RU2426599C2 - Method of extracting samarium and europium ions via ionic floatation using sodium dodecylsulphate - Google Patents

Abstract

FIELD: chemistry. ^ SUBSTANCE: invention can be used in chemical industry. Samarium and europium ions are extracted through ionic floatation with sodium dodecylsulphate, taken in ratio of 1:3 according to the stoichiometric equation Me3+ + 3C12H25OSO3Çè- = Me(C12H25OSO3)3, where Me is a samarium or europium cation, C12H25OSO3 is the dodecylsulphate ion. ^ EFFECT: invention enables to achieve 99,9% extraction of samarium and europium ions. ^ 3 dwg, 1 tbl

Description

The invention relates to methods for producing rare earth metals (REM) or their oxides from poor or man-made materials using the ion flotation method. There is a method for extracting samarium and europium cations, such as ion flotation: in a review of the Adsorptive Bubble Separation techniques // Ed. by R. Lemlich, Academic Press, N.Y., London, 1972, 344 p. first mentioned is the flotation process of samarium ions using dodecylbenzyldiethylenetriamine tetraacetic acid as the sodium salt collector. Flotation recovery in this case was 98%. Europium ions with a stock content of 110 to 210 mg / L were recovered using cetylpyridinium bromide. The recovery was 96%. In addition, there is a method for the extraction of silver, zinc, lead, nickel and platinum ions by ion flotation using isopropylmethyl ethyl thiocarbamate as a collector (Authors: Tall A.B. and Sheldon G.P., Patent No. WO 2008019451).

Copper cations were extracted from aqueous solutions using cationic reagents - formula R ₄ NX (where R ⁺ are the radicals of cationic surfactants, X ^- are halogen ions) (Authors: Engel MD, Moxon NT, Nicol SK патент WO 9217614). The cations of zinc, copper, magnesium by ion flotation method were extracted from aqueous solutions using RX as a collector (R is an organic radical C ₁ -C ₄ , X are phosphonates or sulfonates). (Authors: Viljoen DM, Lubbe LE, Patent No. WO 2007086003).

A feature of the proposed flotation method is the use of sodium dodecyl sulfate as a flotation reagent. There are a number of works in the literature on flotation processes of samarium and europium ions, for example, it is known to use sodium dodecyl sulfate in the process of ion flotation as a collector for the extraction of metals such as copper, cobalt, nickel (Skrylev L.D., Borisov A.V. flotation separation of copper and nickel from wastewater of the Norilsk Mining and Metallurgical Combine // Journal of Applied Chemistry. 1978, Vol. 51, No. 2, p. 344-436).

The technical result of the invention is to increase the extraction of cations of samarium and europium from aqueous solutions by ion flotation. The technical result is achieved by the fact that in the method for the extraction of samarium and europium ions by ion flotation using sodium dodecyl sulfate (NaDS) according to the invention, NaDS is used as a collector in a concentration in the ratio of 1: 3 according to the stoichiometric scheme:

Me ³⁺ + 3C ₁₂ H ₂₅ OSO ₃ ^- = Me (C ₁₂ H ₂₅ OSO ₃ ) ₃ ,

where Me ³⁺ is a samarium or europium cation, C ₁₂ H ₂₅ OSO ₃ ^- is a dodecyl sulfate ion.

The REM extraction parameter is the distribution coefficient K. The K value of the extracted ion between the aqueous and organic phases was calculated by the ratio of the concentration of [Me ³⁺ ] (Sm ³⁺ or Eu ³⁺ ) in the foam to the concentration of [Me ³⁺ ] in the chamber residue according to the formula: K = [Me ³⁺ ] _org / [Me ³⁺ ] _aq (FIG. 1 and FIG. 2).

The dependence of the distribution coefficient of rare-earth metals (REM) between the aqueous and organic phases on the pH of the solution is established in order to find the conditions for the most complete separation of REM of samarium (+3) and europium (+3). As model we used aqueous solutions of samarium (III) and europium (III) nitrates with a concentration of 0.001 mol · l ^-1 ; as a surfactant, sodium dodecyl sulfate, the concentration of which corresponded to the stoichiometry of the reaction. Data on the distribution coefficient in solutions containing NaDS and REM are presented in Table 1.

The ion flotation process was carried out in a high-performance apparatus - a laboratory flotation machine of mechanical type 137 V-FL, with a chamber volume of 1.0 dm ³ , requiring a small amount of production space.

In solution, rare-earth metal ions form strong complexes with surfactants, which, due to the hydrophobicity of alkyl radicals, pass into the foam phase. The destruction of the selected foam was carried out by adding 5 ml of a solution of sulfuric acid with a concentration of 1 mol · l ^-1 . The resulting solution (foam product) and the solution remaining in the cuvette after flotation (chamber residue) were analyzed for the content of the rare-earth element. Extraction of samarium and europium ions by ion flotation using NaDS as a collector reaches 99.9%.

Table 1 pH [Sm ³⁺ ] in the foam, mol · l ^-1 [Sm ³⁺ ] in the chamber residue, mol · L ^-1 TO [Eu ³⁺ ] in the foam, mol · L ^-1 [Eu ³⁺ ] in the chamber residue, mol · L ^-1 TO 3.0 0,00203 0,000236 8.6 0.00228 0,000288 7.9 3,5 0,00186 0.000139 13,4 0,00186 0,000236 7.9 4.0 0,00184 0.000130 14.0 0.00110 0,000218 5,0 4.9 0,00197 0,000171 11.5 0,00183 0.000179 8.2 5.5 0,00223 0,000183 12.1 0.00177 0.000179 9.8 6.1 0,00198 0.000131 15.1 0,00174 0.000105 16.6 6.7 0.00190 0,000023 81.9 0,00229 0.000011 204.0 7.0 0,00153 0.000019 81.5 0,00173 0.000008 208.9 7.9 0.00125 0.000015 81.6 0,00165 0.000009 182.6

Claims (1)

The method of extraction of samarium and europium ions by ion flotation using a surfactant sodium dodecyl sulfate, characterized in that sodium dodecyl sulfate is used as a collector in a concentration of 1: 3 in a stoichiometric scheme:
Me ³⁺ + 3C ₁₂ H ₂₅ OSO ₃ ^- = Me (C ₁₂ H ₂₅ OSO ₃ ) ₃ ,
where Me is the cation of samarium or europium, C ₁₂ H ₂₅ OSO ₃ is the dodecyl sulfate ion.

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