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China, being the world's largest exporter, has now certain environmental commitments such as to achieve carbon neutrality before 2060. These commitments of China has raised a reasonable concern regarding the expected reduction in the production and export of pollution intensive goods in the future. Besides China, the most efficient countries in the region to produce these goods are most of the member countries from ASEAN. The current study therefore aims to analyze if in the future, China reduces the production and export of these goods, whether the selected ASEAN countries can be the next choice for the export of pollution intensive goods. Based on the data availability for the period 1990–2019, this study considers five selected ASEAN countries (ASEAN-5). The results are based on the Auto Regressive Distributive Lag (ARDL) bound testing approach to cointegration and Error Correction Modeling (ECM). The aggregate analysis of five pollution intensive goods (pulp and paper (341), industrial chemicals (351), non-metallic minerals products (369), iron and steel (371) and non-ferrous metals (372)) suggests that Foreign direct investment (FDI) inflow can significantly increase the export of pollution intensive goods only in case of Indonesia, Malaysia and Thailand. However, there is no significant effect of FDI on the export of pollution intensive goods in case of Philippines and Singapore. The disaggregate analyses of the five pollution intensive goods suggest that in each of the ASEAN-5 countries, FDI inflow can significantly increase the export of pollution intensive goods in some of these industries rather than in all of them. In nutshell, it is concluded that ASEAN-5 countries can be a potential choice for the export of pollution intensive goods in some of the pollution intensive industries but not in all of them. [ABSTRACT FROM AUTHOR]

Based on the data of listed companies in China's iron and steel industry from 2007 to 2020, the article investigates the impact mechanism and the path of action of China's carbon emissions trading pilot on the green total factor productivity of iron and steel enterprises by constructing a multi-period difference-in-difference model difference-in-differences. The study finds that: 1) China's iron and steel enterprises significantly improve their green total factor productivity driven by the carbon trading pilot, and the findings pass the corresponding robustness tests. 2) the mechanism analysis indicates that the carbon trading pilot promotes the green total factor productivity of iron and steel enterprises by forcing the technological progress of enterprises. 3) The heterogeneity analysis shows that the positive effect is more significant for large iron and steel enterprises with high social responsibility rating and high local government competition intensity, but not for small enterprises with low social responsibility rating and low local government competition intensity. 4) the dynamic effect shows that there is a certain lag in the promotion effect of the carbon emission trading pilot on the green total factor productivity of iron and steel enterprises, but its long-term effect is more obvious. This paper puts forward corresponding suggestions for accelerating the construction of a national unified green and low-carbon market system and actively promoting the deepening of the "dual-carbon" goal. [ABSTRACT FROM AUTHOR]

The iron and steel industry is an important foundation of the national economy. It is the inevitable choice, to achieve high-quality development in the new era of the iron and steel industry, to speed up the green development of the iron and steel industry. This paper studies the effect of steel industry agglomeration on regional economic growth and air pollution. Through the analysis of the characteristics of iron and steel industry agglomeration, and the empirical analysis of the relationship between iron and steel industry agglomeration, regional economic growth, and air pollution, it is found that: (1) Iron and steel industry agglomeration helps to promote economic growth; (2) Iron and steel industry agglomeration has an obvious spatial correlation effect and obviously drives the development of surrounding areas; (3) Iron and steel industry agglomeration will cause air pollution. The marginal effect of air pollution will decline rapidly with the development of iron and steel industry agglomeration. (4) The impact of green process innovation investment on air pollution presents an inverted U-shaped effect, which has a positive effect on air recovery after exceeding the critical point. (5) The air self-purification capacity represented by precipitation, helps to reduce air pollution. Based on the above conclusions, this paper puts forward some policy suggestions, such as making a scientific development plan for the iron and steel industry, accelerating green process innovation, effectively improving regional precipitation and precipitation times, vigorously promoting high-quality development of the regional economy, and comprehensively promoting coordinated development of the iron and steel industry, so as to cope with the dilemma of the coordinated development of the iron and steel industry, regional economic growth, and smog pollution, and strive for international development in the future. In the competition, we should gain the first opportunity and obvious competitive advantage. [ABSTRACT FROM AUTHOR]

The deployment of energy storage systems can play a role in peak and frequency regulation, solve the issue of limited flexibility in cleaner power systems in China, and ensure the stability and safety of the power grid. This paper presents a comprehensive environmental impact analysis of a lithium iron phosphate (LFP) battery system for the storage and delivery of 1 kW-hour of electricity. Quantities of copper, graphite, aluminum, lithium iron phosphate, and electricity consumption are set as uncertainty and sensitivity parameters with a variation of [90%, 110%]. The results show that global warming potential is 9.08E+01 kg CO2 eq. and fossil resource use is 1.21E+03 MJ, with uncertainty ranges of [8.54E+01, 9.23E+01] and [1.15E+03, 1.23E+03], respectively. Electricity consumption during the manufacture and installation process is the greatest contributor to climate change (CO2 eq. emissions), accounting for 39.71% and largely owing to non-renewable sources, followed by cathode materials at 27.85% and anode materials at 18.36%. The disposal and recycling process offers emission reductions but requires an additional 1.17% use of fossil resources. Sobol T indices for the quantity of electricity are the highest for acidification, climate change, fossil resource use, and ionizing radiation. By considering the pathway of China's electricity mix from 2020 to 2050 under the Paris Agreement's 2° target, the potential for environmental emission reduction in the system is evaluated. The results show that the greener electricity mix could lead to a 24.59% reduction in acidification impact, a 35.74% reduction in climate change impact, a 33.24% reduction in fossil resource use, and a 44.13% reduction in ionizing radiation impact. This study offers a comprehensive view of the environmental impact reductions associated with the lithium iron phosphate battery and its industry. [ABSTRACT FROM AUTHOR]

The average grade of iron ore is low in China, and it is significant for the effective utilization of iron ore to obtain grades. In the paper, the high-precision model was constructed based on the spectrum of hematite and the multiple hidden layers extreme learning machine with random values and dense connection, which took the output of all previous layers as the input of each hidden layer. It has achieved high precision during the detection of the total iron content for hematite, which meets the requirements for the construction and development of new green and intelligent mines. [ABSTRACT FROM AUTHOR]

As part of the ongoing China Fusion Engineering Test Reactor (CFETR) studies, this work focused on the study of the electromagnetic (EM) loads distribution on inboard (IB) and outboard (OB) blanket vertical segments. In this paper, a major central disruption scenario with a 36-ms linear current quench was performed in the ANSYS finite element software. EM forces and moments, both on the single module and the complete blanket segment, were calculated for the updated helium-cooled ceramic breeder (HCCB) blanket. Furthermore, the effect of EM loads with respect to poloidal segmentations on the back plate (BP) was studied. Results show that the EM forces and moments in the IB blanket barely changed, but in the OB blanket, great changes occurred. With poloidal segmentations increasing, EM forces loads on the BP will be reduced. This paper may provide important data to support subsequent optimization of the BP of CFETR and could also be a technical reference for other fusion organizations. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

China is currently the world's largest producer and consumer of iron and steel. This industry is one of the most energy- and emission-intensive industries in China. It is unsuspicious that energy conservation and emission reduction in this industry are crucial for China to fulfill its obligations of reducing greenhouse gas emission and mitigating global climate change. An appropriate allocation of CO2 emissions permit is the most important precondition for establishing an efficient and effective emissions trading system that had recently been launched in China's pilot regions. This paper proposes a new emissions permit allocation method based on a Nash equilibrium data envelopment analysis model. This method is more appropriate in emissions permit allocation for China's iron and steel firms in an imperfectly competitive market where the product price is endogenous. A noncooperative game is formulated and the mixed complementarity problem is utilized to identify a Nash equilibrium in the allocation of emissions permit (AEP). The most up-to-date AEP using a unique data set of China's major iron and steel enterprises in 2014 is provided in this paper. The results show that the AEP improves the desirable output generation by satisfying the reduction targets of the undesirable outputs. [ABSTRACT FROM AUTHOR]

