发展电炉短流程要立足利用国内废钢资源

发展电炉短流程要立足利用国内废钢资源张浩一、钢铁生产流程发展的趋势当今，钢铁生产有两个主要流程。一是高炉───转炉───：连铸───热轧流程，通常称为长流程：二是电炉───连铸───热轧流程，称为短；流程。近年又兴起电炉───连铸连轧流程，称为紧凑...     

用现代工艺流程建设和改造钢铁厂

1 钢铁生产现代工艺流程的基本特征和目标1.1 基本特征 (1)流程紧凑化 生产工序尽可能减少,生产流程尽可能缩短,如在废钢、电力条件适宜情况下发展起来的电炉短流程钢厂(电炉-连铸-轧钢);采用COREX熔融     

2×5t电弧炉短流程全连铸炼钢及实践

电炉短流程紧凑型炼钢是电炉炼钢的发展趋势。本文就2×5t电弧炉进行短流程全连铸改造,进而走电炉—精炼—连铸三位一体炼钢工艺,并就改造后电炉实际生产情况加以分析。     

全连铸电炉炼钢厂时间节奏的衔接匹配

全连铸电炉炼钢厂的多炉连浇问题实质是多工序的衔接匹配问题。为了实现电炉炼钢厂多炉连浇的目标,关键是要缩短电炉出钢—出钢时间,使之能与连铸机的时间节奏一致。通过研究提出：连铸机连浇炉数主要取决于电炉出钢—出钢时间与连铸机一包钢水浇注时间的差值,运用钢铁制造流程中的时间概念分析了多炉连浇规律     

短流程——钢铁生产工艺发展的潮流之一

冶金生产工艺短流程是相对于传统的钢铁生产工艺流程而言的。有关专家表示，冶金企业通过减少传统钢铁生产工艺中的一些工序，以降低生产成本、提高劳动生产率，这是二十世纪七、八十年代以来，钢铁生产工艺流程发展的新潮流。连铸、铁矿石直接还原与熔融还原、超高功率电炉等高新技术装备的发展，为冶金企业实现短流程生产工艺奠定了基础。专家认为，未来典型的钢铁生产工艺短流程将是：     

广州钢铁工业的发展与直接还原

世界上直接还原发展的基本状况 世界钢铁工业的发展,在工艺路线上目前有两种途径,一是传统的焦炉—高炉—转炉法(即长流程法),二是电炉-连铸连轧法(即短流程法),如果以1735年英国人首次采用焦碳炼铁,奠定现代高炉基础之日算起,长流程法已有260年的历史,由于焦煤贮量的日趋减少,钢铁用量的逐年增高,短流程法得到迅速发展,世界电炉钢的比例由1957年的7.2％升至1992年的29.4％,但随之而来的     

南京钢铁厂超高功率电炉—钢包精炼炉—全连铸项目通过可行性研究审查

江苏省冶金厅于1992年4月29～30日召开南京钢铁厂电炉分厂可行性研究审查会。该项目工艺流程的主要特点:采用电炉—钢包精炼炉—全连铸短流程生产线。采用超高功率电炉(850kwh/t钢),计算机控制冶炼操作;氧—油喷枪助熔技术;泡沫渣长弧冶炼技术;偏心炉底出钢;钢包精炼炉精炼;全连铸技术。     

电炉炼钢现状与发展

1 电炉钢发展概况 高炉—转炉—连铸—连轧流程规模投资大,生产灵活性小,效率好的企业年产量必须在1000万t以上。而电炉—连铸—连轧、半连轧流程,其经济规模为50—200万t。 由于电炉炼钢流程的投资少、劳动生产率高,经济规模小,且对环境影响小。二十多年来在世界钢产量的增长中,电炉钢的增长     

