Search

As a source substitution technology that reduces pollutants emission and optimizes sinter properties, H2-rich gas injection-assisted iron ore sintering holds significant practical value. This study analyzed the adaptability of this technology to different ore blend ratios and basicity levels by comparing sintering indexes, pore structure, mineral phase composition, and metallurgical performance before and after H2-rich gas injection. The carbon emission reduction following H2-rich gas injection was calculated. The results indicate that increasing the proportion of high-silica, low-alumina ore (Ore-A) and basicity, along with H2-rich gas injection, can effectively enhance sinter yield and quality, but shrink the pore structure of sinter. Under H2-rich gas injection conditions, decreasing Ore-A ratios and increasing basicity can augment SFCA phase formation and mineral phase uniformity, thereby improving the anti-pulverization ability and reductivity of the sinter. H2-rich gas injection presents better adaptability to sintered ore with lower Ore-A ratio and basicity, which can achieve greater improvements in the sintering indexes, RDI, and RI. For a 265 m2 sinter plant producing sinter with 18 wt% Ore-A and 2.0 basicity, annual CO2 emissions can be reduced by approximately 40,000 t.

Numerous innovative low-carbon ironmaking technologies rely on the use of a high-temperature, highly reducing gas, with examples including the gas-based direct reduction approach, hydrogen-enriched blast furnace fuel injection, and hydrogen-rich carbon circulation oxygen blast furnaces. However, the process of obtaining high-temperature and highly reducing gases inevitably leads to carbon deposition, and effective methods for controlling carbon deposition have yet to be developed for practical applications. Thus, within the context of metallurgical process conditions, this article provides a comprehensive review of the advancements in carbon deposition research by integrating findings from the fields of fuel chemistry and carbon material synthesis. Initially, the thermodynamic fundamentals of the carbon deposition reactions are examined, and subsequently, the influences of temperature, H2, and catalysis on the carbon deposition reactions are discussed. In addition, the growth and erosion mechanisms of carbon on the surface of the medium are analyzed. Finally, this review consolidates the methods available for controlling carbon deposition, encompassing changes in the process conditions, the development of anti-carbon materials, and research into special processes. This article also identifies gaps in the literature and outlines future directions in related fields, notably proposing the application prospects of the sulfur passivation and thermal plasma reforming technologies in the reforming and heating of highly reducing gases.

Cisplatin, a frequently prescribed chemotherapeutic agent, serves as a clinically therapeutic strategy for a broad range of malignancies. Its primary mode of action centers around interference with DNA replication and RNA transcription, thereby inducing apoptosis in cancer cells. Nevertheless, the clinical utility of cisplatin is constrained by its severe adverse effects and the burgeoning problem of drug resistance. Ginsenosides, potent bioactive constituents derived from ginseng, possess an array of biological activities. Recent scientific investigations underscore the substantial amplification of cisplatin's anticancer potency and the mitigation of its harmful side effects when administered concomitantly with ginsenosides. This review aims to explore the underlying mechanisms at play in this combination therapy. Initially, we provide a concise introduction to the cisplatin. Then, we pivot towards illuminating how ginsenosides bolster the anticancer efficacy of cisplatin and counteract cisplatin resistance, culminating in enhanced therapeutic outcomes. Furthermore, we provide an extensive discussion on the reduction of cisplatin-induced toxicity in the kidneys, liver, gastrointestinal tract, nervous system, and ear, accompanied by immune-fortification with ginsenosides. The existing clinical combined use of cisplatin and ginsenosides is also discussed. We propose several recommendations to propel additional research into the mechanisms governing the synergistic use of ginsenosides and cisplatin, thereby furnishing invaluable insights and fostering advancement in combined modality therapy.

