JP2016108624A - Extractant with high selectivity of gold, extraction method or recovery method of gold using the extractant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extraction method and a recovery method capable of extracting gold with one step and high selectivity and without needs for a specific post treatment process of a water phase using a back extraction.SOLUTION: The invention relates to an extractant of gold containing a compound represented by the formula (I): ROH, where Ris a linear or branched alkyl group or alkenyl group having 6 to 20 carbon atoms or a compound represented by the formula (II):ROH(OH), where Ris a linear or branched bivalent saturated hydrocarbon group having 4 to 13 carbon atoms as an essential component.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a highly selective extractant for gold and a method for extracting or recovering gold using the extractant.

  In the electronic industry, wastes, automobile waste catalysts, plating waste liquids, etc. discharged in the manufacturing process of electronic materials contain trace amounts of noble metals. Conventionally, typical industrial extractants used for recovering noble metals from these wastes are sulfides such as dihexyl sulfide (DHS) and dioctyl sulfide (DOS) having sulfur as a coordination atom, , Hydroxyoximes represented by the LIX series and P series. Among these, sulfides are mainly used for recovering gold. However, since sulfides extract gold and palladium at the same time, a step for separating palladium and gold is required.

  Moreover, although dibutyl carbitol may be used as a gold selective extractant, the selectivity for gold is not necessarily high. Therefore, when dibutyl carbitol is used as a gold extractant, by performing a scrubbing step after extraction, metals other than the co-extracted gold are removed by back extraction, so that only gold remains in the organic phase. Need to be processed.

  As described above, the existing extractant cannot selectively extract and recover only gold from a mixture of noble metals in one step.

  In addition, when sulfides are used as an industrial extractant for a long period of time, sulfur atoms in sulfides undergo oxidation with a reagent or air oxidation to become sulfoxide, which causes a problem in that extraction selectivity is lowered. Therefore, sulfides cannot be used in an oxidizing solution.

  Furthermore, the gold extracted into the organic phase by sulfides is back-extracted to the aqueous solution side by the back extractant, and the back extractant used at this time is ammonia, thiourea, (hydrochloric acid + thiourea) solution, etc. For this reason, the use of conventional sulfide extractants is problematic. This is because these back-extracting agents require post-treatment, which complicates the entire treatment process.

  The following documents are disclosed as prior art documents related to the present invention.

JP-A-9-316561 JP-A-10-130744 JP-A-11-335749 JP 2001-316736 A JP-T-2005-523992

  An object of the present invention is to provide a gold extraction method and a recovery method that can extract gold with high selectivity in one stage and that do not require a special post-treatment step of an aqueous phase used for back extraction. And

The present invention includes the following inventions.
(1) Formula (I): R ¹ OH [wherein R ¹ is a linear or branched alkyl group or alkenyl group having 6 to 20 carbon atoms]; and Formula (II) ): R ² OH (OH) [wherein R ² is a linear or branched divalent saturated hydrocarbon group having 4 to 13 carbon atoms] Gold extractant with seed as active ingredient.
(2) A method for extracting gold, wherein gold is extracted from an aqueous solution containing gold using the extractant according to (1).
(3) Extracting gold from an aqueous solution containing gold using the extractant according to (1), and then back-extracting gold from the organic phase containing gold and the extractant using water. How to collect gold.

  According to the present invention, gold can be extracted with high selectivity from a solution containing various metals, particularly noble metals, in one step. In the gold recovery method according to the present invention, since gold can be back-extracted using water, a complicated post-processing step after back-extraction is unnecessary.

It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of each metal by oleyl alcohol (3.0 mol / dm < ³ >). It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of each metal by octanol (3.0 mol / dm < ³ >). It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of gold | metal | money by 2-ethylhexanol (3.0 mol / dm < ³ >). It is a figure which shows the relationship between the hydrochloric acid concentration in an aqueous phase, and the extraction rate of each metal by octanol (stock solution). It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of each metal by 2-ethylhexanol (stock solution). It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of gold | metal | money by dodecanol (stock solution), 2-ethylhexanol (stock solution), octanol (stock solution), and octanol (3.0 mol / dm < ³ >). The relationship between the concentration of hydrochloric acid in the aqueous phase and CHCl _{, org} / CRN _{, 0} for gold extraction with octanol (3.0 mol / dm ³ ) and 2-ethylhexanol (3.0 mol / dm ³ ) is shown. FIG. It is a figure which shows the relationship between the hydrochloric acid density | concentration in an aqueous phase, and the extraction rate of gold | metal | money by 1, 1-octanediol (3.0 mol / dm < ³ >). It is a figure which shows the relationship between the nitric acid concentration in an aqueous phase, and the extraction rate of gold | metal | money by 1, 1-octanediol (3.0 mol / dm < ³ >). It is a figure which shows the relationship between the sulfuric acid concentration in an aqueous phase, and the extraction rate of gold | metal | money by 1, 1-octanediol (3.0 mol / dm < ³ >).

