Correlating mechanical properties of sinter phases with their chemistry and its effect on sinter quality

In this study, pot sinter tests were carried out to study the sintering properties of iron ores of different alumina (2–4–6%) level. It was observed that the 6% alumina level ores have a higher RDI values and decreased tumbler index (TI) compared to its other two counterparts. It was observed that an increase in composite fracture toughness (CFT) of sinter improves the Tumbler as well as RDI of the sinter. Beyond 4 CFT there is remarkable improvement in TI, RDI and RI values. The mechanical strength parameters of sinter phases were further correlated and analysed with respect to the chemistry of sinter and mineralogy of sinter phases. There is strong evidence which suggests that the Al₂O₃ deteriorates the strength of the phases by making them hard and thus generating cracks in them. Unlike alumina, CaO and SiO₂ tend to stabilise and improve the strength of the phase.     

氯化物对烧结矿RDI影响的试验研究

介绍了在烧结矿表面喷洒ＣａＣｌ２等稀溶液以降低宝钢烧结矿ＲＤＩ指数的实验室试验研究，以及在烧结混合料中添加少量ＣａＣｌ２烧结的试验研究结果。     

二氧化硅质量分数对烧结矿多重分形参数的影响

从不同二氧化硅烧结矿的表观形貌出发,对表征烧结矿的分形参数进行解析,发现Δα及f（α）max值的大小表征Fe3O4和CaO·Fe2O3数量的多少及其分布的均匀程度。且随着SiO2质量分数的升高,低硅烧结矿其还原性逐渐变差而其抗压强度呈现出逐渐变好的趋势;而当wSiO2=4.8%时,多重分形谱谱宽Δα达到最小值,多重分形谱最大值f（α）max达到最大值,这就表明,此时不仅低硅烧结矿中的铁酸钙分布较均匀而且生成量最大。所以,随着低硅烧结矿SiO2质量分数的增大,其还原性逐渐变差,抗压强度逐渐变好。     

Advanced monitoring system of sinter plant

Abstract

A correct management of the sinter plant is crucial for the productivity of an integrated steelwork, as the sinter quality has a direct and considerable impact of the blast furnace productivity and efficiency. To this aim, it is of utmost importance to continuously monitor the sintering process in order to preserve its stability as well as the homogeneity of the combustion along the entire length of the sinter bed. In particular, the permeability of the sinter mix once it lays on the strand is a crucial factor to monitor in the different areas of the bed together with the temperature distribution on the final part of the strand, just before the material discharge in the crusher. The charging gates, on the other hand, are the most natural mean to affect permeability itself, as their opening levels affect the distribution of the material on the strand. Here an innovative monitoring system is presented, which have been installed and tested at ILVA Taranto Works and integrates a series of measuring devices distributed on different zones of the machine. All the information collected by the sensing system is jointly exploited in order to obtain a clear and updated picture of the ongoing process, by providing a valuable support to plant engineers and technicians managing the sinter machine both for standard operations and for programming maintenance interventions.     

梅钢烧结配加印度果阿矿的试验研究

研究和分析了印度果阿矿在梅钢烧结现有用料结构条件下的试验情况,结合印度果阿矿的性质特征,提出果阿矿将来在梅钢应用的一些建议。通过实验室试验表明,在果阿矿配比为10％的条件下,烧结矿各项指标均较好。     

Performance of different diagnostic groups on the tachistoscopic and copy phases of the Bender-Gestalt.

Neurotics, alcoholics, organics, and controls (25 Ss in each group) were administered the Bender designs by tachistoscopic exposure (tach phase) and by the standard copying technique (copy phase). Records were scored by blind analysis with the Pascal and Suttell criteria. The copy phase discriminated the diagnostic groups from the controls at the .01 level, but did not discriminate the diagnostic groups from each other. On the tach phase, control Ss were discriminated from alcoholics and organics but not from neurotics; however, the scores of the neurotic group differed from the organic group at the .02 level. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Separation and recovery of potassium chloride from sinter dust of a steel plant

Many companies return sinter dust to sintering directly, resulting in circulation and accumulation of harmful elements, which will affect the collection efficiency, sinter quality, and the grade of blast furnace seriously. A new separation and recovery process of potassium from the dust was proposed, which included water leaching, solid liquid separation, purification, vacuum evaporation and cooling crystallisation. The results showed that the optimum conditions were as follows: the ratio of solid to liquid?=?1:3, leaching time?=?40?min, and leaching temperature?=?80°C, leaching rate of potassium chloride reaches 99.99%. When solution weight loss is 97.5%, the evaporation of potassium chloride product reaches 97.96%, purity of potassium chloride in the crystal can be 75.15%. Based on experiment results, a mathematical model of leaching kinetic of potassium chloride including stirring temperature and leaching ratio is proposed.     

