卤水-石灰法制氢氧化镁除铁工艺研究

以卤水为原料,以石灰乳为沉淀剂制备氢氧化镁.系统考察了反应温度、络合剂用量、还原剂用量、反应时间等工艺条件对氢氧化镁除铁过程的影响,通过正交试验,得到优化除铁工艺条件,即反应温度为40 ℃,络合剂用量为0.15 g,还原剂用量为0.10 g,反应时间为10 min,在此条件下,所得氢氧化镁产品铁的质量分数小于5×10-4.该工艺用于碳酸钙、轻质碳酸镁、高岭土等无机粉体材料的除铁均取得较好的效果.     

利用卤水生产阻燃型氢氧化镁工艺研究

利用运城盐湖的卤水和现有产品硫氢化钠为原料,制取高纯氢氧化镁.以合成的高纯氢氧化镁为原料,进一步水热改性处理,得到阻燃型氢氧化镁.水热改性最佳条件:以氢氧化钠为水热改性剂,浓度为4 mol/L;水热改性温度为200 ℃;水热体系中氢氧化镁质量分数为7.5%;水热改性时间为5 h.在最佳条件下制备的氢氧化镁粒度分布范围窄,比表面积小,产品分散性好,形貌为六方形,符合阻燃型氢氧化镁的质量要求.     

非离子表面活性剂存在下纳米氢氧化镁的水热处理

本文研究了在非离子表面活性剂PEG6000存在下纳米氢氧化镁的水热处理规律。产品采用X射线衍射、热重-差热分析、透射电子显微镜等进行了表征。结果表明:由于PEG6000的空间位阻作用以及与晶面的吸附作用,在PEG6000存在下进行氢氧化镁的水热处理,不仅可以改善氢氧化镁的结晶性和分散性,而且可有效地防止粒径的快速增长。当PEG6000的用量为氢氧化镁质量的4.4%,水热温度为180℃,水热时间为5h时,可制得结晶完整、分散性好、平均粒径61nm的六方片状纳米级氢氧化镁。     

卤水中有机物对硫酸钡等产品质量的影响探讨

南风集团卤水综合利用工程以运城盐湖的高镁卤水为原料,采用独创工艺生产硫酸钡、氢氧化镁和一水氯化钡等系列产品.工程运行几年来为集团公司创造了可观的经济效益,但各种产品的质量与行业同类产品相比还有很大的差距.对原料卤水和产品组成进行了全面的分析,证明了卤水中高含量的有机物是造成产品质量不高的主要原因.采用热氢氧化钠溶液洗涤硫酸钡,有效地去除了硫酸钡产品中的有机物.产品硫酸钡质量分数为97.6%,白度为92%,灼烧质量损失为1.6%,硫酸钡质量达到国标一级品的要求.提出了只有从源头上彻底净化卤水,去除卤水中的有机物才是提高综合利用工程系列产品质量的最根本办法.     

复分解法制备高纯氢氧化镁的研究

以工业氯化镁和硫氢化钡为原料，采用复分解法合成高纯氢氧化镁。研究了工艺条件对产品质量的影响。其最佳反应条件为：反应温度为103～105℃，反应时间为50min，陈化时间为40min，过量的硫氢化钡质量分数不超过10％，洗水用电渗析水，所得产品氢氧化镁纯度高。并进行了中试，制得的产品质量已达到中国的先进水平，生产成本低，工业化容易实现，市场前景非常广阔。     

从淡化后的海水制取纳米级氢氧化镁的工艺

以反渗透海水淡化操作后所得的浓海水为原料,通过控制不同的反应条件,经过一系列的除钙、沉淀、陶瓷膜分离洗涤、离心过滤和真空干燥等工艺制得纯度较高的纳米级氢氧化镁.试验结果表明,采用该工艺最后制得的氢氧化镁产品质量指标远优于氢氧化镁的化工行业标准(其中氧化镁质量分数为67.9%,氧化钙0.2%),平均粒径在100 nm以下.同时从试验情况可以得出,采用陶瓷膜洗涤和分离纳米级氢氧化镁是可行的.在试验条件下,陶瓷膜装置运行稳定,且平均膜通量在331 L/(m2·h)以上,对氢氧化镁的截留率达99%以上.     

水热法制备阻燃型氢氧化镁新工艺研究

以运城盐湖卤水生产的普通氢氧化镁为原料，经水热处理后，制得性能较好的阻燃型氢氧化镁。最佳工艺条件为：氢氧化钠作矿化剂，浓度4mol／L，氢氧化镁质量分数7．5％，水热处理温度200℃，恒温时间4h，搅拌转速200r／min。该方法制备的氢氧化镁粒度分布窄，比表面积小，产品分散性好，形貌为正六方形。     

盐卤水生产阻燃剂氢氧化镁的工艺研究

利用自贡盐卤水镁资源,开发阻燃剂氢氧化镁。通过在盐卤水加入氢氧化钠生产氢氧化镁产品,实验表明卤水氢氧化钠体积比7.5,反应温度65℃、反应时间30min、搅拌速度250r/min和氢氧化钠滴加速度15min为最佳生产工艺。     

非淬水高镁炉渣降镁工艺研究

以高镁炉渣为原料,通过控制pH析出氢氧化镁沉淀,来降低炉渣中的镁含量,并对镁进行回收,得到氢氧化镁产品。考察了盐酸质量分数、反应温度和pH对炉渣中镁溶解性能的影响,得到溶解工艺条件:盐酸质量分数为44%,反应温度为60℃,析出氢氧化镁的pH控制为10.6。在该工艺条件下,炉渣中的镁含量降低了93%。以10 g炉渣为原料得到氢氧化镁3.48 g,纯度为95%。     

有机溶剂--水热法制备阻燃球形氢氧化镁

以青海东台水氯镁石混合物为原料，以含一定量有机溶剂的氢氧化钠为沉淀剂，采用反向沉淀法，利用有机溶剂的疏水特性在水热反应釜合成球状氢氧化镁粒子。通过XRD，SEM，TEM等手段表征了产品的属性及形貌特征，结果表明产品粒子呈球形，粒度分布均匀，分散性好，晶形好，纯度高。该方法既简化了制备工艺，又降低了成本，可望进一步工业放大。研究了有机溶剂在反应体系中的质量分数、水热反应温度及反应时间对氢氧化镁晶体形状的影响，当有机溶剂的质量分数为35％、水热反应温度190℃、反应时间5h时，可以制得球形的氢氧化镁。     

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。