Abstract The petroleum coke (PC) has been widely used as raw materials for the preparation of electrodes in aluminium electrolysis and lithium‐ion batteries (LIB), during which massive CO2 gases are produced. To meet global CO2 reduction, an environmentally friendly route for utilizing PC is highly required. Here, a simple, scalable, catalyst‐free process that can directly convert high‐sulfur PC into graphitic nanomaterials under cathodic polarization in molten CaCl2‐LiCl at mild temperatures is proposed. The energy consumption of the proposed process is calculated to be 3 627.08 kWh t−1, half that of the traditional graphitization process (≈7,825.21 kWh t−1 graphite). When applied as a negative electrode for LIBs, the as‐converted graphite materials deliver a competitive specific capacity of ≈360 mAh g−1 (0.2 C) compared with commercial graphite. This approach has great potential to scale up for sustainably converting low‐value PC into high‐quality graphite for energy storage.

As a modification of the conventional blast furnace (BF), the top gas recycling-oxygen blast furnace (TGR-OBF) has been continuously studied in the context of the technological transformation of low-carbon metallurgy. As it has a set of new gas inlets in the stack and changes the blast operation system in the hearth, the pressure drop and the in-furnace gas flow are the primary problems to be solved in the TGR-OBF’s industrialization. In this paper, a two-dimensional model of a whole blast furnace, based on a softening-and-melting experiment and porous-medium theory, is established. The in-furnace pressure drop and the gas velocity with different oxygen concentrations and tuyere heights are studied. The results show that the suitable height of the stack tuyere is the same as that of the elevation as the cohesive zone inside the furnace. With the gradual increase in oxygen enrichment, the permeability of the cohesive ore layer (COL) increases, while the gas flow through the coke layer (CL) decreases gradually up to 10%. The simulation results provide a theoretical basis for the TGR-OBF to reduce the coke rate and keep the pressure drop from increasing, or even to enable it to decrease.

Direct reduction of iron ore with H2 has become an alternative technology for iron production that reduces pollutant emissions. The reduction kinetics of iron ore fines in an H2 atmosphere under isothermal and non-isothermal conditions were studied by thermogravimetric analysis. X-ray diffraction and scanning electron microscopy were used to measure the mineral composition and analyse the morphology of the reduced fines, respectively. In the isothermal reduction experiment, it was found that the final reduction time was shorter, the higher the temperature, and the metallic iron particles formed a dense matrix structure. It is likely that the initial stages reduction process is the result of a combination of gaseous diffusion and interfacial chemical reaction mechanisms, and that the later stages a combination of interfacial chemical reaction and solid diffusion is the rate control mechanism. In the non-isothermal experiment, the heating rate had a significant effect on the reaction rate. The results show that the non-isothermal reduction proceeded through three stages: mixing control model, two-dimensional diffusion, and three-dimensional diffusion.

Isothermal and non-isothermal gasification kinetics of coal char were investigated by using thermogravimetric analysis (TGA) in CO2 atmosphere, and the experimental data were interpreted with the aids of random pore model (RPM), unreacted shrinking core model (URCM) and volume model (VM). With the increase of heating rate, gasification curve moves into high temperature zone and peak rate of gasification increases; with the increase of gasification temperature, gasification rate increases and the total time of gasification is shortened. The increase of both heating rate and gasification temperature could improve gasification process of coal char. Kinetics analysis indicates that experimental data agree better with the RPM than with the other two models. The apparent activation energy of non-isothermal and isothermal gasification of coal char using RPM is 193.9 kJ/mol and 212.6 kJ/mol respectively, which are in accordance with reported data. Gasification process of coal char under different heating rates and different temperatures are predicted by the RPM derived in this study, and it is found that the RPM predicts the reaction process satisfactorily. Keywords: Coal char, Gasification, Thermogravimetric analysis, Kinetics model

