不同产出环节和处理工艺钢渣的基本性质及其利用

本文测试了铁水脱硫渣、转炉滚筒渣、转炉热泼渣、铸余渣、电炉滚筒渣、电炉热泼渣等六种不同产出环节和处理工艺的钢渣的密度、化学成分、物相组成、金属铁含量、易磨性、游离CaO (f-CaO)含量、胶凝活性指数等理化性质.并根据其性质特点分析了六种钢渣的利用途径.结果表明:不同产出环节和处理工艺的钢渣在理化性质上呈现不同特点,使其在应用途径上也产生差异.     

超纯低压转子钢冶炼渣系研究

一重生产超纯低压转子钢的工艺流程为EAF-LF-VD-VCD,为了满足超纯低压转子钢的成分要求,在理论分析的基础上,通过实验室实验研究和热力学计算,得到能满足超纯低压转子钢成分要求的高效脱磷及脱硫渣的成分.其中,在高效脱硫渣中,SiO2含量小于6％可以保证在LF-VD精炼过程中不发生增硅现象,而Al2O3含量为2％～％...     

超低碳铝硅镇静钢精炼过程中夹杂物的行为及其对钢组织的影响

针对RH精炼并结合典型的渣-钢化学平衡实验,研究了超低碳铝硅镇静钢精炼过程中夹杂物的变化以及钢包顶渣组成对钢中夹杂物的影响. 用激光共聚焦高温扫描显微镜在线观察了再加热过程中钢的微观组织变化,讨论了夹杂物对钢的晶粒长大的影响. 结果表明,本实验条件下精炼前钢中夹杂物是以Fe-Mn氧化物为主的复合夹杂,夹杂物数量和大小受渣碱度、Al2O3含量及CaO/Al2O3比值的影响较大,当碱度为1.5及Al2O3含量为20%时,夹杂物数量最少. 以成分优化的钢包渣与精炼末期钢样进行的平衡实验显示,夹杂物为Al2O3-MgO或Al2O3-MgO-SiO2-MnO为主的复合夹杂,随渣中w(MnO)的增加,复合夹杂中Mn含量有增加的趋势,使钢的晶粒长大过程需要更高的再加热温度. 钢样再加热后,钢中夹杂物变为以Al2O3, MgO, SiO2复合夹杂为主,三者总量占夹杂物总量的90%或以上,复合夹杂中MnO含量受加热制度影响.     

转炉钢渣的形态结构研究

采用x射线衍射、透射电子显微以及化学分析等重要分析手段对转炉钢渣的物相组成及其形态结构特征进行研究,为转炉钢渣的资源化综合利用提供了理论依据。研究结果表明,转炉钢渣中主要含有钙硅酸盐、氢氧化钙、絮状氧化钙、铁酸钙镁、方镁石等物相组成。其中,铁主要赋存在铁酸钙镁相中,方镁石和钙硅酸盐相是镁、钙的主要赋存形式。     

刚玉尖晶石砖的抗渣性能

采用真空感应炉进行了刚玉尖晶石耐火砖的动态抗渣实验,研究了高碱度脱硫渣和铝硅镇静钢精炼渣对该耐火砖的侵蚀,分析了两种碱性渣对其侵蚀机理.结果表明,刚玉尖晶石耐火砖抗铝硅镇静钢精炼渣侵蚀性能优于高碱度脱硫渣.刚玉尖晶石耐火砖抗侵蚀性能主要受渣中氧化铝和氧化钙含量影响.高碱度脱硫渣中CaO,SiO2,CaF2含量较高,与刚玉尖晶石耐火砖中的Al2O3发生反应低熔点物质,降低了渣的粘度,侵蚀较严重;高碱度脱硫渣中Al2O3含量低,导致尖晶石中MgO直接溶解,而铝硅镇静钢精炼渣中Al2O3含量高,在MgO/渣界面形成MA尖晶石,导致间接溶解,抑制渣侵蚀.     