The Naxiguole Banded Iron Formation (BIF), located in the Eastern Kunlun Orogenic Belt, Northwest China, is hosted by the Jinshuikou Group and has a Fe of 75 Mt at a grade of 15–28.83 wt.% Fe. In this paper, we use integrated petrological, geochemical, and geochronological data to limit the age and origin of the Naxiguole BIF. Country rocks mainly comprise marble, felsic paragneiss, plagioclase amphibolite schist, and biotite plagioclase gneiss. The features of sedimentary structure (blastopsammitic texture and blastobedding structure) and trace elements (e.g. La, Ni, Zr) from the country rock indicate that their protoliths are sedimentary rock. The 141 detrital zircons from the Jinshuikou Group yield a minimum age of 908 Ma, which can be considered the upper limit for the Naxiguole BIF. According to the age (602 Ma) of the mafic rocks intruding into the Jinshuikou Group, it is reasonable to assume that the formation age of BIF can be limited at 908–602 Ma (i.e. Neoproterozoic). The high contents of Al2O3 + TiO2 (3–6 wt.%), ΣREE (36–135 ppm) for BIF samples suggest that terrestrial clastic material contributed to BIF formation. The BIF samples show seawater-like features, such as depletion in LREEs, positive Y anomaly and high Y/Ho ratios (30.7–57.5, average = 42.5), implying that the Naxiguole BIF precipitated from seawater. The positive Eu/Eu*PAAS anomalies (average 1.52) suggest the influence of high-T hydrothermal fluids. Based on positive Eu anomalies and high terrestrial clastic components and no obvious Ce anomalies, the Naxiguole BIF was formed in an anoxic or suboxic sedimentary basin within active continental island arc, and is similar to Superior-type BIFs worldwide. [ABSTRACT FROM AUTHOR]

This paper studies the relationship between firms' excess capacity and their environmental behaviour by matching the environmental data of China's major iron and steel firms with the Chinese Industrial Enterprises database. The findings are as follows. (1) A firm's excess capacity leads to myopic decisions, and firms will pay more attention to short‐run economic benefits at the cost of long‐run environmental benefits, which strengthens their dependence on the polluting path. (2) The dependence is positively correlated with the transformation barriers, and either a higher innovation cost or a higher possibility of regulatory capture in local official governance would lead to greater dependence on the pollution path. (3) Mergers & acquisitions (M&As) may hopefully cut such dependency, but only cross‐provincial M&As led by central state‐owned enterprises (SOEs) can effectively alleviate the "pollution effect" of excess capacity, while intra‐provincial M&As led by local SOEs fail to achieve such a goal. [ABSTRACT FROM AUTHOR]

Groundwater resources are an essential component of global water resources. Long-term consumption of groundwater exceeding the standard levels for iron and manganese can lead to chronic diseases, posing a threat to human health. The Sanjiang Plain is the largest swamp wetland area in China and has high levels of iron and manganese in the groundwater, but the cause still needs to be clarified. Based on the results of water quality tests of 41 groundwater samples in the Eastern Sanjiang Plain, this paper analyzes the distribution characteristics and causes of iron and manganese from the perspectives of the original strata environment, redox conditions, pH conditions, and hydrochemical indicator factors in the research area, using statistical methods and GIS technology. The results show that high iron and manganese content in groundwater is prevalent in the Eastern Sanjiang Plain, and the exceedance rate of manganese is higher than that of iron (87.80% and 82.90%, respectively). The primary sources of iron and manganese in groundwater are iron and manganese minerals in the original strata environment. Influenced by factors such as acidic conditions, reducing environment, and rich organic matter, insoluble high-valent iron and manganese oxides are reduced to low-valent and soluble divalent iron and manganese. At the same time, groundwater's high mineralization and evaporation concentration are conducive to increased iron and manganese content, while the influence of human activities is small. [ABSTRACT FROM AUTHOR]

Since the Circular Economy Promotion Law of People's Republic of China came into force in 2009, the concept of circular economy (CE) has gained a rising attention from governments and researchers. Policy makers, companies and researchers have started to establish different sets of principles and strategies for adoption. This paper introduces the CE within China's economy background and reviews the drivers to adopt and facilitate its CE. It integrates several current CE practices in China and conducts an analysis on the recycling rate from the government official reports that show China has made some progress in recycling industrial tangible waste and major renewable resources such as iron and steel with remaining challenges and barriers. Further analysis suggests that China requires a more systematic approach to promote CE by individuals, organizations and the nation. [ABSTRACT FROM AUTHOR]

Based on the 2030 carbon peak target, this paper studies the top-down provincial carbon quota allocation in China's iron and steel industry. Considering the principles of fairness, efficiency, sustainability and development, three provincial carbon quota allocation schemes are constructed based on entropy method, three-stage DEA and ZSG-DEA model respectively, which make up for the gap of carbon quota allocation scheme with the total amount of carbon peak target of the iron and steel industry. The allocation results show that the allocation based on the entropy method can roughly solve the problem of uneven distribution of carbon quota of the steel industry in various provinces, and the carbon quota in the steel industry decreases from the eastern region to the western region. Considering the two environmental indicators of local government competition and urbanization level, the initial carbon quota allocation scheme can be effectively adjusted, which is conducive to promote the enthusiasm of some underdeveloped areas. The allocation scheme, which combines the entropy method with the ZSG-DEA model, can enhance the efficiency of carbon quota allocation among provinces while ensuring fairness. However, this fairness is limited and more advantageous to economically developed regions. [ABSTRACT FROM AUTHOR]

Nanhai I shipwreck was a large wooden merchant ship (22.15 m in length and 9.85 m in width) built in the Southern Song Dynasty (1127–1279 A.D.) of China, which was heavily loaded with a large number of porcelain and iron artifacts. In the South China Sea, it was found in 1987 and lifted as a whole in 2007. Its excavation provides a precious opportunity to reveal the preservation status of Nanhai I shipwreck. Iron compounds give rise to challenges in conservation procedures and the long-term stability of Nanhai I shipwreck. In this paper, the degradation of the wood and the iron deposits in the wood structure are investigated from the aspects of microscopic morphology, composition, and distribution to evaluate the preservation state of the waterlogged wood. Physical parameters, chemical composition, and the results of elemental analysis, and FTIR analysis suggest that the cellulose of wood is degraded, and the relative concentration of lignin increases. The ash content varies greatly among different samples, and the element of the highest content in ash is iron. The study on transverse and longitudinal sections from samples indicate that the deposits are unevenly concentrated in the cell lumen, middle lamella, rays, and pits of the cell wall. The cell lumen is filled with deposits in areas close to the surface of the samples. The XRD analysis demonstrates that the deposits in wood are mainly iron deposits, containing compounds pyrite (FeS2), siderite (FeCO3), iron oxyhydroxides (FeOOH), and magnetite (Fe3O4). The micro-X-ray Fluorescence mapping analysis suggests that the content of iron is relatively richer while containing less sulfur on the exterior of the sample. The presence of iron deposits accelerates wood degradation and increases the safety hazards of shipwrecks in the preservation process. We hope that our findings can make a modest contribution to iron removal from waterlogged archeological wood and shipwreck conservation. [ABSTRACT FROM AUTHOR]

Metal raw materials are essential for industrial production. Global metal markets have changed considerably since the start of the twenty-first century, China being the most influential driver of this change. With China's economic rise, metal demand has skyrocketed, and global production shares in metal raw materials and trade volumes have shifted towards the People's Republic. While China has become the dominant location for global metal production and consumption, older industrial economies like the European countries or the US have lost global share. This paper aims to compare the different developments in China, the European Union and the US regarding markets for the base metals aluminium, copper, lead, nickel, tin and zinc as well as iron and steel. The analysis covers movements in industrial production, metal production locations (mining – refined production – refined consumption) and metal trade volumes (ores and concentrates – waste and scrap – refined products and articles thereof). [ABSTRACT FROM AUTHOR]

