RU2256710C1 - Method of recovering metal ions from aqueous solutions - Google Patents

Abstract

FIELD: hydrometallurgy.

SUBSTANCE: invention relates to recovering metal ions from aqueous solutions with the aid of clay minerals and can find use in nonferrous and ferrous metallurgies as well as in waste water treatment. Essence of invention resides in adding clay materials to solution in question followed by stirring and settling. Recovery of cations is effected at pH 2.6 to 10 over a period of time not exceeding 120 min and recovery of anions at pH 1 to 4 during at most 30 min. Clay minerals utilized are sea-origin hydromicas Irilit-1 and Irilit-7.

EFFECT: enhanced of metal ions recovery efficiency, reduced expenses due to use of non-costly sorbents, and reduced consumption of reagents.

2 cl, 3 tbl, 5 ex

Description

The invention relates to the extraction of heavy metal ions from aqueous solutions of clay minerals irlit-1 and irlit-7 and can be used in non-ferrous, ferrous metallurgy and for the treatment of industrial wastewater.

A known method of sorption extraction of metal ions from solutions with clay minerals, including the preparation of the initial solution and the sorbent, the contact of the solution and the sorbent, the preparation of the initial solution includes the creation of acid-base characteristics of the solution, and the preparation of the sorbent activation in hydrothermal conditions with 10% alkali or acid solutions at a temperature of 105-110 ° C. In this case, the consumption of bentonite clays amounted to 10-20 g / dm ³ [see Proceedings “Kazmekhanobr”, Water circulation, industrial wastewater treatment and tailings management. Alma-Ata, publ. 1983, p. 91-97].

The disadvantages of the method is the high consumption of sorbent and reagents, as well as the extraction of heavy metal ions from slightly concentrated solutions.

Closest to the claimed technical solution is the purification of aqueous solutions of metal ions with bentonite clays, including the introduction of clay materials into the initial solution, followed by stirring and settling [see RF patent No. 2106415, IPC ⁷ C 22 V 3/44, 15/00, 19/00, publ. 03/10/98].

The disadvantages of the prototype are the extraction of metal ions only from slightly concentrated solutions, a significant consumption of reagents due to the regulation of acid-base characteristics of the initial solution and in the process of sorption.

The objective of the invention is to increase the efficiency of extraction of heavy metal ions from aqueous solutions, reducing the cost of the process through the use of readily available and cheap sorbents and reducing the consumption of reagents.

The technical result consists in expanding the range of concentrations of the initial solutions for metal ions.

The technical result is achieved by the fact that in the method for extracting metal ions from their aqueous solutions, including introducing clay materials into the initial solution, sorbing them with stirring and settling, according to the invention, hydromica clays of marine origin, irlite-1 and / or irilite are used as clay materials -7, the extraction of heavy metal cations is carried out at a pH of (2.6 ÷ 10), and the extraction of anions at a pH of (-1 ÷ 4). The extraction of cations is carried out for no more than 120 minutes, and anions - no more than 30 minutes.

This method will improve the efficiency of extraction of metal ions from the initial solutions of a wide range of their concentrations, eliminate the consumption of reagents, reduce the time of the sorption process and use more affordable and cheap sorbents.

Hydromica clays of marine origin, irlit-1 and irlit-7, contain clay minerals - kaolinite, montmorillonite, glauconite, hydromuscovite and non-clay minerals - quartz, feldspars, rutile, phosphorites, carbonates, etc .; oxides of iron, aluminum, silicon, calcium, potassium, magnesium, sodium and organic substances.

The essence of the method is illustrated by: table 1, which presents the results of the extraction of metal ions from solutions of their salts; table 2, which shows the pH values of the aqueous solution obtained by contact of distilled water with irlites with a concentration of 0.5 g / dm ³ , and table 3, which shows the chemical composition of irlites.

Sorption was carried out from aqueous solutions of salts of heavy metals: sulfates, chlorides, nitrates, acetic acids, tungstates, molybdates with an initial solution concentration of up to 1.5 g / dm ³ . For the preparation of initial solutions, salts of the grade hc were used. Irlit-1 and / or irlit-7 were used as a sorbent. The results of the extraction of metal ions from aqueous solutions, shown in table 1, are presented by the pH values of the initial solutions, the distribution coefficient K, defined as the ratio of the metal in the sorbent and in the aqueous phases and the recovery of R.