MgO对高碱度高铝烧结矿的影响

 随着钢铁企业高铝铁矿粉使用比例的提高,带来了高炉炉渣黏度增大、渣铁分离困难等一系列问题。采用烧结杯试验,研究了MgO含量增加对高碱度高铝烧结矿经济技术指标、冷强度和冶金性能的影响,采用Nova400 NanoSEM型场发射扫描电子显微镜分析了烧结矿微观结构。试验结果表明,高碱度高铝烧结矿中MgO质量分数从1.72%提高到2.49%时,垂直烧结速度降低4.38 mm/min,利用系数降低0.51 t/(m2·h),低温还原粉化指数增加6.7%;当烧结矿中MgO质量分数为2.11%时,转鼓指数和还原度最高,分别达到61.93%和86.39%;Mg2+主要固溶在磁铁矿晶格中并替代Fe2+,替代的质量分数最高达3.64%,生成的含镁磁铁矿抑制烧结矿降温过程中由Fe₃O₄→Fe₂O₃氧化过程的相变,减少了二次赤铁矿的生成,有利于改善烧结矿的低温还原粉化性能。研究结果可以为改善高碱度高铝烧结矿性能和提高炉渣流动性提供理论指导和参考依据。     

氧化铝对铁矿石烧结质量和生产率的影响(英文)

烧结矿是现代高炉生产的主要含铁原料。合理控制入炉烧结矿的理化性能与冶金性能对高炉生产和稳定操作是很必要的。铁矿粉是烧结矿的主要原料,其化学成分和烧结料层内的热量条件在烧结过程中起着重要的作用。化学成分等参数也决定着烧结矿矿相结构和质量。由于含氧化铝原料的低反应性及其液相的高粘性,因此在人们的预料中高铝矿石对烧结矿结构组成的影响并不好。烧结混合料中的氧化铝在同化过程中需要消耗大量热量,延迟烧结过程。在确保高炉渣的流动性方面,氧化铝也需要消耗较大热量。不论是烧结还是高炉的生产实绩均表明,氧化铝是有害的。一般而言,高含铁量与低脉石的印度矿与其他矿石的不同特点就是氧化铝含量高。由于高品味铁矿石的消耗殆尽,使用可利用的烧结原料成为生产必需。因此,必须要掌握氧化铝的作用及其对烧结矿质量和生产过程的影响。实验室完成了不同氧化铝含量水平(2.00%～5.46%)的实验,可从中了解氧化铝在烧结矿矿物学、生产率、物理性能和冶金性能方面的影响。随着烧结矿中氧化铝含量的增加,残存赤铁矿、复合铁酸钙(SFCA)和孔隙率增加,而磁铁矿和硅酸盐比例下降。烧结生产率和烧结矿转鼓强度(TI)随着氧化铝含量上升而下降,反映烧结矿冶金性能的诸如低温还原粉化率(RDI)和还原率(RI)提高。     

一种巴西低铝粉矿在宝钢的试验研究

通过采用X射线衍射、微型烧结等方法对巴西的一种低铝粉矿进行试验研究。该低铝粉矿品位较高,SiO2含量中等,Al2O3和磷含量均较低;粒度组成细;含铁矿物主要为赤铁矿,脉石矿物主要是石英;气孔率较低。烧结杯试验和工业试验结果表明,通过少量提高生石灰粉使用比例等,在一定的使用比例范围内烧结矿产量和质量指标可以保持在较好的水平。     

马氏体时效不锈钢高温析出相的热力学计算

利用热力学计算软件Thermo-Calc,研究了新型马氏体时效不锈钢0.007C-13Cr-7Ni-4Mo-4Co-2W在800～1200℃固溶温度下基体组织和析出相的变化。通过透射电镜(TEM)、选区电子衍射花样(SADP)和X-射线能谱分析(EDS)法研究了马氏体时效不锈钢固溶态显微组织结构。结果表明,马氏体时效不锈钢高温析出Laves- Fe₂Mo相,固溶温度超过1 050℃,析出相全部溶解。     

