SU967547A1 - Method of extracting ittrium off aqueous solutions - Google Patents

Description

(5) METHOD FOR EXTRACTING YTTRIUM FROM AQUEOUS SOLUTIONS

one

The invention relates to processes for the isolation of yttrium from aqueous solutions by sorption of salts of heteropoly acids and can be used in the purification of mock water, in chemical analysis, as well as in the processing of yttrium-containing solutions of chemical and radiochemical industries.

A known method for the concentration of yttria, based on the use of ammonium salts of 12-molybdophosphoric and 12-tungstophosphoric acids 1.

However, the known recovery method has been developed with reference to the concentration of trace amounts of yttrium.

The closest in technical essence and the achieved result to the invention is the method of yttrium recovery from aqueous solutions by interaction with ammonium 12-molybdophosphate.

The method is carried out as follows.

A known weight (0.25 g) of ammonium 12-molybdophosphate precipitate is brought into contact with 15 ml of 0.1 N. HNMO solution containing 10 g of yttrium and 250 mg of sodium acetate. The solution in contact with the precipitate is held until the sorption equilibrium is established. Sediment with sorbed yttrium

10 is separated from the solution by settling or filtering. Yttrium is sorbed at pH 2-2.

Applying a known method of extracting yttrium using

15 Ammonium 12-molybdophosphate is not effective enough and is limited to a narrow acidic pH range of the solution. The maximum Kd value, equal to 1-4, was obtained at pH 3 ,. In more alkaline

20 environment yttri extraction drops sharply

Claims (2)

According to a known method for the concentration of yttrium, the sorption of the element is carried out in the presence of sodium acetate. Otherwise, when yttrium is concentrated from solutions, the acidity of the aqueous phase after the sorption process decreases to pH 1.0, where yttrium is not sorbed. Sodium acetate, acting as a buffer here, allows the required acidity of the aqueous phase to be maintained during sorption. All this prevents the introduction of a known method into chemical practice. The aim of the invention is to increase the recovery rate. This goal is achieved by the fact that according to the method of extracting yttrium from aqueous solutions by reacting yttrium with 12-molybdophosphate alkyltrimethylammonium and the process is carried out at pH k-6. The essence of the invention consists in the use of alkyltrimethylammonium 12-molybdophosphate as a sorbent in the proposed method. The sorbent is obtained directly in the process of yttrium extraction by reacting 12-molybdophosphoric acid H -), PMO., A stoichiometric amount of cationic surface-active quaternary ammonium salt (alkyltrimethylammonium chloride R (CHvlN x X Ct, where.,; N 10-16). Method carried out by the following procedure, 12-molybdophosphoric acid, an alkali to establish a pH of k-6 and a stoichiometric amount of alkyltrimethylammonium chloride are introduced into the yttrium-containing solution. As a result of the reaction G to (cn) Njc |; R solution drops out a solution The precipitate is 12-molybdophosphate alkyltrime tylammonium, which absorbs yttrium. The precipitate is kept in contact with the mother liquor for 24 hours, after which the solid phase is separated from the solution by settling or filtration. The maximum sorption properties of the precipitates formed by the interaction of H-PMO 0. with alkyltrimethylammonium chloride, corresponds to a pH value of 4 to 6.8, the value of which is greater. With a higher acidity of the aqueous phase, the competing influence of hydrogen ions occurs, as a result of which the Kd value drops sharply. Since at pH 2.0 the yttrium recovery is practically absent. At, 0, the complex anion of the heteropoly acid under the action of alkali decomposes into complexes with a lower degree of saturation with molybdenum (P0 (.o ()) Example: To 100 ml of an aqueous solution with an yttrium concentration of 10 mg / l dob, c / 1 and 1 ml of a 0.005 M solution of HjPMo, tO /; the solution was adjusted to pH 5.0 by the addition of 0.1 n-NaOH solution and 0.5 ml of a 0.04 M Lc solution (CHj) NJCr was added (mol.m. 235, 5 g. The precipitate formed is kept in contact with the solution for 2k hours, after which the clarified part of the solution is analyzed for yttrium. The distribution coefficient of yttrium between the precipitate and the solution is 1 , 85. EXAMPLE 2. To 100 ml of an aqueous solution with a yttrium concentration of 10 mg / l, add 1 ml of a 0.005 M solution of Ho, PM9 |, j 04 (. (Mol. 1826 g, adjust pH a solution up to 5.0 by adding 0.1 n NaOH solution and injecting 0.5 ml of 0, M solution of CCtjHn ((mol.m., 277.5 g). The formed precipitate is kept in contact with the solution for 24 hours, then the clarified part of the solution is analyzed for yttrium. The Kd of yttrium between the precipitate and the solution is 03-10. An example of an aqueous solution with a yttrium concentration of 10 mg / l is added 1 ml of a 0.005 M solution of 2 0. (mol.m. 1826 g}, the pH of the solution is adjusted to 5.0 by the addition of 0.1 n NaOH solution and 0 , 5 ml of 0.04 M solution) NjCl (mol.m. 319.5 g). The precipitate formed is kept in contact with the solution for 24 hours, after which the clarified part of the solution is analyzed for yttrium. The kd of yttrium between the precipitate and the solution is 1.10 Y. PRI me R 4. To 100 ml of an aqueous solution with a concentration of yttrium 10 mg / l is added with 1 ml of a 0.005 M solution of a drop of 0.1 n. NaOH solution to establish a pH of 4.0-6.0 and 0.5 ml of a 0.04 m solution of R (CH5) N3Cb where R C, H, .j, p 10-16. The precipitate formed is kept in contact with the solution for 24 hours, after which the clarified part of the solution is analyzed for yttrium. The yttrium distribution coefficient between the precipitate and the solution in these conditions is equal. As a precipitant 12-molybdo. The phosphoric acid in the example uses a surfactant, alkyltrimemethylammonium chloride (CK7) 1, M2 n 10-16. The drug is a mixture of homologues with a hydrocarbon chain length of 10 to 16 carbon atoms. The average molecular weight of the preparation is 278 g. The substance is produced with the addition of anhydrous solvents (isopropyl or ethyl alcohols), which dissolve surfactants well. Thus, the distribution coefficient of yttrium at an initial concentration in a solution of 10 mg / l is 10, respectively, the recovery rate is higher than in the known method. DETAILED DESCRIPTION OF THE INVENTION Method for recovering yttrium from aqueous solutions by reacting yttrium with 12-molybdophosphoric acid ammonium salt followed by separation of the solid and liquid phases formed, characterized in that, in order to increase the recovery, 12-molybdophosphate is used as the ammonium salt of 12-molybdophosphoric acid alkyltrimethylammonium and the process is carried out at a pH of C-6. Sources of information taken into account in the examination 1.Surgutsky V.P., Serebrennikov V.V. About the new heteropolycryne-spherical-molybdenum ion exchanger and the separation of rare-earth elements on it / Proceedings of Tomsk University. 19bZ, t.157. with. 29-31. 2.Si.tit a. Van R., Robb W. I. I norg Nucl. Chem., 196, 26, f, p. 509-518.