RU2291908C1 - Method for extraction recovery of palladium from acid solutions - Google Patents

Abstract

FIELD: hydrometallurgy of non-ferrous and precious metals, in particular, extraction recovery of palladium from acid solutions.

SUBSTANCE: method involves using extractant such as mixture of following components, % by volume: 10-15% of 5-(1,1,3,3-tetramethyl butyl)-2-oxybenzophenonoxime; 4-7% of trialkyl amine (C₇H₁₅-C₉H₁₉)₃N; 8-10% of isooctyl alcohol in organic solvent. Utilization of the given extractant provides for an increase in extraction recovery of palladium from concentrated acid solutions (up to 8 mol/l of HCl and 6 mol/l of NNO₃) of up to 97.0-99.9% and increase in metal capacity of organic phase (up to 10 h/l). Extractant is preferably used for extraction recovery of palladium from solutions having increased acidity and high initial metal content.

EFFECT: increased efficiency in extraction recovery of palladium from acid solutions within wide range of acidity values and increased metal capacity of extractant.

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Description

The invention relates to the field of hydrometallurgy of non-ferrous and noble metals, in particular, to the extraction of palladium from acidic solutions by extraction.

A known method of extracting palladium from hydrochloric acid solutions by extraction with tri-n-octylamine [Kawano Y., Osada S., Shiomori K., Baba Y., Kondo K., Yoshizawa H., Hatate Y. Distribution equilibrium of palladium between hydrochloric acid solution and tri-n-octylamine in toluene. J. Chem. Engineering of Japan. 1995. V.28. No. 2. P.227-230]. The disadvantage of this method is that the quantitative extraction of palladium (> 95%) occurs in a narrow range of acidity of the initial aqueous phase, mainly from weakly acidic media (With _HCl <1 mol / l), whereas in the palladium technology, as a rule, concentrated acidic solutions.

There are methods for the extraction of palladium from nitric and hydrochloric acid solutions using reagents of the class of oxy oximes: alkylbenzophenonoxime (ABP), LIX 64N, Acorga P5000 [Buslaeva TM, Travkin VF, Kravchenko VV, Zaitseva M .G. Extraction of palladium (II) with hydroxy oximes. Izv. Universities. Non-ferrous metallurgy. 1994. No. 1-2. S.10-14].

Known extraction method for the extraction of palladium using also a reagent of the class of oxyoximes - LIX 65N [Ying-Chu Hoh, Wen-Shou Chuang, Peng-Shiung Yueh. Fundamental aspects of the extraction and stripping of palladium by LIX 65N. J. Chem. Tech. Biotechnol. 1984. V.34A. P.97-102].

Although these reagents make it possible to isolate metal from solutions with an acid concentration higher than 1 mol / L, the degree of extraction substantially depends on the acidity of the initial solution and is not high enough to be used to isolate palladium from strongly acidic solutions. In addition, these reagents are characterized by a low rate of transition of palladium to the organic phase and a low metal phase capacity of the organic phase.

Closest to the claimed is a method of extracting palladium from acidic aqueous solutions with a mixture containing alkylbenzophenonoxime (ABP) and alkylbenzophenone (2-hydroxy-5-isooctylbenzophenone) in an organic diluent (kerosene) with a ratio of the components of alkylbenzophenone oxime: alkylbenzene 0 = 0: 0.01ben 3 [Buslaeva T. M., Travkin V. F., Koteneva N. A., Kravchenko V. V., Zaitseva M. G. The method of extraction of palladium from solutions. RF patent №2090632, cl. With 22 V 3/30. 1994].

The main extraction component of this mixture is ABP, which is characterized by a low capacity of the organic phase in the metal (not exceeding 2 g / l) and suppression of metal extraction with increasing acidity of the aqueous phase. The addition of alkylbenzophenone in this mixture allows one to increase the rate of transition of palladium to the organic phase, but practically does not affect the rate of palladium recovery. Thus, this method has the following disadvantages:

- the use of this mixture does not allow to achieve high rates of palladium recovery with increased acidity;

- the mixture has a relatively low capacity of the organic phase for metal, not exceeding 1.5-2.0 g / l.

The technical result of the present invention is to increase the degree of extraction of palladium from hydrochloric acid and nitric acid solutions in a wide range of acidity (0.5-8 mol / L HCl; 0.5-6 mol / L HNO ₃ ), increase the capacity of the extractant on the metal .

