JPH0326303A - Separation of element - Google Patents

Abstract

PURPOSE:To simply and continuously separate a specified element from a mixed soln. contg. plural kinds of elements by impregnating an org. extracting reagent selectively adsorbing the specified element into a filter and b arranging the mixed soln. and an extracting solvent with the filter in-between. CONSTITUTION:An org. extracting reagent selectively adsorbing a specified element such as iron, e.g. mono-2-ethylhexyl ester of 2-ethylhexyl-phosphoric acid is impregnated into a filter pipe 3 made of polytetrafluoroethylene resin, etc. A mixed soln. 4 contg. plural kinds of elements such as iron and Cr, e.g. an acid soln. having pH of about 2 and an extracting solvent 2 such as 5M sulfuric acid soln. are arranged with the pipe 3 in-between. The specified element such as iron in the mixed soln. 4 is adsorbed on the org. extracting reagent, extracted by the extracting solvent 2 through the pipe 3 and removed. The specified element can be simply and continuously separated.

Description

[Detailed Description of the Invention] 1 2 [Industrial Application Field] The present invention relates to an element separation method, which allows elements to be separated easily and continuously without using a large amount of organic extraction solvent. be.

[Prior Art] In recent years, as the performance of electronic materials and other highly functional materials has improved, there has been a demand for high-purity products or a desire to remove only elements harmful to the performance of compounds consisting of multiple elements, such as ferrite. It's increasing. Conventional methods for separating a specific element from multiple elements include 1. Solvent extraction method 2. Ion exchange methods and the like are known.

[Problems to be solved by the present invention] The solvent extraction method mainly uses an organic extractant, and there is a wide range of extractants to choose from, but it is dangerous to work because a large amount of flammable organic solvent is handled. accompanies. In addition, the ion exchange method is difficult to operate continuously, so separation and purification costs are high.

The present invention has been made as a result of research to improve the conventional drawbacks as described above, and an object of the present invention is to provide a method by which elements can be easily and continuously separated by improving the solvent extraction method.

[Means for Solving the Problems] The present invention impregnates a filter with an organic extractant that selectively adsorbs specific elements, and places a mixed solution containing a plurality of elements and an extraction solvent through the filter. , a specific element in a mixed solution is adsorbed to an organic extractant, and the element is extracted and removed into an extraction solvent through a filter.

The organic extractant used in the present invention is a reagent commonly used in solvent extraction, such as 5-2-ethylhexyl phosphoric acid, 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, trioctyl phosphate, tributyl phosphate, Organic phosphorus compounds such as trioctylphosphine oxide and tributylphosphine oxide;
-class, secondary, tertiary and quaternary amines, alkyl carboxylic acids such as cabrylic acid and naphthenic acid, -alkyl sulfonic acids such as -aminonaphthalene trisulfonic acid and dinonylnaphthalene sulfonic acid, and chelated amines. As a system extractant, acetylacetone, thenoyl trifluoroacetate1
・β-diketones such as N, alkyl dithiocarbamates such as diethyldithiocarbamate, virolidine dithiocarbamate, oximes such as dimethylglyoxime,
Dialkylthiorubazone such as diphenylthioalbazone, oxine derivatives such as 58-quinolinol, nitrosophenol type, xanthate type, oxydiazo type,
Trobolone series etc. can be used.

In addition to organic extractants, auxiliaries such as viridine and orthophenanthroline that form addition complexes with extraction elements (ternary compounds of one extraction element, one part of the isotype extractant, and one part of the auxiliary agent) are added to the mixed solution before separation. Separation efficiency can be increased by adding or impregnating with an organic extractant.

Further, the organic extractant may be appropriately selected and used depending on the element to be separated and removed.

Furthermore, the filter used in the present invention is a porous material, and its materials include fluorine resins such as PTFE (polytetrafluoroethylene), olefin resins such as polyethylene, and vinyl resins such as vinyl chloride. Alternatively, a microporous material such as cellulose may be used.

``The filter is impregnated with an organic extractant capable of extracting the element to be separated, and uses the filter as a boundary membrane,
A mixed solution containing multiple elements is placed on one side, and an extraction solvent is placed on the other side.

To impregnate a filter with an organic extractant: If the extractant is liquid, immerse the filter directly in a solution diluted with an organic solvent, and then reduce the pressure to separate the air inside the filter and the organic extractant. Replace. In this case, it is not necessarily necessary to dilute with an organic solvent.

When the organic extractant is solid, it may be dissolved in a hardly volatile organic solvent, such as decane alone or in a mixed solvent with Ariiso solvent, and impregnated into a filter in the same manner as described above. Thereafter, the filter is removed, the pressure is reduced, and the organic solvent is removed by evaporation. Further, as the extraction solvent used in the present invention, an acid solution or an alkaline solution is appropriately selected and used depending on the element to be separated.

