996 resultados para CYANEX 272


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The separation of Sc(III) from Y(III), La(III) and Yb(III) in [C(8)mim][PF6] containing Cyanex 925 has been investigated, and is reported in this paper. A cation exchange mechanism of Sc(III) in [C(8)mim][PF6] and Cyanex 925 is proposed by study of the influence of anionic and cationic species on the extraction. The coefficient of the equilibrium equation of Sc(III) was confirmed by slope analysis of log D-Sc vs log [Cyanex 925], and the loading capacity also confirmed the stoichiometry of Cyanex 925 to Sc(III) was close to 3:1. Infrared data for Cyanex 925 saturated with Sc(III) in [C(8)mim][PF6] indicated strong interaction between P=O of Cyanex 925 and Sc(III). In addition, the relationship between log D-Sc and temperature showed that temperature had little influence on the extraction process, and the resulting thermodynamic parameters indicated that an exothermic process was involved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The book addresses a number of pressing social and environmental issues of global concern. It takes the reader on a socio-legal journal of climate change and explores a range of challenging and complex topics including renewable energies, emissions reduction, carbon trading, deforestation, migration and corporate governance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In Julstar Pty Ltd v Lynch Morgan Lawyers [2012] QDC 272 Dorney QC DCJ considered whether an applicant for an assessment of all or part of their costs under s 335 of the Legal Profession Act 2007 (Qld) (LPA) must provide grounds on which they dispute the amount of the costs charged or their liability to pay them. His Honour also made an order for inspection of the solicitor’s file, despite a claimed lien for unpaid fees.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The question ‘is the planet full?’ is not new but it needs a critical assessment to provide a good answer. Obviously, the capacity of the planet should be evaluated in relation to the size and distribution of its human population and how relevant resources of the planet are used and managed. When we are discussing human population and resource management, multidimensional issues such as welfare, technologies and social changes are essential...

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O Substitutivo nº 2 estabelece que as jazidas e recursos minerais sejam bens da União. O aproveitamento, a lavra e a pesquisa dos minérios somente poderão ser realizados por empresas nacionais com concessão do Governo Federal. A Deputada Raquel Cândido (DMDP-RO) defende que 50% da matéria-prima sejam industrializadas no local da jazida. Constituintes também reivindicam a promoção e desenvolvimento social dos garimpeiros. O Deputado Ademir Andrade (PMDB-PA) defende a criação de cooperativas no garimpo e a permanência dos garimpeiros nas jazidas onde já trabalham. A Comissão de Sistematização rejeita a proposta de pluralidade sindical. Aprovado o destaque do Deputado Geraldo Campos (PMDB-DF) que não permite a criação de mais de um sindicato por categoria profissional ou econômica na mesma base territorial. O Partido dos Trabalhadores (PT) vota contrário ao destaque. O Deputado Luís Inácio Lula da Silva (PT-SP) propõe outro destaque mantendo a liberdade sindical. O PT também protesta contra o imposto sindical. O Deputado Geraldo Campos (PMDB-DF) defende, mais uma vez, a unicidade do sindicato. O Deputado José Genuíno (PT-SP) critica o destaque aprovado. O Deputado Vivaldo Barbosa (PDT-RJ) enfatiza que a aprovação do destaque é um avanço por desvincular os sindicatos ao Estado.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