Pure chemical reagents Fe2O3, Al2O3, and Ca(OH)2 were used to investigate the formation of calcium ferrite in the solid state. The phase composition of the prepared samples was determined using X-ray powder diffraction and by SEM. The TG-DSC analysis was performed to analyze the decomposition behavior and formation of calcium ferrites. The formation rate of calcium ferrite was determined by in-situ X-ray diffraction (XRD) and by the K-value method. The X-ray diffraction analysis was performed using Pt as the internal standard for application of the K-value method. The formation of Ca2Fe2O5 (C2F) occurred much earlier than the formation of CaFeO4 (CF). C2F and CF were formed at approximately 600 °C and 700−800 °C, respectively. With an increase of Al2O3 content, there was a tendency to decrease the melting temperature. There was a heating scheme in this study (i.e., 10 °C per minute to 1250 °C under a flowing atmosphere of high-purity air). The total amount of CF increased with an increase of the Al2O3 content, and the Al2O3 content reaching the maximum value of CF was 1.4%. As the Al2O3 content increased from 1.4% to 2.8%, the total amount of CF reduced slightly. When the Al2O3 concentration was greater than 2.8%, the content of CF generated significantly decreased with the increase of Al2O3.

According to the mineral composition characteristics of high-phosphorus iron ore, the reaction mechanism of fluorapatite was investigated using pure substance and gangue under vacuum carbon thermal reduction (VCTR) conditions. The effects of reduction temperature, basicity, and C/O ratio on the metallization ratio, dephosphorization ratio, and phosphorus content of pellets were studied. The reaction process of fluorapatite in high-phosphorus iron ore was investigated. The results showed that when the metallization ratio of pellets reached maximum (95%), the dephosphorization ratio was only 5.6%, thus indicating adverse result. The reduction processes of high-phosphorus iron ore under vacuum and nitrogen environment were, respectively, compared under the optimal condition. It was found that the metallization ratio of pellets in the vacuum condition was higher than that under the nitrogen condition, while the dephosphorization ratio showed an opposite result. This indicated that in the process of vacuum reduction, fluorapatite not only reacted with carbon to form gaseous phosphide, but also with iron to form compounds containing the Fe⁻P bond. Therefore, a new mechanism of reduction of fluorapatite was proposed as follows: 2Ca5(PO4)3F + 12Fe + 9SiO2 + 15C = 9CaSiO3 + 6Fe2P + 15CO + CaF2.

Copper staves have been widely applied in large blast furnaces especially those whose inner volumes exceed 2000 m3 due to high cooling capacity. In the past decade, copper staves suffered severe damages in some blast furnaces, which not only shortened their campaign lives, but also caused huge economic losses. In order to make out this phenomenon, the damage mechanism of copper staves was investigated via analyzing the chemical composition, thermal conductivity, metallographic aspects and microstructure in this paper. As a result, the working state was more likely to damage copper staves instead of their materials. At the beginning, the poor quality of the coke and the large bosh angle promoted the development of edge airflow, which intensified the erosion of refractory materials, resulting in the fall-off of slag crusts and damage of cooling water pipes. After repair, the cooling capacity of copper staves still declined, causing the temperature to rise easily; consequently, hydrogen attack happened when the temperature reached 370 °C, which degraded the performance of copper staves. Therefore, copper staves were worn too quickly to form slag crusts, which finally failed under the hydrogen attack and the scouring of the edge airflow at high temperatures.

The influence of BaO on the structure, viscosity and sulfide capacity at 1500°C of CaO-SiO2-MgO-Al2O3-BaO-MnO slag was investigated comprehensively. The activity of O2-and activity coefficient of S2- were discussed, and the sulfur distribution ratio was deduced and analyzed from sulfide capacity. The results revealed that the viscosity increased slightly owing to an increase of BaO content, and the complexity of [SiO4]-tetrahedra and the connection between [SiO4]- and [AlO4]-tetrahedra structure were tighter. The sulfide capacity was lager due to the increased sum of basic component, but the increased range was weakened when BaO was more than 3wt-%. The activity of CaO increased and activity coefficient of CaS descended firstly and then enhanced, but the difference between logaCaO and logαCaS tended to be bigger as a function of BaO. The sulfur distribution ratio was in range of 40-50, similar to the variations of sulfide capacity. [ABSTRACT FROM AUTHOR]