  The compound represented by the formula (I) or (II), which is an active ingredient of the gold extractant of the present invention, is almost immiscible with water and dissolves in gold and the compound or, optionally, the organic solvent used for dilution. Since an easy complex can be formed, gold can be efficiently extracted particularly from an aqueous solution containing gold. When the compound represented by formula (I) or (II) is a liquid, it is advantageous in that it is not necessary to use a diluent (organic solvent) for extraction, and even when it is a solid, the formula of the present invention is used. The compound represented by (I) or (II) is advantageous in that the diluent used in the extraction is not limited because it is soluble in most of the commonly used organic solvents.

In the compound represented by the formula (I), R ¹ is a linear or branched alkyl group or alkenyl group having 6 to 20 carbon atoms, preferably 6 to 19 carbon atoms, more preferably 6 to 13 carbon atoms. It is. The alkyl group or alkenyl group may be substituted with 1 to 3 unsubstituted or substituted monocyclic or bicyclic aromatic ring groups. Examples of the monocyclic or bicyclic aromatic ring group include a phenyl group and a naphthyl group. The compound of the formula (I) may be any of primary alcohol, secondary alcohol and tertiary alcohol. When R ¹ is an alkenyl group, the number of unsaturated bonds may be plural or singular. Preferred specific examples of R ¹ include, but are not limited to, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, oleyl, isopropylbenzyl and the like. Examples thereof include phenylalkyl such as alkylbenzyl, phenylethyl, phenylpropyl, phenylbutyl and phenylhexyl, diphenylalkyl such as diphenylmethyl, triphenylalkyl such as triphenylmethyl, and naphthylalkyl groups such as naphthylmethyl. And octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl and oleyl are preferred. Since the compound represented by the formula (I) is very stable, it can withstand long-term industrial use.

In the compound represented by the formula (II), R ² is a linear or branched saturated hydrocarbon group having 4 to 13 carbon atoms, preferably 6 to 10 carbon atoms. Specific examples of the compound represented by the formula (II) include butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, butane-2,3-diol, and pentane-1. , 2-diol, pentane-1,3-diol, pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol, pentane-2,4-diol, hexane-1,2 -Diol, hexane-1,3-diol, hexane-1,4-diol, hexane-1,5-diol, hexane-1,6-diol, hexane-2,5-diol, heptane-1,2-diol 1,7-heptanediol, 1,1-octanediol, 1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,2-decanediol, 10-decanediol, 1,2-dodecanediol, 1,12-dodecanediol, 1,13-tridecanediol, etc., among these, 1,1-octanediol, 1,2-octanediol and 1,2-decanediol is preferred. Since the compound represented by the formula (II) is very stable, it can withstand long-term industrial use.

  The method for recovering gold according to the present invention includes a step of extracting gold from an aqueous solution containing gold using a compound represented by formula (I) or (II) (hereinafter sometimes referred to as “extraction step”); And a step of back-extracting gold using water from a phase containing gold and the compound represented by formula (I) or (II) (hereinafter sometimes referred to as “back-extraction step”). To do.

The extraction step is performed by bringing an aqueous solution containing gold (aqueous phase) into contact with an organic phase containing a compound represented by formula (I) or (II). In the extraction step, the compound represented by formula (I) or (II) may be used alone as the organic phase, but the compound represented by formula (I) or (II) diluted in an organic solvent is used as the organic phase. Also good. The method of diluting the compound represented by the formula (I) or (II) with an organic solvent is preferable because it is economical. As an organic solvent that can be used as a diluent, various organic solvents from aliphatic compounds to aromatic compounds can be used, among which toluene, n-hexane, cyclohexane, benzene, xylene, 1,2-dichloroethane, chloroform, tetrachloride. Carbon or a mixture thereof can be suitably used. When the compound represented by formula (I) or (II) is a solid, in order to extract gold more efficiently and selectively, the compound represented by formula (I) or (II) is used as an organic solvent. It is preferred to dilute. Specifically, the compound represented by the formula (I) or (II) is preferably diluted to 0.1 to 5 mol / dm ³ , more preferably 0.3 to ³ mol / dm ³ .

  The “aqueous solution containing gold” is typically “an aqueous solution containing gold chloride”. The aqueous solution containing gold chloride can be obtained, for example, by chlorinating and dissolving waste containing gold. Chlorination and dissolution can be performed by a conventional method, for example, by using hydrogen peroxide and hydrochloric acid in combination or by using chlorine gas and hydrochloric acid in combination.

  The concentration of hydrochloric acid (or sulfuric acid, nitric acid) in the gold chloride-containing aqueous solution used in the extraction step is not particularly limited, and is appropriately selected in relation to other metals to be removed.

