莱钢高炉解剖软熔带含铁炉料特性分析

基于莱钢2007年120 m3生产高炉科学解剖研究内容,系统分析了含铁炉料在软熔带位置物化属性。结果表明,高炉软熔带呈不规则倒V形分布,软熔层矿石还原度由低温侧向高温侧逐渐增加,其中烧结矿的还原度由40%~70%增加至80%~95%,球团矿的还原度由40%~50%增加至70%。软熔层低温侧烧结矿金属化率为20%~45%,球团矿的金属化率为10%~20%,在高温侧烧结矿的金属化率为70%~95%,球团矿的金属化率约为50%~70%。含铁炉料在软熔带区域发生了剧烈的还原反应,其中烧结矿金属化率增加的幅度大于球团矿的主要原因为烧结矿的还原性好于球团矿的还原性。矿相分析表明软熔带中球团矿已没有Fe₂O₃、Fe₃O₄存在,铁主要以FeO和金属铁存在,在软熔带区域存在被还原生成中空的铁壳球团矿。     

综合权衡还原性和还原粉化率确定烧结矿的冶金性能

制定了一项检测高炉炉料质量的试验方法。在这项试验中,在接近于高炉内温度和煤气成分的条件下对炉料的强度和还原性的变化进行测定。已采用该试验方法对烧结矿、球团矿以及由烧结矿和球团矿组成的混合炉料进行了检测。本文介绍了检测所得出的还原粉化率和还原性能之间的关系,以及在霍戈文炼铁生产中应用的情况。     

混装铁焦对人造富矿还原行为的影响

 高炉炼铁是资源、能源的消耗大户,节能潜力巨大。铁焦是一种高反应性焦炭,将合适粒度和数量的铁焦与含铁炉料混装入炉,从理论上说具有降低焦比,取得节约稀缺炼焦煤资源和降低生产成本的潜力。对混合试样的还原机理进行了分析,并对铁焦与人造富矿的耦合反应进行了实验室研究,证明混入铁焦对烧结矿和球团矿的还原反应有明显的促进作用,提高温度和增加铁焦用量对提高铁矿石的还原度有利。     

钒钛铁矿石的还原,熔滴性能及高炉炉料结构的探讨

研究了各种类型钒钛铁矿石(不同碱度烧结矿以及球团矿和块矿)的低温、高温还原性及熔滴性能。在此基础上探讨了全钒钛铁矿石高炉冶炼的合理炉料结构。认为:高钛型钒钛铁矿石高炉冶炼的最佳炉料结构是:高碱度烧结矿加酸性氧化球团矿;在攀钢现有工艺和设备条件下,应实行提高烧结矿碱度的方针。     

不同类型铁矿石的低温还原粉化特征

以炼铁厂常用烧结矿、球团矿以及块矿为研究对象,考察了不同含铁原料在高炉炼铁工艺和COREX非高 炉炼铁工艺2种煤气条件下的低温还原粉化行为。研究结果表明:①铁矿石的结构组成决定了其粉化形式,块矿 和烧结矿的粉化形式均表现为“裂开式”,粉化产生的细小粒级颗粒较均匀地分布于-6.3 mm范围;不同于烧结矿 和块矿,球团矿则属于“剥落式”粉化,粉化产物粒径主要集中在-0.5 mm范围;②在还原气氛和温度相同的情况 下,烧结矿粉化程度最高,球团矿次之,块矿最低;③还原温度对3种含铁炉料的还原粉化程度均具有重要影响,当 还原煤气条件相同时,3种含铁炉料的低温还原粉化指数均在550℃时达到最大值;④COREX炼铁工艺的煤气条 件加剧试验用铁矿石的低温还原粉化程度,但对不同类型铁矿石的影响有所差异,综合粉化产生的细小颗粒的增 幅可知,块矿受其影响程度较大,其次是球团矿,而烧结矿对煤气性质改变的敏感性最小。     