成分改质对转炉钢渣方镁石的影响

方镁石的水化反应是制约转炉钢渣作为硅酸盐水泥材料的因素之一.依据实际转炉钢渣的成分特性,建立了以CaO-MgO-SiO2-Fe2O3-P2O5为主的实验渣,通过对此渣系的方镁石性质的深入研究,提出了成分改质法来消除渣中方镁石,研究结果如下:高碱度(C/S)转炉钢渣的镁元素主要以游离态方镁石形式存在,且固溶了少量的Fe、Mn等二价金属元素,而其它矿物中不含镁;随改质剂SiO2含量不断增加,实验渣的方镁石数量逐渐减少;当加入20％的SiO2后,即C/S值小于1.67,方镁石基本消失.而减少的方镁石会溶入C2S和C2F矿物,最终以CMS和MF形式稳定存在.研究证实成分改质处理方法可消除转炉钢渣的游离方镁石,进而利于它的资源化利用.     

热闷渣基础性能分析及应用前景

为了综合利用经过热闷法技术处理过的转炉钢渣,以酒钢热闷渣为试验原料,采用半定量全分析和多项化学分析方法确定钢渣化学成分,利用X衍射、光学显微镜、扫描电镜及能谱仪测定对热闷渣的物相和铁物相进行了分析,并对钢渣的粒度、抗压强度、和磨矿细度进行了测定分析.通过对热闷渣的综合分析得出:热闷渣中CaO含量高,S、P等有害元素少,可代替部分熔剂返回烧结利用;游离氧化钙含量较少,可用于建筑、建材和道路工程行业;由于易磨性较差,不建议用于磨钢渣微粉.     

电石泥脱硫渣对水泥性能影响的试验研究

针对目前采用的电石泥烟气脱硫技术,研究了亚硫酸钙含量较多的电石泥脱硫渣对于水泥力学性能、凝结时间的影响,并分别与经氧化处理后的脱硫渣、脱硫石膏进行了对比分析。结果表明：电石泥脱硫渣的主要成分为亚硫酸钙、硫酸钙及未充分反应的氢氧化钙,其对水泥的凝结时间可以起到一定的调节作用,但亚硫酸钙含量直接影响水泥的力学性能及凝结时间;经过氧化处理后的电石泥脱硫渣可以作为水泥缓凝剂用于水泥生产中,有利于水泥后期强度的增长。     

电炉还原渣对转炉钢渣的重构机理

以电炉还原渣为调节组分,探讨其对转炉钢渣的重构机理。采用X射线衍射仪、热重-差示扫描量热仪、扫描电镜等分析重构前后钢渣的物相组成、结构和胶凝性能。结果表明:高温作用下转炉钢渣中部分原有低熔点矿物熔融,为高温重构反应提供了液相环境。掺入的电炉还原渣为转炉钢渣补充了钙离子,并促进转炉钢渣中硅铝惰性组分(黄长石和钙铁(钙镁)辉石等)的解体和活性胶凝矿物硅酸二钙、硅酸三钙和七铝酸十二钙的生成,增加重构钢渣的活性。与掺重构钢渣前相比,28d龄期的水泥净浆掺重构钢渣后抗压强度增加18.0%,重构钢渣水化产物数量提高,水化进程明显加快。     

转炉渣的显微结构分析

以涟源钢厂转炉顶底复合吹炼法的冶炼转炉渣为样本,采用化学组成分析、扫描电镜和EDS分析等手段,研究了炉渣在冶炼过程中的物相变化规律和显微结构特点.结果表明:在转炉吹炼过程中,炉渣主晶相变化由含镁较高的橄榄石、镁硅钙石到不含镁的硅酸二钙相,基质物相组成变化由开始的单一低熔点相到生成铁酸钙相和RO相;Al、Ti和V元素主要存在于炉渣中的低熔点相和铁酸钙相中,终渣中的金属Fe相夹杂S、Ca元素.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。