The iron and steel production was accompanied by the emission of gaseous and solid phases, containing greenhouse gases and metal pollutants, respectively, constituting environmentally harmful by-products. In this work, waste blast furnace slag containing available alkaline oxides CaO and MgO was used to prepare via the method of co-precipitation and hydrothermal crystallization for carbon capture. The maximum CO2 adsorption capacity of the production reached 4.88 mmol center dot g(-1) under conditions of 75 vol% CO2 and 873 K. The CO2 adsorption process could be accurately described via the Avrami order kinetic model and Fractional order kinetic model with fitting degree exceeding 0.99. The Avrami kinetic model (A3) was identified as the most suitable for describing the CO2 desorption behavior. Additionally, the heating rate exerted little effect on the desorption rate but significantly shortened the desorption completion time. Chemical reactions and CO2 diffusion were identified as sequential limiting factors in the adsorption process, and the underlying reaction mechanism was further elucidated. To address the large volumes of solid slag, this work conducted a feasibility of using solid slag derivatives for flue gas capture, providing theoretical support for subsequent practical application.

Metallurgical slag contains numerous valuable components, but its low utilisation rate has caused significant environmental issues. The synthesis of a slag-based CO2 adsorbent was beneficial for treating solid waste and achieving the carbon peak target of the iron and steel industry. In this study, layered double oxides synthesized from blast furnace slag were employed for CO2 adsorption, and the adsorption performance and industrial application stability were investigated. The breakthrough time and adsorption capacity of adsorbent were 13.67 min and 2.44 mmol‧g-1, respectively. The concurrent adsorption of SO2 affected CO2 adsorption, whereas H2O(g) contributed to the two adsorption processes. Therefore, research on the antisulfur modification of layered double oxides and flue gas desulfurization is necessary for decarbonisation. Considering the effect of multicomponent flue gas on the adsorbent, the number of service cycles of the adsorbent should theoretically not exceed 6, resulting in preferable regeneration performance such that the adsorption capacity reaches 65% of the initial condition within that range. Finally, this novel work offered an innovative path for achieving high-value-added utilisation of blast furnace slag and carbon reduction in the iron and steel industry.

The environmental impacts caused via coal combustion had become a critical issue in achieving carbon neutrality of iron and steel industry. Biomass substitution for coal was beneficial for resource recycling and shrinking carbon emissions, however, low char yield and low heat value of biomass limited the utilization in metallurgical industry. In this work, the energy value-added utilization technology of biomass/coal collaborative carbonization loading Fe2O3 additive solved the dilemmas, which aimed to prepare carbon-based composite fuel. That the solid yield and heat value of composite fuel reached 57.31 % and 30.15 MJ & sdot;kg- 1, respectively, via loading 4 wt% Fe2O3 and insulation for 30 min at 550 degrees C. Moreover, the straw/bituminous coal co-carbonization was accompanied by the reduction of iron oxides, and the above reaction processes were highly coupled after increasing temperature. The reactive oxygen species and oxygen vacancies generated during the iron oxide reduction process, capable of adsorbing and promoting the collaborative carbonization of macromolecules in straw/bituminous coal. This study revealed the Fe2O3 catalytic mechanism on the synergistic carbonization process of biomass/coal, which provided an effective path for the application of biomass energy in iron and steel industry.

