兑卤法生产氯化钾工艺原理及优缺点

目前,国内的氯化钾生产已经形成了一定的规模,其生产工艺也卓见成熟。“冷分解一浮选法”工艺和“反浮选一冷结晶”法已经成为生产氯化钾的主流,同时也代表着国内钾肥生产技术的最高水平。而为了提高资源利用率,氯化钾生产中还存在着“兑卤一冷结晶法”、“冷分解一热溶结晶法”等生产工艺,这些工艺虽然没有得到规模生产和广泛应用,却也不容忽视,因为这些工艺生产过程需要具备一些特殊条件,也存在一些优缺点。本文是对“兑卤一冷结晶法”生产工艺在钾肥生产中存在的优缺点的一点见解,供同行参考!     

氯化物型卤水制取氯化钾加工方法的评述

本文对盐田光卤石溶解—重结晶工艺、盐田光卤石冷分解—浮选法、盐田光卤石冷分解—热溶结晶法、盐田光卤石冷结晶—浮选法、盐田光卤石反浮选—冷结晶法等加工方法作了较详细的论述,从而使关心盐湖开发的领导和同志对氯化物型卤水提钾工艺研究的科研进展及现状有概括的、系统的了解     

兑卤——冷结晶法生产氯化钾工艺的研究

兑卤-冷结晶法生产氯化钾是利用晶间卤水和老卤生产氯化钾的新工艺，文章介绍了该工艺的基本原理，工艺过程和技术指标，并进行了技术经济核算。     

反浮选-冷结晶法从光卤石中提取氯化钾

介绍了反浮选－冷结晶法从光卤石中提取氯化钾工艺。由此工艺生产的产品质量高,粒度好。     

西藏鄂雅错盐湖卤水兑卤蒸发研究

用鄂雅错盐湖卤水进行兑卤,通过改变卤水的镁钾比,使其在蒸发过程中不会析出钾石盐,直接析出含钾品位较高的光卤石。实验结果表明:兑卤蒸发的析盐顺序为氯化钠、硫酸镁—氯化钠、光卤石,蒸发过程中钾收率达79.26%。     

察尔汗盐湖兑卤生产光卤石工艺讨论

察尔汗盐湖光卤石生产工艺由早期的沟槽盐田到日晒盐田中兑卤进而完成了在容器中兑卤脱钠，成为实际运用工艺。介绍了该工艺的原理，优缺点及合理的生产规模。     

硫酸镁亚型盐湖低钾混盐矿提钾工艺的研究

利用西台吉乃尔盐湖盐田老卤池中低钾高硫光卤石混盐矿为原料,及硫酸钾镁肥生产车间排出的母液及盐田水氯镁石,通过兑卤工艺-先正浮选提取氯化钾-后反浮选提取低钠光卤石混盐的工艺流程,并对光卤石混盐矿粒度、母液量、分解时间、正反浮选药剂相互影响关系等主要因素进行条件实验,验证工艺流程的可行性并获得最佳实验条件;同时通过先反浮选提取硫酸钾镁肥-后正浮选提取氯化钾的工艺流程,验证其可行性并取得试验钾回收率。     

我国氯化钾生产工艺概述

分析我国钾肥现状和青海盐湖工业股份有限公司钾盐储量及生产现状;介绍青海盐湖股份采用冷分解浮选法、反浮选冷结晶法和兑卤冷结晶法生产氯化钾的工艺流程、生产方法和技术指标;提出我国需建立钾肥战略储备机制,引进国外钾盐先进技术,以增强钾肥的国际竞争力。     

立足国内资源的钾肥生产技术取得突破性成果

取消传统的盐田滩晒卤水制取光卤石工序，直接将调节好的光卤石点卤水泵送车间与水氯镁石点卤水兑卤脱钠生成的低钠光卤石，在室温下加水分解脱镁结晶产出优质氯化钾。引入控速分解结晶理论设计流程结构，在具有内循环结晶分极装置的新型结晶反应器内处理芒硝和氯化钾，使物料反应，结晶，分级，杂质分离，及母液循环同步进行而生产出优质硫酸钾。     

反浮选法生产过程中氯化钠对钾收率的影响

反浮选-冷结晶法制取氯化钾是世界上较为先进的一种新工艺。运用相图知识对反浮选-冷结晶法生产氯化钾的过程从两个方面进行了较为详细的分析,并通过计算得出不同含量的氯化钠与氯化钾收率变化关系,其结果是随着光卤石矿中氯化钠含量的增高,氯化钾回收率呈线性减少的关系;盐田滩晒的光卤石矿,用反浮选-冷结晶法制取氯化钾的收率一般在50%左右,因此,控制盐田滩晒光卤石矿中氯化钠含量,可提高氯化钾收率,还可节约大量用水,以便在生产过程中对提高氯化钾的产量及质量起指导作用。     

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。