This technical result is achieved by the fact that palladium is extracted with a mixture of reagents of the following composition: 10-15% ABP + 4-7% TAA + 8-10% IOS (concentration is given in vol.%) In kerosene, where ABP is 5- (1, 1,3,3-tetramethylbutyl) -2-hydroxybenzophenonoxime; TAA - trialkylamine ((C ₇ H ₁₅ -C ₉ H ₁₉ ) ₃ N); IOS - isooctyl alcohol. The addition of isooctyl alcohol is necessary to prevent the formation of a third phase during extraction.

The phase ratio during extraction is 1: 1, the contact time is 4-6 minutes, room temperature. The acidity of the aqueous phases ranged from 0.5-8 mol / L hydrochloric acid; 0.5-6 mol / L nitric acid. The concentration of palladium was 0.2-15 g / L.

A distinctive feature of the method is that, in addition to the main component of ABP, the composition of the extraction mixture includes TAA, as a result of which the metal is effectively extracted by extraction from nitric and hydrochloric acid solutions (E≥97%) in a wide range of acidity (up to 6-8 mol / l).

The following are examples of the method.

Example 1

Aqueous acidic solutions with a palladium concentration of 0.2 g / l and various concentrations of hydrochloric and nitric acids (from 0.5 to 8 mol / l) are treated with a mixture of 10% ABP + 5% TAA + 9% IOS (concentration is given in vol.% ) in kerosene. For comparison, data were obtained on the recovery of palladium using identical conditions 10% ABP and 2% 2-hydroxy-5-isooctylbenzophenone (concentration is given in vol.%) In kerosene, which corresponds to the ratio of ABP: alkylbenzophenone = 1: 0.1. The experimental results are shown in the table.

Table The dependence of the extraction of palladium from acidic solutions on the acidity of the initial aqueous phase source palladium recovery,% hydrochloric acid concentration, mol / l nitric acid concentration, mol / l 0.5 1,0 2.0 5,0 8.0 0.5 1,0 2.0 4.0 6.0 prototype 99.7 87.7 83.9 63.0 61.5 99.8 98.1 95.0 75.8 70,2 mixture 99.9 98.8 99.9 98.9 99.8 97.5 98.3 97.5 98.2 97.0

From the data obtained, it can be seen that when using a mixture of reagents as an extractant, the extraction of palladium is little dependent on the acidity of the solution and remains almost constant at the level of 99.0 ± 1.0% for hydrochloric acid solutions and 98.0 ± 1.0% for for nitric acid solutions. When used for extraction of the mixture proposed in the prototype, the recovery of palladium drops from 99.7% to 61.5% (from hydrochloric acid solutions) and from 99.8% to 70.2% (from nitric acid solutions).

Example 2

Palladium is extracted from 0.1 mol / L hydrochloric acid solutions with various palladium concentrations from 0.2 g / L to 15 g / L. A mixture of 10% ABP + 5% TAA + 9% IOS (concentration is given in vol.%) In kerosene is used as an extractant. Under these conditions, the organic phase is saturated with a metal at a palladium concentration in the initial solution above 10 g / l. For comparison, data were obtained on the recovery of palladium using, under identical conditions, a mixture of 10% ABP and 2% 2-hydroxy-5-isooctylbenzophenone (concentration is given in vol.%) In kerosene - saturation occurs already at a palladium concentration <1.0 g / l Thus, the mixture allows the metal to be extracted from palladium-concentrated solutions with initial concentrations of up to 10 g / l.

Thus, the application of the method provides an increase in the extraction of palladium from concentrated acidic solutions to 97.0-99.9% and an increase in the capacity of the organic phase in the metal (up to 10 g / l), which makes this mixture suitable for the extraction of palladium from solutions with high acidity and high initial metal content.

Claims (1)

A method of extracting palladium from acidic solutions, including extraction with a solution of an organic extractant based on alkylbenzophenone oxime in an organic solvent, characterized in that the extractant is a mixture consisting of 5- (1,1,3,3-tetramethylbutyl) -2-hydroxybenzophenone oxime, trialkylamine and isotropic alcohol, in the following ratio of components, in vol.%: 5- (1,1,3,3-tetramethylbutyl) -2-hydroxybenzophenonoxime 10 ÷ 15 Trialkylamine 4 ÷ 7 Isooctyl alcohol 8 ÷ 10 Organic solvent Up to 100