烧结铁矿中FeO含量对其在富氢高炉中还原行为的影响

Japan started the national project “COURSE 50” for CO₂ reduction in the 2000s. This project aimed to establish novel technologies to reduce CO₂ emissions with partially utilization of hydrogen in blast furnace-based ironmaking by 30% by around 2030 and use it for practical applications by 2050. The idea is that instead of coke, hydrogen is used as the reducing agent, leading to lower fossil fuel consumption in the process. It has been reported that the reduction behavior of hematite, magnetite, calcium ferrite, and slag in the sinter is different, and it is also considerably influenced by the sinter morphology. This study aimed to investigate the reduction behavior of sinters in hydrogen enriched blast furnace with different mineral morphologies in CO–CO₂–H₂ mixed gas. As an experimental sample, two sinter samples with significantly different hematite and magnetite ratios were prepared to compare their reduction behaviors. The reduction of wustite to iron was carried out at 1000, 900, and 800°C in a CO–CO₂–H₂ atmosphere for the mineral morphology-controlled sinter, and the following findings were obtained. The reduction rate of smaller amount of FeO led to faster increase of the reduction rate curve at the initial stage of reduction. Macro-observations of reduced samples showed that the reaction proceeded from the outer periphery of the sample toward the inside, and a reaction interface was observed where reduced iron and wustite coexisted. Micro-observations revealed three layers, namely, wustite single phase in the center zone of the sample, iron single phase in the outer periphery zone of the sample, and iron oxide-derived wustite FeO and iron, or calcium ferrite-derived wustite 'FeO' and iron in the reaction interface zone. A two-interface unreacted core model was successfully applied for the kinetic analysis of the reduction reaction, and obtained temperature dependent expressions of the chemical reaction coefficients from each mineral phases.     

Mg和La对Ca–Ti 处理钢中夹杂物演变和组织的影响

The evolution of inclusions and the formation of acicular ferrite (AF) in Ca–Ti treated steel was systematically investigated after Mg and La addition. The inclusions in the molten steel were Ca–Al–O, Ca–Al–Mg–O, and La–Mg–Ca–Al–O after Ca, Mg, and La addition, respectively. The type of oxide inclusion in the final quenched samples was the same as that in the molten steel. However, unlike those in molten steel, the inclusions were Ca–Al–Ti–O + MnS, Ca–Mg–Al–Ti–O + MnS, and La–Ca–Mg–Al–Ti–O + MnS in Mg-free, Mg-containing, and La-containing samples, respectively. The inclusions distributed dispersedly in the La-containing sample. In addition, the average size of the inclusions in the La-containing sample was the smallest, while the number density of inclusions was the highest. The size of effective inclusions (nucleus of AF formation) was mainly in the range of 1–3 μm. In addition, the content of ferrite side plates (FSP) decreased, while the percentage of AF increased by 16.2% due to the increase in the number of effective inclusions in the La-containing sample in this study.     

微生物浸矿技术在我国的研究现状及发展前景

As the world’s second largest economy experiencing rapid economic growth, China has a huge demand for metals and energy. In recent years, China ranks first, among all the countries in the world, in the production and consumption of several metals such as copper, gold, and rare earth elements. Bioleaching, which is an approach for mining low grade and refractory ores, has been applied in industrial production, and bioleaching has made great contributions to the development of the Chinese mining industry. The exploration and application of bioleaching in China are reviewed in this study. Production and consumption trends of several metals in China over the past decade are reviewed. Technological processes at key bioleaching operations in China, such as at the Zijinshan Copper Mine and Mianhuakeng Uranium Mine, are presented. Also, the current challenges faced by bioleaching operations in China are introduced. Moreover, prospects such as efficiency improvement and environmental protection are proposed based on the current situation in the Chinese bioleaching industry.     

不同结构和形态的天然镁硅酸盐:与K反应制备生物柴油的K2MgSiO4催化剂

In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile (which have the same general formula Mg₃Si₂O₅(OH)₄), and talc (Mg₃Si₄O₁₀(OH)₂) were reacted with KOH to prepare catalysts for biodiesel production. Simple impregnation with 20wt% K and treatment at 700–900°C led to a solid-state reaction to mainly form the K₂MgSiO₄ phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K₂MgSiO₄ formation. All the materials showed catalytic activity for the transesterification of soybean oil (1:6 of oil : methanol molar ratio, 5wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K₂MgSiO₄.     