Efficient thermal management of superheated surfaces via fine water mist impingement is critical across numerous industrial applications, yet quantifying and optimizing the intricate heat-mass coupling remains a significant challenge. Here, we reveal and quantify a nonlinear cooling enhancement/suppression mechanism driven by the transient coupling of droplet kinetic energy, Leidenfrost vapor film evolution, and interfacial heat transfer. Through the numerical simulations incorporating an interface-confined phase change model, we rigorously elucidate the genesis of the M-shaped heat flux distribution. We mechanistically attribute this M-shape to non-uniform central vapor accumulation and pressure-gradient-driven radial transport, demonstrating its non-uniform suppression on local heat transfer. Crucially, we identify and quantitatively define "critical impact conditions"-encompassing critical droplet size and critical impact velocity-that effectively circumvent the profound inhibition of the Leidenfrost effect to maximize cooling efficiency. For instance, increasing impact velocity from 0.50 to 1.00 m/s leads to a remarkable 110.2% surge in total heat transfer, marking a fundamental transition from a low-efficiency (14.9% increase for 0.25-0.50 m/s) to high-efficiency cooling regime. The identification of this abrupt, stepwise enhancement, rather than a gradual trend, confirms the existence of a critical velocity threshold-the finding that fundamentally extends beyond parametric sensitivity analyses prevalent in the literature. This study provides unprecedented mechanistic insights into droplet-wall heat transfer and offers a novel parameter-based cooling strategy for precise enhancement and optimization of high-temperature cooling processes.

The adoption of environmental protection and energy conservation measures has led to increased interest among researchers and scholars in the centrifugal granulation of metallurgical slag and waste heat recovery technology. Variations in the production processes of metallurgical slag result in significant disparities in the physical properties of slag from different sources. Blast furnace slag and copper slag are two types of metallurgical slags distinguished by their characteristic properties. Blast furnace slag exhibits higher viscosity and surface tension, whereas copper slag displays lower viscosity and surface tension, resulting in differing granulation characteristics. This study employs numerical simulations to examine the flow patterns during centrifugal granulation and elucidate the mechanism of centrifugal granulation. The study determined that the breaking length to tip diameter ratio was consistent with the findings of Weber's research. Additionally, it observed the atypical granulation evolution of two types of slag at elevated flow rates, and examined the variation rules of breakup wavelength, tip diameter, crushing length, particle size distribution, and average particle size across varying flow rates. The study also noted that the centrifugal granulation effect of copper slag was significantly influenced by its surface tension. The aforementioned findings can offer theoretical guidance for the implementation of the centrifugal granulation process in the treatment of metallurgical slag. (c) 2025 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The efficient utilization of the coke oven gas and recovery of steel slag waste heat were difficult problem for iron and steel industry. An innovative integrated technology was put forward to produce syngas by CO2/H2O(g) co-assist coke oven gas reforming reaction with steel slag. A thermodynamic analysis based on the Gibbs free energy and exergy-exergy analysis were conducted for providing the theory guidance of practical application. The syngas could be obtained with main components of H2 and CO under the temperature of 1173 K and 0.10 MPa with different CO2/H2O(g). By adjusting the CO2/H2O(g) addition ratio, the yields of H2 and CO in the equilibrium syngas could be tuned to synthesize organic products. The system of coke oven gas reforming reaction with steel slag had well energy and exergy efficiency. The integrated energy efficiency and exergy efficiency were higher than 77 % and 71 %, respectively. The avoidable exergy loss was significantly greater than the unavoidable exergy loss. Economic feasibility of the technology was analyzed and the resulted significant economic benefits. The systematic research and development of CO2/H2O(g) co-assist coke oven gas reforming with steel slag could facilitate the efficient utilization of by-product and heat energy in the iron and steel industry.

To address the urgent need for decarbonization in ironmaking, this study investigates the sustainable co-injection of hydrogen-rich fuels, including hydrogen (H2), coke oven gas (COG), and natural gas (NG) with pulverized coal into blast furnaces. Based on a comprehensive mass-energy-exergy balance model incorporating the Rist operation line, a systematic evaluation model has been developed. This model enables synergistic assessment of technical indicators, CO2 emission reduction, and optimization of the matching relationship among hydrogenrich fuels, pulverized coal, and oxygen enrichment ratio at a critical raceway adiabatic flame temperature (RAFT) of 2050 degrees C and reasonable top gas temperature. Under optimal operating conditions, the maximum injection rates for H2, COG, and NG are determined to be 165, 97, and 85 m3/THM, respectively, while the maximum carbon reduction amount with pulverized coal and H2 co-injection reaches 9.03 %. In comparison to a traditional blast furnace, the input exergy of pulverized coal for H2, COG, and NG co-injection decreases by 7.11, 8.98 and 12.47 %, whereas the output exergy of blast furnace gas (BFG) increases by 20.29, 17.28 and 24.41 %, respectively. Furthermore, hydrogen-rich blast furnaces exhibit favorable performance in terms of energy efficiency and thermodynamic perfection degree. However, maintaining a constant RAFT in hydrogen-rich blast furnaces requires higher exergy input. This study provides a quantitative framework for optimizing the hydrogen-rich fuels injection in blast furnaces, establishing decarbonization roadmaps for achieving low-carbon ironmaking.