Max Weber came to see his "rational bureaucracy" as also something of an "iron cage." The reliance on regularized paperwork can result in a separation of the administrative procedure from actual substance, and the level-by-level transmission of documents can result in the resolution of problems on paper only. The complex specialized and standardized procedures of the formal, hierarchical bureaucracy are therefore often ineffective because they have lost touch with reality. In China, the problem of the "involution" of public power found by central inspection teams 中央巡视组 during the course of their inspections is in essence the "formalist" 形式主义 response of bureaucracy when supervised and reviewed. Weber believed that the iron cage of bureaucracy, or the irrationality of rationality, needs an outside "charismatic" authority to check and counterbalance it. The practice of the central inspection teams, however, shows how bureaucratic organizations only further intensify formalism to preserve themselves in the face of such outside authority. That is to say, if the charismatic authority does not break through the trap of bureaucratized patterns of thought and behavior, the iron cage will only be further strengthened and perpetuated. [ABSTRACT FROM AUTHOR]

Antimony is classified as a critical/strategic metal. Its primary production is predominated by China via pyrometallurgical routes such as volatilization roasting—reduction smelting or direct reduction smelting. The performance of most of the pyro-processes is very sensitive to concentrate type and grade. Therefore, technology selection for a greenfield plant is a significant and delicate task to maximize the recovery rate of antimony and subsequently precious metals (PMs), mainly gold, from the concentrates. The current paper reviews the conventional pyrometallurgical processes and technologies that have been practiced for the treatment of antimony concentrates. The blast furnace is the most commonly used technology, mainly because of its adaptability to different feeds and grades and a high recovery rate. In addition, several other more environmentally friendly pyrometallurgical routes, that were recently developed, are reviewed but these are still at laboratory- or pilot-scales. For example, decarbonization of antimony production through the replacement of carbonaceous reductants with hydrogen seems to be feasible, although the process is still at its infancy, and further research and development are necessary for its commercialization. At the end, available refining methods for removal of the most important impurities including arsenic, sulfur, lead, iron, and copper from crude antimony are discussed. [ABSTRACT FROM AUTHOR]

The aim of this study is to consider the economic, resource, energy and environmental factors in a low-carbon economic efficiency evaluation system and to analyze the factors affecting iron and steel enterprises. A combined data envelopment analysis and Malmquist index model have been used in this paper. We empirically investigate the low-carbon efficiency of the Chinese steel industry using observations of 17 listed enterprises from 2009 to 2013. The results show that the economic efficiency of China's iron & steel enterprises is generally low. The Malmquist productivity index also shows a decreasing trend. Based on our findings, some policies are proposed to improve the low-carbon economic efficiency of China's steel industry. [ABSTRACT FROM AUTHOR]

Copyright of Review of International Affairs (04866096) is the property of Institute of International Politics & Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Confluenze. Rivista di Studi Iberoamericani is the property of Universita di Bologna, Dipartimento di Lingue, Letterature e Culture Moderne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, a novel descriptor estimator-based incipient fault estimation scheme is designed for Lipschitz nonlinear descriptor systems with process disturbances and measurement output noises. By using the proposed estimator, incipient sensor faults, abrupt actuator faults, and measurement noises can be estimated asymptotically. Application results conducted on a three-phase inverter system of China railway high-speed trains are given to illustrate the effectiveness of the developed approach. The main contributions are summarized in two aspects: 1) the unified framework designed for actuator and sensor fault reconstruction/estimation problem is capable of dealing with actuator and sensor faults at the same time and 2) a linear matrix inequality optimization method is formulated to achieve optimal performance of signal estimation. [ABSTRACT FROM AUTHOR]

With the thriving development of China's steel industry, iron tailings have become one of the most deposited industrial solid wastes in China, the treatment of which has become a key link faced by mining and smelting enterprises. With the perspective of effective utilization of iron tailings resources, the paper discussed the current research status of iron tailings in China used as concrete raw materials, sand slurry raw materials, roadbed materials, brick fabrication materials, aerated concrete materials, mine backfill materials and so on, as well as the existing problems and outlook for future development, in hope that it can provide references for the comprehensive utilization of iron tailings. [ABSTRACT FROM AUTHOR]

Xuxiebian is an iron‐smelting site located in Pujiang county of Sichuan province, China. Two excavations were carried out in 2007 and 2011, and four bowl‐shaped furnaces were excavated. Ten slag samples from the site were prepared and analysed. The present paper reports the results of metallographic and elemental examination of the specimens. It is concluded that both pig‐iron‐smelting and refining process were applied at the Xuxiebian site, and the bowl‐shaped furnaces are possibly refining furnaces. The function of the site was probably to produce pig iron and refine the pig iron into wrought iron. [ABSTRACT FROM AUTHOR]

Some toe-deck crack cases in China have been reported after about 10 years of service in suspension and beam bridge steel orthotropic decks with trough stiffeners. In this paper, a reference stress method used in design practice and a hot-spot stress method provided by the International Institute of Welding are used to investigate toe-deck fatigue of the newly built Taizhou Yangtze River Bridge. Shell and solid finite element models with different mesh sizes are compared. The hot spot at the weld toe and the point at the trough-deck intersection are discussed. One is a shell-model hot spot with no weld. The other is a solid-model hot spot with the weld. Hot-spot stress calculated with the shell model is larger than that with the solid model. Different extrapolation methods of hot-spot stress are discussed; stress calculated with the linear extrapolation method is almost the same as with the quadratic method. The stress of the joint under a moving unit wheel load is studied. Fatigue strengths against reference and hot-spot stresses are derived. Fatigue damages under the truck load, evaluated based on the reference stress method and the hot-spot stress method, are compared. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • Fluid overpressure plays a key important role in the formation of skarn iron deposit. Skarn iron deposits are important resources for iron-rich ores and their genesis has been a topic of debate. The Nanminghe iron deposit is a typical skarn iron deposit in Wu'an, Hebei Province, China which provides a good example to investigate the metallogenic mechanism. In this paper, we present a detailed study of the geology, petrography, and geochemical characteristics of magnetite in the Nanminghe iron deposit. Two types of magnetite can be identified in the massive ores: Mag1 is euhedral with radial cracks developed in the margin. It is a low-Si magnetite, with SiO 2 content ranging from 0.07% to 0.92%, with an average value of 0.49%. The SiO 2 content of Mag2 is from 0.90% to 3.29%, and an average value of 2.03%. The Mag2 is associated with quartz, goethite, and apatite. Geochemical characteristics of Mag1, together with the ore textures suggest its crystallization from an iron magma. There are significant differences in the geochemical characteristics between Mag1 and Mag2. Mag2 is rich in Nb, Ta, high field strength elements, large ion lithophile elements and has higher silica content. The Nb/Ta of Mag2 is higher than that of the original mantle. These characteristics as well as La/Ta vs Th/La, Th/U vs Sm/Nd and Nb/Ta vs Nb features show that Mag2 is formed in the environment of supercritical fluids. The δ56Fe of Mag1 is 0.157‰-0.172‰, with an average value of 0.166‰, and the δ56Fe of Mag2 is 0.119‰-0.160‰, with an average value of 0.139‰. The Fe isotope of Mag2 is lighter than Mag1. There is a negative correlation between δ56Fe and SiO 2 of Mag1 and Mag2, suggesting that the lighter δ56Fe of Mag2 was caused by injection of Si-rich fluids. We propose a genetic model where we envisage that the iron-rich melt formed in the deep magma chamber by reaction of dioritic rocks and carbonates. Mag1 formed by cooling of the iron-rich magma, following which Si-rich supercritical fluid were injected into the deep chamber resulting in fluid overpressure. The iron-bearing melt-fluid migrated upward along the magmatic conduit, when Mag2 formed. Our study provides insights into the formation mechanism of skarn iron deposits. [ABSTRACT FROM AUTHOR]