废槽衬火法处理过程热力学分析

采用自由焓函数法计算了废槽衬火法处理过程中几个主要反应的自由焓变化,分析了各反应可能的方向和趋势,其结果将为选择废槽衬无害化处理工艺提供基础数据。     

Discussion on transformation of precipitate phases in 2205 duplex stainless steel with different isothermal treatment situation

Due to isothermal heat treatment or welding,duplex stainless undergoes a variety of decomposition processes at a temperature ranging from 300 - 1 100℃,which could form inter-metallic phases likeσ-phase and xphase,as well as Cr₂N and M₂₃C₆,etc.These processes are not only influenced by temperature and cooling speed, but also are affected by alloy element content.The purpose of the research was to work out the qualitative and quantitative analysis of precipitate phases in 2 205 duplex stainless steel with different isothermal heat treatment situation.After choosing the electrolyte and electrolytic systems,we use electrochemical method to extract precipitate phases from the matrix.Scanning electron microscope（SEM） and X-ray diffraction（XRD） were used to examine their modality and structure.Particle size distribution was performed by dynamic laser scattering sizer （DLS-Sizer）.Furthermore,oxygen-nitrogen analyzer and carbon-sulfur analyzer were applied to measure the content of nitrogen and carbon in precipitate phases.Separation and quantitative analysis of precipitate phases were carried out by wet chemical analysis and inductively coupled plasma spectrometry（ICP）.In a word,combining chemical and physical methods,our research reveals the transformation of precipitate phases’species,content, elemental composition and particle size distribution during different isothermal heat treatment situation.     

降低烧结法氧化铝工艺能耗的节能措施

本论述了烧结法氧化铝生产过程中降低工艺能耗的工业实践情况，提出了降低烧结法氧化铝工艺能耗的有效途径。     

烧结配料优化方法及算法对比分析

依据已经报道的相关研究,对当前用于烧结配料的各种优化算法进行了对比分析。结果发现,对于关系简单、规模较小的模型,线性规划法方便易用,求解效率高;对于大规模复杂问题,遗传算法、粒子群算法和蚁群算法能灵活有效解决问题;神经网络能够基于大数据对生产结果进行预测;基于神经网络而建立的专家系统能够很好地指导生产实践。未来优化配料应以铁水成本最低及保证烧结矿冶金性能为目标进行多目标优化。     

Thermodynamic Properties of Cu-Ce-O and Cu-RE-O Melts

ＴｈｅｒｍｏｄｙｎａｍｉｃＰｒｏｐｅｒｔｉｅｓｏｆＣｕ－Ｃｅ－ＯａｎｄＣｕ－ＲＥ－ＯＭｅｌｔｓ￥ＨｏｎｇＬａｎ；ＳｕｉＺｈｉ－Ｔｏｎｇ；ＷａｎｇＣｈａｎｇ－Ｚｈｅｎ（ＤｉｖｉｓｉｏｎｏｆＭｅｔａｌｌｕｒｇｉｃａｌＰｈｙｓｉｃｏｃｈｅｍｉｓｔｒｙ，Ｎｏ...     

不同热处理状态下2205双相不锈钢中析出相变化的讨论

双相不锈钢因热处理或焊接过程,在300～1100 ℃影响区域内析出σ相,χ相等金属间相以及Cr2N,M23C6等析出相,这种析出倾向既受温度范围、冷却速度等因素的影响,又受合金元素含量的影响。本研究的目的是考察2205双相不锈钢不同热处理状态下析出相的变化。在选择好合适的电解制度后,实验利用电解分离的方法将不同时效条件下的析出相从基体中分离出来。通过扫描电镜（SEM）和X射线衍射（XRD）定性分析了析出相的形貌和结构特性,并利用激光粒度仪（DLS-sizer）分析提取残渣的粒度分布。此外,利用氧氮仪和碳硫仪分析了不同时效条件下析出相中氮和碳的含量,同时用化学湿法和电感耦合等离子光谱仪对析出相的分离与定量成分检测进行研究。实验用化学和物理的手段揭示了双相不锈钢在不同热处理状态下析出相种类、含量、元素组成和颗粒粒度的变化。     

The Thermodynamic Property of Rare Earth Complexes with L-Threonine

In this paper the stability constants and thermodynamic parameters for complexes of rare earth elementswith L-threonine have been measured systematically by potentiometry and calorimetry at 25℃ and ionicstrength of 0.15 mol/L(NaCl).The thermodynamic values for protonation of the anion of L-threonine havebeen obtained.The dependence of stability,enthalpy and entropy change of the complex upon atomic number ofcation is investigated,and the coordination of L-threonine to rare earth is also discussed in detail.