The escalating demanded for Zn and environmental imperatives for sustainable resource management had intensified the focus on recovering Zn from Zn-containing dust generated in iron and steel industry. This review comprehensively examined the formation mechanisms, physical and chemical properties of typical Zn-containing dust and evaluated the current and emerging technologies for Zn recovery. Physical method like magnetic separation and hydrocyclones were preliminary treatments with low Zn enrichment. Hydrometallurgical method showed selectivity in metal dissolution but suffered from corrosion issues. Pyrometallurgical method exceled in high-temperature Zn recovery at the cost of energy and CO2 emissions. Emerging technologies such as microwave and vacuum methods provided eco-friendly alternatives but required further development. Coupling method was presented as a synergistic strategy to enhance Zn recovery efficiency and purity, although with increased operational complexity and costs. Future research directions were identified to optimize existing methods and develop new technologies to achieve implementability, intersectionality, economic viability and intelligent control. This review emphasized the need for a subtle understanding of Zn-containing dust properties and development of innovative, efficient, environmentally friendly treatment technologies to support transition to a circular economy.

For meeting requirements of "green steel" and "circular economy", there was great potential and value to synthesize CO2 adsorbent with low price and excellent performance by using multiple solid wastes. In this study, a novel method was proposed to synthesize zeolite by blast furnace slag. CO2 adsorption isotherm, thermodynamic and kinetic were investigated comprehensively. Zeolite exhibited favorable physical and chemical structure. Sips model was more suitable to describe isotherm of CO2 adsorption. CO2 adsorption process of zeolite was a spontaneous adsorption process without additional energy need, which could be determined as physisorption process. Four kinetic models were used to fit experimental data. CO2 adsorption by slag-derived zeolite was complicated multi-path adsorption involving adsorption sites and activity. Film diffusion and intraparticle diffusion were rate-limiting steps for CO2 adsorption by slag-derived zeolite. Generally, it was economically and environmentally beneficial to synthesize zeolite from blast furnace slag to achieve CO2 adsorption.

Iron and steel industry production played an important in construction, machinery manufacturing, aviation and military, as well as generated the huge CO2 emission and environmental pollution. However, a large amount of waste heat resources produced by production units were waste, and the utilization efficiency was only about 50 %. Especially, the utilization efficiency of high-quality slag waste heat was only about 35 %. Therefore, the recovery of waste heat from slag into beneficial resources along with the iron and steel production was to improve the consumption of energy, carbon emission and environmental pollution. This review paper was to aim at giving an overview of the latest technology of slag waste heat recovery by chemical method. Firstly, the mechanism, parameters and equipment of energetic carbon material conversion driven by waste heat were discussed detailed. Secondly, the technology of direction carbonation with hot slag were explored and elaborated as comprehensively as possible. Furthermore, the waste heat using to improve the slag properties and produce high value-added materials were summarized from the aspect of slag resource utilization. Ultimately, problems existing in the development of slag waste heat utilization by chemical method were analyzed and suggested the future direction and challenges. This paper aiming to pave the way for the slag waste heat recovery by chemical method while supporting the industrial application and enhancing the role in the fight against carbon emission reduction for iron and steel industry.

