湘钢2号高炉炉身中下部结瘤原因分析及处理

从原燃料条件和操作制度两方面分析了高炉结瘤事故发生的原因和处理方法，认为炉温、烧结矿碱度大幅波动是高炉结瘤的基础，原燃料差是导致结瘤的直接原因，并对此提出了解决意见。     

烧结燃料二次分加优化试验研究

为进一步探明燃料种类及其搭配，燃料粒度等对燃料二次分加效果的影响，就二次分加时，无烟煤与焦粉的搭配顺序，焦粉粒度对钒钛磁铁精矿烧结指标的影响进行了研究。找出了适宜的燃料种类（焦粉）及其适应的粒度范围。为燃料二次分加工艺优化工业性试验提供了依据。     

Gd_2O_3添加对UO_2芯块物理性能的影响研究

含钆UO_2芯块制造过程中Gd_2O_3的添加会导致混料不均匀和烧结后芯块缺陷。针对上述问题进行了理论分析和工艺试验,研究了Gd_2O_3对芯块物理性能的影响。针对Gd_2O_3与UO_2粉末极难混匀的特性,通过实施多种试验并对试验后粉末中Gd_2O_3含量的检测结果进行分析计算,确定了含钆芯块制造中Gd_2O_3混合均匀化的工艺和参数。在此基础上进行了Gd_2O_3添加对芯块压制、密度控制、微观结构等方面的影响规律研究。研究表明,Gd_2O_3粉末的添加会微弱降低芯块的最终密度,同时使芯块出现烧结缺陷;微湿气氛烧结可解决含钆芯块出现烧结缺陷的问题。     

烧结固体燃料分加的研究

进行了在不同原料条件下实行固体燃料分加的烧结试验研究。研究了不同外配比例、不同燃料种类及其粒度等的燃料分加对烧结矿产量、质量和燃耗等指标的影响。     

用煤粉代替焦粉的烧结实践

广钢的烧结燃料是焦粉,燃料成本偏高。为降低燃料成本,决定用价格较低的无烟煤粉代替焦粉,在烧结杯实验的基础上,进行了生产试验,取得了降低烧结燃料成本的成效。研究与实践表明,煤粉配入比例占燃料的40%左右比较合适。     

应对原燃料变化调整高炉操作制度

分析了宝钢集团八钢公司2500m3高炉在原燃料变化较大时,高炉操作制度的调整,全年没有出现大的炉况失常事故,取得了较好的技术指标。     

应对原燃料变化调整高炉操作制度的探讨

分析了河北唐银钢铁有限公司450m^3高炉在原燃料变化较大时,高炉操作制度的调整,全年没有出现大的炉况失常事故,取得了较好的技术指标。     

沥青浆体燃料及其燃烧试验

介绍了两种最新研究开发的沥青浆体燃料：硬沥青－水浆和沥青乳化燃料；并报道了这两种新型燃料的实验室规模燃烧试验和性能试验结果。试验表明，它们的燃烧特性十分接近于重油，完全可以在冶金工业炉窑上代油应用。     

核反应堆用碳化硼芯块常压烧结工艺研究

以核级碳化硼粉为原料,酚醛树脂作粘结剂与助烧剂,用钢模成形方法制备出碳化硼生坯,在碳管炉中用常压烧结方法在2250℃保温40 min,制备出高温气冷堆控制棒用碳化硼环形芯块。用化学分析方法分析了原料粉与碳化硼烧结体的化学成分,用排水法对芯块的密度进行测试,研究了碳质量分数对碳化硼芯块密度的影响,用扫描电镜对生坯与芯块的微观结构进行研究,对1:1大尺寸碳化硼芯块的变形量进行统计。结果表明:碳对碳化硼具有很好的助烧作用,碳化硼的密度随碳含量的增加而增加,当碳质量分数为5%时,最高密度达到2.35 g/cm~3;碳掺量为3%时,制得的1:1碳化硼芯块的密度为2.0 g/cm~3,化学成分等各项指标均满足反应堆用核级碳化硼芯块的技术条件要求。     

