利用X射线荧光分析仪测碱含量

2001年8月,应市场需求,我公司开始组织生产低碱水泥,要求出厂水泥碱含量小于0.60％[以0.658w(K2O)+w(Na2O)计]。由于所用矿山石灰石碱含量波动很大[w(K2O)=0.01％-2.4％,W(Na2O)=0.01％-1.6％],导致生料中的碱含量不易控制[w(K2O)=0.23％-0.58％,w(Na2O)=0.06％-0.16％],最终导致半成品、成品碱含量不易控制[成品w(K2O)=0.40％-0.88％,     

机场跑道用低碱水泥的研制及使用

碱是混凝土中的有害成分,通过碱-集料反应导致混凝土破坏已被许多工程所验证,水泥是混凝土中碱的主要来源之一,为有效防止碱-集料反应的发生,目前国内许多重点工程已开始采用满足施工质量的低碱水泥。国际上通常将碱含量小于或等于0.6%的水泥叫做低碱水泥,在碱-集料反应研究中碱含量用Na2O物质的量来表示,计算公式:Na2O(%)+0.658K2O(%)=碱含量(%)。某军用机场建设机场跑道及停机坪全部采用施工要求的低碱水泥,其主要质量指标要求:碱含量≤0.6%,初凝和终凝时间差2小时左右,水泥熟料C3A≤6.5%,水泥28d抗压强度≥48MPa。我厂通过技术攻关,…     

回归分析在配料管理中的运用

我厂所属的石灰石矿山品位低,CaO含量在38%～43%之间,但K2O含量比较高,平均在1 40%左右.在生产过程中尽管采取了一系列的排碱措施,使K2O的排放率达到40%～50%,但熟料中K2O的平均含量仍高达1 25%左右.受其影响,我厂的熟料标号一直低于全国大中型水泥企业的平均水平.     

提高100%无烟煤煅烧熟料早期强度的探索

1997年投产的国内首条100%燃无烟煤生产线——龙岩三德2000t/d熟料线的熟料3d强度一直偏低,平均仅为25.5MPa(新标准)。通过对3d强度因素及其相关性分析,排序为w(C2S)>熟料KH值>生料细度>入窑生料的w(Al2O3)。在此基础上,提出了调整配比,提高煤粉和生料细度质量指标以及提高石灰石和燃煤质量等一系列技术措施。     

提高预分解窑高镁熟料质量的技术措施

山水集团安丘山水水泥有限公司2×5000t/d预分解窑熟料生产线的自备矿山中有大量高镁石灰石,该公司一直重视高镁石灰石的使用和经验积累.生产中曾发现随着MgO含量的升高,出窑熟料结粒明显增大且大小不匀,飞砂严重,黄块较多.f-CaO严重偏高,升重大幅下降.对此,该公司采取了控制石灰石中w(MgO)=2.8%±0.2%;根据熟料镁含量的大小调整配料方案:降低并稳定分解炉出口、窑尾、C5筒温度;降低并稳定入窑分解率不超过94%;以及加强篦冷机操作和调节煤粉燃烧器用风等系列措施后,熟料质量得到明显改观.     

低碱水泥生产途径的探讨

水泥中碱含量主要来自熟料,影响熟料减含量的主要因素是石灰石和粘土质原料中的碱含量。文章通过对石灰石和粘土质原料质量特征的分析,提出了生产低碱水泥的途径,并就旁路放风对降低熟料碱含量的影响作了探讨。     

大掺量低品位石灰石生产32.5砌筑水泥

通过优化生料配方,适当提高熟料饱和比、硅酸率,并严格控制碱含量,提高熟料28d强度,同时采用大掺量石灰石专用助磨剂,实现32.5砌筑水泥生产及水泥混合材中低品位石灰石掺量提升至35%～40%,从而降低水泥生产成本,同时满足更多用户需求。     

生产低碱熟料的体会

1原料情况我公司熟料中的碱含量相对较低,以钠当量计,一般在0.65%左右,略高于低碱熟料要求的上限0.60%,其中Na2O一般在0.1%左右,比较稳定,而K2O一般在0.75%~0.85%之间波动,所以只要对原料中的K2O稍加控制,就可以满足低碱熟料的要求。由于所用辅助原料是由供应商供给的,所以控制     

高镁石灰石在水泥生产中的使用

江山南方水泥有限公司是国家“一五”时期投资兴建的浙江省第一家大型水泥企业，于2007年加入南方水泥，现有 2 500 t/d 和 5 000 t/d 熟料生产线各一条，年产 260 万t熟料。 随着企业的发展，江山本地优质石灰石资源日趋枯竭，公司使用的石灰石大部分外购于玉山，石灰石成本高。为降低石灰石成本，提高企业竞争力，江山南方从2011年开始开发使用用自备北蕉矿石灰石，北蕉矿石灰石具有MgO含量高、CaO含量低的特点，属于低品位高镁石灰石。     

预处理方式对小麦秸秆制备高吸水性树脂的影响

以小麦秸秆为原料合成高吸水性树脂需首先对秸秆进行预处理,通过实验分析,比较了预处理方式如酸处理、碱浸泡、氨水浸泡、碱蒸煮及其联合处理对秸秆及高吸水性树脂的影响;用晶相显微镜、IR等表征了处理前后秸秆的微观形貌、化学结构及树脂的化学结构等;结果表明,比较理想的预处理方式是碱蒸煮处理〔w(NaOH)=14%的水溶液、150℃、0.6 MPa、30 m in〕结合浓度为1 mol/L的硝酸在100℃下处理30 m in,及w(NH3.H2O)=10%的氨水室温浸泡48 h结合浓度为1 mol/L的硝酸在100℃下处理45 m in;两种方式所得高吸水性树脂吸收纯水的质量倍率分别为405 g/g和293 g/g,吸收w(复混肥)=0.1%的水溶液的质量倍率分别为124 g/g和82g/g〔复混肥中w(N)=w(P)=w(K)=10%,N、P、K分别以尿素、过磷酸钙、氯化钾存在〕。     

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。