Molten magnesium chloride (MgCl2), a high-temperature by-product from titanium metal production, currently results in substantial thermal energy loss and environmental issues during conventional cooling. This research investigates rotary cup granulation technology to recover this significant waste heat and enhance the overall process safety and environmental performance. The study experimentally examined the breakup dynamics of molten MgCl2 at the rotary cup's edge, evaluating the influence of rotation speed, cup diameter, and mass flow rate on granulation characteristics. Principal findings indicate that rotary cup granulation effectively forms small, uniform spherical particles, predominantly ranging from 0.6 to 1.5 mm. At a rotating speed of 800 rpm, particle uniformity was optimal, with a standard deviation (S-value) below 0.245, suggesting favourable sphericity. Increasing mass flow rate, however, led to larger, less uniform particles and undesirable flake formation. This granulation process is foundational for enhancing waste heat recovery, as the resulting small and uniform spherical particles (0.6-1.5 mm) provide a large surface-area-to-volume ratio, making them an ideal medium for efficient heat transfer in subsequent recovery systems.

Biochar from slow pyrolysis was applied to Chemical Looping Ammonia Generation (CLAG) to avoid the preparation of ammonia from fossil fuels and relatively expensive H-2. The effects of pyrolysis atmosphere, temperature, heating rate, and residence time on the biochar reactivity in the N-adsorption reaction were investigated. The relationship between specific surface area, average pore diameter, micropore percentage, and disorder degree of biochar on reactivity was evaluated by simple and multiple linear regression and Analysis of Variance (ANOVA). The results showed that the biochar prepared in a CO2 atmosphere with a pyrolysis temperature of 700 degrees C, a heating rate of 10 degrees C/min, and a resident time of 30 min had the highest conversion rate of 57.79 % in the N-absorption reaction. When the pyrolysis temperature was increased from 600 degrees C to 700 degrees C, the biochar conversion in the N-adsorption reaction was significantly increased due to the Boudouard reaction during biomass pyrolysis. The linear regression and ANOVA results show that the micropore percentage and disorder degree of biochar significantly positively affected the reactivity, guiding feedstock selection and optimization of the preparation method of the carbon source used for CLAG.

Chemical looping ammonia generation is a promising, efficient, and environmentally friendly synthesis of ammonia by cycling N-absorption and N-desorption reactions. A portion of the generated NH 3 decomposes at the reaction temperature of the N-desorption reaction. In order to promote the N-desorption reaction and inhibit the decomposition of NH 3 , the effect of alpha-Al 2 O 3 loading on the N-desorption reaction was investigated in this paper by fixed-bed experiments. The mechanism was revealed using Density functional theory (DFT) calculations. The results showed that when the reaction temperature increased, the conversion of AlN and the yield of NH 3 increased, but the actual NH 3 conversion decreased. When the steam concentration increased, the conversion of AlN, the yield of NH 3, and the actual NH 3 conversion increased. The loading of alpha-Al 2 O 3 could facilitate the Ndesorption reaction and inhibit the decomposition of NH 3 . The 40 wt% alpha-Al 2 O 3 had the highest conversion of AlN. The 80 wt% alpha-Al 2 O 3 had the highest yield of NH 3 . The actual efficiency of ammonia production at 1075 degrees C with 80 wt% load increased from 45.5% without load to 58.5%. The DFT calculations revealed the mechanism: alpha-Al 2 O 3 surface promotes the dissociation of H 2 O molecules to make more hydroxyl groups in the reaction system, which promotes the transfer of H + and the N-desorption reaction. Meanwhile, the adsorption of NH 3 by the alpha-Al 2 O 3 surface protected NH 3 and inhibited its decomposition.

Introducing cooling airflow is an effective method for achieving the localized cooling rate required during waste heat recovery of blast furnace slag. However, the associated parasitic loads must be considered. This study investigates moving bed heat exchanger with airflow-assisted cooling from an exergy perspective. The effects of the granular side Peclet number, airflow side Reynolds number, and the height ratio of the airflow section on heat loss, exergy destruction, and its distributions were examined experimentally. The results show that the trends of temperature and pressure exergy destruction with each parameter tend to be opposite. Therefore, optimizing the parameters requires a trade-off between different types of destruction. Additionally, reducing exergy destruction while meeting the cooling rate requirement was considered. The optimal parameter set was determined by taking the cooling rate requirement as a constraint and minimizing the dimensionless temperature and pressure exergy destruction to obtain the Pareto front.

