SU788789A1 - Method of extracting uranium - Google Patents

Abstract

URANIUM EXTRACTION METHOD, from salt solutions such as seawater, including the isolation of uranium on an inorganic material, is characterized in that, in order to increase the degree and selectivity of the extraction of uranium, metallic aluminum l with a specific surface of 1-10 m per 1 is used as the inorganic material gram of material.

Description

The invention relates to the field of chemistry and technology of rare radioactive elements, mainly to the technology of obtaining uranium from seawater.

There is a known method for extracting uranium from seawater, in which seawater is passed through algae that are viable at elevated concentrations of uranium relative to seawater.

A known method for the adsorption of uranium fibrous material coated with polyvinyl alcohol titanate.

The disadvantages of these methods are the length of the process, environmental pollution and the difficulty of applying the method on an industrial scale.

Closest to the present invention is a method for extracting uranium from salt solutions such as marine

f

LO

water, including the release of uranium on the inorganic material.

The disadvantages of this method are the low degree and selectivity of the extraction of uranium.

Vj

The aim of the invention is to improve the degree and selectivity of the extraction of uranium.

This goal is achieved by using metallic aluminum as the inorganic material with a specific surface area of 1-10 m per 1 g of material.

The method is as follows.

Initially, uranium (Vl) in the form of uranyl ions is adsorbed onto an oxide protective film covering aluminum. Thus, near the metal surface, a sufficiently high concentration of uranionions is created. Then, due to the diffusion of oxide film defects (pores, cracks, etc.), uranium (VI) enters the surface of metallic aluminum, where it is electrochemically reduced to a mixture of lower valence oxides that are not soluble in salt solutions such as seawater. This process is commonly called cementation. Kinetically, this process is limited by the stage of diffusion of uranium (vi) into oxide. Therefore, in order to obtain a L. sufficiently high rate of extraction of uranium from solution, it is necessary either to have a material with a large (HQ-less than 1 and / g) specific gravity on the metal, or to change the thickness and defectness of the oxide film by etching it acids or the effects of any mechanical or physical stress (ultrasound, irradiation with heavy particles, etc.). The process described above on metallic aluminum is determined mainly by redox. potential potentials. Therefore, metals that are more electronegative than aluminum (Ca, Mg, Sr, Na, Cs, K, and others) will not be released on aluminum. These metals constitute the main amount of the sorbed metals in the prototype. Therefore, this is proposed. the method is more selective with respect to uranium, since the above metals make up the majority of the metal to be sorbed in the prototype. Example: In a 50 ml flask, 0.1 g of finely chopped aluminum foil with a thickness of 1 mm and a suitable surface are added and 20 ml of a quirbonate-containing uranium solution labeled with uranium 233 with a predetermined specific (X-radioactivity of the solution, Solution composition: Na O, - (8 g-ion / l; K 0.053 g-ion / l, 0.01 g-ion / l,, io | 2, g-ion / l, S0 | - 0.029 gion / l, - Cl 0.56 g-ion / l, C0 | 1x 10 g-ion / l, pH 8.0, The experiment was carried out at room temperature while stirring the solution using a paddle stirrer. After a certain period of time I took samples of the solution (0.025 ml each)to measure the specific C-radioactivity of the solution, which is carried out with the n 9-. instrument power 2) 51-I-IM Prototype. Based on the obtained results, the degree of uranium recovery is calculated by the formula Г „UY. (1, .g / s. L ™ Ae --po ujp - initial concentration of uranium in solution, g / ml; - solution volume, ml; - mass of aluminum foil in the experiment, g;, ria - weight on the surface of aluminum foil,, Ipg and 1p - initial and current specific-radioactivity of the solution, im / (sec. ml), Example2. Under the conditions logical to Example 1, ff was loaded into the flask, 1 g of aluminum powder / specific surface area — 5 w / r, the concentration of uranium and ion carbonate in the solution were respectively i, 06–10 2 and 3,3-Sg— ion / l, pH 8, .2 / Radiometric analysis of the solution showed that after 100 hours the extraction of uranium with aluminum powder reaches l, 50 mg of uranium per 1 g of powder, which corresponds to a value of T 1 μg / cm. Differences in speed; extraction of uranium from sea salt solutions; water with foil, powder, and powdered metallic aluminum is explained by different thicknesses and the degree of defectiveness of the protective oxide film on the metal surface. The results show that if a porous material containing metallic aluminum with a specific material is used to extract uranium. the aluminum surface And 1 then the extraction of uranium will reach at least 10 mg of uranium per 1 g of aluminum, which greatly exceeds the sorption capacity for the uranium of the prototype. In addition, alkaline and alkaline-earth ions will not be absorbed in the process of extracting uranium on metallic aluminum, which increases the selectivity of the proposed method for uranium. Comparative characteristics of the prostate and the proposed method are given in the table.

T

Characteristic

Absorber

Activated carbon impregnated with titanium hydroxide

9

2 101 .0

i:

The proposed method

prototype

Porous material containing metallic aluminum, with a specific surface on the metal l / 1 m / g

1.8-10

0.15 10

Claims (1)

METHOD OF URANIUM EXTRACTION, from salt solutions such as seawater, including the isolation of uranium on an inorganic material, differing by the fact that, in order to increase the degree and selectivity of uranium extraction, metallic aluminum with a specific surface of 1-10 m ^g per 1 gram of material.