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本文研究低浓度伯胺从低浓度含钨水溶液中按照溶剂化历程萃钨的规律。发现伯胺从含钨浓度高或低的水溶液溶剂化萃取的机理不同,过去的工作表明从高浓度钨水溶液萃入有机相的是H_2WO_4,本工作表明从低浓度水相萃入有机相的是其它钨的络合物,初步认为是WO_2(OH)_2,并且在萃取过程中,首先形成亲水性的水合络合物,然后脱水而进入有机相。实验表明水合络合物的形成能力是随水相支持电解质浓度的增大而降低,讨论了测得的有关的红外和紫外光谱。 研究了叔胺萃钨的特点,认为叔胺与伯胺及仲胺一样,也可按溶剂化历程萃钨,由于叔胺不含活性氢原子,因此它的溶剂化能力要较伯胺和仲胺弱,从而需要大量的过量叔胺,才能得到较高的萃取率。

Solvation extraction of W(VI) from dilute tungstate solutions by dilute organic solutions of amines was studied. It has been found that the mechanism of solvation extraction of W from dilute and concentrated tungstate solutions respectively is different. The W compound extracted into the organic phase from concentrated tungstate solutions by primary amines is indicated to be normal tungstie acid (H_2WO_4) from our earlier work. The present work indicates, however, that the W(Ⅳ)compound or complex extracted by primary amine from dilute tungstate solutions is some other tungsten compound or complex such as WO_2(OH)_2. The hydrophilie complexes were formed first during solvation extraction from dilute W solutions. The complexes are then dehydrated slowly and then transferred into the organic phase. Experiments show that the formation of hydrophilie complex is decreasedwith the increasing of concentration of electrolytes in the aqueous phase. The related infrared and ultraviolet spectra were measured and discussed. Using of tertiary amines as solvation extractant for W was also investigated. It has been found that the tertiary amine just like primary and secondary amines can be used as solvation extractants. As there is no active hydrogen atom in the molecules of tertiary amine, its power of solvation extraction is much lower in comparison with that of primary amines or secondary amines. Large excess amount of tertiary amine has to be used to arrive a high percent of extraction by solration.