溶剂萃取由于具有处理量大、操作简单、易于连续化等优点,被广泛应用于湿法冶金工业。而溶剂萃取过程通常都伴随着有机相微乳体系的形成、变化、甚至完全破乳的过程以及萃合物分子聚集状态的不断变化,因此可以认为,液-液萃取体系提供了一系列可调控的微乳体系。相对于液液萃取在金属分离方面的广泛应用,液液萃取过程中形成的微乳体系在材料制备方面的应用研究还处于起始阶段。本论文在广泛调研文献资料的基础上,开展了利用硫代有机膦萃取剂Cyanex 301萃取体系制备纳米硫化物的研究,取得了一些有意义的结果。该工作的开展将对促进溶剂萃取分离与纳米材料制备一体化研究起到一定的作用,并为寻找简便易行且适用于大规模生产的纳米材料制备新方法提供思路。主要内容如下: 1. 通过两相热法,利用Cyanex 301-AgNO3两相萃取体系制备了尺寸均匀、分散性好的Ag2S纳米粒子。并且发现了与通常纳米材料制备过程不一样的现象,即Ag2S产物的粒径随着反应温度的升高逐渐增大,这与通常观察到的产物颗粒随反应温度升高而变小的现象完全不同。通过红外谱图分析,确定了反应机理,并提出了影响产物粒径的可能机制,认为产物粒径的变化是Cyanex 301作为硫源与作为表面修饰剂相互竞争的结果。 2. 通过两步法合成了四面体、类六角锥和六角片型的Ag2S/CdS纳米复合材料。Ag2S纳米粒子在产物的形成中起到了晶种与模板导向作用,溶剂对产物的形貌也起到诱导作用。 3. 利用两相热法,一步合成了CuS微米花和微米球自组装结构,产物的形貌随水相金属离子浓度的改变而发生变化。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文系统研究了酸性单硫代磷酸萃取剂Cyanex302萃取抗、忆、斓和礼的单一体系热力学,钦、钻和饵的协同萃取热力学,抗、忆、斓和礼的动力学机理及其各种因素影响下的界面活性,在以下四个方面得到了具有学术意义和应用前景的结果。1.推导了Cyanex302萃取Sc(111),Y(111),La(111)和Gd(111)的平衡方程式,比较了Cyanex302与纯化后Cyanex302对稀土的萃取性能和分离选择性。以斓为例,深入探讨了Cyanex302中不同组份在萃取过程中的地位和作用,明确了cyanex302与TOPO混合对稀土元素萃取具有明显的协同效应,推测了纯化cyanex302与TOPO混合萃取悯的热力学机理,计算了协萃系数,确定了萃合物组成。2.探讨了Cyanex302与不同类型(酸性,中性和胺类)萃取剂混合对钦、钻、饵的萃取性能。比较了Cyanex302与不同类型萃取剂等物质的量混合后,对三种稀土元素萃取能力的强弱顺序和分离选择性顺序。明确cyanex302与不同类型萃取剂混合可以构成协萃和反协萃体系,计算了协萃体系的协萃系数。以cyanex302与CA-100萃取YCl3为例,推导了协萃机理,确定了协萃配合物的组成。3.借助于不同的数据处理方法研究了cyanex302萃取杭、钻、斓和锐的动力学,考察了各种因素对萃取速率的影响,获得不同方法下的速率方程,得出不同的萃取机理。比较了Cyanex302正向萃取和反萃取YCl_3的动力学方程,得出一些具有指导意义的结论。Vll4.用不同的数学处理方法研究了Cyanex302在没有离子强度维持下各种稀释剂对界面活性的影响,比较了各种数据处理方法下结论的不同,分析了不同稀释剂对Cyanex302界面活性影响的原因。重点讨论了CyaneX302-庚烷-(H,Na)Cl体系中温度、水相酸度和离子强度对界面活性的影响,把界面吸附与萃取动力学相结合,探讨了二者之间的关系。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Synergistic extraction and recovery of Cerium(IV) (Ce(IV)) and Fluorin (F) from sulfuric solutions using mixture of Cyanex 923 and di-2-ethylhexyl phosphoric acid (D2EHPA) in n-heptane have been carried out. in order to investigate the synergistic extraction of Cyanex 923 + D2EHPA, extraction Ce(IV), F, Ce(III) and Ce-F mixture solution using D2EHPA or Cyanex 923 as extractant alone were studied firstly, and then Synergistic extraction of Ce(IV), F and Ce(IV)-F mixture solution with D2EHPA + Cyanex 923 were carried out. The largest synergistic coefficient of Ce(IV) is obtained at the mole fraction X-Cyanex (923) = 0.8. The synergistic enhancement coefficients (R-max) obtained for Ce(IV) are 23.12 in Ce(IV) solution, and in Ce-F mixed solution R-max for Ce(IV) and F are 2.24 and 3.25 respectively.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

提供了一种固定Cyanex 923的新方法-溶胶-凝胶法。在溶胶-凝胶过程中离子液体的加入增加了复合材料的比表面积和孔容,并在硅胶网络中为Cyanex 923提供了一个可以扩散的介质。包埋离子液体和Cyanex 923的有机-无机复合材料的制备过程不需要其他有机溶剂,绿色、环保。结果表明,该复合材料对Y(Ⅲ)和重稀土元素有较好的分离效果。经过4次萃取/反萃过程,该复合材料对Y(Ⅲ)去除率仍高于78%。表明材料性能稳定,可多次重复使用。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The extraction behavior of lanthanides and yttrium usinsg CYANEX 925 (mixture of branched chain alkylated phosphine oxides) in n-heptane from nitrate medium has been studied. The effects of aqueous phase ionic strength, CYANEX 925 concentration in the organic phase, and temperature on Sm3+, Nd3+ and Y3+ extraction have been investigated. The extractability of the lanthanides and yttrium increases with increasing nitrate concentration, as well as with increasing CYANEX 925 concentration. An extraction mechanism is proposed based on slope analysis. Furthermore, the infra-red spectra of CYANEX 925 saturated with lanthanides are employed to provide evidence of the composition of the complex. The relationship between the logarithm of the distribution ratio and lanthanide atomic number is also discussed which indicates that yttrium can be separated from fight lanthanides. In addition separation of the light and heavy lanthanide groups is also possible using CYANEX 925. From the temperature dependence data, the thermodynamic parameters values (Delta H, Delta S and Delta G) are calculated.