• A multi-stage Malmquist-Luenberger index model is constructed for the multiple production of iron and steel industry. • The proposed model can evaluate environmental total factor productivity (ETFP) growth of whole system and sub-process. • Technical regression of steel-making sub-process is the main source of restricting system ETFP growth. • The change of system ETFP varies greatly, being highest in the eastern region, and lowest in the western region. • Compared with the single-stage conventional MLPI, the multi-stage MLPI is smaller and has more discriminatory power. This paper develops a multi-stage Malmquist-Luenberger index (MLPI) model by considering the joint production of desirable and undesirable outputs in multiple production processes. The proposed approach not only evaluates the environmental total factor productivity (ETFP) growth of the whole system but also investigate the progress and regress of each sub-process, i.e., the iron-making sub-process and the steel-making sub-process. Driving factors of ETFP change are identified through multi-stage MLPI decomposition. With an application of the proposed model in China's 48 iron and steel enterprises over the period of 2009–2013, the validity of the proposed models has been demonstrated. Moreover, this study explores the regional difference analysis of system and multi-stage ETFP among 31 provinces in eastern, central and western regions. Results show that the ETFP of system, iron-making sub-process and steel-making sub-process experienced increase annually, the most important finding is that the environmental efficiency increase is the most critical driving factor in promoting ETFP growth. Technical regression of steel-making sub-process is the main source of restricting system ETFP growth. In addition, the change of system ETFP varies greatly in different regions, being highest in the eastern region, and lowest in the western region. Compared with the single-stage conventional MLPI, the multi-stage MLPI is smaller and has more discriminatory power. [ABSTRACT FROM AUTHOR]

The Kaladawan iron deposit is located in the North Altyn Tagh and exhibits occurrences of iron ore bodies at the contact zone between Ordovician magmatic rocks (basalts, rhyolite, and granodiorite) and marble. However, controversy persists regarding the genetic classification and metallogenic mechanism of this deposit. Through a field investigation, single mineral in situ geochemical analysis, whole-rock geochemical analysis, and Fe isotope determination, the following conclusions are made: (1) Ti-(Ni/Cr) and (V/Ti)-Fe diagrams indicate that the magnetite from all studied rocks underwent hydrothermal metasomatism, while (Ni/(Cr + Mn))-(Ti + V) and (Ca + Al + Mn)-(Ti + V) diagrams suggest a skarn origin for these magnetites. Therefore, it can be inferred that the Kaladawan iron deposit is skarn-type. (2) The iron ore exhibits similar rare-earth-element characteristics to the altered basalt. Additionally, the altered basalts (δ56Fe = 0.024~0.100‰) are more enriched in light Fe isotopes than the unaltered basalts (δ56Fe = 0.129~0.197‰) at the same location, indicating that the ore-forming materials of the Kaladawan iron ore are mainly derived from basaltic rocks. (3) According to the law of mass conservation and the intermediate Fe isotopic composition of the iron ore between the granodiorite and basalt, the hydrothermal fluid for the formation of iron ores was inferred to be derived from the late intrusive granodiorite. [ABSTRACT FROM AUTHOR]

Iron isotope compositions, along with the partial extraction of iron in its various forms, can be utilized to investigate the complex interplay of iron migration and transformation with respect to iron isotope patterns. This study investigated the iron composition of a typical loess-paleosol sequence in Northeast China and aimed to understand the influence of iron migration and transformation of the typical loess-paleosol sequence on iron isotopes and environmental and climatic changes that occurred in the region over time by analyzing the distribution and characteristics of iron compositions in sedimentary layers. Samples were collected from Chaoyang in Northeast China, and the iron isotopic composition was analyzed using the multi-receiver inductively coupled plasma mass spectrometer (MC-ICP-MS). The findings revealed depth-dependent variations in the content of different iron forms, reflecting paleoclimatic shifts primarily through pedogenic transformation processes. Notably, iron migration within the section was observed to be limited. The variations in the reddening index and magnetic susceptibility of the loess-paleosol were primarily influenced by the presence of free iron (Fed), exhibiting a range of colors from yellow to red-yellow and red. The δ56Fe values for loess and paleosols ranged from 0.097 ± 0.035‰ to 0.167 ± 0.010‰, with an average of 0.133 ± 0.024‰ and a coefficient of variation (CV) of 15.66% at the stratum scale. These values indicated a systematic enrichment of heavy iron isotopes and a significant negative correlation with the slightly fluctuating total iron content. Specifically, our analysis highlighted distinct differences in δ56Fe values between paleosol (0.126 ± 0.024‰) and loess (0.146 ± 0.021‰). The δ56Fe in Fed was negative, averaging −0.101 ± 0.022‰, while the δ56Fe in silicate-bound iron was positive, averaging 0.156 ± 0.032‰. Intense pedogenesis, driven by warm and wet climates, facilitated iron transformations and migrations, resulting in the accumulation of light iron isotopes in the paleosols. These transformations and migrations were predominantly observed in microdomains characterized by iron depletions and concentrations, as reflected in the profile morphologies. However, the limited iron transformations and migrations did not result in significant Fe redistribution within the soil section, as evidenced by the limited variations in δ56Fe with soil depth at the stratum scale. Sampling from the stratum or pedogenic horizon could potentially create the illusion of the minimal fractionation of iron isotopes within the sequence. Therefore, a detailed examination of the iron isotope composition in the micro-domains of the loess-paleosol sequence is crucial to elucidate the fractionation processes and mechanisms of iron isotopes during the formation of these sequences. [ABSTRACT FROM AUTHOR]

Photocatalytic reactions during the daytime, alongside aqueous-phase reactions occurring during both daytime and nighttime, are identified as the two primary processes facilitating the conversion of aerosol iron (Fe) from the insoluble state to the soluble state within the atmospheric environment. This study investigated the levels of total Fe (Fe T) and soluble Fe (Fe S) in PM 2.5 samples collected during daytime and nighttime in Qingdao, a coastal city in eastern China, evaluating the distinctive roles of these two pathways in enhancing aerosol Fe solubility (%Fe S , defined as the ratio of Fe S to Fe T). Under clean and humid conditions, characterized by prevailing sea breezes and a relative humidity (RH) typically above 80 %, an average daytime %Fe S of 8.7 % was observed, which systematically exceeded the nighttime %Fe S (6.3 %). Photochemical conversions involving oxalate contributed to the higher %Fe S observed during daytime. Conversely, in scenarios where air masses originated from inland areas and exhibited slightly polluted, daytime %Fe S (3.7 %) was noted to be lower than the nighttime %Fe S (5.8 %). This discrepancy was attributable to the variations in RH, with nighttime RH averaging around 77 %, conducive to the more efficient generation of acidic compounds, thereby accelerating Fe S production compared to the daytime, when RH was only about 62 %. Furthermore, the oxidation rates of sulfur (SOR) displayed a strong correlation with RH, particularly when RH fell below 75 %. A 10 % increase in RH corresponded to a 7.6 % rise in SOR, which served as the primary driver of the higher aerosol acidity and %Fe S at night. These findings highlight the RH-dependent activation of aqueous-phase reactions and the augmentation of daytime photocatalysis in the formation of Fe S in the coastal moist atmosphere. [ABSTRACT FROM AUTHOR]

