DD286747A5 - PROCESS FOR EXTRACTION OF COPPER FROM WAESSREN SOLUTIONS - Google Patents

Abstract

The invention relates to a process for the extraction of copper from aqueous solutions and is used in the processing or purification of aqueous solutions containing copper salts. The invention is based on the technical object to develop, starting from technically easily accessible a-Hydroxyiminoketonen novel extractant for the extraction of copper from aqueous solutions. According to the invention, the technical problem is solved by using the extractant * of the general formula. Formula {extraction; Copper; Hydrometallurgy; selective extractant; * *}

Description

R = H, hydroxy, alkyl, alkoxy, nitro R ¹ = phenyl, alkylphenyl, alkyl R ² = alkyl, phenyl

X = N, N ⁺ -O- -OH

be used. As is technically customary, the metal salt solution is contacted with the solution of the 2- (2'-hydroxyaryl) oxazole derivative in an organic solvent, the two phases are subsequently separated and the organic phase is subjected to back extraction with dilute mineral acid.

2- (2'-hydroxyaryl) oxazole N-oxides {X = N ⁺ -O ") are in the reaction of a-hydroxyiminoketonen with a 2-hydroxyarylaldehyde in an equimolar ratio in a suitable solvent, preferably glacial acetic acid, in G: The a-Hydroxyiminoketone can be used in the form of isolated pure products, but also in the form of the product mixtures of the a-oximation (isonitrosation) of phenylalkyl ketones or nuclear-substituted phenylalkyl ketones For example, the product mixtures or the isolated a-Hydroxyiminoketone from the implementation of ketones such as phenylethyl ketone, phenylpropyl ketone or 4-Methylphenylperitylketon etc. are used with alkyl nitrites in the presence of HCl or with other Oximierungsregenzien.As aldehydes are 2-hydroxy-substituted aromatic aldehydes, such as For example, salicylaldehyde (2-hydroxybenzaldehyde), o-vanillin (2-hydroxy-3-methoxybenzaldehyde) and others orteilhafterweise used in the form of HCI gas. The reaction is carried out at room temperature, wherein in the reaction solution with stirring HCl gas is introduced to saturation and the reaction mixture is then allowed to stand. It turned out to be favorable after 6-8 hours, even with partial precipitation, again briefly initiate HCL gas. Part of the 2- (2'-hydroxyaryl) -oxazole-N-oxide precipitates out of the reaction mixture as a solid after just a short time. Further target product is obtained by diluting the reaction solution with water or by neutralization of the reaction solution. The crude product thus obtained is purified by recrystallization.

The 2- (2'-hydroxyaryl) -oxazole N-oxides can be converted by reduction into the corresponding 2- (2'-hydroxyaryl) -oxazoles. The 2- (2'-hydroxyaryl) -oxazole N-oxides in the form of the purified compound or preferably as a crude product with the system Zn / glacial acetic acid (acetic acid) are reduced at room temperature to 100 ° C. The reduction can also be done with other conventional reduction systems. After separation of the inorganic constituents, the reaction mixture is diluted with water and the resulting 2- (2'-hydroxyaryl) -oxazole is purified by recrystallization. The 2- (2'-hydroxyaryl) -oxazoles have a slightly better solubility than the corresponding 2- (2'-hydroxyaryl) -oxazole-N-oxides in common organic solvents, such as benzene, Tcluen and chloroform on. The 2- (2'-hydroxyaryl) -oxaol derivatives prepared by the process of the invention are well suited for the liquid-liquid extraction of the 3d metals, in particular copper. They show z. B. in the pH range of 4-6.5 a strong selectivity of extraction for copper over cobalt, nickel and zinc.

Ausführungsbeisplel

Dio invention will be explained in more detail with reference to 5 examples. Dio physical data of selected 2- (2'-hydroxyphenyl) oxazoloerivatives9 are summarized in Table 1.

example 1

2- (2 '· ΗγαΓθχνρηβηνΙ) -4-βΐηγΙ-5-ρηοηγΙοχ3ζοί-Ν-οχϊα (Compound 3 in Table 1) is prepared by equimolar amounts of 1-phenylbutene-1,2-dione-2-oxime and salicylaldehyde ii Glacial acetic acid is dissolved (per 0.1 mol of a-Hydroxyiminokcton 150 ml of glacial acetic acid) and then the solution is saturated with HCl gas. After 8 hours, HCI gas is introduced again and after 24 hours, the precipitated product is filtered off with suction. Neutralization of the reaction solution gives further product, which is purified by recrystallization from methanol. Analytically pure 2- (2'-hydroxyphenyl) -4-ethyl-5-phenyl-oxazole N-oxide is in a yield of 45% d. Th. And has a melting point of 109-111 ⁰ C.

Example 2

.V (2'-Hydroxyphenyl) -4-methyl-5-phenyl-oxazole (Compound 6 in Table 1) is prepared by dissolving equimolar amounts of 1-phenylpropane-1,2-dione-2-oxime and salicylaldehyde in glacial acetic acid (per 0.1 mol of a-Hydroxyiminoketon 150ml glacial acetic acid) and then the solution is saturated with HCl gas. After 8 hours, HCl gas is introduced again and, after 24 hours, 33 g of Zn dust are added in portions to the reaction mixture per 0.1 mol of monoxime. The reaction mixture is left until the decaying Hj development at room temperature and then heated to boiling temperature for 30 minutes. The solution is then filtered hot and the filtrate is neutralized after cooling with aqueous ammonia. The precipitated solid is recrystallized from ethanol. Based on the used a-Hydroxyiminoketon was 2- (2'-hydroxyphenyl) -4-methyl-5-phenyl-oxazole in a yield of 62% d. Th. (Mp 115 ⁰ C).

