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1.
偏高岭石-碱-硅酸钠水热反应体系13X分子筛的合成   总被引:3,自引:0,他引:3  
以煤系高岭石为主要原料,经破碎、粉磨、煅烧、水热处理等工艺,在偏高岭石-碱-硅酸钠水热反应体系中合成了13X分子筛.扫描电镜分析表明:产物晶形完整、粒度为1μm左右且分布均匀.用X射线衍射测试方法研究混合物的硅铝的摩尔比[n(SiO2)/n(Al2O3)]、钠硅的摩尔比[n(Na2O)/n(SiO2)]、水钠的摩尔比[n(H2O)/n(Na2O)]以及陈化时间对13X分子筛合成的影响.研究表明:该水热反应体系的最佳配比为n(SiO2)/n(Al2O3);高于13X分子筛中自身的n(SiO2)/n(Al2O3)=2.5.反应适宜的碱度条件为:n(Na2O)/n(SiO2)=1.9,n(H2O)/n(Na2O)=40,碱度过高或过低均会出现P型分子筛杂相.陈化过程在13X分子筛的合成过程中不可缺少,其适宜的陈化时间为24h.该水热反应过程遵循分子筛的液相转化机理.  相似文献   

2.
李燕  黄嘉晋  梁忠城 《硅酸盐通报》2016,35(10):3426-3430
以油页岩渣为原料,采用水热合成法制得4A分子筛.重点考察了n(Na2O)/n(SiO2)比、n(H2O)/n(Na2O)比、晶化时间、晶化温度对分子筛Ca2+交换量的影响.适宜的合成条件为:n(Na2O)/n(SiO2)=2.5,n(H2O)/n(Na2O) =50,晶化时间18 h,晶化温度90℃.并用XRD、SEM测试手段对合成的分子筛的晶体结构、表面形貌等进行了表征,结果表明,制备的样品为4A型分子筛结构,属于立方形晶型.  相似文献   

3.
孔德顺  宋说讲  王茜  张鲁超 《硅酸盐通报》2017,36(11):3653-3658
研究了含有石英成分的高岭土的活化方法,并采用水热法制备了干燥剂NaP分子筛.研究了碳酸钠对高岭土的活化效果、不同水热反应条件对NaP分子筛吸水率的影响,得到该高岭土的活化条件为:m(高岭土):m(碳酸钠)=1:1、在750℃下煅烧2 h;制备NaP分子筛的优化条件为:n(SiO2)/n(Al2O3)=4.0、n(Na2 O)/n(SiO2)=1.4、n(H2O)/n(Na2 O)=40、93℃下晶化8 h.  相似文献   

4.
劣质煤矸石合成4A沸石分子筛   总被引:1,自引:0,他引:1  
为了利用高铁高砂型劣质煤矸石来合成4A沸石分子筛,先将该煤矸石在350℃煅烧2 h,然后加入过量10%的浓度为20%的盐酸,在90℃的条件下酸浸3 h,除铁率为95.1%,铝元素浸出率为总铝含量的10%;将除铁后的煤矸石粉在750℃煅烧2 h后,煤矸石中的炭等有机质被除去、高岭石转变为无定形态的偏高岭石;然后向该750℃煤矸石煅烧粉中按照m(煤矸石)∶m(氢氧化钠)=1∶1的比例加入氢氧化钠,混匀后在400℃恒温2 h,煅烧粉中的石英等成分转变为可溶于水的硅酸钠和硅铝酸钠,因此获得了高活性的原料;合成4A沸石分子筛的体系组成为n(SiO2)/n(A12O3)=2.0、n(Na2O)/n(SiO2)=1.7、n(H2O)/n(Na2O)=45,该体系先在40℃老化2 h,然后在95℃水热晶化4 h,最后运用XRD及SEM等手段对晶化产物进行了表征,结果表明:产物为纯净的4A沸石分子筛、晶形完好、平均粒径约为1μm、Ca2+交换量为296 mg CaCO3/g干沸石。  相似文献   

5.
采用水热法合成了4A分子筛,以4A分子筛的钙离子交换度为指标,通过单因素试验和正交试验考察了4A分子筛的合成条件。实验结果表明,合成4A分子筛的最佳条件为:n(Si O2)/n(Al2O3)=1.8,n(Na2O)/n(Si O2)=3.0,n(H2O)/n(Na2O)=40,晶化温度为100℃(常压),晶化时间为6 h。在此条件下合成的4A分子筛的钙离子交换度为323 mg·g-1。同时通过XRD和SEM对最佳条件下的4A分子筛进行了表征。  相似文献   

