粒度级配对神府煤成浆性能的影响

为提高神府煤制备水煤浆的成浆性能,分析了神府煤的原煤性质,说明神府煤的成浆指标为11.55,属于很难成浆煤种。对不同粒度级配的干基煤样进行粒度分析,通过粗、细煤粉单独制浆实验和不同粒度级配煤粉的成浆性实验,研究了不同粒度级配对水煤浆成浆性的影响。结果表明:经过级配的干基煤样具有双峰粒度分布特征,适宜制浆;粗煤粉不能单独成浆,细煤粉单独制浆的最大成浆浓度为61%;粗细煤粉质量比约为1∶2时,水煤浆具有较好的流动性和稳定性,最大成浆浓度可达63.8%,此时水煤浆黏度为1000 mPa·s,符合工业水煤浆制备标准,说明合理的粒度级配可降低水煤浆黏度,增强流动性及稳定性。     

粒度级配对混煤水煤浆浓度与黏度的影响

水煤浆浓度与黏度是衡量水煤浆性能的两个重要指标.粒度级配是影响水煤浆性能的关键因素,合适的粒度级配可提高水煤浆性能.以某水煤浆厂所用的精煤和分散剂为实验基础,研究了在该水煤浆厂常用的混配煤和两种常用的分散荆条件下,粒度级配和水煤浆浓度、黏度的关系,获得了使用不同分散剂时水煤浆性能最佳时所对应的粒度级配.     

甲醇厂废水制水煤浆的工业运行分析

基于湿式溢流型棒磨机制备工艺,采用华亭煤和甲醇厂废水制备水煤浆,分析了废水水煤浆与原水水煤浆的性能差异,研究了粒度分布和添加剂用量对废水水煤浆性能的影响。结果表明:废水水煤浆具有较高的p H值,表观黏度有所降低,稳定性较好;适宜的粒度分布可以提高水煤浆浓度,改善煤浆稳定性;适宜的添加剂用量可以明显降低煤浆的表观黏度,提高煤浆的稳定性;通过工业试验,获得了煤浆性能最佳时的磨机钢棒填充量为80 t和添加剂用量为1.24‰。     

神府煤制备高浓度水煤浆的研究

由于神府煤内在水分含量高且氧含量高,很难制得高浓度的水煤浆.通过粒度配比和分散剂复配等实验,研究其成浆工艺条件,得出神府煤三级级配粒度比为500目∶325目∶200目=5∶1∶4,复配添加剂月桂醇聚氧乙烯醚和木质素磺酸钠比为0.8∶0.8时,可以制备出黏度为1 020 mPa·s,稳定性为15 d,浓度为62％的较高浓度水煤浆.     

再谈水煤浆及其在陶瓷工业中的应用

1水煤浆技术1.1制备水煤浆是对原煤经过洗选、筛分及研磨、加水（约为30%～35%）和加少量添加剂（<1%），经充分强力搅拌而制成的一种浆体燃料。由于磨粉粒度的级配要求严格，以及少量添加剂的作用，使水煤浆不同于一般的煤水混合物。水煤浆具有一定的稳定性（半年以上不沉淀、不分层）和良好的流变性（存放时粘度很大，而流动时粘度小于1000MPa·s），可以象重油一样方便地泵送、管输、船载、车运和雾化燃烧。水煤浆制备过程中的关键技术包括：颗粒的级配及其相应的磨煤工艺；不同煤种分别要求的添加剂性能及添加剂系列的开发；不同煤种的…     

直径间隙法制水煤浆级配技术研究

采用双珠级配与三珠级配模型,探讨了球料比、研磨时间、温度、入料尺寸和研磨速度对灵武煤制水煤浆成浆性的影响,分别采用干法配浆与湿法配浆的方法进行实验,利用DV-1+PRO数字式黏度计和Rise-2008型激光粒度分析仪对配置浆料的黏度和粒度进行测试.结果表明,当入料尺寸<1mm,球料比为6∶1,研磨速度为72r/min时,水煤浆的浓度可以达到68%.10#自制添加剂的使用可以获得性能稳定的水煤浆浆体.     

级配粒度对宁东煤成浆性影响的研究

以宁东煤为研究对象,采用正交试验法进行了煤粉粒度分布对水煤浆成浆性能影响的分析研究。自制了不同颗粒区间的煤粉,并将各种粒径的煤粉配制成相同浓度的水煤浆,以水煤浆的黏度和流动性作为试验指标,探讨了不同粒度级配对宁东煤成浆性的影响。采用超声衰减粒度仪进行了粒度分布测定,并得到了分布曲线。试验结果表明:双峰级配的煤粉粒度级配合理,大颗粒和小颗粒之间相互填充,煤粉堆积效率达到最大,煤粉空隙中的水量最小,表现为浆体的黏度低、流动性好。     

伊泰煤、神府煤及其配煤的水煤浆成浆性比较与分析

通过伊泰煤、神府煤及其配煤的成浆性试验,在煤浆浓度、黏度和目测流动性等方面进行了比较与分析,并讨论了粒度级配对煤浆浓度的影响。结果表明,伊泰煤可以制得浓度和流动性均较好的水煤浆,制得的水煤浆粒度呈双峰分布,煤浆浓度较神府煤水煤浆略高。随着煤浆中粗粒子(8目~40目)的增加,煤浆浓度增加,但对水煤浆气化过程中大颗粒煤粉的碳转化率也有影响。     

聚羧酸系水煤浆分散剂的合成试验

介绍了丙烯酸、苯乙烯磺酸钠和自制的丙烯酸—聚乙二醇单酯大分子单体在水溶液中自由基聚合出一种新型的聚羧酸系水煤浆分散剂的实验过程。将该类分散剂用于鹤壁煤的成浆试验,当煤浆浓度达到77.44%时,黏度值为1104.15mPa·s,表明分散剂具有较高的分散作用。     

管输煤浆黏度测定值的影响因素

为了探索黏度测定方法、粒度级配、质量分数以及温度4个因素对管输煤浆黏度值的影响,以陕西神南矿区煤样制备浆体为样本,通过试验研究来探索上述因素对黏度测定的影响规律。试验结果表明:旋转黏度计黏度测定值比毛细管黏度计黏度测定值高约30%;黏度测定值随着Ⅳ粒度区间占比、质量分数的增加呈增加趋势,且随温度的降低而增加;管道煤浆黏度值测定的试验,均需进行黏度测定方法、粒度级配、质量分数以及温度4个影响因子的试验设计。     

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.     

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。     

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.