钙基膨润土提纯制备球团黏结剂试验

以朝阳钙基膨润土为原料,采用擦洗-分散-分选的流程对其进行提纯,并对提纯膨润土进行挤压钠化改型试验.试验结果表明,当选用朝阳钠化提纯膨润土做球团黏结剂,粘结剂添加量为1.1％时,生球的落下强度为4.0次,爆裂温度为525℃,干球抗压强度为306 N/个,可以满足冶金球团性能需要.采用钠化提纯膨润土制备球团黏结剂可以有效降低球团中黏结剂的添加量.     

宁明膨润土制备有机包膜复合粘结剂中试研究

以宁明膨润土矿制备有机包膜复合粘结剂,通过钠化、挤压、有机促进剂、包膜等工艺的中试研究,生产出胶质价350mL／3g,膨胀倍90mL／g,膨胀指数22mL／g,吸水率640％的高效钠基复合膨润土。在精矿粒度-200目47％,水份10％条件下,控制膨润土粘结剂用量为0．6％,所造生球各项指标达到工业生产要求。此研究方法为生产铁矿球团高效复合粘结材料提供了可靠依据。     

有机物/膨润土复合球团粘结剂的研究

本文利用X射线、红外光谱、TG等分析方法,研究了某膨润土及有机物的特性,通过试验分析研究,确定了用于工业生产的有机物/膨润土复合球团粘结剂的制备工艺,分析了球团粘结剂的作用原理,该粘结剂应用于工业生产使其添加量降低为1.3％,各项指标满足生产要求.     

低品质膨润土提质改性技术研究

以江苏某企业的低品质钙基膨润土为原料,采用提纯-钠化工艺进行提质改性实验研究,系统研究了分散剂种类及用量、矿浆液固比、搅拌及沉降时间、钠化剂种类及用量和钠化时间等因素对提纯钠化的影响效果.结果表明,在分散剂选择焦磷酸钠、用量是0.6％、液固比为4:1、搅拌30min、沉降30min条件下,得到的提纯土胶质价为100mL/15g,膨胀倍数18mL/g,吸水率为140％,蒙脱石含量为76％左右;在以提纯土为原料、钠化剂选用焦磷酸钠、用量是2.5％、钠化时长30min、沉降时长30min条件下,得到的钠化土胶质价为950mL/15g,膨胀倍数70mL/g,吸水率为597％,蒙脱石含量为86％左右,性能指标提升很大.     

废粉末活性炭的造粒再生

本文介绍了废粉末活性炭添加水溶性高分子化合物造粒再生的方法。具体操作过程:将水溶性高分子化合物加入脱水的废粉末活性炭中,造粒后用回转炉进行水蒸气活化。粘结剂为藻朊酸钠和动物胶时,可得优质再生炭。当粘结剂用量为废粉炭重量的     

氢氧化镁粉体的表面改性研究

主要研究了氢氧化镁的湿法表面改性的工艺过程，用浊度分析方法对改性效果进行了比较，确定了最佳工艺条件。实验结果表明：最佳改性剂为硬脂酸钠，改性剂用量为6％（质量分数），改性温度为85℃，改性时间为20min。同时，最佳条件下改性样品的红外光谱分析表明：最佳改性条件下，硬脂酸钠有效包覆在氢氧化镁粒子表面，使氢氧化镁表面有机化，增强了氢氧化镁粉体与有机体的亲和性，这对于制取添加型的氢氧化镁阻燃剂具有指导意义。     

窑法磷酸还原反应物料的造球研究

研究窑法磷酸还原反应物料的造球工艺及球团性能。结果表明,以磷矿、硅石以及煤等为原料造球时黏结剂采用腐植酸钠比膨润土有更好的黏结性和球团强度,润磨可以显著地改善球团的抗压强度和落下强度。获得了适宜的造球工艺条件：磷矿粒度0．147～0．110mm,腐植酸钠添加量为物料量的1．5％,润磨时间3min。在此条件下,所得球团抗压强度≥70N、落下强度≥12次,爆裂温度≥700℃,能够满足窑法制磷酸对还原球团的性能要求。     

油酸钠与胲铵类药剂协同浮选金红石的机理

采用单矿物浮选试验研究了金红石在油酸钠和胲铵类药剂组合体系中的浮选行为，利用zeta电位、表面张力、接触角、紫外光谱等手段从界面化学角度详细研究了组合药剂在液液、液固界面的作用机制。结果表明：单一药剂对金红石捕收能力的大小顺序为：油酸钠(SO，51.55%)＞N-亚硝基萘胲铵(CF，18.72%)＞N-亚硝基苯胲铵(NF，14.01%)。组合药剂添加顺序对金红石回收率的影响大小为：先添加N-亚硝基苯胲铵后油酸钠＞先添加油酸钠后N-亚硝基苯胲铵＞油酸钠和N-亚硝基苯胲铵预混后再添加＞油酸钠和N-亚硝基萘胲铵预混后再添 加＞先添加油酸钠后N-亚硝基萘胲铵＞先添加N-亚硝基萘胲铵后油酸钠，该顺序与药剂之间的协同效应指数有较好的一致性。油酸钠分子中的双键与胲铵类分子中的苯环和萘环之间存在电子共轭效应，该效应对组合药剂的吸附特性及缔合行为有较大影响，药剂之间所生成缔合物的数量及空间构象是影响金红石浮选行为的主要原因。     

MCMB/水性粘结剂体系锂离子电池负极制备工艺研究

在锂离子电池炭负极的制备中，粘结剂和导电炭黑用量、不同的碾压及封装条件都将影响电池的电化学性能。通过循环伏安及恒电流充放电测量技术，研究了中间相炭微球（MCMB）／水性粘结剂负极制备中上述因素的影响，发现水性粘结剂含量为2wt％（羰甲基纤维素钠：丁苯橡胶=1：1，质量比）、导电炭黑含量为3wt％、负极碾压压力为25MPa、封装压力50MPa时，MCMB作为负极材料时表现出了较好的充放电性能，可逆放电容量达到了320．3mAh／g。且水性粘结剂工艺性能良好，可以考虑代替成本高且对环境有污染的有机粘结荆。     

阜新某膨润土钠化试验研究

采用单因素试验,研究了阜新膨润土的钠化工艺条件;利用XRD、SEM等分析方法,对钠化前后膨润土的基本性能、结构和形貌特征等进行了对比,钠化效果较明显,钠化后的膨润土具备钠基土的特性.试验结果分析表明膨润土在弱碱性的条件下进行的钠化效果较好,而且Na2CO3的用量应适中,并对试验结果进行了作用机理研究.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.     

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.