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.     

具有良好可再生性的新型二氧化硅磁性氧化石墨烯纳米复合材料

Graphene oxide (GO) wrapped Fe₃O₄ nanoparticles (NPs) were prepared by coating the Fe₃O₄ NPs with a SiO₂ layer, and then modifying by amino groups, which interact with the GO nanosheets to form covalent bonding. The SiO₂ coating layer plays a key role in integrating the magnetic nanoparticles with the GO nanosheets. The effect of the amount of SiO₂ on the morphology, structure, adsorption, and regenerability of the composites was studied in detail. An appropriate SiO₂ layer can effectively induce the GO nanosheets to completely wrap the Fe₃O₄ NPs, forming a core-shell Fe₃O₄@SiO₂@GO composite where Fe₃O₄@SiO₂ NPs are firmly encapsulated by GO nanosheets. The optimized Fe₃O₄@SiO₂@GO sample exhibits a high saturated adsorption capacity of 253 mg·g?1 Pb(II) cations from wastewater, and the adsorption process is well fitted by Langmuir adsorption model. Notably, the composite displays excellent regeneration, maintaining a ~90% adsorption capacity for five cycles, while other samples decrease their adsorption capacity rapidly. This work provides a theoretical guidance to improve the regeneration of the GO-based adsorbents.     

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.     

含钛高炉炉渣微波合成碳化钛及其介电性能测定

The preparation of functional material titanium carbide by the carbothermal reduction of Ti-bearing blast furnace slag with microwave heating is an effective method for valuable metals recovery; it can alleviate the environmental pressure caused by slag stocking. The dynamic dielectric parameters of Ti-bearing blast furnace slag/pulverized coal mixture under high-temperature heating are measured by the cylindrical resonant cavity perturbation method. Combining the transient dipole and large π bond delocalization polarization phenomena, the interaction mechanism of the microwave macroscopic non-thermal effect on the titanium carbide synthesis reaction was revealed. The material thickness range during microwave heating was optimized by the joint analysis of penetration depth and reflection loss, which is of great significance to the design of the microwave reactor for the carbothermal reduction of Ti-bearing blast furnace slag.     

信息化录井技术组成探索

基于信息技术的现代录井技术是一项集合了传感器技术、计算机技术和通信技术的现代综合信息技术。围绕现代信息技术的3个主要技术要素(传感器技术、计算机技术和通信技术)分析了实现现代信息化录井的理论方法。     

浅谈几种真空热处理技术

真空热处理技术是传统的热处理技术和现代化的真空技术、电子计算机技术、自动化技术相结合而成的一种高效、优质、节能的先进热处理技术,具有无脱碳、无氧化、可保持零件表面光亮、可使零件脱脂、脱气、变形小、节能且易于控制等优点,已在国内外广泛运用。简单阐述了真空油淬技术、对流加热技术、真空渗碳技术、真空渗氮技术、真空加压气淬等真空热处理技术,以说明该技术的发展情况及发展趋势。     

浅谈面向对象技术、Agent技术和网格技术

目前，面向对象技术、Agent技术和网格技术是三种重要的计算机技术。文章主要阐述了三种技术的基本概念、技术特点与软件设计方法和三种技术间的区别及联系。     

洞庭湖区生态农业发展的技术支撑研究

当下,洞庭湖区生态农业面临着一系列技术挑战。洞庭湖区生态农业技术支撑体系可以从生态农业环境改良技术体系、生态农产品标准化技术体系、电子信息技术体系、循环技术体系四方面构建。其发展思路应从加大对湖区技术项目研发及资金投入、加强对农业技术人才的培养、完善农业科技服务推广体系、创新农业科技管理体制、建立生态农业技术采用的激励机制等方面思考。     

科技中介与技术供需方动态关系影响研究——基于三方演化博弈视角

当前,科技中介作为技术市场中的关键主体,应有的市场功能作用未能充分发挥。本文从中微观层面研究科技中介如何解决技术市场普遍存在的道德风险、机会主义等问题,运用演化博弈理论构建技术提供方、技术需求方和科技中介三方博弈模型,引入信任、信息共享要素变量分析科技中介对技术供需方的动态关系影响,厘清其影响机理。研究发现,科技中介积极的信息甄别行为会降低技术供需双方之间技术势差引起的信息非对称影响,有利于提升技术供需方的信任水平,提高信息共享的质量,并从创新激励模式、完善信息甄别体系建设、提升专业技术能力3个方面给出科技中介的管理实践启示。     

纳米科技发展现状及趋势

纳米科学技术的出现标志着人类科学技术已进入了一个新的时代，本文从纳米科学技术研究发展的状况和发展方向两方面阐述了纳米科技发展的趋势。首先概述了什么是纳米科技，国内外纳米科学技术研究发展现状；然后论述纳米技术研究与开发的关键，纳米技术发展的某些动向以及纳米技术发展前景。     

提高计算机系统性能的若干技术

随着现代计算机技术的迅猛发展,如何提高计算机系统的性能变得十分重要,而提高计算机系统性能的方法有多种.本文讨论了目前计算机主要采用的技术方法,如多级存储体系技术、中断技术、总线控制技术以及指令重迭和流水线控制技术.     

双孢菇保鲜与加工技术

双孢菇兼具营养与保健功能,是我国出口创汇的重要食用菌品种。阐述了目前常用的双孢菇低温、气调、辐射等保鲜技术和盐渍、酸渍、干制以及下脚料加工技术。     

新形势下跨国公司技术转让特点及其启示

技术转让是指技术供应方通过某种方式把某项技术以及与该技术有关的权利转让给技术受让方的行为。它不同于技术引进、技术扩散、技术转移等概念。当技术转让发生于不同国家之间,即为国际技术转让。在当前新形势下,跨国公司技术转让特别强调以全球领先技术为基础创造技术转让条件、以全球研发网络为基础展开技术转让活动、以内部化为基础实施技术转让战略、以生命周期为基础选择技术转让时机、以扩张国际生产为基础彰显技术转让效果等。基于此,我国企业特别是中小企业应该紧紧抓住跨国公司国际生产网络进一步扩大的趋势,积极融入其中,寻求新的发展路径。     

论发展我国高新技术产业的技术供给

目前我国技术供给的主要途径是依靠软技术引进,并向高新技术产业方向发展.外资企业是我国技术引进的主体.跨国公司是我国技术供给的主体.我国国内技术供给能力在不断增强,但是还存在R＆D投入不足、国内专利授权量较低、技术引进与消化吸收比例严重失调、科技成果转化率低等问题.我国要有效地提高高新技术产业的技术供给,必须加强软技术引进,同时要注重消化、吸收和自主创新.