RU2430173C1 - Extraction method of niobium (v) from fluorine-containing water solution - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: invention refers to extraction of niobium (V) from water fluorine-containing solution with the use of sorbents and can be used in non-ferrous and ferrous metallurgy, as well as for cleaning of industrial and domestic sewage systems. Method involves sorption by contact of solution and anionite. At that, sorption is performed at pH=1-4 with AM-2b anionite pre-treated with acid or water, and containing the following exchange groups: -CH2-N(CH3)2, -CH2-N(CH3)3. ^ EFFECT: providing optimum conditions for quick and effective extraction method of niobium (V) anions from fluoride-containing water solution. ^ 4 dwg, 2 tbl, 3 ex

Description

The method of sorption of niobium (V) from an aqueous solution relates to the field of extraction of substances using sorbents and can be used in non-ferrous and ferrous metallurgy, as well as for the treatment of industrial and domestic wastes.

It is known to use ion-exchange resins for processing solutions of complex (with HF) niobium anions [R. Ripan and I. Chityanu. Inorganic chemistry. Volume 2. Chemistry of metals. M .: "World". 1972. P.183]. To this end, strongly basic anion exchangers are used, followed by elution of niobium with a solution of NH ₄ Cl and Hcl.

The disadvantage of this method is that the sorption of fluorniobates from aqueous solutions on anion exchangers AM-2b has not been studied.

The closest technical solution is a method for extracting niobium (V) from a fluorine-containing aqueous solution [KB Lebedeva Ionites in non-ferrous metallurgy. M., Metallurgy, 1975, p.186-191], including sorption by contact of the solution and anion exchange resin.

The disadvantage of this method is that the sorption of fluorniobates from fluorine-containing aqueous solutions on anion exchange resin grade AM-2b has not been studied.

The problem to which the claimed invention is directed is to find optimal conditions for a quick and effective method for extracting niobium (V) anions from a fluorine-containing aqueous solution.

The technical result that can be achieved by carrying out the invention is the efficiency of the process of sorption of niobium (V) from an aqueous solution.

This technical result is achieved by the fact that in the known method for extracting niobium (V) from a fluorine-containing aqueous solution, including sorption by contacting the solution and anion exchange resin, sorption is carried out at pH = 1-4, pre-treated with acid or water, anion exchange resin brand AM-2b, containing exchange groups CH ₂ —N (CH ₃ ) ₂ , —CH ₂ —N (CH ₃ ) ₃ .

The essence of the method is illustrated by the data in Tables 1-2 and FIGS. 1-4, where the dependences of the residual concentration of Nb (V), mg / dm ³ , and the sorption exchange capacity (СОЕ) of the sorbent are given, in mg Nb (V) per 1 g of sorbent , from the time of sorption, h, the pH value and the method of pre-treatment of the sorbent.

Examples of specific performance of the method.

Sorption of Nb (V) was carried out from 100 cm ^{3 of the} initial solution of K ₂ NbF ₇ , the mass of the sorbent was 1 g. The sorbent was preliminarily kept at 0.1 N for a day. solutions of NaOH, Hcl or in distilled water.

Mixed basic porous anion exchange resin AM-2b with spherical granules was obtained by amination of a chloromethylated copolymer of styrene and divinylbenzene with a mixture of dimethyl and trimethylamines. It contains exchange groups

.-CH ₂ -N (CH ₃ ) ₂ ,

.

Granule size 0.63-1.6 mm; specific volume of swollen resin 2.7-3.2 cm ³ / g; specific surface area 50-100 m ² / g; total pore volume 0.80-0.87 cm ³ / g, mechanical strength 98-99%; POE 3.3-3.7 mEq / g.

In the process of sorption, mixing and maintaining the set pH value was carried out to a constant SOE value of the sorbent, which indicated the onset of sorption equilibrium.

Sorption was carried out at room temperature.

As the source used solutions of salt K ₂ NbF ₇ . The concentration of niobium ions was determined on a KFK-3 photocolorimeter; the acid-base characteristics of the solution were monitored by a pH-121 pH meter.

Using the values of the concentrations of niobium ions in the aqueous solution of the initial and after sorption, SOE, mg / g was calculated.

Example 1 (Figure 1).

Figure 1 from a solution with an initial concentration of 500-900 mg / DM ³ Nb (V) shows the dependence of SOE, mg / g, sorbent on the pH of the solution and pre-treatment of the sorbent for the interval pH = 1-6.

Studies have established that the best results were obtained at pH = 2-4 and acid treatment of the sorbent (graph 1, sorption time 2 hours, SOE = 75-78 mg / g), as well as at pH = 2-3 and aqueous treatment of the sorbent (graph 2, sorption time 2 hours, SOE = 71-74 mg / g). After 3 hours of sorption, the solution became cloudy, and a day later a precipitate precipitated from the solution. In the case of alkaline treatment of the sorbent, as well as at pH = 5-6 during acidic and aqueous treatment of the sorbent, the solution became cloudy immediately as soon as the contact of the sorbent and the solution arose and a precipitate soon precipitated during sorption. The appearance of turbidity in the solution reduces the results of sorption.

Example 2 (table 1 and figure 2).

The sorbent was preliminarily kept at 0.1 N for a day. HCl solution.

In table 1 and figure 2 shows the results of sorption of Nb (V) ions at pH = 4 within 3 hours of sorption and the initial concentration of the solution 1014-2712 mg / DM. It can be seen that at pH = 4 and acid treatment of the sorbent, the best sorption results were obtained at a sorption time of less than 3 hours, when there was no turbidity of the solution. It was established that the SOE of the sorbent increases with an increase in the concentration of the initial solution, at a concentration of the initial solution of 2712 mg / dm ³ Nb (V) SOE = 148 mg / g.

Example 3 (table 2 and figure 3).

The sorbent was preliminarily kept for one day in distilled water.

In table 2 and figure 3 shows the results of sorption of Nb (V) ions at pH = 3 within 3 hours of sorption and the initial concentration of the solution 1014-2712 mg / DM ³ . It can be seen that at pH = 3 and aqueous treatment of the sorbent, the best sorption results were obtained at a sorption time of less than 3 hours, when there was no turbidity of the solution. It was established that the SOE of the sorbent increases with increasing concentration of the initial solution, so at a concentration of the initial solution of 2712 mg / dm ³ Nb (V) SOE = 128 mg / g.

In Fig. 4, according to the data of Tables 1 and 2 and Figs. 2 and 3, the sorption isotherms are shown — the dependence of SOE, mg / g, sorbent on the equilibrium concentration of the solution, mg / dm ³ Nb (V), when acidic (graph 1) and water (schedule 2) treatment of the sorbent (sorption time 2 hours).

From the data table. 1-2 and figure 1-4 it follows that at room temperature the results of sorption depend on the preliminary processing of the sorbent, the concentration of the initial solution, the pH of the solution during sorption and the time of sorption.

Compared with the prototype, sorption on AM-2b brand anion exchange resin under optimal conditions is a fast and efficient way to extract niobium (V) ions from aqueous solutions.

Claims (1)

A method of extracting niobium (V) from a fluorine-containing aqueous solution, including sorption by contacting the solution and anion exchange resin, characterized in that the sorption is carried out at pH = 1-4 with an AM-2b anion exchange resin pre-treated with acid or water containing exchange groups:
-CH ₂ -N (CH ₃ ) ₂ , CH ₂ -N (CH ₃ ) ₃ .

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