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The extraction and separation of Ho, Y, and Er(III) with the mixtures of bis(2,4,4-trimetylpentyl)monothiophosphinic acid (Cyanex 302) and another organic extractant, such as acidic organic extractant (di-2-ethylhexyl phosphoric acid P204, 2-ethythexyl phosphoric acid mono-2-ethylhexyl ester P507, di-2-ethylhexyl phosphinic acid P229, and sec-nonylphenoxy acetic acid CA-100), neutral organic extractant (tri-n-butyl phosphate TBP, di-(1-metylheptyl)metyl phosphate P350, and branched trialkylphosphinic oxide Cyanex 925) or primary amine N1923, has been investigated in this paper. The extractability and separation ability for the Ho, Y, and Er with the mixtures of Cyanex 302 and organic extractants has been compared. The synergistic effect of the Ho, Y, and Er extraction with the mixtures of Cyanex 302 and P229, Cyanex 925, CA-100, or N1923 has been explored and the synergistic enhancement coefficients have been calculated. At last, the Y3+ synergistic extraction with the mixtures of Cyanex 302 and CA-100 has been determined and the extracted complex has been deduced.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work, studies were carried out on the extraction properties of Mn(II) and MnO4- in sulfuric acid medium using Cyanex 923. Effects of different variables on the extraction of Mn(II) and MnO4-, such as the concentrations of acid, the extractant, and the temperature, were investigated. Results indicated that Mn(II) was extracted weakly by Cyanex 923; however, MnO4- could be strongly extracted into the organic phase. The extraction mechanism of MnO4- was proposed, and the influence of MnO4- on the extraction of cerium was identified when KMnO4 as oxidizer added into the bastnasite sulfuric acid leaching liquor. As MnO4- was easier to be extracted into the organic phase than Ce(IV) and then lost its ability for oxidization, a new device was designed to realize sufficient oxidization of cerium from III to IV, and which has been applied to industrialization.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The extraction kinetics of Sc, Y, La and Gd(III) from the hydrochloric acid medium using Cyanex 302 (hereafter HL) in heptane solution have been measured by the constant interfacial cell with laminar flow. Reaction regions are explored at liquid-liquid interface. Extraction regimes are deduced to be diffusion-controlled for Sc(Ill) and mixed controlled for Y, La and Gd(Ill). Extraction mechanisms are discussed according to the dimeric model of Cyanex 302 in non-polar solution. From the temperature dependence of rate measurement, the values of E-a, Delta H-+/-, Delta S-+/- and Delta G(300)(+/-) are calculated and it is found that the absolute values of these parameters keep crescent trend for Sc, Y, La and Gd(III). At the same time, it is found that it can easily achieve the mutual separation among the Sc, Y and La(III) with kinetics extraction methods.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The solvent extraction of La3+ from hydrochloric acid solutions was investigated using his (2, 4, 4-trimethylpentyl) monothiophosphinic acid (Cyanex 302, HL) as an extractant. The effect of equilibrium of aqueous acidity on extraction of La3+ using Cyanex 302 In different diluents was discussed. The effects of extractant concentration and chloride ion on the extraction reaction were also studied. Stoichiometry of the extraction reactions and the nature of metal complexes formed were determined using slope analysis technique and IR measurement.