提高厚料层烧结燃料燃烧性的试验研究

厚料层烧结是烧结技术发展的重要方向,但料层增厚引起一系列烧结行为的变化,如自动蓄热加强,导致料层高温区变厚,气体体积膨胀量增加,透气性恶化,氧气的质量含量降低,燃料燃烧速度减慢,高温区宽度进一步增加,还使得残碳和无益燃烧增加,下部烧结矿过熔,影响烧结矿的产、质量,进而降低厚料层的节能效果。为了解决这些问题,采用粒度为1.00~3.15 mm的高燃烧性燃料,选择燃料的配加方式为"燃料分加"或"燃料、熔剂共同分加"等方案提高厚料层烧结固体燃料的燃烧性,并对各试验方案下的透气性和烧结指标进行研究,结果表明上述3个措施均有利于厚料层烧结的实施。     

Investigation into the influence of microstructural parameters of fuel pellets on their stability under the effect of thermal shocks

The parameters of tests and the main results of investigations into the behavior of VVER- and RBMK-type domestic fuel pellets under the effect of thermal shocks are investigated. Fine-grain pellets with a high level of closed porosity are shown to be more resistant to failure, which can appear in the pellets during startup and while maneuvering over the reactor power, as well as if there is cladding failure of the fuel cell. The pellet strength decreases as the grain size increases to ≥25 μm. The residual failure resistance of pellets simultaneously decreases, which leads to a loss in their integrity.     

事故容错燃料包壳用Mo合金的研究进展

2011年发生福岛严重核事故后,锆合金包壳材料的安全可靠性受到严重的质疑,国内外对事故容错燃料(ATF)开始了广泛的研究。Mo合金由于其优异的高温性能成为了ATF的候选包壳材料之一。本文综述了Mo合金包壳材料在高温氧化性能,力学性能,抗辐照性能,中子经济性能以及加工和焊接性能方面的研究进展,并指出在工业应用中面临的挑战,最后展望了Mo合金在ATF包壳材料中的应用前景。     

粉末冶金法制备核燃料包壳FeCrAl合金研究进展

燃料包壳是核反应堆安全运行的重要保障。福岛核事故后,国内外开展了大量新型事故容错燃料包壳的研发工作。由于具有抗高温氧化和高强度等优异的综合性能,FeCrAl合金已成为新一代事故容错燃料包壳的重要候选材料之一。经过多年积累,核燃料包壳FeCrAl合金的设计和制备研究已取得一定进展。利用粉末冶金方法制备性能更为优异的氧化物弥散强化FeCrAl合金前景广阔,受到国内外学者的广泛关注。本文综述了核燃料包壳FeCrAl合金的成分设计、熔炼制备和粉末冶金制备的研究现状,分析了不同方法制备合金的组织性能及存在的问题,对未来核燃料包壳FeCrAl合金的设计和制备进行了展望。     

Fuel pellets based on uranium dioxide and alloyed with nanodispersed additives of Al(OH)3 and TiO2

The influence of alloying additives Al(OH)₃ and TiO₂ on the structure and properties of uranium dioxide fuel pellets is investigated. It is established that their introduction improves the characteristics of the macrostructure and microstructure of fuel pellets and positively affects their properties. For example, the grain size in the fuel pellet increases to 39 mm (instead of 10–15 mm in the case of usual technology), the number of large (>10 mm) pores decreases, and the strength and thermal conductivity increase slightly.     

certain trends in the development of technology and improvement in quality of nuclear fuel (review)

