CaO-CaF2对钢包精炼顶渣性能的影响

为减少密封合金化精炼钢包浸渍罩粘渣,采用按m(CaO)/m(CaF<,2>)=2:1配制的混合调质剂对钢包顶渣进行调质处理,研究调质剂对钢包顶渣性能的影响.熔化性能研究结果表明:调质剂能显著降低钢包顶渣的熔化温度和黏度,当其加入量为钢包下渣量的10%时,渣熔化温度从调质前的1 439℃降至1 400℃;在1 500℃时,未调质的钢包顶渣黏度约为6.5 Pa·s,而调质后渣的黏度低于2 Pa·s.渣金反应实验表明,调质后的渣可使钢液脱硫,但同时会引起钢液少量回磷.工业试验表明,对钢包渣调质处理后,浸渍罩粘渣得以控制,使用寿命提高1倍以上.     

钢包粘渣的机理研究

通过对粘渣物、钢包渣、工艺因素、保温剂和钢包残样等的分析,指出钢包粘渣是冶炼钢种、钢包热状态和包衬耐火材料共同作用的结果.高Al2O3的渣冷凝后析出高熔点物质、小修后钢包热状态差以及渣钢渗入耐材是粘渣的主要原因.     

梅钢钢包粘渣原因分析

近年来梅钢公司的钢包在使用中出现严重的粘渣,造成了钢包使用寿命降低、钢包周转紧张、粘渣污染钢水等不良后果和现象,通过实验深入地开展了钢包粘渣机理的研究分析,结果表明,脱氧产物Al2O3的含量、包衬耐火材料表面状况、钢包覆盖剂的使用等都会导致粘渣。     

Li_2O对钢包精炼渣的调质处理

为减少钢包合金化精炼浸渍罩粘渣,以Li2O作调质剂对钢包顶渣调质处理,研究Li2O对钢包顶渣的熔化温度、黏度及脱硫能力的影响。半球法熔化温度测定结果表明:Li2O的助熔效果明显,当其加入量为5%时,渣熔化温度从调质前的1439℃降至1300℃;旋转柱体法黏度测试结果表明:钢包顶渣的黏度高以及合金化精炼处理后顶渣黏度进一步升高,是造成浸渍罩粘渣的主要原因,Li2O能有效降低精炼处理后钢包顶渣的黏度,在1500℃时,未调质的钢包顶渣黏度约为6.5 Pa.s,调质后渣的黏度低于2 Pa.s。调质处理后的钢包渣不会引起钢液的回硫,并可使钢中硫的含量进一步降低。     

安钢25t钢包粘渣原因分析

本文通过对安钢25吨钢包粘渣原因进行分析,找出了钢包粘渣的主要原因,制定了减轻粘渣的对策,提高了钢包包龄.     

精炼钢包的粘渣及其处理方案

为了解决精炼钢包粘渣问题,通过分析概括钢包粘渣的主要原因,制定了钢包的粘渣状况及减轻粘渣的措施,提出了减轻粘渣方案,减轻了精炼钢包的粘渣。     

马钢新区钢渣处理技术及综合利用

根据中国钢渣处理率和处理后钢渣再利用偏低的情况,马钢新区的渣处理按照在线全处理的模式进行设计.通过自行设计的风碎渣处理线和滚筒水淬渣处理线的实际运行,对生产中存在的设备和工艺问题进行了完善,解决了风碎渣处理和滚筒水淬渣处理的诸多难题.结果表明:目前这2条线对转炉渣和钢包渣的处理率超过90%;处理后回收废钢全部返回转炉利...     

钢渣配比对3~#烧结机烧结矿冶金性能的影响

转炉钢渣包括炼钢过程中造渣、喷溅物、清理钢包、铁包以及中间包的粘渣、钢包铸铁等物质,钢渣的CaO和MgO含量都比较高,同时SiO_2含量和P含量也比较高,钢渣的矿物组成主要由铁酸钙、铁方镁石和硅酸二钙组成、含有少量的金属铁。钢渣的表面比较粗糙,反应性比较高,表面张力和接触角在烧结熔剂中最小,亲水性比较好。选取不同的钢渣配比进行烧结机工业性试验,系统地研究烧结混合料中钢渣配比对烧结工艺过程和烧结矿冶金性能的影响规律。根据承钢炼钢工艺过程对铁水中P含量的要求和承钢高炉目前的炉料结构特征,从提高烧结机利用系数的角度出发,烧结混合料中钢渣配比不宜超过5%。     

钢包粘渣原因分析及措施

针对梅山钢铁股份有限公司在钢包使用中出现的粘渣问题,通过对铝脱氧和铝硅脱氧钢种的转炉渣以及钢包顶渣、钢包内壁粘结物的化学组成和使用后的耐火砖物相的分析,结果表明,脱氧方式、钢包状态、保温剂是影响粘渣的主要因素.采取了相应措施,取得了很好的效果.     

降低钢包浇余提高钢水收得率的实践

<正>连铸生产过程中,控制每炉钢包浇注后期钢渣下渣量的大小,是钢铁企业普遍面临的现实问题。如果钢包下渣量过大不但会降低钢水的结净度,影响铸坯质量,而且还会加快中间包耐火材料的侵蚀,缩短其使用寿命,增加中间包渣量,甚至导致拉漏事故,影响连铸正常生产的进行。钢包下渣量少能够有效地阻止大量钢渣流入中间包,但是钢包内不可避免地还残留大量的纯净钢水,据宝钢申屠理锋等人研     

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.