In the conventional data envelopment analysis (DEA) window analysis, a decision-making unit (DMU) in each window is treated as different units in each period so that the evaluation for one unit is performed on different scales over time. This paper proposes a novel window analysis based on common weight across time (CWAT), which evaluates each unit in each window by its common scale independent of time. The model for obtaining common weights is described as linear programming. And the paper suggests the Malmquist productivity index (MPI) on CWAT, CWAT MPI, to analyze productivity change by inheriting the result of window analysis. The numerical experiments are illustrated to examine the validity of CWAT and MPI, and the result shows that the proposed method provides a new evaluation scale compared to previous studies. The proposed model is applied to evaluate the performance of China 45 iron and steel enterprises during 2009–2017. The energy and environmental efficiency are calculated using CWAT, and CWAT MPI analyzes the productivity change. • We study a DEA window analysis based on common weights. • The proposed DEA window is represented by linear programming. • We discuss the Malmquist index in the DEA window. • The MPI is the geometric mean of all indices calculated in individual windows. • The performance of the iron and steel enterprises is evaluated. [ABSTRACT FROM AUTHOR]

Analysis of deindustrialisation remains dominated by studies of the OECD countries. The process has only recently been studied in newly industrialised countries and regions yet in a geographically constrained manner, dominated by macro-level, sectorial-based analytical frameworks. China so far has not featured highly in this emerging literature as its deindustrialisation is a more recent phenomenon overshadowed by ongoing industrialisation. This article contributes to an understanding of deindustrialisation in a microscopic empirical analysis of a China case. The microscopic approach is particularly relevant in China where state-owned, self-contained enterprises, or 'danweis', used to shape the industrial and social lives of urban Chinese, but it is also relevant to understanding processes of deindustrialisation elsewhere where these involve iconic, single industry or company communities. Adopting a case-study ethnographic approach, this study examines the transformation experienced by the iconic Wuhan Iron and Steel Company (WISCO) in Wuhan, Central China, and reveals variations in the pace of change in industrialisation and the 'half-life' of deindustrialisation as it is moderated by the institutionalisation and social life of danweis in China. [ABSTRACT FROM AUTHOR]

• Decarbonisation of the industrial sector is key to achieve net-zero emission target on schedule. • For the cement and iron and steel industry, some new technologies which based on their production material(CaO, steel slag) have been gradually developed. • The economic benefits generated by chemical industry can promote the application of carbon reduction technologies in other fields. • The small-scale projects can reduce economic costs through enhancing regional synergy. With the continuous increase in anthropogenic CO 2 emissions, many countries have researched and implemented carbon reduction technologies for large-scale industrial processes. In addition to the power industry, the cement, steel and iron, and chemical production industries are large sources of CO 2 emissions. However, the processes and flue gas characteristics of each industry differ; thus, the carbon capture methods applicable to each industry differ. This paper reviews the key technologies, status, and development trends of carbon reduction methods for each industrial source with a focus on the unique characteristics of each industry. As emission reduction targets become stricter, the large-scale development of carbon reduction demonstration projects will inevitably lead to a decrease in the costs of emission reduction technology. This review would be useful for obtaining an overview of the current progress and future prospect for carbon reduction of nonpower industries in both fundamental research and commercial applications. [ABSTRACT FROM AUTHOR]

Background: Ferroptosis is known to play a crucial role in diabetic osteopathy. However, key genes and molecular mechanisms remain largely unclear. This study aimed to identify a crucial ferroptosis-related differentially expressed gene (FR-DEG) in diabetic osteopathy and investigate its potential mechanism. Methods: We identified fibronectin type III domain-containing protein 5 (FNDC5)/irisin as an essential FR-DEG in diabetic osteopathy using the Ferroptosis Database (FerrDb) and GSE189112 dataset. Initially, a diabetic mouse model was induced by intraperitoneal injection of streptozotocin (STZ), followed by intraperitoneal injection of irisin. MC3T3-E1 cells treated with high glucose (HG) were used as an in vitro model. FNDC5 overexpression plasmid was used to explore underlying mechanisms in vitro experiments. Femurs were collected for micro-CT scan, histomorphometry, and immunohistochemical analysis. Peripheral serum was collected for ELISA analysis. Cell viability was assessed using a CCK-8 kit. The levels of glutathione (GSH), malondialdehyde (MDA), iron, reactive oxygen species (ROS), and lipid ROS were detected by the corresponding kits. Mitochondria ultrastructure was observed through transmission electron microscopy (TEM). Finally, mRNA and protein expressions were examined by quantitative real‐time PCR (qRT‐PCR) and western blot analysis. Results: The expression of FNDC5 was found to be significantly decreased in both in vivo and in vitro models. Treatment with irisin significantly suppressed ferroptosis and improved bone loss. This was demonstrated by reduced lipid peroxidation and iron overload, increased antioxidant capability, as well as the inhibition of the ferroptosis pathway in bone tissues. Furthermore, in vitro studies demonstrated that FNDC5 overexpression significantly improved HG-induced ferroptosis and promoted osteogenesis. Mechanistic investigations revealed that FNDC5 overexpression mitigated ferroptosis in osteoblasts by inhibiting the eukaryotic initiation factor 2 alpha (eIF2α)/activated transcription factor 4 (ATF4)/C/EBP-homologous protein (CHOP) pathway. Conclusions: Collectively, our study uncovered the important role of FNDC5/irisin in regulating ferroptosis of diabetic osteopathy, which might be a potential therapeutic target. [ABSTRACT FROM AUTHOR]

Commercial utilization of high-sulfur diasporic bauxite is challenging because of the hazards of sulfur to the Bayer process. This article discusses a case study of producing alumina from high-sulfur bauxite containing chlorite at an alumina refinery in Zunyi, Guizhou, China. Application of flotation desulfurization and chemical oxidation method can control the iron content of the alumina product and retard equipment corrosion, but there are problems of the sulfur balance and low alumina extraction efficiency. To clarify the reasons for this, the changes of chemical compositions during the Bayer process as well as the mineralogical compositions and occurrences of high-sulfur bauxite, alumina concentrate and red mud were investigated. Pyrite and pyrite symbiotic with diaspore can be easily separated by flotation desulfurization. Most of the diaspore and pyrite in the alumina concentrate can react with the Bayer liquor. The generated sulfur-bearing ions can reprecipitate into the red mud as sulfur-containing desilication products, which partially convert into sulfur-free hydrogarnet because of the substitution of Ca for Na during the digestion process, while the pyrite and diaspore encapsulated by the slowly reacting chlorite layer cannot be digested. [ABSTRACT FROM AUTHOR]

The cycle of precipitation change is key to understanding the driving mechanism of the East Asian summer monsoon (EASM). However, the dominant cycles of EASM precipitation revealed by different proxy indicators are inconsistent, leading to the "Chinese 100 kyr problem". In this study, we examine a high-resolution, approximately 350,000-year record from a low-latitude loess profile in China. Our analyses show that variations in the ratio of dithionite−citrate−bicarbonate extractable iron to total iron are dominated by the ~20-kyr cycle, reflecting changes in precipitation. In contrast, magnetic susceptibility varies with the ~100-kyr cycle and may be mainly controlled by temperature-induced redox processes or precipitation-induced signal smoothing. Our results suggest that changes in the EASM, as indicated by precipitation in this region, are mainly forced by precession-dominated insolation variations, and that precipitation and temperature may have varied with different cycles over the past ~350,000 years. Earth's orbit has tuned the variations of the East Asian summer monsoon. Here, a low latitude loess palaeoclimate record provides evidence that variation in monsoon rainfall is dominated by the precession cycle. [ABSTRACT FROM AUTHOR]