电炉—全连铸—热送—热轧生产线定为国家“八五”工业性试验项目

无锡锡兴钢铁联合公司电炉——全连铸——热送——热轧生产线,是1400多家地方中小型冶金企业中唯一的一条高效节能短流程生产线。4月25日,冶金部钢铁研究总陈、北京钢铁设计总院、宝钢设计院、江苏省冶金设计院和北京科技大学、东北工学院等15个单位的17     

全废钢电炉流程电炉-连铸“界面”优化研究

"界面"技术优化是钢铁制造流程优化的重要切入口。阐述了电炉-连铸区段"界面"技术的内涵和分类,并以唐山某钢厂为例,对全废钢电炉流程电炉-连铸区段"界面"进行物质流运行过程事件解析、时间解析和温度解析。在此基础上,采用排队论方法对该钢厂钢包在线周转数量进行优化,结果表明:钢包在线周转数量有望从现有的6～7个减为5个。     

重庆高校推进产学研合作的案例分析

以重庆大学、重庆邮电大学和重庆理工大学为例,剖析重庆高校推进产学研合作的基本模式,已经取得的突出成绩,分析总结其基本经验.从完善政策法规体系、强化经济调控、建立组织机构、加强中介建设及开展国际产学研合作等方面,提出了深入推进重庆高校产学研合作的对策建议.     

Benzimidazole resistance in cyathostomes in horses in the Ukraine

The efficacy of treatment with cambendazole was tested in 1-year-old horses on a farm in Dubrovka, Ukraine. Thirty-five horses were treated. Their egg output was compared on the day of treatment and 14 days later with that of 33 untreated horses. Before treatment the mean number of eggs g-1 faeces was 614 in the controls and 766 in horses that had been treated. After 14 days the mean egg output in the controls was 580 and in the treated horses 369. This means a reduction of 54.5%. Only cyathostome larvae could be cultured from faeces collected after treatment. It can be concluded that benzimidazole resistance in cyathostomes is present in the Ukraine.     

Apoptosis in experimental myocardial infarction in situ and in the perfused heart in vitro

We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.     

Fractures in childhood in Khartoum

A prospective study of fractures in 231 children received at Khartoum North Teaching Hospital(KNTH) was carried out for a period of six months. The incidence of child fracture rated as one per day, then it increased from the age of 5 years onwards in boys and between 6 and 8 years in girls. Most injuries were sustained during the day time, especially between late afternoon and sunset. 82% of injured children presented to a medical facility, while 18% were taken to native healers first. Non-road traffic accidents accounted for 84% of the fractures mainly due to sports, domestic injuries and falls; whereas road traffic accidents were 16% and occurred mainly in pedestrians. Forty three percent of the fractures needed only first aid and splintage while 42% needed closed reduction. Thirty one percent of all patients were treated as inpatients. The long bones were affected in 91% of all fractures, the commonest site being the distal end of the forearm (26%), followed by supracondylar fracture of the humerus (15.6%). In the upper limb, left-sided fractures predominated. The epiphyseal injuries were 3.5% of all fractures, mainly at the distal radial epiphysis. Boys were commonly affected between 13-15 years of age. Open fractures constituted 9.8% of the series and were mainly due to traffic accidents in town dwellers, the most vulnerable bones were those of the leg and foot. Pathological fractures accounted for 2.2% and were due to bone cysts and osteogenesis imperfecta. The problem of child safety and the preventive measures need to be more stressed.     

Heatstroke in runners in Oklahoma

It is a common opinion that general surgery is the first step for whoever approaches a surgical discipline, and that whoever practices training in general surgery should learn the rudiments of each surgical branch. The role of microsurgery in the training of the general surgeon has not been well-established. Clinical applications of microsurgery in general surgery are few and are rarely required, and have been connected strictly to restricted indications. However, we think that microsurgery could be very useful to the general surgeon because it allows the execution of experimental research on rats, the only possibility permitted by law. In these studies the microsurgeon can perform many times and in a short time the same surgical operation, thus improving his skill, and easily getting familiarity with surgical instruments and sutures.