电炉采用大比例直接还原铁冶炼技术分析

对中东某钢铁企业电炉采用大比例直接还原铁冶炼的技术特点进行分析,实际生产表明:电炉采用大比例直接还原铁冶炼时采用大留钢量、炉顶连续加料、100%直接还原铁连续冶炼、泡沫渣冶炼、熔池搅拌等技术均有利于生产组织及钢水质量。     

直接还原铁在特钢行业中的应用

国内不少特钢企业针对直接还原铁(DRI)不同配入量对电炉炼钢的冶炼时间、吨钢电耗、钢水收得率及残余元素的影响进行试验研究,以实现冶炼过程对DRI的合理添加比例和方式,达到最佳使用效果。发展直接还原铁有利于实现节能减排、绿色发展,以及钢铁业的转型升级。     

Emirates钢公司短流程钢厂创生产纪录

Emirates钢公司短流程钢厂不断创造生产纪录,这归功于电炉炼钢车间与位于上游生产线的高效Energiron直接还原铁生产设备有效的直接连接,从而使它们形成一个高效运行的整体。Energiron直接还原设备以212t/h的速率,不断向电炉车间提供高质量热直接还原铁,高于200t/h的设计生产能力。达涅利目前为Emirates钢公司提供了两套直接还原生产设备,使Emirates钢公司热直接还原铁生产能力超过300万t。Energiron直接还原铁生产设备和电炉炼钢车间之所以能够直接相连,是由于配备有HYTEMP-热直接还原铁气     

狠抓直接还原铁质量

直接还原过程中矿石的脉石转入DRI,给电炉冶炼带来一系列影响.直接还原铁质量,必须兼顾直接还原生产和电炉炼钢两个生产环节.     

150t超高功率电弧炉配加直接还原铁冶炼工艺

石油用无缝钢管对钢中金属残余元素（Ni，Cr，Cu）和五害元素（Ph，Sn，As，Sb，Bi）的含量有严格的限制。一般在炉料中配一定量的直接还原铁以降低钢中残余元素含量。例如俄罗斯OEMK钢厂在冶炼中配加比例高达80％的直接还原铁生产棒、板、管材；加拿大的Cidbec－Dosco厂在冶炼中配用60％、100％的直接还原铁生产冷轧卷、棒材、管材“‘天津钢管公司自1992年6月至1996年8月电炉炼钢使用直接还原铁（包括直接还原铁DRI和热压块HBI）共计19．34万t，平均年用直接还原铁量约为5．0万t，逐年使用量见表1，约占全国历年使用量总和之60％…     

电炉炼钢原料及直接还原铁生产技术

中国电炉炼钢的铁源原料由废钢铁料、生铁块、热铁水、直接还原铁等组成。直接还原铁(DRI/HBI)是电炉冶炼纯净钢最佳的残留元素的稀释剂。直接还原是钢铁工业技术发展的重要方向,气基竖炉和煤基回转窑是成熟的直接还原工业化生产技术。中国直接还铁的生产仍处于起步时期,2008年产量约60万t,占世界总产量不足1.0%。直接还原铁在中国有广阔的发展前景,以国内铁矿资源为原料的氧化球团-煤制气-竖炉是中国发展直接还原铁的主要方向。     

直接还原铁相对废钢的价值

直接还原铁的主要市场是电炉炼钢,所以它的价值通常与废钢对比。直接还原铁对废钢的相对价值要考虑以下几个因素。一、化学成分对炼钢来说,直接还原铁的最大价值是生产高质量的钢种,诸如扁平产品(钢板、钢带、扁钢)、无缝钢管、高质量拉拔钢丝、冷顶锻钢捧、特殊条形品种。这时,电弧炉操作对原材料和最终产品中的杂质元素如Cu、Sn、Mo、Cr、Ni、S、P等有极严格的要求。表1是不同等级碳素钢中杂质元素的通用极限。与之相对,表2是不同等级废钢和直接还原铁中杂质元素的含量。这两个表揭示了直接还原铁作为电炉炼钢稀释剂的价值——即用低质量废钢可以生产高质量的钢。     

直接还原铁在电弧炉炼钢中应用

据预测到2000年我国的电弧炉用废钢将出现较大缺口。可能的对策有：（1）进口废钢和直接还原铁；（2）国内建设直接还原铁厂；（3）使用冷生铁；（4）铁水热装。本文从电炉炼钢的技术经济指标和钢质量等方面，论述了直接还原铁及其它金属炉料的使用特点。     

直接还原铁在转炉的应用效果分析

太钢二炼钢在80 t转炉上采用直接还原铁代替专用废钢冶炼品种钢的试验并推广使用,结果表明,直接还原铁代替废钢合适的比例为35%～50%,使用部分直接还原铁后转炉脱磷能力增加,脱磷率提高2.4%;80 t转炉配加5 t直接还原铁,石灰消耗增加9.3 kg/t;使用直接还原铁代替部分专用废钢,钢中残余元素及有害元素含量都很低.     

山东省电炉炼钢直接还原铁的应用分析

对山东省电炉钢生产状况进行分析,同时结合市场的需求,提出采用直接还原铁冶炼高附加值的纯净钢是提高产品竞争能力的一项有效措施。     

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.