烧结矿混装焦丁对高炉冶炼的影响研究

高炉冶炼众多减少焦炭消耗量的方法中,不仅仅要关注如何减小焦炭的溶损反应,也要寻找其它方法,如称之为“焦丁”的小颗粒焦炭代替块焦。现代高炉在烧结矿中混装不同量（10—40kg／tFe）和不同粒级的焦丁可以减少焦炭的溶损。本文的目的在于模拟高炉条件研究使用焦丁对料柱透气性和烧结矿还原性的影响;在冷态下各种网素诸如焦丁比、气体流速、料层厚度对料柱透气性的影响;以及焦丁对不同气体组成、不同温度下烧结矿的等温还原和非等温还原性能的影响。烧结矿的等温还原实验是在30％CO＋70％N2气氛中、大于l373K的高温下进行,还原阻力随还原气体中CO2气体含量的增加而增加,随H2的增加而减小。烧结矿中？昆装焦丁能够提高烧结矿的还原性从而抑制还原延迟现象。     

富氢气氛下不同含铁炉料的还原行为

 高炉低碳富氢冶炼技术如高炉喷吹煤粉、富氢燃料等会导致炉内炉腹煤气中氢气体积分数增加,为探究富氢对高炉上部炉料的影响,对富氢条件下不同含铁炉料的还原行为进行了试验研究。粉化试验结果表明,在20%H₂(体积分数)条件下,块矿和烧结矿的粉化率明显改善,RDI_{>3.15 mm}分别增加了11.08%和30.23%,同时富氢条件有利于含铁炉料粒度的均匀化。还原试验结果表明,在CO体积分数不变、改变H₂加入量条件下,球团矿和烧结矿还原度最高时的H₂体积分数为25%,块矿H₂体积分数则为10%。在保持(CO+H₂)体积分数30%不变、改变H₂加入量时,当H₂体积分数超过20%时,各含铁炉料的还原度均超过90%。扫描电镜分析结果表明,还原后的块矿明显生成渣相和铁相,球团矿出现良好的赤铁矿和磁铁矿相,烧结矿则呈“针状铁酸钙相-磁铁矿相-铁相”分层现象。     

碳循环氧气高炉内软熔带上部炉料反应行为

近年来，在中国“碳达峰”“碳中和”战略背景下，低碳高炉炼铁已成为中国低碳冶金技术发展的重要方向。在高炉炼铁工序，由于大量使用化石燃料及炉顶煤气利用率低，导致CO₂排放量过多。为降低高炉炼铁的碳排放，提出富氢碳循环氧气高炉新工艺。以碳循环氧气高炉为研究对象，通过数值模拟与实验室试验相结合的方式，对高炉内软熔带上部含铁炉料的还原行为和焦炭气化行为进行了研究。通过SEM-EDS对烧结矿和球团矿的还原程度及渣铁分离现象加以分析，同时采用矿相显微镜对焦炭气化后的微观形貌进行表征。通过数值模拟和实验室试验得到的高炉内含铁炉料还原度变化规律基本一致，验证了数值模拟与实验室试验相结合方法的可行性。研究表明，在高炉的同一竖直方向上，随着位置的降低，含铁炉料的还原度和金属化率不断升高，焦炭的气化率不断上升。在高炉中心位置软熔带上方，含铁炉料的还原度为0.91,金属化率为67.58%,焦炭的气化率为20.91%。在高炉边缘位置软熔带上方，含铁炉料的还原度为1,金属化率为96.91%,焦炭的气化率为21.36%。并且，随着炉料下行，还原后含铁炉料的金属铁面积越大，渣铁分离越明显，观察到的...     

安钢高炉低烧结矿比例炉料结构合理配置的试验研究

对不同碱度烧结矿、不同碱度球团矿、块矿,以及混合炉料结构进行了高温冶金性能试验,结果表明,安钢高炉采用烧结矿+块矿+酸性球团矿+碱性球团矿"的四元结构模式,炉料结构的高温冶金性能得到了显著改善.碱性球团矿还原性能和高温冶金性能明显好于酸性球团矿,与烧结矿搭配,可以改善高炉顺行条件,降低燃料消耗.从稳定和改善炉料的高温冶...     

武钢8号高炉炉料状况分析

对武钢8号高炉目前使用的不同含铁炉料进行了冶金性能试验。结果表明,武钢四烧烧结矿的质量性能在武钢烧结矿中处于中等水平,2015年四烧烧结矿的低温还原粉化率有一定的波动,900℃还原度基本维持在80%左右;鄂州球团矿的TFe稍稍次于程潮球团矿,两者冶金性能相差并不大;澳块与南非块的性能差异很小,但是南非块的软熔滴落性能明显优于澳块。研究表明,在目前四烧烧结矿冶金性能的条件下可以优先考虑与程潮球团矿或南非块搭配使用。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.