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1.
针对传统二水法磷酸副产的磷石膏杂质含量高、色泽差、资源化利用率低的问题,发明了湿法磷酸副产白石膏技术,所产的白石膏杂质含量低,可全部资源化利用。以我国目前湿法磷酸年产量计,年可产出白石膏5 000万t,市值达数百亿元,经济与社会效益好。  相似文献   

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针对二水法磷酸杂质含量高、过滤酸浓度低、副产磷石膏质量差等缺点,提出将其技改为半水-二水法磷酸、二水-半水法磷酸。分析半水-二水法磷酸、二水-半水法磷酸工艺优缺点,介绍改造内容及方案,并进行工艺比较。二水-半水法适合只考虑磷石膏资源化利用、企业自有硫酸副产蒸汽配套的企业,半水-二水法适合磷酸用于制造高端磷化工产品的企业。  相似文献   

3.
湿法磷酸工艺路线的探讨   总被引:1,自引:0,他引:1  
以节能降耗和磷石膏综合利用为目的,重新研究、比较湿法磷酸的生产工艺对中国磷化工产业可持续发展具有重要的意义。对国内外湿法磷酸工艺路线(特别是二水法工艺、半水法工艺、半水-二水法工艺)进行技术经济比较;重点对中国磷酸盐用湿法磷酸工艺路线的选择给出了建议,详细叙述了半水-二水湿法磷酸生产技术、二水-半水湿法磷酸生产技术和二水-DCP耦合联产湿法磷酸生产技术;提出中国磷酸企业应根据磷酸盐产品生产对磷酸的质量要求及磷石膏利用价值来选择磷酸的工艺路线。  相似文献   

4.
石膏矿物学分析及除杂研究   总被引:1,自引:0,他引:1  
磷石膏在工业副产石膏中排放量最大,利用率最低,主要原因是磷石膏杂质较多。各粒级物料的成分分析显示,粒度越细SO_3含量越高,杂质组分SiO_2和P_2O_5含量越低。通过湿法分级可以去除部分杂质,提高磷石膏品位,进而用磷石膏开发高端模具石膏、高档装饰材料和墙体材料,更高程度扩大应用领域和消耗量,提升产品附加值。  相似文献   

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在四川大学洁净石膏发明专利技术基础上,开发出了具有自主知识产权的新型半水物湿法磷酸工艺流程,并成功实现工业化应用.该流程继承了半水物流程的优点,并实现磷石膏的提纯和高效利用,可充分利用中低品位磷矿生产湿法磷酸;节省磷酸生产的原材料及能耗;产品磷酸浓度和质量提高;副产磷石膏品质好,可代替天然优质石膏用于开发高附加值产品,...  相似文献   

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针对二水法湿法磷酸生产中磷石膏枸溶磷含量高的问题,研究了影响磷石膏枸溶磷含量和磷矿分解率的主要因素,以及降低磷石膏中枸溶磷、提高磷矿分解率的相关改进技术。生产应用后,稳定控制了萃取槽中SO3的质量浓度,磷石膏w(P2O5枸溶)由0.55%下降至0.14%,磷矿分解率提升2.05%。  相似文献   

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800万块/年免烧石膏砖生产工艺的探讨   总被引:4,自引:0,他引:4  
每生产1t湿法磷酸(以P2O5计)约副产磷石膏5t。2001年全国生产磷铵、重钙等高浓度磷肥300万t(折纯量),相应生产湿法磷酸约150万t,配套生产磷酸盐用磷酸约60万t,合计全国生产磷酸约210万t,相应副产磷石膏1000万t以上。磷石膏的大量排放,不仅占用大量土地、污染环境,而且还需相应的处理费用。日本是磷石膏利用较好的国家,其湿法磷酸副产的磷石膏被看成产品,而不是副产品,其质量与磷酸同样受到重视。笔者根据工作实践,对磷石膏用于制造普通建筑用砖的生产工艺进行探讨。1 磷石膏的特性磷矿与硫酸反应生成磷酸的同时,还副产硫酸钙,通常称之…  相似文献   

8.
湿法净化磷酸副产半水石膏,晶体细小,含磷高,过滤难度较大,不仅影响生产效率,而且磷损失大,生产成本高。基于二水石膏具有易过滤、含磷低、品质高等优点,通过控制反应温度约60℃、液相SO3质量浓度约38 g/L、反应时间2 h等参数,将半水石膏转晶为二水石膏,所得石膏总磷、非水溶磷含量大幅度降低,湿法磷酸净化系统磷收率大幅度提升,可达95%左右。  相似文献   

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<正>我国磷矿资源储量虽大,但富矿少贫矿多、易选矿少难选矿多。长期以来,我国磷肥生产一直采用湿法磷酸为原料,二水法磷酸生产工艺对磷矿品位、杂质含量都有一定要求,中低品位磷矿不仅需要选矿才能使用而且品位低于20%的磷矿就难以入选,同时每年还产生大量磷石膏,目前全国磷石膏  相似文献   

10.
针对硫酸法湿法磷酸生产副产的磷石膏,研究了用其生产β 型半水石膏粉的工艺流程.分析了目前常用的工业副产石膏生产工艺,结合磷石膏原料特性及试验数据,设计了球磨法处理磷石膏杂质+预干燥+流态化煅烧+冷却等整套工艺流程,并进行了产品质量及经济性预估,认为该工艺流程可减少原料中的有害杂质,提高产品质量和稳定性.  相似文献   

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It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  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   

15.
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   

16.
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   

17.
建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。  相似文献   

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