低温烧粘土作水泥混合材的研究(一)

在水泥生产过程中加入混合材,既可降低水泥生产成本,又能减少环境污染,且能改善水泥性能。因此,如何提高水泥中混合材的掺量和开辟新的混合材品种关系到节能降耗和节约资源。烧粘土属人工火山灰质混合材,其综合利用已得到重视。作者用盐城地区的粘土,进行了低温煅烧粘土的火山灰活性和用作水泥混合材的试验研究。结果表明:（1）煅烧温度对烧粘土的火山灰活性有很大影响。经550℃～600℃温度煅烧的烧粘土,其火山活性最高;在无外加剂的情况下,掺入30％经550℃烧的烧粘土,其水泥与纯熟料水泥28d的抗压强度比为0.71。（2）烧粘土掺入量在15％～30％时,随烧粘土掺量的增加,水泥强度降幅较小,但掺量>30％时,水泥强度几乎成直线下降。     

煅烧碳质页岩用作水泥混合材的研究

对恩施当地廉价的碳质页岩,进行煅烧后用作水泥混合材的实验研究.采用XRD研究了煅烧前后碳质页岩的矿物组成变化,通过水泥胶砂试验研究了煅烧温度、碳质页岩掺量对水泥力学性能的影响.研究表明,在一定范围内,随着煅烧温度的升高,碳质页岩的活性逐渐增加,可用做水泥混合材.其中,当经850℃的煅烧碳质页岩掺量为40％时,其制备的水泥28 d抗压强度达到37.9 MPa,完全满足PC32.5水泥标准.     

铝土矿尾矿活化制备水泥基材料的研究

尾矿是氧化铝工业产生的固体废渣。文章以铝土矿浮选尾矿为研究对象,探讨了煅烧工艺和早强剂对尾矿活性的影响,目的是在不影响水泥强度的前提下,找到这种活性掺和料的最大添加量。研究结果表明,尾矿经过煅烧,配以适量早强剂和粉煤灰类活性废渣,能获得一种性能优良的高性能水泥基材料,能替代矿渣、粉煤灰、偏高岭土作为水泥混合材或混凝土掺合料,这种技术方法不仅能够大量消耗工业废渣,还具有良好的社会、经济和环境效益。     

废弃混凝土中基质胶凝组分作原料煅烧水泥熟料的研究

每年拆除建筑物所产生的废弃混凝土数量巨大,因此废弃混凝土中基质胶凝组分作原料煅烧水泥熟料的再利用研究具有重要的意义。采用热处理和加入表面活性剂与机械粉碎相结合的方法将废弃混凝土中的骨料与基质胶凝组分进行了分离。将分离出的基质胶凝组分按不同配合比制备生料,分别在1400℃,1450℃下进行了熟料煅烧试验,并进行了结构和力学性能测定。试验结果表明,水泥净浆试体的抗压强度随基质胶凝组分配合比的增大而降低,但适当掺入(小于25%)时降低幅度不大;XRD和SEM分析结果表明,1450℃煅烧的熟料矿物结构与常规原料煅烧的熟料基本相同。根据晶种理论和水化物脱水相的反应活性分析了熟料烧成机理。     

煅烧煤矸石作水泥混合材的研究

文章从利废、环保、开拓混合材资源出发,对煤矸石的物理、化学、热值作了分折,通过不同煅烧温度及SO_3含量对烧矸石活性的影响试验,以及大量的强度对比试验、不同掺量试验、不同品种水泥的试验等,得出如下结论。 ①经600～800℃煅烧的煤矸石活性较高,可作为水泥混合材; ②熟料质量好,可以生产425号普通水泥、火山灰水泥、复合水泥(另加磷渣); ③生产成本低,利废保环境,经济、社会效益好;     

垃圾焚烧灰作为水泥混合材的研究

研究了垃圾焚烧灰的组成,探讨了垃圾焚烧灰作为水泥混凝土活性混合材的可能性.研究表明:垃圾焚烧灰主要由黏土类矿物组成,具有一定的活性.在垃圾焚烧灰掺量(质量分数,下同)不高于20%的情况下,垃圾焚烧灰在水泥中的作用类似于低钙粉煤灰,但垃圾焚烧灰的掺量达30%时,水泥的后期强度增长缓慢;垃圾焚烧灰与矿渣等混合材复合,可改善水泥的后期强度.垃圾重新煅烧对改善其性能没有积极作用.     

煅烧电解锰渣-粉煤灰复合掺合料的试验研究

将电解锰渣分别在300℃、600℃、700℃、750℃、800℃和850℃温度下煅烧,制得煅烧电解锰渣料,再将其与不同比例的粉煤灰配合制成煅烧电解锰渣-粉煤灰复合掺合料,利用化学成分分析、DTA和XRD图谱分析及强度测试,对各掺合料-水泥体系的水化性能进行了研究。研究表明:电解锰渣属工业副产品化学石膏,未经煅烧的电解锰渣无水化活性和胶凝性,经一定温度煅烧后,具有较好的脱水石膏活性和火山灰活性,煅烧电解锰渣对粉煤灰-水泥体系有较好的强度激发作用,选择适宜的锰渣煅烧温度和掺入量可制得性能良好的复合掺合料。     

电解锰渣煅烧脱硫并用作水泥混合材的研究

本文提出了电解锰渣煅烧脱硫并用作水泥混合材的资源化利用途径。采用半工业回转窑试验系统进行了纯干锰渣和96%干锰渣+4%焦炭两种方案的煅烧脱硫试验,对脱硫锰渣用作水泥混合材进行了一系列性能检测。结果表明：纯干锰渣方案的脱硫效果不理想,脱硫率仅83.2%,且煅烧成品没有活性,不能用作活性混合材。加入4%焦炭的方案可使脱硫率大幅提高至99.2%,且煅烧成品的活性可达73%,活性较好,将其按30%的比例加入水泥后,水泥的强度、安定性、凝结时间等技术指标均能符合GB175-2007中的规定。     

利用废弃混凝土制作再生水泥的研究

以废弃混凝土为主要原料,添加部分矿渣、钢渣及脱硫石膏,即可直接粉磨生产免煅烧再生水泥。该水泥中废弃混凝土的掺量可达40%~50%,3d抗压强度大于10MPa,28d抗压强度可达20~40MPa。XRD和SEM分析表明,废弃混凝土再生水泥的水化产物主要是钙矾石和C-S-H凝胶,有部分废弃混凝土参与了水化反应,其余部分被水化产物所包裹,起骨架作用。     

云南先锋硅藻土作水泥混合材的试验研究

云南先锋硅藻土矿是我国的一个特大型硅藻土矿床。它矿层厚、储量大,宜露天开采。但烧失量高达24％,因此,原土无活性,不宜作水泥混合材。但经过煅烧之后,活性好,煅烧温度以600～800℃为宜。由于它本身含有796～1366kcal/kg的发热量,因此,煅烧时不必外加燃料。     

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。