低浓度有机磷萃取剂P204促进普通小球藻(Chlore11a vulgaris)生长的研究

本文以普通小球藻为实验对象,研究了有机磷萃取剂P204在低浓度（

二-(2-乙基己基)磷酸P204与三烷基叔胺N235协同萃取钼

研究了P204(二-(2-乙基己基)磷酸,HA)和N235(三烷基叔胺,R3N)二元体系在HC l介质中对金属钼的萃取。结果表明,P204和N235混合萃取剂在萃取钼时存在协同效应,并且在N235摩尔分数为0.7时协萃系数为2.24;考察了溶液酸度、P204或N235浓度及温度对萃取钼的影响,确定了协萃络合物为(R3NH)3.HMo8O26.(HA)2,并比较了负载前后有机相的红外光谱。

氟碳铈矿分离过程中的氧化问题及工艺改进

针对Cyanex 923萃取分离铈、钍、稀土过程中Ce(IV)在萃取过程中被有机相中的还原性物质还原的问题，提出采用高锰酸钾氧化萃余水相中的Ce(III)。研究结果表明，在酸性条件下，高锰酸钾能有效的氧化水相中的Ce(III)，但在萃取过程中，高锰酸根会先于Ce（IV）被萃入到有机相中，从而失去氧化Ce(III)的能力，由此提出氧化过程必须无含Cyanex 923有机相存在并参与设计了一套油水分离氧化装置。经过高锰酸钾氧化后，萃余水相中铈可低于0.5g/L，铈收率达到98%。 针对攀西氟碳铈矿新流程中直接制备的纳米级氟化铈，考察了氟化铈的紫外吸收性能，发现其在254nm处有特征吸收峰，还考察了分散剂的极性强弱、分散物浓度、粒径、温度及表面包覆等因素对紫外吸收性能的影响；发现随着粒径的减小，紫外吸收峰发生明显的红移；经TiO2包覆后CeF3的紫外吸光域范围扩展。 研究了Cyanex 923与P204组成的双溶剂萃取体系及其单独体系萃取Ce(IV)、F及Ce(IV)-F混液的热力学性质，得出了协同萃取机理，获得了萃取平衡方程式以及协萃物的组成。研究发现混合体系对Ce(IV)及Ce(IV)-F混液中的Ce、F均有明显的协萃作用，这为该萃取体系应用于现实分离中提供了可靠的保证。 在上述工作的基础上，提出了Cyanex 923与P204组成的双溶剂萃取体系分离攀西氟碳铈矿的新清洁冶金流程。对影响这一流程的化学因素进行了系统研究，并给出了工艺运行参数。

The extraction and separation of Ho, Y, and Er(III) with the mixtures of Cyanex 302 and another organic extractant

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.

The extraction of rare earths using mixtures of acidic phosphorus-based reagents or their thio-analogues

The solvent extraction of rare earths from chloride solution has been investigated using mixtures of 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP, P507) and organophosphorus acids [di-(2-ethylhexyl)phosphoric acid (HDEHP, P204), isopropylphosphonic acid 1-hexyl-4-ethylocryl ester (HHEOIPP), bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272), bis(2,4,4-trimethylpentyl)monothiophosphinic acid (Cyanex 302), and bis(2,4,4-trimethypentyl)dithiophosphinic acid (Cyanex 301)]. Results show that the extractability of the selected extractants for rare earths decreases in the order: HEHEHP/HDEHP > HEHEHP/Cyanex 301 > HEHEHP/HHEOIPP > HEHEHP/Cyanex 302 > HEHEHP/Cyanex 272. A possible explanation of the different extractabilities is given based on the structure of the extractants. Furthermore, the possibilities of the separation of adjacent rare earths with these mixtures were investigated according to the extractabilities; the results show the possibility of separating the rare earths.