) was significantly lower than that on α-Fe2O3(110) surfaces. The α-Fe2O3(110) system was more stable, and minerals readily adhered to the α-Fe2O3(110) surface, whereas none of these minerals readily bound to NiO(001) and Cr2O3(001), maintaining their adhesion state. Consequently, nickel and chromium coatings demonstrated excellent resistance to ash adhesion and deposition, with nickel coatings being more effective.

Investigation of Slagging-Fouling and Mineral Contents in Low-Rank Coals for Improved Combustion Performance

ABSTRACT Despite the problems associated with low-rank coal, this type of coal is still widely used in various applications including the power generation sector. In this study, three low-rank coals (LRC) with high mineral content of SiO2, Al2O3, and MgO were selected and comprehensively investigated. Investigations include ash fusion temperature (AFT), theoretical calculation, combustion experiment with drop tube furnace (DTF), and ash analysis using scanning electron microscope (SEM) and x-ray diffraction (XRD). The investigation revealed that T-Coal with high SiO2 and P-Coal with high Al2O3 mineral produce ash deposition which did not adhere on the probe surface of either slagging or fouling area. T-Coal ash consists of fine and solid particles, but the presence of the dominant albite mineral, 29.09% in slagging probe and 28.71% in fouling probe, may have a negative impact on ash deposition. P-Coal ash is dominated by fine particles with a predominance of quartz and other high-melting minerals. A-Coal with high MgO mineral has good results in slagging aspects. However, the high Fe2O3 on A-Coal results in low ash fusion and produces more hematite mineral (17.70%) in the fouling probe. This study shows that several types of LRC have good evaluation on ash-related problems which potentially can be used as coal blending for further utilization in power generation.

Experimental investigation on high-temperature co-gasification and melting behavior of petrochemical sludge and bituminous coal in CO2 atmosphere

High-temperature co-gasification of petrochemical sludge (PS) and bituminous coal (BC) can melt heavy metals and fly ash in hazardous waste, decompose dioxins, and generate syngas, which can achieve clean disposal and high value resource utilization of wastes. In this investigation, the high-temperature co-gasification and ash melting experiments of PS mixed with BC were carried out in a high-temperature tube furnace under CO2 atmosphere. The effects of gasification temperature and blending ratios (PS:BC) on co-gasification characteristics and ash melting behavior were investigated. The synergistic effect of co-gasification of PS-BC was examined. The results show that the yield of syngas (CO + H2) was proportional to the temperature and the proportion of BC. As the temperature increased from 1100 °C to 1400 °C, the yield of syngas increased from 1.42 m3/kg to 1.54 m3/kg. At 1300 °C, as the blending ratio of PS:BC shifted from 1:0 to 0:1, the yield of syngas increased significantly from 0.49 m3/kg to 1.88 m3/kg. The most significant synergistic effect of PS-BC co-gasification was the enhanced CO yield. At a blending ratio of 1:1, the synergistic coefficient of CO yield reached a maximum of 1.31. As for the residues, with the increase of temperature and the proportion of BC, the ash melting got promoted. The leaching toxicity of heavy metals in the residues can meet the release standard (GB5805.3–2007), being safe for disposal.

Synergistic effects of Co-pyrolysis on the immobilization and transformation of lead (Pb), chromium (Cr), nickel (Ni), and fluorine (F) in phosphogypsum-biomass mixtures