The trends in the improvement of the economic characteristics of nuclear power plants, one of which is the prolongation of the reactor campaign, i.e., the period in which the fuel is situated in the active zone under the due increase in its burnup level, are considered. Such an increase can be achieved, specifically, via using fuel with burnable absorbers, as well as by improving the quality of fuel pellets obtained by powder metallurgy. It is necessary to toughen the technical requirements for fuel pellets and improve the technology of their production and the equipment used in their fabrication. It is noted that the works for improving the operational factors of fuel pellets (particularly, lowering their gas release and decreasing the interaction of the fuel with the cladding) are currently mainly oriented to producing pellets with burning absorbers; obtaining the optimal microstructure (porosity and grain size) of the pellets; improving their shape; excluding dust on their surface after smoothing; and stabilizing their properties in regards to geometric sizes, density, and aftersintering.     

Hydrogen Isotopes Permeation in Clean or Unoxidized FeCrAl Alloys: A Review

Metallurgical and Materials Transactions A - The US Department of Energy is working with fuel vendors to develop accident tolerant fuels (ATF) for the current fleet of light water reactors (LWRs)....     

Thermophysical properties of Kachkanar titanomagnetite pellets

The thermophysical properties of Kachkanar titanomagnetite pellets of different basicity are determined. By mixing, the dependence of the mean physical specific heat of the pellets on the temperature and phase composition is found. The apparent specific heat of the pellets is determined by means of a gravimetric system with continuous recording of the change in pellet mass. By establishing an oxidative or neutral atmosphere, it is possible to distinguish between oxidation and decarbonization. The thermal diffusivity of the pellets is determined by means of a quasi-steady method, which permits the use of simple formulas in continuous heating. The thermal conductivity of the pellets is found from an equation relating their density, specific heat, and thermal diffusivity. The results are of great interest and may be used in the design of new roasting systems and also in optimization of the operational parameters of existing systems.     

Behaviour of iron ore–fuel oil composite pellets in isothermal and non-isothermal reduction conditions

Abstract

Self-fluxing iron ore pellets as an alternative to the agglomeration process led to the use of low price fuel oil as a binder and reducing material. Composite pellets containing 5–15% fuel oil were isothermally and non-isothermally reduced at 750–1000°C in a flow of H₂ or N₂ gases. The total weight loss resulting from O₂ removal from the reduction of Fe₂ O₃ and from the thermal decomposition of fuel oil was continuously recorded as a function of time at different reduction conditions. The actual reduction extent at a given time was calculated from the chemical analysis of partially reduced samples at a given time and temperature. Microscopic examination and X-ray phase analysis were applied to characterise the reduction products. The isothermal reduction of composite pellets indicated that the reduction rate increased with the increase in fuel oil content at the early stages. At the later stages, the reduction rate increased in the order 12>10>5> 15% fuel oil containing pellets. The non-isothermal reduction of composite pellets in N₂ atmosphere showed the presence of an incubation period at initial reduction stages. The low intensity magnetic separation technique was applied with the aim of increasing the iron content at the expense of associated impurities. The magnetic and non-magnetic fractions were analysed and the overall recovery was determined.     

Preparation methods and production of initial materials to prepare gadolinium oxide pellets used in fabrication of composite uranium–gadolinium fuel

The production method of efficient composite uranium–gadolinium fuel, the application of which will make it possible to improve the technical and economic performance of nuclear power plants, is developed in a laboratory. Based on the analysis of results, the substantiation of implementing the proposed method in industrial conditions is performed. Methods for the preparation and production of the initial materials to prepare gadolinium oxide are described. Necessary characteristics of the pellets of the promising composite uranium–gadolinium fuel are established in the course of experiments, and final requirements for these pellets are formulated allowing for them.     

固体氧化物燃料电池的中低温化研究

中低温固体氧化物燃料电池(IT—SOFC)是目前固体氧化物燃料电池研究的热点和发展的趋势。对中低温固体氧化物燃料电池的研究现状进行了综述，重点对降低SOFC操作温度主要途径，如电解质薄膜化、新型高电导率电解质材料和高性能电极的研究等几方面进行了论述。