6.
以高岭土微球为全部硅铝原料,经焙烧、碱抽提、水热处理等工艺,直接原位晶化合成了Y分子筛。扫描电镜分析表明:在高岭土微球上均匀生成了晶型完整、粒度为1 μm左右的Y分子筛。结合X射线测试方法详细研究了体系硅铝比、碱度、碱抽提时间、导向剂构成及添加时间对Y分子筛合成的影响。研究表明:该水热反应体系的最佳配比为n(SiO2)/n(Al2O3)=10.0。反应适宜的碱度条件为:n(Na2O)/n(SiO2)=0.56,n(H2O)/n(Na2O)= 35,碱度过高或过低都易有P杂晶生成。碱抽提过程对合成Y分子筛十分关键,最佳的抽提时间控制在12 h。导向剂构成为透明高清状,加入时间控制在碱抽提结束时最优,此时合成的Y分子筛品质最好。  相似文献   

7.
吴涛  杜美利  司玉成  李莹 《硅酸盐通报》2015,34(5):1348-1353
黄陵煤矸石的灰成分以SiO2、Al2O3为主,这些组分正是合成分子筛的原料.将煤矸石经过煅烧活化、酸浸除铁、碱熔预处理后,采用水热合成的方法制备4A分子筛.通过正交试验考察了n(Na2O)∶n(SiO2)、n(H2O)∶n(Na2O)、老化时间、晶化温度、晶化时间5个因素对分子筛钙离子交换性能的影响,实验结果表明:n(Na2O)∶n(SiO2)是对4A沸石钙离子交换量影响最大的因素,其次是晶化温度,最小的为老化时间;且在n(Na2O)∶ n(SiO2)为1.3,n(H2O)∶ n(Na2O)为45,老化时间8h,晶化时间4h,晶化温度85℃下制备所得4A分子筛的钙离子交换量达到296.84 mg CaCO3/g干沸石.自制分子筛的XRD及SEM检测分析表明,最优条件下制备出的4A分子筛晶型完整,轮廓清晰,呈立方体,颗粒大小均匀,在1~2 μm左右.  相似文献   

8.
在无模板剂条件下,采用水热反应体系合成NaA/X复合沸石,研究了原料配比及凝胶化条件对NaA/X复合沸石合成的影响.结果表明,该反应体系钠的优化配比为n(SiO2)∶n(Al2O3)=2.8,反应的适宜碱度条件为:n(H2O)∶n(Na2O) =25~30、n(Na2O)∶n(SiO2)=1.6~3.0,碱度过高或过低均会导致X型沸石的消失.产物为复合沸石,粒径为150nm,分散度较好.产物的钙离子交换能力达到300 mg/g,镁离子交换能力优于纯4A、X及高铝P型沸石.  相似文献   

9.
以13X分子筛的低成本制备与煤基固废协同利用为目标,利用煤矸石与高铝粉煤灰碱法提铝过程中副产的脱硅液为原料,通过水热反应制备了13X分子筛,实现了两种固废资源的协同利用.考察了水热反应体系水钠比、硅铝比、晶化温度、搅拌速率等因素对合成产物晶型和比表面积的影响规律.通过X射线衍射、红外光谱和扫描电镜等方法对产物结构和形貌的演化过程进行了表征分析.结果表明,在优化工艺为n(SiO2/Al2O3)=3.0,n(Na2O/SiO2)=1.9,n(H2O/Na2O)=60,室温下老化24 h,100 r·min-1下于95 ℃水热晶化8 h制备的13X分子筛比表面积为681.7 m2·g-1,相对结晶度94.59%.通过对水热反应过程分析,13X分子筛合成过程前期主要为煤矸石与脱硅液反应形成无定型凝胶,后期为凝胶相溶解和分子筛晶体的生长.  相似文献   

10.
以伊利石合成4A分子筛的实验研究   总被引:1,自引:0,他引:1  
在常压下将伊利石进行高温焙烧处理。经过对原料的焙烧处理、水热合成实验,合成了4A沸石分子筛。焙烧实验确定了优化焙烧参数:m(伊利石)∶m(碳酸钠)=1∶1,焙烧温度850℃,伊利石粒度75μm,保温时间为90min。采用正交设计法确定了水热法合成的优化工艺参数:n(H2O)/n(M2O)=50,n(M2O)/n(SiO2)=1.4(M为Na,K),晶化时间4h,晶种加入量占水体积分数8%。合成沸石纯度较高,吸附量达到国家化学工业产品标准。  相似文献   

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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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

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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.  相似文献   

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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。  相似文献   

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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.  相似文献   

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