Co-pyrolysis of biomass with phosphogypsum (PG) presents an effective strategy for facilitating the recycling of PG resources. However, it is crucial to note the environmental threats arising from the presence of Pb, Cr, Ni, and F in PG. This study investigated the effect of immobilization and transformation of four elements during co-pyrolysis with biomass and its components. The co-pyrolysis experiments were carried out in a tube furnace with a mixture of PG and corn stover (CS), cellulose (C), lignin (L), glucose (G). Co-pyrolysis occurred at varying temperatures (600 °C, 700 °C, 800 °C, and 900 °C) and different addition ratios (10%, 15%, and 20%). The results indicated that an increase in co-pyrolysis temperature was more conducive to the immobilization and transformation of harmful elements in PG, demonstrating significant efficacy in controlling F. Additionally, the addition of biomass components exerts a significant impact on inhibiting product toxicity, with small molecules such as glucose playing a prominent role in this process. The mechanism underlying the control of harmful elements during co-pyrolysis of PG and biomass was characterized by three main aspects. Firstly, biomass components have the potential to melt-encapsulate the harmful elements in PG, leading to precipitation. Secondly, the pyrolysis gas produced during the co-pyrolysis process contributes to the formation of a rich pore structure in the product. Finally, this process aids in transforming hazardous substances into less harmful forms and stabilizing these elements. The findings of this study are instrumental in optimizing the biomass and PG blend to mitigate the environmental impact of their co-pyrolysis products.

Effect of hybrid ratio and sintering temperature on hardness properties of hybrid AMCs

The present research work is aimed toward fabrication of hybrid Aluminium matrix composites (AMCs) of different hybrid ratios of Alumina (Al2O3) and Silicon Carbide (SiC) followed by investigation of their microstructure and hardness properties. Hybrid AMCs were fabricated through powder metallurgy process by adding 5 wt% and 10 wt% mixture of Al2O3 and SiC reinforcements of various hybrid ratios (0:1, 1:3, 1:2, 1:1, 3:1, 2:1 and 1:0) with the pure Aluminium powder. The mixture powder were properly mixed by ball milling arrangements for 6 h. The mixture powder were preheated at 500 °C for 2 h in a high temperature programmable tube furnace followed by immediate compaction under a closed die at 1500 psi pressure through automatic hydraulic press. The compacted specimens were then sintered at 350 °C, 500 °C and 650 °C for 2 h in the same furnace. Hardness test of the fabricated hybrid AMCs were carried out by Vickers Micro-hardness testers and hardness values were measured by the integrated software. The hardness properties of hybrid AMCs also were compared with the hardness properties of pure Aluminium specimens fabricated through the same process route and process parameters. It is interestingly observed that hardness of hybrid AMC is more when pure Aluminium powder is reinforced with only SiC of same wt.% for both the cases (5 wt% and 10 wt% reinforce AMCs) and it decreases with decrease of weight fraction of SiC and simultaneously increase of weight fraction of Al2O3 keeping total weight fraction of mixture as constant.

Comprehensive Inspection Solution for Boiler Water Wall Tube Corrosion

A substantial number of domestic coal-fired boilers, most of which have been in operation for numerous years, are susceptible to corrosion and tube ruptures within their high-temperature environment, often resulting in unplanned shutdowns. Despite the annual planned maintenance shutdowns, which involve routine inspections of water wall and furnace tubes to detect potential corrosion and erosion, the current non-destructive testing methods are generally localized. This approach, particularly with the considerable height variation of the water wall tubes (ranging from approximately 10 to 25 meters), may overlook segments with severe corrosion during localized ultrasonic thickness gauging. Although the experience of inspection teams reduces the chance of defect oversight, the demand for a comprehensive and effective inspection technique remains a priority for boiler operators. This study utilizes the characteristic of guided waves to propagate over a certain distance along pipelines, initiating an exploration into a comprehensive inspection solution for water wall tubes. Finite element simulation results demonstrate the suitability of utilizing a 120 kHz frequency for shear horizontal mode (SH0) testing on the fire side of water wall tubes. This mode effectively screens for localized corrosion within a 3-meter range. In the field of on-site boiler inspection, electromagnetic coils are employed to generate guided waves within water wall tubes. The gathered signals from each electromagnetic guided wave testing (EMGWT) are consolidated into a distribution map, indicating suspicious signal locations. Pulse eddy current testing (PECT) is employed to identify potential issues with guided waves without requiring surface preparation. If PECT reveals anomalies, the affected surface is polished, and phased array ultrasonic testing (PAUT) is conducted to quantitatively measure the remaining wall thickness due to corrosion. The theoretical exploration and on-site inspection outcomes affirm the feasibility of this approach, aimed at enhancing operational safety for boiler water wall tubes and mitigating the risks of tube ruptures and leaks. This comprehensive inspection solution amalgamates three advanced detection technologies, each capitalizing on its unique inspection characteristics to facilitate corrosion screening, corrosion scanning, and wall thickness sizing. Through the integration of these technologies, the overall inspection strategy ensures the utmost level of reliability.

