磷石膏与硫化氢气体反应制硫化钙的实验研究

对磷石膏在硫化氢气氛中还原分解制取硫化钙的过程进行了研究,经过热分析实验对磷石膏在硫化氢气氛中反应的机理进行研究,管式炉实验探讨了反应温度、反应时间和不同添加剂对磷石膏分解率及硫化钙产率的影响。结果表明:磷石膏在反应温度为950℃、反应时间为45 min,且添加Ca Cl_2或者Fe_2O_3的情况下磷石膏分解率能达到95%以上,分解渣中80%以上是硫化钙,Mg O对硫化氢气氛下磷石膏的分解率和硫化钙的产率影响较小。     

实验研究磷石膏分解制备硫化钙反应的最佳工艺条件

针对云南磷石膏中二氧化硅高的特点,通过磷石膏分解基本反应的热力学分析,实验研究了反应温度、碳硫摩尔比和铁粉加量对硫化钙收率的影响。得到磷石膏分解制备硫化钙的最佳工艺条件为n(C)/n(SO3)=3、反应温度900℃、反应时间150min,硫酸钙转化率可达99.0%以上。研究结果为开展磷石膏分解制硫酸新工艺的开发和设计提供了基础数据。     

磷石膏脱硫钙渣浸取液中杂质对碳酸钙晶型的影响

磷石膏脱硫钙渣是磷石膏化学分解后产生的以氧化钙为主要成分的尾渣。以氯化铵溶液浸取磷石膏脱硫钙渣并碳化浸取液以制备轻质碳酸钙是一种有效利用磷石膏脱硫钙渣中钙资源的方法。本文分析了该方法在不同氯化铵浓度下浸取液的组成、钙浸出率及pH,同时为了研究浸取液中NH₄⁺、铁、铝、镁等对产品碳酸钙晶型的影响,配制了含有杂质离子的NH₄Cl-NH₃·H₂O溶液,比较了其碳化产品与相同条件下脱硫钙渣碳化产品的晶型差异。结果表明,随氯化铵浓度升高,浸取液pH降低,铝含量降低,铁、镁含量升高。在氯化铵浓度范围内,NH₄⁺对球霰石形成有促进作用,而铁、镁杂质对方解石形成有促进作用,由于铝离子存在形态不同,铝在1mol/L时对形成球霰石有促进作用,在大于1mol/L时对形成方解石有促进作用。当氯化铵浓度小于4mol/L时,各种杂质相互作用形成球霰石晶型,氯化铵浓度等于4mol/L时,各种杂质相互作用形成球霰石和方解石混合晶型。     

减少铝进入湿法磷酸的有效途径

在以湿法磷酸为原料生产精细磷酸盐时 ,影响磷收率的关键因素之一是在净化过程中磷的沉淀率。湿法磷酸中有大量杂质 ,在除杂过程中 ,与磷结合形成沉淀的元素主要有铝、铁、钙等。为了防止大量的铝进入酸中 ,从理论分析和实验中得出了磷矿中的 n(F) / n(Al)是影响铝进入磷酸中的关键因素 ,并发现当矿中 n(F) / n(Al)为 3时 ,进入酸中的铝离子最少     

城市污水处理厂含铝污泥回流除磷分析

以含铝污泥为例,分析了含铝污泥除磷的机理和影响因素,在含铝污泥除磷可能性的基础上提出了城市污水处理厂含铝污泥回流除磷的建议,并分析了污泥回流的可行性,通过对含铝污泥的再利用来解决化学除磷药剂和化学污泥处理的高费用问题。     

城市污水处理厂含铝污泥回流除磷分析

以含铝污泥为例,分析了含铝污泥除磷的机理和影响因素,在含铝污泥除磷可能性的基础上提出了城市污水处理厂含铝污泥回流除磷的建议,并分析了污泥回流的可行性,通过对含铝污泥的再利用来解决化学除磷药剂和化学污泥处理的高费用问题。     

硅,铝钙三元系统玻璃快速分析法

采用普通玻璃分析法分解硅、铝、钙三元系统玻璃时,SiO_2熔样易结块。难脱出,结果数值常偏低。本文介绍了采用强氧化性混合熔剂分解试样以及解决因硅酸的存在给测定钙所带来的干扰问题。试样在20～30分钟内即能全部分解,且只需取一试样就能完成整个分析,比用KOH法所测得的SiO_2数据准确、偏差小、重现性好。     

铝率及液相性质对高硅酸三钙含量硅酸盐水泥熟料烧成过程的影响

研究了由于铝率变化 ,导致液相性质的改变 ,及其对高硅酸三钙 (C3S)含量硅酸盐水泥熟料烧成过程和亚微观结构的影响。分析结果表明 :对于具有相同C3S含量的熟料 ,当煅烧温度高于 14 0 0℃ ,高硅高铝熟料的易烧性反而会优于低硅高铁熟料。对于高硅熟料 ,提高熟料铝率 ,液相增多 ,可促进A矿形成 ;对于低硅熟料 ,铝率增加 ,导致液相粘度增加 ,则会抑制A矿形成。当铝率 >1.68,烧成熟料中才会出现较多铝酸三钙 (C3A)结晶 ;当铝率 =1.6～ 1.8时 ,对于硅酸率 =3 .0 0的熟料 ,结晶的铁铝酸四钙 (C4 AF)数量最多 ;当铝率处于 1.0～ 1.9之间时 ,熟料中A矿晶体的尺寸随铝率增加而减小 ,同时晶体长径比明显增加 ,晶体内部包裹物数量显著增多。     

硫磷铝锶矿焙烧制肥的研究

总结８０年代初期四川什邡系含磷品位低、性质特殊的硫磷铝锶矿焙烧制肥中磷和锶的变化，并明确了加泥磷提高和直接接触煤降低有效磷含量和转化率。为工业化制肥制订了较为完善的技术指标和工艺流程。     

硫磺分解磷石膏制硫化钙工艺研究

研究了以硫磺为还原剂分解磷石膏得到硫化钙产物的方法。在热力学研究的基础上,考察了反应温度、反应时间、硫磺物质的量分数和二氧化硫物质的量分数对硫磺分解磷石膏的影响。通过实验得出优化工艺条件:反应温度为800℃、反应时间为2 h、硫磺(以S1计)物质的量分数为40%。在该条件下磷石膏的分解率达到98%以上。同时证明了二氧化硫对反应有明显的抑制作用。借助X射线衍射(XRD)对磷石膏分解产物进行物相解析,结果表明所得产物主要为硫化钙。     

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。