以转底炉技术利用钛资源的基础研究

提出了一种以转底炉煤基直接还原技术利用钛资源的新工艺及两个不同的方案。该工艺以攀枝花钒钛磁铁精矿或钛精矿粉、煤粉和少量添加剂组成的复合球团为原料,在高温加热条件下将含钛矿中的氧化铁还原为铁,经渣铁分离后获得生铁和富集了的钛渣。第一方案以钒钛磁铁精矿配20%钛精矿为原料,还原后渣铁自然分离,得到块铁和品位为50%左右的钛渣;第二方案以钛精矿为原料,还原后经破碎磁选分离得到粒铁和TiO2富集率为～75%的钛渣。对这两种方案均进行了初步试验,确定了合理的工艺条件。     

钒钛磁铁精矿低温综合利用新工艺

为了实现钒钛磁铁精矿的低温综合利用,采取碳热钠化工艺降低还原和熔分温度,考察了铁、钒、钛的富集回收情况。结果表明,钠化剂显著改善了钒钛磁铁精矿的还原及熔分效果,当钠化比为1.2时,1 100℃还原60 min即可达到90%以上的金属化率,1 250℃以上的温度下熔分后,铁的收得率达到96%,钒在铁水中的富集率为75%。熔分渣在无酸环境下经湿法处理后TiO_2含量达到77%,经还原熔分去除铁后品位可进一步提升。     

攀枝花氧化钛精矿碳热还原动力学

以焦粉为还原剂,开展了氧化钛精矿含碳球团等温碳热还原试验研究,采用积分法进行了碳热还原动力学分析,还原温度分别为1 000、1 100、1 200、1 300℃。氧化钛精矿中铁氧化物还原度随还原温度和时间增加而增加,还原度可达91%。氧化钛精矿在1 000~1 300℃固相还原前期(60 min)受界面化学反应控制,反应活化能为51.23 k J/mol;反应后期(60 min)受扩散控制,反应活化能为93.53 k J/mol。氧化钛精矿碳热还原过程物相转变历程为:Fe2Ti O5→Fe3Ti3O10→Fe Ti O3,物相转变过程增加颗粒内部空隙,增加还原比表面积,改善还原过程气体扩散条件,加快还原初期化学反应速率。     

钛精矿碳热还原制备碳氮化钛的研究

以钛精矿和石墨为原料,在氮气气氛下通过碳热还原法制备出碳氮化钛(Ti CN)粉体。结合XRD、SEM、化学成分分析和TG-DSG综合热分析研究了配碳量及反应温度对钛精矿碳热还原进程的影响。研究结果表明,配碳量的增加影响逐级还原反应温度以及反应总失重,当配碳量达到23%时碳氮化钛产物中出现游离碳。钛精矿碳热还原过程中铁氧化物优先还原,钛氧化物经逐级还原形成Ti CN,还原顺序为Ti O2→Ti4O7→Ti3O5→Ti N→Ti(C,N,O)→Ti CN。得到的碳氮化钛粉体呈微米级不规则形状。     

添加剂对钒钛磁铁精矿球团熔融还原冶炼的影响

对钒钛磁铁精矿预还原球团熔融还原冶炼中添加剂的影响进行了研究,并对渣型制度进行了优化。熔融还原渣碱度、添加剂氧化镁和氧化铝对钒钛磁铁精矿的熔融还原作用明显。在添加剂作用下,1 500℃电炉冶炼10min后的熔融还原产物为含96.9%铁、0.52%钒的生铁,以及含66.13%TiO_2的熔融还原渣,实现了钒钛磁铁精矿冶炼中铁钒和钛的有效分离。     

直接还原处理低品位钒钛磁铁精矿

在1 000~1 300℃添加少量Na_2CO_3+NaCl复配添加剂,以无烟煤做还原剂等温还原低品位钒钛磁铁精矿,再通过磁选分离获得铁精粉和钒钛渣。考察了C/Fe摩尔比、还原温度和还原时间对铁的还原、钒钛迁移富集行为以及物相转化规律的影响。结果表明,C/Fe摩尔比和反应温度对直接还原过程中有价组分迁移富集的影响很大,当C/Fe摩尔比为1.2时,在1 200℃还原2h,钒钛磁铁矿精矿的金属化率可达到92.8%,还原后钒主要富集在钛渣相中,有效实现了铁与钒/钛的分离。     

钒钛烧结矿高温冶金性能的研究

试验中研究了钒钛烧结矿的高温冶金性能。试验结果指出,在一定范围内,提高碱度和增加烧结矿中MgO含量来改善钒钛烧结矿高温还原性能及软熔性能是有效的。增加MgO还可抑制硅、钛的还原及碳氮化物的生成,有利于渣铁熔融分离而滴落。钒钛磁铁精矿配入普通富矿粉及适当增加烧结混合料配碳量,可以降低炉渣中TiO_2的活度,增加炉渣的氧化能力,有利渣铁分离。但不利于烧结矿的高温还原性和软熔性能的改善。     

国内外新闻

攀钢钒钛矿高效分离课题通过国家科技部验收由攀钢牵头承担的"十一五"国家科技支撑计划课题---"攀枝花钒钛磁铁矿高效分离与资源综合利用技术开发"课题,2月27日在北京顺利通过国家科技部验收。该课题由中国有色金属工业协会组织,攀钢牵头,北京科技大学、北京大学参加。通过实验研究、工业试验和装备研发,攀钢建成了具有完全自主知识产权的"攀钢100 kt/a钒钛资源综合利用新工艺中试线",解决了钒钛磁铁矿直接还原温度高、易粘接、转底炉布料出料不均匀及出料设备寿命短、热金属化球团氧化粘结料罐、冶炼钒钛金属化球团时钒还原率低及渣铁难分离、高镁铝低品位含钛炉渣提钛等诸多技术难题,铁、钒、钛从精矿至半钢、片     

CO还原钛精矿的研究

采用热重、XRD,SEM等技术检测CO还原钛精矿的失重率、物相转变及显微结构。结果表明,预氧化钛精矿还原度随还原温度和时间增加而增加,在1150℃还原270min后还原度达到87.97%。还原产物的主要组成为金属铁、FeTi_2O_5和少量的TiO_2。     

含钛高炉渣碳化及超重力分离碳化钛的研究

以热力学计算为依据,研究在焦炭还原攀钢含钛高炉渣的过程中,反应温度和保温时间对碳化钛的生成量的影响,同时利用超重力技术来分离还原产生的碳化钛.研究结果表明:含钛高炉渣经高温碳热还原后得到有价组元碳化钛,当实验温度设定在1 600 ℃保温5 h时,还原渣中碳化钛的含量最高,熔渣中钛氧化物转化为碳化钛的转化率达到最佳.另外,还原渣经超重力分离后碳化钛被截留在碳毡上部的精矿中,脉石相则被分离到下部坩埚中,还原渣在重力系数G=300于1 320 ℃等温分离20 min后,精矿中碳化钛的含量由还原渣中的12.1 %提高到26 %,通过超重力技术可以使碳化钛含量提高一倍多.      

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。     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.     

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.     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

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.