Fabrication of a Molybdenum Dioxide/Multi-Walled Carbon Nanotubes Nanocomposite as an Anodic Modification Material for High-Performance Microbial Fuel Cells.

A nanocomposite of multi-walled carbon nanotubes (MWCNTs) decorated with molybdenum dioxide (MoO2) nanoparticles is fabricated through the reduction of phosphomolybdic acid hydrate on functionalized MWCNTs in a hydrogen-argon (10%) atmosphere in a tube furnace. The MoO2/MWCNTs composite is proposed as an anodic modification material for microbial fuel cells (MFCs). MWCNTs have outstanding physical and chemical peculiarities, with functionalized MWCNTs having substantially large electroactive areas. In addition, combined with the exceptional properties of MoO2 nanoparticles, the synergistic advantages of functionalized MWCNTs and MoO2 nanoparticles give a MoO2/MWCNTs anode a large electroactive area, excellent electronic conductivity, enhanced extracellular electron transfer capacity, and improved nutrient transfer capability. Finally, the power harvesting of an MFC with the MoO2/MWCNTs anode is improved, with the MFC showing long-term repeatability of voltage and current density outputs. This exploratory research advances the fundamental application of anodic modification to MFCs, simultaneously providing valuable guidance for the use of carbon-based transition metal oxide nanomaterials in high-performance MFCs.

Sublimation‐Induced Vapor Deposition of Cyanuric Acid‐Melamine Supramolecular Single Crystals on Surfaces

AbstractHerein, a low‐temperature sublimation‐based vapor deposition (SVD) method is developed to synthesize hexagonal crystal plates of cyanuric acid‐melamine (CAM) with outstanding crystallinity. Through meticulous design of the reaction apparatus and careful selection of source materials, substrate‐confined SVD in a tube furnace is explored to grow single crystals of CAM in hexagonal shapes. Additionally, the orientation preference of the (202) facet is revealed, corresponding to the 2D arrangement of the H‐bonded network, of single‐crystalline plates on surfaces using selected area electron diffraction and X‐ray diffraction techniques. By employing atomic force microscopy and scanning electron microscopy for topography characterization, a mechanism of three‐stage step‐growth crystallization is proposed, including nucleation, in‐plane expansion, and out‐of‐plane growth. Furthermore, it is found that the interactions among melamine molecules in CAM synthesized via SVD are more intense compared to those in CAM synthesized via water‐based methods, as evidenced by infrared and photoluminescent spectra studies. Subsequent nanoindentation tests on the (202) facet of CAM single‐crystalline plates reveals a reduced modulus and hardness of 12.8 and 0.82 GPa, respectively. This methodology addresses the longstanding challenge of synthesizing hexagonal CAM single crystals and provides valuable insights for the fabrication of functional organic crystalline materials.