Extraction of metal cations at pH <2.6 does not occur, and at pH> 10.0 their extraction is significantly impaired.

Examples of specific performance of the method

Example 1 for copper cations using irlite-1. In the initial solution of copper (II) sulfate with a concentration of 0.689 g / dm ³ by copper (II) ion at pH = 6, 2.5 g / dm ^{3 of} irlite-1 was introduced, the solution was stirred for 60 min. In the clarified aqueous phase, the residual concentration of copper (II) ion was determined, which was 0.0001 g / dm ³ , distribution coefficient K = 55120, recovery P = 100%.

Example 2 for anions of tungstate ions (VI) using irlite-1. 5 g / dm ^{3 of} irlite-1 was introduced into the initial solution of sodium tungstate with a concentration of 0.184 g / dm ³ by tungsten (VI) ion at pH = 2, the solution was stirred for 30 minutes. In the clarified aqueous phase, the residual concentration of tungsten (VI) ion was determined, which amounted to 0.024 g / dm ³ , distribution coefficient K = 266.67, recovery P = 86.96%.

Example 3 for lead (II) cations using irlite-7.

5 g / dm ^{3 of} irlite-7 was introduced into the initial solution of lead (II) nitrate with a concentration of 0.570 g / dm ³ by lead (II) ion at pH = 5, the solution was stirred for 30 min. In the clarified aqueous phase, the residual concentration of lead (II) ion was determined, which was 0.365 g / dm ³ , distribution coefficient K = 22.47, recovery P = 35.96%.

Example 4 for anions of tungstate ions (VI) using irlite-7. In the initial solution of sodium tungstate with a concentration of 0.230 g / dm ³ by tungsten (VI) ion at pH = 3, 5 g / dm ^{3 of} irlite-7 was introduced, the solution was stirred for 15 minutes. In the clarified aqueous phase, the residual concentration of tungsten (VI) ion was determined, which was 0.106 g / dm ³ , distribution coefficient K = 46.79, recovery P = 53.91%.

Example 5 for copper (II) cations using irlite-1 and irlite-7. In the initial solution of copper (II) sulfate with a concentration of 1.370 g / dm ³ by copper (II) ion at pH = 4.9, g / dm ³ mixtures of Irlit-1 and Irlit-7 in a ratio of 1: 1 were introduced, the solution was stirred for 120 min . In the clarified aqueous phase, the residual concentration of copper (II) ion was determined, which was 0.554 g / dm ³ , distribution coefficient K = 58.92, recovery P = 59.56%.

Using the proposed invention in comparison with the prototype will allow:

- to extract metal ions from solutions with a wide range of concentrations of metal ions 0.10≥ With _ref ≥ 1.5 g / DM ³ ;

- carry out the extraction of metal ions in a wide range of pH of the initial solutions -1≥ pH≥ 10;

- carry out the sorption process without adjusting the pH of the solution;

- to neutralize acidic and alkaline solutions when using irlit-1 and / or irlit-7.

All this leads to an increase in the efficiency of the extraction of metal ions from aqueous solutions, a reduction in the cost of the process through the use of readily available and cheap sorbent, and a decrease in the consumption of reagents.

The method of extraction of heavy metal ions ...

The pH of the aqueous solution in contact with irlites with a concentration of 0.5 g / DM ³ .

Claims (2)

1. The method of extraction of metal ions from their aqueous solutions, including the introduction of clay materials in the initial solution, their sorption with stirring and sedimentation, characterized in that the clay materials are hydromica clays of marine origin Irlit-1 and / or Irlit-7, extraction cations of heavy metals are carried out at a pH of 2.6-10.0, and the extraction of anions is carried out at a pH of (-1.0 ÷ 4.0). 2. The method according to claim 1, characterized in that the extraction of cations is carried out for no more than 120 minutes, and anions no more than 30 minutes