Zero-valent iron (ZVI)-based materials are among the most widely used engineered particles in the field of environmental remediation. To provide a comprehensive overview of the status and trend of the research on them, this study conducted a quantitative and visual analysis of 6296 relevant publications obtained from Web of Science between 1994 and 2022 using CiteSpace software. By using the bibliometric method, this work systematically analyzed the knowledge structure, research hotspots and trends of ZVI-based materials in this field. The results show that the research on ZVI-based materials in this field developed rapidly over the past 28 years. China is the greatest contributor with the most published articles and collaborations. Still, the USA has the most academic influence with the highest average citations per article. Chinese Academy of Sciences and Tongji University are the primary establishments that produced the greatest number of publications and had the highest h-index. Keyword cluster analysis indicates that the primary research topics are related to reductive dechlorination, sulfate radical, arsenic removal, graphene oxide, porous media, peroxymonosulfate, groundwater remediation, and permeable reactive barrier. Meanwhile, keyword burst analysis reveals that the primary research hotspots and frontiers of ZVI focus on its modification, the refractory and emerging contaminants treatment, persulfate activation, and electron transfer. However, no keywords or topics related to the environmental impact and toxicity of ZVI-based materials are available in the keyword clustering and burst analysis results, indicating this direction deserves more attention in future research. Through a comprehensive and in-depth bibliometric analysis, this paper provides new insight into the research hotspots and development trends of the research on ZVI-based materials in environmental remediation. [Display omitted] • Application of scientometrics to analyze ZVI in environmental remediation. • 6296 publications of ZVI-based materials in environmental remediation were analyzed. • The most influential countries, institutions, and authors were identified. • Research hotspots and trends of ZVI in environmental remediation were revealed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Langwashan iron deposit in submarine volcanic rocks is a Fe-skarn deposit. • Magnetite properties indicate iron mineralization and hydrothermal processes. • Many submarine volcanic iron deposits are likely to be Fe-skarn deposits. Carboniferous submarine volcanic rocks hosting iron deposits are widely distributed in the Tianshan and Beishan orogenic belts. However, the genesis of these deposits remains unresolved, with contrasting magmatic and magmatic-hydrothermal models being proposed. The Langwashan iron deposit (83.18 Mt @ 37% Fe) is one of the largest iron deposits in the Beishan orogenic belt. In this paper, we present detailed textural and trace-elemental properties of magnetite from the Langwashan iron deposit to elucidate the genesis and evolution of iron mineralization hosted in Lower Carboniferous submarine volcanic rocks. The Langwashan iron deposit has various types of iron ore that are closely associated with skarn minerals, including garnet and epidote. Magnetite in these samples can be classified into two distinct types, early-stage mushketovite (Mag1) and late-stage granular magnetite (Mag2), both of which show oscillatory zoning, with low Ti (mean of 0.03–0.07 wt%) and V (mean of 0.03–0.04 wt%) contents, and variable Si contents (mean of 0.74–6.50 wt%). These textural and compositional data classify the Langwashan deposit as a typical Fe-skarn deposit. Results also reveal that iron oxides in the Langwashan deposit underwent a complex evolution comprising three episodes: (1) early-stage influx of low-oxygen-fugacity, calcium-rich hydrothermal fluids, causing the transformation of original hematite to mushketovite (Mag1-1) and the formation of scheelite inclusions; (2) subsequent dissolution–reprecipitation between high-temperature magmatic-hydrothermal fluids and Mag1-1, generating trace-element-rich mushketovite (Mag1-2) and the precipitation of trace-element-rich granular magnetite (Mag2-1) from magmatic-hydrothermal fluids; and (3) final multiple fluid metasomatism under the influence of trace-element-poor hydrothermal fluids, involving dissolution–reprecipitation that produced trace-element-deficient Mag1-3, Mag2-2, and Mag2-3. Results also highlight that the submarine volcanic iron deposits from both the Tianshan and the Beishan orogenic belts were probably formed in a similar geological setting, with similar timing of formation, mechanism of mineralization, and evolution, and they are likely Fe-skarn deposits. [ABSTRACT FROM AUTHOR]

This paper demonstrates the feasibility of using a ceramic medium stirring mill to reduce the energy consumption of grinding operations through an industrial verification experiment. Compared with the original two-stage ball milling process, the cost of grinding power consumption is significantly reduced by about 50.16%, which provides a reference for the subsequent research on energy saving and consumption reduction in ball milling operations. The optimal grinding parameters were determined to be grinding concentration of 50%, material ball ratio of 0.6, 3:2:5 media ratio (10:15:20 mm) of 3:2:5, medium filling rate of 90%, as well as stirring speed of 110 rpm. Under the optimum grinding parameters, an iron concentrate with an iron grade of 68.18% and an iron recovery rate of 94.17% were obtained by two-stage magnetic separation. The successful case of ceramic medium stirring mill replacing two-stage ball grinding provides a feasible solution for energy conservation and consumption reduction in mines in China. [Display omitted] • An industrial validation test of reducing energy consumption in grinding operations. • The applicable grinding parameters were determined by experiment. • A 36-h stable operation experiment was carried out. • The ceramic media stirring mill were studied. [ABSTRACT FROM AUTHOR]

Photocatalysis reactions occurring during daytime and aqueous-phase reactions during both daytime and nighttime constitute the two primary processes responsible for converting aerosol iron (Fe) from insoluble to soluble forms within the atmosphere. This study investigated the composition of total Fe (FeT) and soluble Fe (FeS) in daytime and nighttime PM2.5 in Qingdao, a coastal city in eastern China, and evaluated the distinctive roles of the two pathways in enhancing the solubility of aerosol Fe (%FeS, the ratio of FeS to FeT). In clean and humid conditions characterized by sea breezes, with relative humidity (RH) prevalently exceeding 80 %, an average daytime %FeS of 8.7 % was observed, which systematically surpassed its nighttime %FeS (6.3 %). In contrast, when the air originated from land regions and was slightly polluted, the daytime %FeS (3.7 %) was noted to be lower than the nighttime %FeS (5.8 %). This discrepancy was attributable to the variations in RH, as the nighttime RH approximated to be 77 %, facilitating the more efficient formation of acidic substances and resulting in faster FeS production than during daytime, when RH was about 62 %. Furthermore, the oxidation rates of sulfur (SOR) and nitrogen (NOR) displayed strong correlations with RH, particularly when RH was below 75 %. A 10 % increase in RH resulted in a 7.6 % increase in SOR and a 7.2 % elevation in NOR, which served as the primary reason for the differences in aerosol acidity and %FeS between daytime and nighttime. These findings highlight the RH-dependent activation of aqueous-phase reactions and the augmentation of daytime photocatalysis in the formation of FeS in the coastal moisture atmosphere. [ABSTRACT FROM AUTHOR]

The recovery of iron from high-iron red mud is an important method for the large-scale utilization of red mud. Traditional fossil energy sources such as coking coal are usually used as reducing agents in the smelt reduction process of high-iron red mud, but they are not conducive to the early achievement of carbon neutrality in China. Straw carbon is a clean energy source with over 65% carbon content. Thus, the feasibility of straw carbon as a reducing agent to recover iron from high-iron red mud was investigated. Pig iron was obtained under the optimal reduction conditions of experimental temperature of 1400°C, alkalinity of 0.8, reduction duration of 20 min, MCaF2/MCaO of 4%, and carbon matching ratio of 1.1. More than 99% of the iron was recovered, and the results showed that straw carbon, which could effectively replace coking coal, achieved good results in the recovery of iron from high-iron red mud. [ABSTRACT FROM AUTHOR]