摩擦焊接碳钢（EN24）和镍基高温合金（IN718）的显微组织和力学性能

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel (EN24) and nickel-based superalloy (IN718), and the microstructures of three distinct weld zones—the weld interface (WI)/thermo-mechanically affected zone (TMAZ), the heat-affected zone (HAZ), and the base metal—were examined. The joint was observed to be free of defects but featured uneven flash formation. Electron backscatter diffraction (EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and HAZ. Moreover, significant refinement in grain size (2–5 μm) was observed at the WI/TMAZ with reference to the base metal. The possible causes of these are discussed. The microhardness profile across the welded joint shows variation in hardness. The changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening precipitates. The tensile test results reveal that a joint efficiency of 100% can be achieved using this method.     

汽车暴露面板带有表面条状缺陷的夹杂物分布特征分析:一种定量电解方法

The specific distribution characteristics of inclusions along with the sliver defect were analyzed in detail to explain the formation mechanism of the sliver defect on the automobile exposed panel surface. A quantitative electrolysis method was used to compare and evaluate the three-dimensional morphology, size, composition, quantity, and distribution of inclusions in the defect and non-defect zone of automobile exposed panel. The Al₂O₃ inclusions were observed to be aggregated or chain-like shape along with the sliver defect of about 3–10 μm. The aggregation sections of the Al₂O₃ inclusions are distributed discretely along the rolling direction, with a spacing of 3–7 mm, a length of 6–7 mm, and a width of about 3 mm. The inclusion area part is 0.04%–0.16% with an average value of 0.08%, the inclusion number density is 40 mm?2 and the inclusion average spacing is 25.13 μm. The inclusion spacing is approximately 40–160 μm, with an average value of 68.76 μm in chain-like inclusion parts. The average area fraction and number density of inclusions in the non-defect region were reduced to about 0.002% and 1–2 mm?2, respectively, with the inclusion spacing of 400 μm and the size of Al₂O₃ being 1–3 μm.     

在酸性溶液中加压氧化三价砷离子和二价铁离子

The co-oxidation of As(III) and Fe(II) in acidic solutions by pressured oxygen was studied under an oxygen pressure between 0.5 and 2.0 MPa at a temperature of 150°C. It was confirmed that without Fe(II) ions, As(III) ions in the solutions are virtually non-oxidizable by pressured oxygen even at a temperature as high as 200°C and an oxygen pressure up to 2.0 MPa. Fe(II) ions in the solutions did have a catalysis effect on the oxidation of As(III), possibly attributable to the production of such strong oxidants as hydroxyl free radicals (OH·) and Fe(IV) in the oxidation process of Fe(II). The effects of such factors as the initial molar ratio of Fe(II)/As(III), initial pH value of the solution, oxygen pressure, and the addition of radical scavengers on the oxidation efficiencies of As(III) and Fe(II) were studied. It was found that the oxidation of As(III) was limited in the co-oxidation process due to the accumulation of the As(III) oxidation product, As(V), in the solutions.     

活化天然矿石选择性还原二氧化碳为无定形碳

Natural magnetite formed by the isomorphism substitutions of transition metals, including Fe, Ti, Co, etc., was activated by mechanical grinding followed by H₂ reduction. The temperature-programmed reduction of hydrogen (H₂-TPR) and temperature-programmed surface reaction of carbon dioxide (CO₂-TPSR) were carried out to investigate the processes of oxygen loss and CO₂ reduction. The samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the stability of spinel phases and oxygen-deficient degree significantly increased after natural magnetite was mechanically milled and reduced in H₂ atmosphere. Meanwhile, the activity and selectivity of CO₂ reduction into carbon were enhanced. The deposited carbon on the activated natural magnetite was confirmed as amorphous. The amount of carbon after CO₂ reduction at 300°C for 90 min over the activated natural magnetite was 2.87wt% higher than that over the natural magnetite.     

