混料式石灰竖窑发展的关键技术及方向

回顾了混料式石灰竖窑的建设情况以及技术进步和关键技术特点,指出混料式石灰竖窑建设时的技术选择及实现优质、低耗、高产的主要措施。     

机械化石灰竖窑技术改造及体会

论述了混料式机械化石灰竖窑的发展、主要技术特点及存在的缺陷。通过引进、消化、吸收国外技术,对国内的机械化石灰竖窑进行改造,取得了较好的效果,并对投资建窑提出了合理化的建议。     

适应新的市场需求的大型麦尔兹并流蓄热式石灰窑

阐述了麦尔兹并流蓄热式石灰竖窑的原理及技术特点,对并流蓄热式石灰竖窑与回转窑进行了对比,对开发大型并流蓄热式石灰竖窑充满信心。     

石灰竖窑窑底新结构

石灰窑是化学工业的重要设备。电石行业通常都采用机械通风的竖式混料窑。这种窑的底部配有不同型式的机械卸料装备。国内外石灰竖窑的卸料装备在不断更新和发展,目前已有盘式卸料篦子、往复式卸料篦子、辊式卸料器、塔式卸料盘、摆动扇形板卸料器、振动卸料器及安东诺夫卸料器和埃别尔加尔特卸料器等多种卸料装备。石灰窑燃料一般用固体燃料如煤或焦碳,     

浅谈石灰竖窑技术改造

老式机械化石灰竖窑装备落后,其生产出的石灰质量低,已满足不了冶炼优质钢种生产的需求。针对这种情况．马钢股份公司第三钢轧总厂对该种窑进行了技术改造。改造后的石灰竖窑能生产出优质的活性石灰,采用活性石灰炼钢,可缩短冶炼周期,降低吨钢石灰消耗。     

麦尔兹并流蓄热式石灰窑工艺除尘器风机控制的优化

通过对并流蓄热式石灰竖窑在生产过程中除尘风机负载变化的跟踪和分析,对关键控制参数进行了优化,保证除尘风机高效稳定的工作。     

国外炼钢用活性石灰煅烧设备及其衬用耐火材料

本文叙述了回转窑、并流蓄热式竖窑、套筒式竖窑以及双梁石灰坚窑的优点、特点操作及其窑衬里耐火材料、并将石灰窑的一些操作参数作了比较。     

利用机械竖窑煅烧电石用高品质石灰攻关总结

由于国家优化钢铁产能,本公司作为石灰生产基地,为谋求新的发展,需要拓展外销市场生产更优质的石灰产品。本文论述了采用工业型焦利用新建的机械竖窑进行电石灰的煅烧试验,指出用工业型焦能够生产出高品质石灰产品。     

套筒石灰窑拱桥用方镁石-尖晶石耐火砖的损毁原因分析

概述了环形套筒石灰竖窑的基本结构及其耐火材料的使用情况,分析了套筒石灰竖窑中核心部位拱桥使用的方镁石-尖晶石砖的损毁机制,并针对如何提高套筒石灰竖窑中拱桥的寿命提出了建议.     

石灰窑星型出灰机结构改造与应用

介绍大型混料式机械化竖窑的三种窑底出料装置,纯碱行业石灰窑普遍采用星型出灰机。分析我公司星型出灰机在生产中存在石棉盘根密封老化、滑动轴承磨损等问题的原因,提出采用刚性密封挡环和滚动轴承的结构改造措施。     

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.