The compression release of pore water in clayey aquitards has a significant impact on groundwater quality. Iron is an active variable element that mediates biochemical reactions in groundwater systems, but its transformation mechanisms in clayey aquitards remain unclear. The sediment and pore water samples from the shallow clayey aquitard (thickness = ~20 m) in the Chen Lake area of China were collected in three boreholes. The spatial distribution and influencing factors of Fe occurrence in the aquitard were revealed using hierarchical extraction, statistical analysis, and simulation calculations. The results indicate that the background value of alluvial–lacustrine sediments primarily affects the Fe concentration of clayey sediments. The dissimilatory reduction in free Fe oxide was the main source of Fe ions in pore water, resulting in a major percentage of Fe2+ in the total Fe concentration (0.07−5.91 mg/L). The abundant organic matter in organic-rich clay promoted a dissimilatory reduction in Fe (III) oxides, while the Fe concentrations of sediment and pore water were lower in the sand-rich stratum because of its weak adsorption capacity. The impact of human reclamation activities on the aquitard was mainly concentrated in the shallow layer ( > − 3   m ), resulting in water drainage and O2 and CO2 input, which induced the crystallization of poorly crystalline Fe oxides. The input of reactive organic matter from reclaimed crops promoted the dissimilatory reduction in Fe oxides and the enrichment of Fe in deep pore water. The copious Fe2+ in deep stratum pore water tended to interact with CO32− and S2− to form coprecipitation with Fe (II). The concentrations of As, Cr, Sr, Zn, and Mn in pore water followed a similar variation trend to the Fe ion concentration, and their release could be attributed to the reduction dissolution of sediment Fe (III) oxides. [ABSTRACT FROM AUTHOR]

Respiratory diseases have been proven to be directly related to air pollutants. Xuanwei, located in South China, has been known to have the highest mortality rate for lung cancer in China because of the air pollutants emitted through local coal combustion. However, the mechanism of lung cancer induced by air pollutants is not clear. Based on the fact that a large number of iron-bearing mineral particles was found in Xuanwei coal combustion particles, the iron-containing particles were hypothesized to play important roles in the pathogenesis of the high incidence rate of lung cancer in this area. In this study, raw coal samples were collected from a coal mine in the Xuanwei area. Size-resolved particles emitted from the raw coal samples were collected using an Anderson high-volume sampler. Mineralogical characterization and an assessment of the oxidative potential of the iron-containing particles were conducted using cutting-edge technologies, and the biological activity of the particles were evaluated via DTT assay. Our data showed that the iron-containing minerals accounted for more than 10% of the measured particles emitted from Xuanwei coal combustion samples. The content analysis of ·OH generated from Xuanwei coal combustion particles showed that ·OH content was dependent on the size of particles in the surrogated lung fluid. The concentration of ·OH increased as the particle size decreased. The DTT assay data further demonstrated that when the mass concentration of dissolved irons increased, the oxidation potential of the particles increased. The highest proportion of divalent iron in the total dissolved iron was found in the submicron particles in low pH solution(pH = 1), which indicated that the oxidative potential induced by submicron particles was stronger than that induced by coarse particles and fine particles. Armed with the above data, the toxicological mechanism of the iron-containing mineral particles can be investigated further. [ABSTRACT FROM AUTHOR]

This paper presents the results of the geochemical and mineralogical investigation of siderite in the Late Permian coal-bearing strata from western Guizhou, SW China. Siderite occurs as fine-grained ooids, as recrystallized stellate-like forms, as ellipsoidal, rhombohedral, and oolitic aggregates, indicating their authigenic origin. In contrast, pore filling and veinlet siderite are of epigenetic origin. The low sulfur contents, absence of pyrite, and Sr/Ba ratios indicate that the siderite was deposited in a freshwater (non-marine) environment. The V/(V + Ni) values of studied samples, ranging from 0.68 to 0.86, indicate that the siderite developed under anoxic conditions. The presence of authigenic kaolinite and epigenetic siderite in the same samplesuggests that the chemical conditions changed from acidic to alkaline conditions during early diagenesis. Iron in the siderite was not only derived from silicate weathering of high-Ti basalts in the sediment source regions followed by transport as ions by ground and surface waters, but was also generated from in situ alteration of the Fe-bearing minerals within the peat itself. In addition, ascending hydrothermal solutions would also contribute some Fe, with the Fe probably sourced from the leaching of the basaltic basement. The presence of siderite-rich layers indicates enhanced chemical weathering rates in the sediment source regions. The δ 13C PDB , δ 18O PDB , and δ 18O SMOW values of siderite in claystones and mudstones vary within the ranges of −7.7 to 5.8‰, −12.1 to −6.6‰, and 18.4 to 24.1‰, respectively, indicating that carbon and oxygen primarily originated from marine carbonate, dehydroxylation of organic matter, carbonate dissolution, and hydrothermal fluids. The released CO 2 invoked the alteration of reactive silicate minerals in the sediments, and ultimately the formation of siderite. Circulating pore fluids dissolving iron, which is derived from the silicate weathering of high-Ti basalts in the sediment source regions and from in situ alteration of the Fe-bearing minerals within the peat, would transport some iron from the overlying peat into the underlying sediments, and the flow of fluids would be diminished or stopped at the base of the peat due to the mechanical barrier of the impervious claystone or mudstone layers. The ferrous iron was precipitated due to the alkaline environment conditions of the peat, by reaction with HCO 3 − dissolved in the waters to form siderite. [ABSTRACT FROM AUTHOR]

The carbon trading market is an effective way to mitigate the threat of climate warming. In the context of carbon neutrality, what is the carbon emission trading scheme's carbon reduction effect? This paper answers the question by examining the carbon efficiency of China's iron and steel industry. This study first constructs CO 2 emission efficiency by employing the data envelopment approach. It then uses the synthetic control method to identify the impact of the carbon emission trading scheme on the CO 2 efficiency of the iron and steel industry. The results show that CO 2 emission efficiency in pilot provinces increased at a 5% significance level compared with the counterfactual scenario. The carbon trading market plays a vital role in industrial CO 2 emission efficiency improvement in Guangdong, Shanghai, Tianjin, Hubei, and Chongqing. From a dynamic perspective, the policy effect of enhancing CO 2 efficiency becomes more prominent over time. Moreover, the effectiveness degree of the carbon emission trading scheme varies across pilot provinces, caused of regional policy differences. Based on the findings, we put forward targeted suggestions for improving the newly-established national carbon trading market. • The DEA model and the synthetic control method are employed in the study. • Impact of carbon market on CO 2 efficiency of iron and steel industry is verified. • The heterogeneity of carbon market effects is explored from regional perspective. • Carbon market significantly promotes industrial CO 2 efficiency in pilot provinces. • China should develop the national carbon market to achieve carbon neutrality. [ABSTRACT FROM AUTHOR]

In over 60 years of research, my team and I have focused on Fe/Mn removal and the application of KMnO 4 in drinking water purification, and we have made several technological innovations during this period. In response to the basic need to remove Fe and Mn from groundwater sources in the early days of People's Republic of China, I firstly introduced a catalytic technology involving the application of natural manganese sand produced in China as one of the simplest, cost-effective techniques. During experiments, many phenomena that were inconsistent with conventional theories were observed and a new mechanism was proposed, indicating iron/manganese active films as a catalytic agent instead of MnO 2. These films were found to be attached to the surface of natural manganese sand. Fe/Mn-containing compounds with special structures and catalytic features were identified by applying various analytical methods. Drinking water safety was also strengthened by applying KMnO 4 as a new cost-effective chemical for source waters facing environmental pollution in China. Experiments showed that KMnO 4 can effectively remove many pollutants, including trace organic micro-pollutants, by the combined effects of oxidation and adsorption, which were revealed and confirmed for the first time. Through the application of GC/MS analysis of water samples before and after KMnO 4 treatment of samples from various surface water sources, the oxidation by-products from KMnO 4 were found to be nontoxic. Therefore, KMnO 4 is considered to be a safer chemical in comparison with other conventional oxidants (e.g. HOCl). Previous studies also showed several novel features of KMnO 4 , such as enhanced coagulation with chlorine, improved algae removal, and increased removal of organically bound manganese. In particular, the combined use of KMnO 4 and chlorine could achieve the same disinfection effect at much lower (50%) chlorine dosages. In addition, there are various chemicals and substances that can be combined with KMnO 4 to improve decontamination performance. Based on extensive experiments, permanganate compounds were found to be highly efficient in removing heavy metals, e.g., thallium. My research also found that both KMnO 4 and powdered activated carbon were highly effective for removing odors and taste. Therefore, we developed a hybrid combination of these two technologies and successfully applied them in many water treatment plants, not only for taste and odor, but also to remove organic micro-pollutants in drinking water. This paper provides a summary of the aforementioned studies that were conducted by me, in collaboration with water treatment industry experts in China, and my graduate students. As a consequence of these studies, several techniques are now widely used in drinking water production in China. [ABSTRACT FROM AUTHOR]