"邓小平理论热":校园高雅文化的理性选择

近些年来在校园高雅文化活动中,"邓小平理论学习热"引人注目,体现出强烈的高雅性与平俗性、广博性与专业性、创新性与务实性的融合效应.它是改革开放的社会大文化氛围、大学生自身社会实践和邓小平"三进"工作的综合产物.高校要因势利导,把"邓小平理论热"引向理论文化育人的新高度,适应新世纪新要求,切实提高青年学生的文化力、创新力和综合力,发挥理论文化在人才培养中的独到作用.     

做弘扬先进文化的促进派

该文以江泽民总书记“三个代表”的讲话为指导,具体阐述了代表中国当代先进文化的前进方向是坚持党的先进性的必然要求这一论题。     

邓小平的人才学说对高校人事管理工作的启示

邓小平理论宝库中，有关人才的发现、选拔、培养、使用、开发和人事管理等的一系列论述，已成为指导我国高校人事管理的科学理论依据。遵照邓小平同志的有关教导，高校组织人事部门应牢固树立“尊重知识、尊重人才”的观念，把选好、用好人才，努力做到“人尽其才，才尽其用”作为高校人事管理工作的理想目标，把改革旧的人事管理体制作为高校人事管理工作的关键来抓。     

邓小平的民族统一战线思想

通过对邓小平统一战线思想的深刻分析，指出其是建设有中国特色社会主义理论科学体系的重要组成部分，是毛泽东统一战线思想发展的新阶段。科学地回答和解决了新时期统一战线的新课题和新任务。     

关于《中图法》中邓小平理论的立类研究

本文论述了在《中图法》Ａ大类中增设邓小平理论类目的前提,说明了在Ａ大类中增设邓小平理论类目的理由,探讨了邓小平理论在《中图法》中立类和归类的方法。     

邓小平社会结构理论探析

社会结构问题是马克思主义所特别关注的一个极为重要的问题。邓小平坚持从实际出发，创造性地运用马克思主义社会结构的思想，多层次、多视角地分析我国社会主义初级阶段的社会结构状况，并提出了许多关于解决当代中国社会结构问题的精辟见解，形成了独具特色的社会主义社会结构理论。解放生产力和发展生产力是邓小平社会结构理论的核心内容，优化中国社会主义的社会结构是邓小平社会结构理论的现实出发点和着眼点。学习和研究邓小平社会结构理论具有重要的理论意义和现实意义．     

解读邓小平关于民族发展的思想

邓小平民族理论是邓小平理论的重要组成部分,其中的核心内容是关于民族发展的理论。论述了邓小平民族理论的形成和主要特点,着重阐述了邓小平关于民族发展的思想:观察少数民族地区主要是看那个地区能不能发展起来;国家帮助少数民族发展的政策是坚定不移的;改革开放是各民族发展的必由之路;共同富裕和“两个大局”的战略构想。     

邓小平外交思想研究综论

邓小平外交思想是邓小平理论的重要组成部分,是当代中国外交工作的指导思想,它是对中国的现状和当今世界各种矛盾分析的产物,是实事求是原则在外交领域的有效延伸,是维护中国国家权益的生动表现。本文从邓小平外交思想的精神内涵、主要内容、重要特色和现实意义四个方面,综合探讨了邓小平同志的外交思想。     

邓小平民主思想研究——作为手段的民主与作为目的的民主

邓小平民主思想是作为手段的民主与作为目的的民主并存的民主思想,他抓住了政治建设的首要任务是为经济建设也即为民生建设保驾护航这一历史规律。从世界各国的经验教训来看,脱离了经济建设,追求形式的和以西方为模式的民主建设,不仅实现不了真正的民主,反而带来的是国家的混乱和民主政治的不可能。作为目的的民主思想又从根本上解决了社会主义民主与资本主义民主的区别,为我国的民主政治建设指明了方向,开拓了民主的内涵和实质,具有很强的现实指导意义。     

邓小平行政体制改革思想及其现实指导意义

邓小平行政体制改革思想具有丰富的内涵及现实指导意义.他设计了中国特色行政体制的基本架构,为当今行政体制改革奠定了基础;确立了行政体制改革的价值取向,为后来的行政体制改革指明了方向;采用了"循序渐进"的行政改革方式,为新时代行政体制改革提供了蓝本;树立了政府职能转变的改革核心观,为历次行政体制改革的根本任务做出了规定.