Climate change posed the greatest threat to human sustainable development, and reducing carbon emissions was a pressing issue for all humanity. Among the most energy-intensive and carbon emissions industries, the iron and steel industry (ISI) represented almost 5% of energy consumption and 7% carbon emissions around the world. The ISI faced severe challenges from the “relative constraints” of carbon emissions intensity to the “absolute constrains” of total carbon emissions. Waste heat played an indispensable role in the low-carbon development of ISI. The heat contained in the blast furnace slag (BFS) was considerable, and it was an important position to be occupied. In recent decades, the proposal and development of dry centrifugal granulation (DCG) technology had provided researchers with great encouragement and brought the dawn to overcome the problem of slag waste heat recovery. This technology had been hailed as one of the most suitable technologies to boost sustainable transition of the ISI. This paper provided a detailed review of DCG technology including granulation characteristics of BFS, flight and impingement behavior of slag particles, slag transformation in granulation chamber, waste heat recovery process, etc. Furthermore, the implementation and technical characteristics of semi- and industrialization implementation for DCG technology were explored and elaborated as comprehensively as possible. Ultimately, the problems existing in the development of this technology were analyzed, and suggested the future direction and challenges. This paper aiming to pave the way for the waste heat recovery of BFS while supporting the market penetration and enhancing the role in the fight against climate change for ISI.

Blast furnace slag, a main by-product of ironmaking process, contained high-quality sensible heat, accounting for almost 30 % of total energy consumption in iron and steel industry. This paper proposed CO2 coal gasification method aimed at recovering waste heat from blast furnace slag. Based on Gibbs free energy minimization, influence of temperature, CO2/C, pressure and steam were investigated. Under optimal operating conditions at 1023-1198 K, CO2/C of 1.5-2.0 and atmospheric pressure, total amount of syngas was 2.78 kmol, with 67.1 % CO and 8.79 % H2. Addition of steam could adjust compositions of syngas. H2/CO of syngas reached 1.0, 1.5 and 2.0 when H2O(g)/CO2 were 1.45/0.55, 1.73/0.27 and 1.95/0.05, which could be used as organic raw materials for chemical industry. Meanwhile, energy and exergy efficiencies of coal gasification were found to be 63.84 % and 62.58 %, respectively, under optimal operating conditions. For different syngas products, when H2O(g)/CO2 was 1.95/0.05, exergy loss was the lowest, with internal and external exergy loss amounting to 31.80 % and 2.16 % respectively. These works provided theoretical guidance on use of the coal gasification reaction for recovering waste heat from blast furnace slag and contributed to the achievement of the strategic goal of CO2 energy saving and emission reduction.

A novel thermodynamic equilibrium model for coke oven gas reforming reaction with steel slag was developed and the influence of operating parameters on the integrated process were investigated. The sensitivity analysis revealed that the optimal condition for the reforming reaction was the temperature of 1073 similar to 1173 K, CO2/C of 1.5-2.0 and atmospheric pressure. When the temperature reached 1073 K, H-2 and CO yield exceeded 107.75 kmol and 50.21 kmol, respectively. Meanwhile, the comparison of tar removal condition in the coke oven gas reforming reaction with/without steel slag were conducted. The yield of tar decreased from 2.45 x 10(-3) mu mol to 6.27 x 10(-7) mu mol. Furthermore, the influence of steel slag components on coke oven gas reforming reaction were considered at the range of slag basicity (2.0-5.0) and FeO content (18%-24%). The increase of FeO content was benefited to the conversion of tar components with the C6H6 decreased from 1.96 x 10(-6)mu mol to 6.27 x 10(-7) mu mol. Finally, the mechanism of coke oven gas reforming reaction with steel slag was established. This study offered valuable insights into improving coke oven gas reforming reaction with steel slag and provided the guidance of experiment and industrial production.