Energy conservation and emission reduction in China's iron and steel industry are crucial for mitigating its environmental pressures. However, uncertainties raise significant management risks when setting energy conservation and emission reduction pathways. Therefore, this paper explores the energy conservation and emission reduction potential in China's iron and steel industry. A 10,000-time Latin hypercube sampling is conducted to simulate the distribution of five types of uncertain factors. In addition, this study uses a Sobol' sensitivity analysis method to recognize the most sensitive factor, and, in specific, analyzes the cost-effectiveness of the technologies via conservation supply curve. The results show that: (1) The uncertainty factors lead to significant fluctuate to the results. In particular, energy conservation will fluctuate by 18.24–40.77%, carbon mitigation by 28.96–55.34%, and SO 2 , NO x and PM mitigation effects will fluctuate by 48.32–79.53%, 22.12–51.77% and 23.92–50.03%, respectively. (2) Structure and equipment parameters are more the most sensitive to energy conservation and carbon mitigation targets, whose Sobol' indices are beyond 0.45. End-of-pipe treatment technologies are more the most sensitive to SO2 and PM reduction targets with Sobol' indices above 0.9. Penetration rates and equipment parameters are more the most sensitive to economic cost targets above 0.8. (3) In 2035, 33 energy conservation technologies and 34 emission reduction technologies will be cost-effective, and they can achieve 69.05–70.14% of energy conservation and 79.03–81.58% of emission reduction potentials, respectively. Based on these findings, this study proposes policy recommendations such as changing the raw material/product structure, upgrading equipment, cooperating actively, and introducing economic incentives and guidelines for technology application. • We establish the energy conservation and emission reduction measure inventory. • Simulation of possible fluctuations due to uncertainties by Latin Hypercube Sampling. • The sensitivity factors are identified through Sobol approach. • Effective management policies need to consider uncertainty factors and sensitivities. [ABSTRACT FROM AUTHOR]

Due to the strong variations in the distribution of the sedimentary strata, the degree of denudation of carbonate strata is not consistent across the different regions. In the Huanglong ore field, the carbonate strata hosting the Longqiao ore body is relatively stable, and its protolith comprises dolomitic limestone and dolomitic marlstone, whereas the lithology of that hosting the Mabianshan ore body shift from Fe-Mn bearing dolomite and dolomite to dolomitic limestone and marlstone in the extension direction of the ore body. The content of Al, Si, Mg, Mn and Ca in the carbonate strata in Mabianshan varies more greatly in this direction. [Display omitted] • The Mabianshan and Longqiao deposits in Luzong volcanic basin had different heat sources. • The protolith of Mabianshan magnetite ore body varies greatly in the content of Al, Si, Mg, Mn, and Ca. • The complex protolith lithology of magnetite results in tracing fluid source using Si, Al, Mg, and Mn hard to effectively. The composition of host rocks is essential in determining the composition of hydrothermal magnetite formed via fluid-rock interactions in skarn deposits. The HuangLong ore field in the Luzong volcanic basin, Eastern China, hosts several stratabound iron (Fe) skarn deposits, including Mabianshan and Longqiao. In this paper, we analyse the composition of different lithologies of carbonate strata and trace element concentrations in magnetite from Mabianshan, which has complex lithology carbonate strata, and compare it with magnetite from Longqiao, which has uniform lithology carbonate strata. The objective is to investigate the influence of lithology variation on magnetite trace elements and enhance the indicative significance of magnetite trace elements in prospecting and exploration. Our results demonstrate that the lithology of ore-bearing carbonate strata varies greatly due to inversion and different degrees of denudation in the ore field, resulting in variations of Al, Si, Mg, Mn, and Ca in the protolith across different areas. The alteration mineral assemblage of the Mabianshan deposit primarily included epidote, chlorite, and magnetite, while only a few diopside-magnetite relatively high-temperature assemblages developed in the southeastern part of the deposit. Moreover, higher concentrations of Ti and V in magnetite samples from the southeastern area of the deposit suggest that the heat sources related to Fe mineralization may be located there. Compared with the regular spatial variations of Mg, Mn, Al, and Si in the magnetite from Longqiao, the magnetite from Mabianshan does not show evident spatial variations due to the complex lithology of the magnetite protolith in different regions. The protolith lithology of magnetite from Longqiao is relatively stable, mainly dolomitic limestone. However, the protolith lithology of magnetite from Mabianshan is complex and includes dolomitic marlstone, dolomitic limestone, dolomite, and Fe-Mn bearing dolomite, resulting in a significant increase of Si, Al, Mg, and Mn in magnetite. Therefore, it is difficult to effectively trace the temporal-spatial evolution of the hydrothermal fluids using these elements in magnetite. Special attention should be paid to the uniformity of the protolith lithology of the ore when using these elements in magnetite to trace the fluid source. [ABSTRACT FROM AUTHOR]

With the gradual depletion of high-grade uranium resources in southern China, it is necessary to recover uranium from low-grade complex and refractory uranium resources However, the traditional acid mining process has certain drawbacks such as high acid consumption, low uranium recovery, and potential environmental pollution. There is an urgent need to develop new technologies for the extraction of refractory uranium ores. A tonne-scale column bioleaching for low-grade refractory vocanogenic uranium ore containing brannerite and pitchblende was performed. The uranium leaching efficiency reached 85.86% with an acid consumption of only 10.15% after leaching for 130 d. In the bioleaching stage, the Fe3+ concentration had a good correlation with the Eh value; the higher the Fe3+ concentration, the better was the leaching of uranium. The solution pH was kept below 2.5 during the leaching process, which avoided the precipitation of iron and ensured a higher Fe3+ concentration in the solution. Efficient leaching of uranium from UTi2O6 and UO2 was achieved through oxidation of Fe3+ and the action of microorganisms. The results may provide technical support for industrial leaching of low-grade volcanogenic uranium deposits. [ABSTRACT FROM AUTHOR]

Sedimentary facies color is an important paleoclimate indicator, but may be unreliable in thick continental red beds. The Danxia Formation is the landscape strata of the Danxia basin, and its color fluctuates between reddish-brown and reddish-purple vertically. This study examined the ferric oxides characteristics, distribution, and mineral composition of the Danxia Formation using a variety of analytical techniques, including optical microscopy, high-resolution scanning electron microscopy, electron probe microanalysis, X-ray diffraction, and micro-Raman spectroscopy. The results indicate that the reddish-brown mineral is composed primarily of fine hematite with traces of goethite, while the reddish-purple mineral consists solely of fine hematite. These hematites exhibit a particle size range of submicron to micron and display various morphologies, including spherical, flake, and fibrous forms. Goethite particles are needle-shaped and often form star-shaped aggregates containing twins. Whole rock geochemical analysis reveals a strong positive correlation between iron and iron group elements, as well as phosphorus and rare earth elements. The findings suggest that the reddening of the Danxia Formation occurs during diagenesis, with fine hematite forming as a result of the alteration of iron-bearing detrital grains. In addition, vertical color variations in Danxia Formation are not attributable to the paleoclimate records, but rather the result of the differentiation of sediment sources. This study provides a novel viewpoint for examining the coloration of thick continental red beds in other regions. [ABSTRACT FROM AUTHOR]