Anwendung der Merkmalsklassenanalyse auf feinkörnige Reststoffe aus der Eisen- und Stahlindustrie

Pyrometallurgical processes invariably yield large amounts of fine residues containing high grades of valuable elements, but often also of detrimental ones. Instead of being disposed of entirely they can be treated by means of mineral processing techniques and recycled, which requires prior characterisation of the dusts‘ relevant properties. A range of residues from iron and steel production was subject to fractional analysis. As common findings, magnetic separation is not able to split the valuable and detrimental elements in these samples whereas air classifying does work. Portability of this approach onto other metallurgical areas and other types of business is presumed.     

Biomasse �C Ein Ausweg aus der CO2-Problematik im Metallrecycling!?

The global warming caused by the enhanced emissions of greenhouse gases induced an environmental legislation which restricts the emissions of CO₂ more and more. Due to the high emissions of greenhouse gases in the recycling of metals as a result of the utilization of fossil carbon carriers as energy carrier and reducing agent, this sector of industry is forced to reduce the emissions significantly. In the field of reducing agents it is possible to substitute fossil carbonaceous materials typically used until now by biomass. For this purpose it is necessary to convert the biomass in a carbonization reactor under the absence of air and at elevated temperatures into charcoal. This charcoal has ?C depending on the process conditions ?C very similar properties to different coal or coke grades. Therefore, such charcoals can be with some restrictions perfectly used as alternative and climate neutral reducing agent. The present work illustrates the potential of different biomasses in terms of the production of charcoal as well as the utilization of the resulting by-products with the target of the application of these substances as reducing agent in the recycling of metals and with this the substitution of fossil carbon carriers in these processes.     

Abbauplanung mit der Natur �C Gestaltung von Abbaub?schungen unter Ber��cksichtigung des Trennfl?chengef��ges

Failure of blocks along discontinuities are frequently observed in rock slopes, which often results into a safety problem for employees and equipment. The problem is especially relevant at mining activities, when fresh slopes are produced with each mining progress. The kinematic failure analysis, which uses the orientation of discontinuities to identify potential risks of failure, proofs as a smart and easily to use tool in rock slopes. The analysis can be done in nearly every project phase during a mine lifetime. An example shows the influence of the slope orientation to the risk of hazardous block failures along discontinuities.     

Sb2S3?ZnO?C体系热力学分析及应用

对Sb₂S₃-ZnO-C低温焙烧体系进行了热力学分析,首先分析了Sb-S-O和Sb-Zn-S-O系的优势区图,表明硫化锑直接转化为金属锑是可行的,且随着温度升高,Sb和ZnS的共存稳定区对氧分压和硫分压的要求降低;计算了在500～1 000 ℃下体系中各反应的标准吉布斯自由能变 (ΔG^θ),表明Sb₂S₃与ZnO交互反应极易首先进行,而后发生Sb₂O₃直接还原;对Sb₂O₃和ZnO的还原平衡CO含量计算表明,Sb₂O₃较ZnO易还原。高低品位两种硫化锑精矿的焙烧试验证实了热力学分析的准确性,锑生成率和固硫率分别达90%以上和89%左右,并有进一步提高的空间。     

速溶性C.M.C简介

羧甲基纤维素（即C.M.C）是一种被广泛应用于钻井泥浆中的一种处理剂，它主要是一种降失水与增粘剂，在低固相不分散性泥浆与分散性泥浆中均可使用，并能取得较好的效果，每年用量较大，据不完全统计，我国每年仅用于钻井泥浆中的用量就达6000吨左右（石油部门5000吨，地质、煤炭、冶金部门约用1000吨左右），但是长期以来，它存在一个突出的问题，是不易溶解，往往在钻探现场使用时，要予先浸泡较长时间后才能部份溶解，或者长期形成“面疙瘩”状，需加温后才能逐渐溶解，这样就给野外使用带来十分不便。七九年十月份，地质部赴日泥浆考察团从日本带回速溶性C.M.C的新产品，日本钻探现场已普遍使用这种新产品，它的商品名称叫“帝石テ     

浅谈C＆C08交换机的维护

介绍了C&C08交换机故障处理的基本方法、维护界面的利用、某些特定功能的实现及维护工作中的注意事项等.     

C＆C08B型交换机常见故障处理

叙述了交换机在使用中经常出现的问题及解决办法。     

航空刹车用C／C复合材料断口分析

利用SEM断口形貌分析了现役航空刹车用C／C复合材料的结构和界面结合状况，探讨了其断裂机理，分析了化学气相沉积炭的沉积机理。结果表明：C／C复合材料的断裂以“弱界面断裂”为主，裂纹优先在基体炭、炭布层间或长纤维束和短纤维间的弱界面等薄弱环节处产生。当裂纹尖端扩展到基体炭中的微裂纹处时，裂纹扩展转向；当裂纹扩展到纤维时，取道纤维与基体炭间弱界面层向前扩展，纤维经历与基体炭脱粘、弯曲、拔出、断裂等过程，导致整个材料断裂。航空刹车用C／C复合材料中的CVD炭以粗糙层状结构为主，CVD过程包括碳氢气体热解、成核、炭化、沉积生长等过程，其中，成核以物理成核为主。图2，表1，参16。