To evaluate the risk stratification by HPV-integration levels and HPV integration status conversion in HPV integration-positive women after 1-year follow-up. This prospective cohort study conducted in Tongji hospital between June 2020 to August 2022 with 1297 consecutive HPV-positive women. The level of integration reads was stratified for risk assessment. A total of 194 women were HPV integration-positive and followed-up for at least 1 year. The immediate risk of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) increased from 36.2% (25/69) in women with 6-20 integration reads to 93.8% (30/32) in women with more than 1000 integration reads (Ptrend < 0.001). The 1-year cumulative risk of CIN2+ increased from 39.1% (27/64) in women with 6-20 integration reads to 96.9% (31/32) in women with more than 1000 integration reads (Ptrend < 0.001). The 1-year cumulative risk of CIN2+ with HPV integration reads more than 40 was 93.8% (90/96), which was significantly higher than that of HPV integration reads less than 40 (38/85, P < 0.001). At one-year follow-up, in women with HPV integration reads more than 40, 99.0% (95/96) of women progressed with positive outcomes (persistent integration at the same site, immediate CIN2+ and 1-year CIN2+). The progression rate of women with persistent integration at the same site was 41.6% (5/12), which was significantly higher than those of HPV-integration negative conversion (0/41, 0%, P < 0.001). The number of HPV integration reads may have the potential in CIN2+ risk stratification to facilitate the clinical management of high-risk patients.

To further unlock the circular economy potential of iron and steel industry and achieve peak carbon and carbon neutrality targets, this study provides a comprehensive analysis of the high value-added use of blast furnace slag (BFS) for the synthesis of X-type zeolite. The thermodynamic and dissolution behaviors during acid leaching are investigated through theoretical analysis, identifying the optimal pH is 0-1.63 and Eh is- 1.01-2.00 V. Experiments determine that there are obvious improvement in silica gel leaching ratio at 353 K, 4 mol & sdot;L-1- 1 HCl and V (HCl):m(slag) ratio of 12:1. Obtained silica gel has 91.56% whiteness and 86.86% SiO2. 2 . The optimal conditions for X-type zeolite synthesis are crystallization at 363 K for 6 h, with n(SiO2):n(Al2O3), 2 ):n(Al 2 O 3 ), n(Na2O):n(SiO2) 2 O):n(SiO 2 ) and n (H2O):n(Na2O) 2 O):n(Na 2 O) establishes as 2.8, 2.8 and 45 respectively and resulting material has high crystallinity, purity of crystals and excellent performance. Furthermore, the mechanism is elucidated from the perspective of micro- structural and molecular level. Economic evaluation along with carbon tax assessment indicated that it is economically beneficial both in direct profit and potential CO2 2 capture. These findings emphasize the feasibility, efficacy and economy of X-type zeolite synthesis from BFS, which contributes to turning waste into treasure and promoting the concept of "Green steel".

As main by-product in iron and steel industry, high value-added utilization of blast furnace slag had received extensive attention. In this paper, a novelty technology was proposed for using blast furnace slag as raw material to obtain excellent CO2 adsorbent-layered double oxides. The characteristics of layered double hydroxides and layered double oxides were investigated in detailed. Most notably, the laminate structure of layered double hydroxides collapsed and the pore structure, particle size distribution and functional groups of the sample had been greatly changed. The layered double oxides were occupied by phases of CaO, Ca12Al14O32Cl2 and MgO. The transformation mechanism of the layered double oxides preparation was obtained. In addition, CO2 concentration and temperature influencing on CO2 adsorption of layered double oxides were studied and established a suitable kinetic model. The optimal kinetic mechanism model of CO2 adsorption by layered double oxides was PSO. The activation energy and pre-exponential factors were 56.88 kJ‧mol-1 and 12.26 min-1, respectively. Ultimately, CO2 adsorption capacity comparison and preliminary economic evaluation were conducted to assess the industrial feasibility of this technology. This work achieved the goals between CO2 reduction and high value-added utilization of solid waste in iron and steel industry.