Example 3

2- {2'-Hydroxypienienyl) -4-methyl-5- (4'-methylphenyl) -oxazole {Compound 8 in Table 1) was obtained by reacting 0.1 mol of 2- (2'-hydroxyphenyl) -4 Methyl-5- (4'-methylphenyl) -oxazole-N-oxide golöst in 10OmI glacial acetic acid and the solution is slowly added with 33g Zn dust. After the evolution of hydrogen at room temperature has subsided, the mixture is heated for 30 minutes to the boiling point of the solvent, then filtered while hot, and the filtrate is diluted with water until no more solid precipitates. The precipitated crude product is recrystallized from methanol. Analytically pure 2- (2'-hydroxyphenyl) -4-methyl-5- (4'-methylphenyl) oxazole is obtained in a yield of 80% of theory with a melting point of 133-136 ° C.

Example 4

A synthetic mixture of copper, cobalt, nickel and zinc sulfate having a total concentration of 0.002 M, at a single concentration of each metal salt of 0.0005 M each, is mixed with a 0.0005 M solution of 2- (2'-hydroxyphenyl) 4-methyl-5-phenyl-oxazole-N-oxide in chloroform in the phase ratio V _w / V ₀ = extracted 1/1. At pH = 6.0, Cu is converted to 85% and Ni, Co, Zn <5% into the organic phase.

Example 5 A synthetic mixture νυη copper, cobalt, nickel and zinc sulfate with a total concentration of 0,002M, at a Each metal salt of each 0.0005M is concentrated with a 0.0005 M solution of 2- (2'-hydroxyphenyl) -4-methyl-

5-phenyl-oxazole in chloroform in the phase ratio Vyu / Vo = extracted 1/1. At pH = 6.16Cu, it becomes quantitative,

Zn <10%, Ni and Co <57o converted into the organic phase.

Table 1: 2- (2'-Hydroxyaryl) oxazole derivatives

Ser. X R R ' R ' yield Fp ( ⁰ C) No. (%) (Umkrist.-m.) 1 NMT H Ma Ph 80 136-139 (MeOH) 2 NMD " H Ph me 46 129-130 (MeOH) 3 NMJ- H Ph et 45 109-111 (MeOH) 4 NM) " H 4-MeC ₆ H ₁ me 45 167-169 (MOOH) 5 NMD " 5-NO ₃ Ph me 42 199-201 (EtOAc) 6 N H Ph me 62 115 (EtOH) 7 N H Ph et 66 77-78 (EtOH) 8th N H 4-MeC ₆ H ₄ me 67 135-137 (EtOH)

7Η6747

OH

R ¹ R ² Σ

H, hydroxy, alkyl, alkoxy, hi tr ο phenyl, alkylphenyl, alkyl alkyl, N, N ⁺ -O "

Claims (1)

Process for the extraction of copper from aqueous solutions, the aqueous solution being treated with a solution of an extra! In an organic solvent is contacted, both phases are separated and then subjected to the organic phase of the Rückextraktion, characterized in that as extracting agent 2- (2'-hydroxyaryl) -oxazolderivate the general formula With R = H, hydroxy, alkyl, alkoxy, nitro R ¹ = phenyl, alkylphenyl, alkyl R ² = alkyl, phenyl X = N, N ⁺ -O " R
be used. Field of application of the invention The invention relates to a process for the extraction of copper from aqueous solutions and is used in the workup or purification of copper salts containing aqueous solutions application. Characteristic of the known state of the art For the extraction of copper from aqueous metal salt solutions, various methods are known that the Nachtei! have that the production of the extraction agent used is associated with high economic cost. Applied are excipients of the LIX series (US Pat. No. 3,655,347, US Pat. No. 3,224,873) and the Kelex series (US Pat. No. 3,637,711, US Pat. No. 3,721,046). Some other substances such as 2- (2'-hydroxyphenyl) benzimidazoles, 2- (2'-hydroxyphenyl) benzoxazoles, 2 (2'-hydroxyphenyl) -1,3-diaza-cycloalk-2-enes are proposed for use (US Pat. PS 3637476, US-PS 3843887, DE-OS 2703593, DD-PS 155295, DD-PS 155296). In particular, such reaction steps as the rearrangement under the action of aluminum chloride and the complete oximation of ketones are difficult to control in the synthesis of LlX compounds. The Kelex compounds require for their preparation numerous, sometimes not easy to perform precursor steps. The preparation of the other proposed Extragenzien is technically and economically complex. Object of the invention The aim of the invention is, by using easy to produce and therefore cheaper Extrak! ^: onsmittol for copper to reduce the expense of liquid-liquid extraction of copper from aqueous solutions. Explanation of the essence of the invention The invention is based on the technical object, starting from technically easily accessible a-Hydroxyiminoketonen neuartigo extraction agent for the extraction of copper bus aqueous solutions to develop. According to the invention the technical object is achieved in that as extractant 2- (2'-hydroxyaryl) -oxazolderivate the general formula