高碳镍钼矿碱性还原熔炼-水浸分离与提取镍钼

在理论分析的基础上,以贵州遵义镍钼矿为原料,提出了镍钼矿碱性还原熔炼?水浸提钼的清洁冶金新工艺,考察了Na2CO3用量、温度、还原剂用量、反应时间对镍还原率及钼浸出率的影响,在最优条件下进行了扩大实验. 结果表明,在碱性介质及强还原气氛下,镍钼矿中的镍被还原成高品位镍铁合金,钼转化为可溶性的钼酸盐;最佳工艺条件为Na2CO3用量为理论量的2倍、熔炼温度1000℃、还原剂添加量为镍钼矿的5wt%、反应时间1.5 h. 最佳条件下扩大实验金属镍回收率为94.92%,金属钼挥发率为9.36%,浸出率为99.94%,固硫率接近100%,得到了高品位镍铁合金和含钼浸出液,镍钼有效分离.     

硫化钼镍矿加碱焙烧后钼镍的回收率分析

通过焙烧、水浸实现了原生硫化镍钼矿中镍和钼的分离,得到的较优工艺条件为:焙烧时,原矿和无水碳酸钠质量比1:0.9、560℃焙烧6h,650℃焙烧1.5h,焙砂中镍品位为2.67%,钼品位为5.81%;在固液比1:4,温度95℃的条件下,水浸焙烧渣2h,98.21%的镍留在滤渣中,95.43%的钼进入滤液,有效地实现了钼...     

从钙镁磷肥副产物镍磷铁中湿法提镍的研究

采用硫酸浸出工艺从镍磷铁中浸出镍,考察温度、固液比、硫酸质量分数和浸出时间对浸出过程的影响。研究结果表明,在温度为80℃,固液比为1∶10,硫酸质量分数为40%和加入少量过氧化氢浸出12 h时,镍磷铁中镍和磷的浸出率分别为91.0%、85.9%。     

镍电解一次铁渣浸出的研究

控制不同工艺条件浸出镍电解一次铁渣研究表明,升高温度有利于铁渣中铁、镍、铜元素的浸出;当反应体系温度≥60℃时,采用浓度为20%的硫酸浸出镍电解一次铁渣,反应1.5 h,可以将铁渣中的绝大多数铁、镍、铜元素浸出;正交实验表明,当控制反应时间为1.5 h时,镍电解一次铁渣浸出的最佳工艺条件为:硫酸浓度20%,反应液固比10∶4,反应温度90℃。     

高碳镍钼矿制备钼酸铵

研究了高碳镍钼矿制备钼酸铵的工艺,通过氧化酸浸分离镍、钼,制得高品位的钼酸浸出渣。通过单因素、正交实验以及优化实验的探究,确定了氨浸的最佳工艺参数：液固比3∶1,反应温度60℃,反应时间2 h,氨的过量系数为1.6,碳酸氢铵与钼的质量比为0.1,钼的浸出率达98%以上。将氨浸液调节pH、搅拌、加晶种、陈化后析出浅绿色的钼酸铵晶体,产品质量符合GB/T 657-1993标准,钼的总产率达90.67%。     

低品位钼镍焙烧矿常压同时浸出钼镍的工艺研究

以低品位的钼镍矿石为原料与CaO混合高温焙烧,所得焙烧矿采用常压氨-碳铵浸出,对同时浸出镍和钼的工艺条件进行了研究。探讨了温度、液固比、浸出时间、碳酸铵的用量等因素对钼和镍浸出率的影响。结果表明,在浸出温度45℃,液固比4∶1(mL/g),浸出时间24h,碳酸铵用量w((NH4)2CO3)∶w(焙烧矿)=0.3的最佳浸出条件下,钼和镍的浸出率分别为94.0%和90.1%。     

含砷钴镍渣中砷碱介质氧化浸出机理

研究了某厂ZnSO4溶液砷盐净化工艺产生的含砷钴镍渣中砷在惰性和氧气气氛的碱介质中的氧化浸出机理. 结果表明,砷氧化浸出与温度、介质碱浓度、浸出气氛均密切相关. 在惰性气氛、碱介质中,渣中CuO和Cu2O均可作为砷氧化浸出的氧化剂,在80℃及以下低温下,CuO对低价砷起主要氧化作用,还原产物为Cu2O,砷最高浸出率不超过53%;在100℃及以上较高温下,CuO和Cu2O均参与低价砷的氧化浸出过程,还原产物均为单质Cu,最高浸出率约为90%;在氧气气氛、碱介质中,砷浸出率可达98%以上,除O2作为氧化剂直接氧化浸出砷外,渣中的铜可作为O2与低价砷之间电子传递的载体,强化氧化反应.     

从红土镍矿镍铁渣中分离浸取镍铬工艺

将镍铁渣破碎、球磨后磁选富集Ni于精矿中,富集Cr于尾矿中. 磁选后Ni从0.26%富集至2.57%(w),Cr从4.55%富集至4.61%(w). 考察了H2SO4常压酸浸精矿时Ni的浸出规律. 结果表明,在酸浸温度110℃、酸浓度220 g/L、酸浸时间2 h、液固质量比5的优化酸浸条件下,Ni浸出率为91.5%. 在80~120℃内,Ni浸出反应活化能为19.6 kJ/mol. Ni浸出反应主要受扩散控制. 用Na2CO3碱熔焙烧尾矿,在温度1000℃、Na2CO3/渣质量比0.65、时间1 h、镍铁渣尾矿粒度<74 mm的优化条件下,Cr浸出率为94.1%.     

镍基含铼废合金氧化酸浸工艺

在硫酸体系中,采用熔融雾化制粉、硫酸体系双氧水氧化酸浸工艺浸出铼,钨钽等稀有金属富集在渣中,研究了酸度、双氧水用量、温度、粒度、液固体积/质量比、时间对浸出的影响. 结果表明,最佳浸出条件为：在硫酸体系中,废合金雾化粉20 g,粉末粒度71~100 mm,温度75℃,液固比8 mL/g,硫酸浓度3.5 mol/L,滴加30%双氧水65 mL,反应6 h. 该条件下铼、镍和钴的浸出率均超过99%,钨钽浸出率均低于1%,钼浸出率为28%,实现了铼浸出与稀有金属在渣中富集.     

尾矿砂的酸溶特性与镍的浸出研究

通过粉末X射线衍射（XRD）分析了金川尾矿砂的物相组成和脉石矿物的相对含量,利用热力学原理计算并分析了矿物在硫酸中的溶解难易程度。通过正交设计与实验, 得到浸出镍的最佳工艺条件：酸矿质量比为 0.9∶1、液固质量比为2∶1、反应温度为90 ℃、反应时间为4 h。在此酸浸条件下,尾矿砂中镍的浸出率可达93.3%,而蛇纹石和白云石可以完全溶解,并产生大量无定形二氧化硅。     

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。