Control of Ash-Related Problems During Pf-Combustion: Drop-Tube Observations with Additives and Blending of Low-Rank Coals

ABSTRACT Coal switching from high- or medium- to low-rank categories is massively practiced. However, coal consumers, especially from power plant, often experience problems such as slagging and fouling. To overcome these problems, adding additives and coal blending can be carried out. In this study, five different low-rank coals were tested in a drop-tube combustor to grade the coals from the best to the lowest grade according to their ash deposition. Furthermore, the effect of adding four different compositions of additives and coal blending on ash deposition of the lowest grade coal was investigated. The study comprised theoretical calculation prediction, drop tube furnace (DTF) combustion, ash morphology analysis, and ash mineralogy analysis. The test results showed that MgO-rich coal is the best grade coal among the five tested coals, while sodium-rich coal being the lowest grade coal. Additionally, addition of aluminum-based additives at 0.05 wt% into the low-grade coal revealed less ash deposition propensities compared to the addition of other additives (0.05 wt% MgO, 0.1 wt% MgO, and 0.05 wt% MgO + 0.05 wt% Al2O3) and coal blending method. This result is consistent with the results of probe observations, ash morphology, and ash mineralogy which show clean probe surface with unfused particles predominantly containing quartz.

Fabrication and application of two-dimensional tungsten disulfide thin film

To form a tungsten disulfide film, a tungsten trioxide film is deposited first and then hydrogen sulfide is injected into the furnace tube to sulfide the tungsten trioxide film in a high-temperature environment. Due to the need to accurately control the thickness of tungsten trioxide, the power of the RF sputtering machine was reduced as much as possible in a stable condition in the experiment and the bias voltage during each process was monitored. In this experiment, a sapphire substrate and a silicon substrate with 200[Formula: see text]nm silicon dioxide are used. Then use optical instruments such as Raman optics, ellipsometers and high-resolution electron transmission microscopes, atomic force microscopes and other instruments for further measurement. The analysis results show that we have successfully made tungsten disulfide films of different thicknesses. Moreover, two-dimensional tungsten disulfide thin film has a response to light, gas and pH and related devices have been successfully fabricated in experiments. Among them, comparing the single-layer film and the double-layer film, the film quality of the double-layer film is better. The quality of the film grown on the sapphire substrate is also better than the quality of the film grown on the silicon dioxide substrate.

Oxidation Study and Mechanism Analysis of Desulfurization Ash in Dense-Phase Tower

Dense-phase-tower desulfurization technology is an emerging semi-dry flue-gas desulfurization ash process, i.e., the flue gas is allowed to enter the desulfurization tower from the bottom up and, at the same time, is sprayed with a desulfurizing agent that undergoes an acid–base reaction with the flue gas in the ascent process. The calcium sulfite and calcium sulfate produced by the reaction and the part of the desulfurization agent that is not involved in the reaction will enter the subsequent dust removal system, and what is retained is the by-product desulfurization ash. This desulfurization ash contains a large amount of calcium sulfite, which leads to its unstable nature; it is easily oxidized and expands in volume, and, if used in the field of building materials, it will lead to cracking and other problems, so it is difficult to effectively use it. In order to solve this problem, XRF, XRD, and iodometric and other analytical methods were used to determine the specific composition of desulfurization ash, and the muffle furnace and vertical tube furnace were used to study the thermal oxidative modification of calcium sulfite in desulfurization ash, to investigate the effects of the oxygen content, reaction temperature, medium flow rate, and chloride content on the oxidation of calcium sulfite, and to analyze the thermodynamics in the high-temperature oxidation reaction. The results showed that the oxidation rate of calcium sulfite increased with higher reaction temperatures. Increased oxygen content promoted the oxidation rate, particularly at low oxygen levels. The oxidation rate of calcium sulfite correlated positively with the medium flow rate until a rate of 75 mL·min− was reached. At a reaction temperature of 420 °C and a gas flow rate of 85 mL·min−1, the oxidation conversion efficiency exceeded 89%. Chloride content significantly reduced the oxidation rate of calcium sulfite, although this inhibition weakened at temperatures above 500 °C. Kinetic analysis suggested that the oxidation reaction of calcium sulfite predominantly occurred below 500 °C. These findings have both theoretical and practical implications for the thermal oxidation treatment and disposal of desulfurization ash.