[Function] Among the elements in the mixed solvent, the elements that are selectively extracted by the organic extractant impregnated in the filter are adsorbed by the organic extractant and separated from the mixed solution. It is extracted and separated into an extraction solvent placed on the opposite side.

In this case, the mixed solution can be continuously supplied, and in this case, the specific element in the mixed solution is continuously adsorbed and removed by the organic extractant impregnated in the filter. Furthermore, since the adsorbed elements are continuously extracted and removed into the extraction solvent placed on the opposite side of the filter, specific elements in the subsequent mixed solution can be adsorbed and removed one after another.

The present invention can be used, for example, when removing iron from a mixed solution containing chromium and iron, when removing copper from a mixed solution containing iron and copper, or when removing copper from a mixed solution containing manganese and iron. Separation of various elements can be easily achieved, such as when removing iron from

Furthermore, if an organic extractant is appropriately selected, it is also possible to separate anions. For example, by using trioctyl-methyl-ammonium chloride as an organic extractant, dichromate ions can be removed from a mixed solution containing permanganate ions and dichromate ions.

Furthermore, since the present invention is capable of removing only specific elements, it is possible to remove elements harmful to the purpose of use from a mixture containing a plurality of elements without affecting the content of other elements.

Although the filter described above is formed in the shape of a membrane, in the present invention, the filter may be formed in the shape of a pipe. That is, if the filter is formed into a pipe shape, the mixed solution is conducted inside the filter, and the extraction solvent is placed outside the filter, the probability of contact between the mixed solvent and the organic extractant can be increased. In this case, by flowing the extraction solvent and the mixed liquid in countercurrent flow, fresh extraction solvent is always in contact with the mixed liquid, so that the separation efficiency can be further improved.

[Example] The present invention will be specifically explained below with reference to practical examples, but the present invention is not limited thereto in any way.

(Example 1) PTFE filter pipe (outer diameter 5 mm, inner diameter 4 mm,
A length lm) is impregnated with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester as an organic extractant, and an apparatus as shown in FIG. 1 is assembled.

That is, a 5Mi acid solution is poured into a container 1 as an extraction solvent 2, the filter 3 is immersed in the solution, and a mixed solution containing iron and chromium (p
An acid solution of approx. 2 H) 4) is passed continuously. In this case,
The 5M sulfuric acid solution and filter 3 were kept at about 80°C,
Keep stirring the 5M sulfuric acid solution.

Table 1 (unit: ppm) Fe 500 Cr 500 The components of the purified liquid recovered from the filter 3 are shown in Table 2.

Table 2 (unit: ppm) Fe 1.8 Cr 500 From Tables 1 and 2, more than 99% of the iron in the mixed solution 4 was removed, and most of the removed iron was transferred to the 5M sulfuric acid solution.

On the other hand, chromium was not removed at all and remained as it was in the purified liquid.

(Example 2) PTFE filter pipe (outer diameter 3 mm, inner diameter 2 mm,
A length of 3rn) is impregnated with diphenylcarbazone as an organic extractant together with decane, and an apparatus as shown in FIG. 2 is assembled.

That is, polyethylene pipe (outer diameter 10 mm, inner diameter 8 mm)
mm) 5, the filter pipe 6 is inserted to form a double pipe structure. 6 between pipe 5 and filter pipe 6
M hydrochloric acid was used as the extraction solvent 7, and the extraction solvent 7 was continuously introduced as shown by the arrow in FIG. Solution 8 is passed through continuously.

1l Fe 2100 Mn 7880 Table 3 (Unit: ppm) Ni Co Cr Cu5.4
8. ．． 9 2.1 5.2 The components of the separated liquid recovered from the filter pipe 6 are shown in Table 4.

Table-4 (unit: ppm) Fe Mn Ni Co
Cr Cu2050 7920
5.3 8.8 2, 0 <0
．． From 01 Table-3 and Table-4, Cu in the mixed solution is 90%.
Most of the removed Cu was transferred into the 6M hydrochloric acid solution.

On the other hand, elements other than Cu were not removed at all and remained as they were in the purified liquid.

[Effects of the Invention] As described above, the present invention utilizes an organic extractant. Not only is the dose small and there is no danger in operation, but
It has high elemental separation efficiency and can be processed easily and continuously.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an example of a device for carrying out the present invention;
FIG. 2 is an explanatory diagram of another device. 1: Container, 2, 7: Extraction solvent, 3: Filter 4, 8:
Mixed solution, 5: pipe, 6: filter pipe,

Claims (2)

[Claims] (1) A filter is impregnated with an organic extractant that selectively adsorbs specific elements, a mixed solution containing multiple elements and an extraction solvent are placed through the filter, and the specific elements in the mixed solution are A method for separating elements, which comprises adsorbing the elements to an extractant and extracting and removing the elements into an extraction solvent through a filter. (2) A patent claim characterized in that the filter is formed into a pipe shape, which is immersed in an extraction solvent, and at the same time, a mixed solution containing a plurality of elements is conducted through the pipe-shaped filter. The element separation method according to item 1.