高硫铝土矿的焙烧预处理

采用回转窑对我国高硫铝土矿进行焙烧预处理,考察了焙烧温度、焙烧时间对矿物中硫含量及氧化铝溶出性能的影响,利用SEM和XRD技术对焙烧矿的微观形貌、晶型结构变化进行了分析,并对高硫矿脱硫机理和焙烧机理作了探讨. 结果表明,焙烧脱硫处理高硫型铝土矿是可行的,焙烧温度为750℃、焙烧时间为60 min时,焙烧矿中硫含量低于0.7%,达到我国 氧化铝生产的工业要求;焙烧矿在溶出温度220℃、溶出时间60 min的条件下,氧化铝溶出率达到97%以上.     

高硫高硅铝土矿焙烧–溶出性能研究

采用悬浮焙烧对高硫高硅铝土矿进行处理,考察了不同焙烧温度对矿石中硫含量的影响,通过X射线衍射和扫描电子显微镜分析了不同温度条件下焙烧对铝土矿中物相变化及微观形貌的影响,研究了焙烧温度对矿石中氧化铝溶出性能的影响。结果表明,悬浮焙烧温度600℃及以上时,能够使铝土矿硫化型硫含量降至0.2wt%以下。焙烧使铝土矿中高岭石相发生分解生成非晶态的偏高岭石,同时破坏矿颗粒致密结构,出现晶粒细化,但温度过高(650℃)会出现局部烧结现象。焙烧使一水硬铝石晶体破坏而活化,600℃时晶体破坏最完全,使600℃焙烧矿在相同溶出条件下溶出效果较原矿及其他焙烧矿优势明显,在溶出温度270℃、苛碱浓度245 g/L、石灰添加量14wt%的条件下,相对溶出率能达96%以上。     

含硫铝土矿预焙烧动力学研究

使用马弗炉、旋转管式炉及流化床对我国含硫一水硬铝石型铝土矿进行预焙烧脱硫性能的研究.考察了焙烧温度、焙烧时间和矿石粒度对焙烧矿中硫含量的影响,并根据实验结果对750~800℃温度范围内不同焙烧方式下矿石脱硫预焙烧动力学进行分析.实验和计算结果表明,不同焙烧方式下焙烧矿中硫含量在750和800℃焙烧温度下均随焙烧时间的延长而下降,马弗炉、旋转管式炉焙烧矿在该焙烧条件下反应表观活化能分别为46.895l和33.090kJ/mol,流态化焙烧反应表观活化能为505.727kJ/mol.     

低温磁化焙烧对高铁铝土矿溶出及磁选性能的影响

为实现高铁铝土矿铝铁元素的高效利用，采用“低温磁化焙烧-拜耳溶出-赤泥磁选”的方式处理高铁铝土矿，考察了焙烧温度、H₂浓度及通入时间对高铁铝土矿溶出及磁选性能的影响。结果表明，焙烧过程中一水硬铝石脱水转变为过渡态Al₂O₃，矿物发生热破裂现象，比表面积增大，氧化铝溶出活性增加，在焙烧条件为焙烧温度530℃、H₂浓度20vol%、H₂通入时间5 min时，氧化铝相对溶出率可达97.65%。磁化焙烧过程中，针铁矿转变为赤铁矿，再由赤铁矿转变为磁铁矿，通过溶出解除了铝铁元素之间的嵌布关系，对焙烧矿的赤泥进行磁选，其铁精矿品位达62.05wt%，铁回收率为86.36%。     

丁黄药用作高硫铝土矿浮选除硫的捕收剂

采用浮选方法对我国含硫一水硬铝石型铝土矿进行脱硫,采用单因素实验研究了高硫铝土矿在浮选剂丁基钠黄药作用下反浮选除硫的工艺条件,考察了浮选剂用量、浮选时间、浮选矿浆浓度(液固质量比)、pH值及矿石粒度对浮选的影响. 结果表明,反浮选除硫的合适工艺条件为,矿浆pH 10、浮选剂用量0.16 kg/t、起泡剂20 g/t、浮选刮泡时间15 min、液固质量比10、矿石粒度0.15 mm. 在此工艺条件下,铝土矿中硫含量由2.08%降低到0.41%,符合我国氧化铝工业对矿石中硫含量的要求,Al2O3回收率达90.83%. 浮选过程基本符合一级动力学反应方程.     

利用铝土矿和铝酸钙制备聚合氯化铝的研究

对利用铝土矿和铝酸钙采用二步法制备聚合氯化铝的工艺进行了研究.考察了制备聚合氯化铝的各种影响因素,确定了一段溶出的最佳条件：铝土矿焙烧温度650 ℃,焙烧时间1 h,酸浸温度85～95 ℃,盐酸质量分数20%,酸浸时间2 h;二段溶出过程中可以根据不同的盐基度要求控制铝酸钙的加入量.除浊实验结果表明,二步法制备的聚合氯化铝具有良好的混凝性能.     

高硫铝土矿溶出过程中脱硫研究

研究了高硫型高品位铝土矿溶出过程的脱硫效果,考察了石灰添加量、溶出温度、苛性碱浓度和溶出时间对铝土矿中脱硫效果的影响。结果表明,在溶出高硫铝土矿时,脱硫效果最佳条件是:石灰添加量10%,温度245℃,脱硫时间70 min,碱液浓度240 g/L。此时,硫的溶出率仅为31.3%,同时又能保证氧化铝溶出率不低于81%。     

铝土矿硫酸焙烧与水浸提取铝铁

通过单因素实验和正交实验研究了铝土矿硫酸焙烧与水浸提铝铁过程中焙烧温度、焙烧时间和酸/矿摩尔比对铝和铁提取率的影响. 结果表明,在酸/矿摩尔比3.75:1、焙烧温度325℃,焙烧时间2.5 h的条件下,Al提取率达98%, Fe提取率达80%,各因素对铝铁提取率的影响顺序为：酸/矿摩尔比>焙烧温度>焙烧时间. 该工艺具有焙烧温度低、金属提取率高等特点,对铝土矿的开发利用具有重要的意义.     

贵州某高硫铝土矿氧化铝溶出研究

对贵州某矿区高硫铝土矿的化学成分及物相进行了分析,了解矿物存在形态,采用中国铝业贵州分公司生产中的种分母液和蒸发母液进行适当配制后作为溶出用碱液,利用正交实验研究方法,考察了石灰添加量、苛性碱浓度、温度、时间对氧化铝溶出率的影响。实验结果表明,该矿区矿石氧化铝溶出率不高,在较佳溶出条件:温度260℃,时间90 min,石灰添加量为6%,碱浓度235 g/L时,氧化铝相对溶出率为95.21%。     

高钙低品位硫氧混合锌矿氧化焙烧矿相的转变规律

针对低品位硫氧混合锌矿含钙高的特点,在低温下对其进行氧化焙烧,通过控制气相中的硫势和氧势,使矿石的矿相发生转变,促进锌在氨性体系中溶解;同时利用矿石中钙的固硫作用,使硫转化成CaSO_4,有效避免SO_2对环境的污染.结果表明,锌品位为5.45%的硫氧混合锌矿在300℃下焙烧3h,矿石中的异极矿和闪锌矿转化成了易溶出的ZnO,方铅矿和黄铁矿分别转化成了PbSO_4和Fe_2O_3,方解石转化成了CaSO_4,所得焙砂在NH_3-(NH_4)_2SO_4-H_2O体系中45℃下浸出,锌浸出率可达73.27%;焙烧温度大于300℃时,焙砂中会产生大量铁酸锌,使锌浸出率下降.     

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。