  The extraction conditions are not particularly limited. For example, an aqueous solution containing gold (aqueous phase) and an organic phase containing a compound represented by formula (I) or (II) are 1:10 to 10: 1, more preferably 1: 5 to 5: Gold can be extracted into the organic phase by contacting at a volume ratio of 1 at 5 to 50 ° C. for 0.5 to 48 hours.

  It is preferable to separate the organic phase and the aqueous phase after extracting gold into the organic phase by the extraction step.

  Subsequently, a back extraction step of back extracting gold from the organic phase containing the compound represented by formula (I) or (II) and gold is performed. As explained in the background section, water cannot be used as a medium for back-extracting gold from the organic phase in the conventional method using sulfides as a gold extractant, and ammonia, thiourea, (hydrochloric acid + It was necessary to use a thiourea) solution or the like. In contrast, the present invention advantageously allows the back extraction of gold from the organic phase using water. The water used for back extraction may contain other components (for example, 0.01 M or less hydrochloric acid, sulfuric acid, nitric acid) as long as the back extraction efficiency is not adversely affected.

  The conditions for back extraction are not particularly limited. For example, the organic phase containing the compound represented by the formula (I) or (II) and gold and water are mixed in a volume ratio of 1:10 to 10: 1, more preferably 1: 5 to 5: 1. Gold can be back-extracted into the aqueous phase by contact at -50 ° C for 0.5-48 hours.

  It is preferable to separate the organic phase and the aqueous phase after back-extracting gold into the aqueous phase by the back extraction step.

  Gold in the aqueous phase can be reduced and precipitated using a reducing agent according to a conventional method and recovered. Examples of the reducing agent include oxalic acid or sodium oxalate. It can also be reduced and precipitated by bubbling hydrogen gas.

  According to the present invention, only gold is highly selected from a mixed solution containing noble metals such as silver, platinum, palladium, rhodium, iridium, ruthenium and osmium, as well as base metals such as iron, lead, copper, nickel, cobalt, zinc and cadmium. Can be extracted.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the description of the examples.

Experiment 1: Extraction of various metals (1) Oleyl alcohol (3.0 mol / dm ³ )
All experiments were performed in a batch process. The aqueous phase, each metal that is a metal concentration ^1.0x10 -3 mol / dm ³ was adjusted to the concentration of hydrochloric acid ^{(1.0x10 -1 ~5.0mol / dm 3)} (Au, Pd, Pt, Rh) of A hydrochloric acid solution was used. As the organic phase, a toluene solution of oleyl alcohol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

In FIG. 1, the horizontal axis indicates the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis indicates the extraction rate of each metal. The extraction rate (E (%)) was determined by the following equation.
E = 100x (C ₀ -C _e ) / C ₀ (%)
Wherein, C ₀ represents the initial concentration of metal ions in the aqueous phase, C _e indicates the concentration of metal ions in the aqueous phase after equilibration.

FIG. 1 shows that the gold extraction rate is sufficiently higher than other metals, and gold is selectively extracted. Even in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ), the gold extraction rate shows a high value, which is used when gold is recovered by dissolving noble metals from waste catalysts and waste materials of electronic materials. Considering that the acid concentration is 5 to 6 mol / dm ³ , this is an advantageous result from an industrial viewpoint.

(2) Octanol (3.0 mol / dm ³ )
All experiments were performed in a batch process. The aqueous phase, each metal that is a metal concentration ^1.0x10 -3 mol / dm ³ was adjusted to the concentration of hydrochloric acid ^{(1.0x10 -1 ~5.0mol / dm 3)} (Au, Pd, Pt, Rh) of A hydrochloric acid solution was used. As the organic phase, a toluene solution of octanol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

  In FIG. 2, the horizontal axis represents the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis represents the extraction rate of each metal. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 2, only gold is selectively extracted. Particularly in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ), the gold extraction rate shows a high value, which is used when gold is recovered by dissolving precious metals from waste catalysts and waste materials of electronic materials. Considering that the acid concentration is 5 to 6 mol / dm ³ , this is an advantageous result from an industrial viewpoint. In addition, the low extraction rate in the region where the horizontal axis log [HCl] is small suggests that the extracted gold is recovered with water.

(3) 2-ethylhexanol (3.0 mol / dm ³ )
All experiments were performed in a batch process. As the aqueous phase, a hydrochloric acid solution of Au having a metal concentration of 1.0 × 10 ⁻³ mol / dm ³ adjusted to each hydrochloric acid concentration (1.0 × 10 ^{−1 to} 5.0 mol / dm ³ ) was used. As the organic phase, a toluene solution of 2-ethylhexanol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

  In FIG. 3, the horizontal axis represents the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis represents the gold extraction rate. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 3, the gold extraction rate is particularly high in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ). This is because gold is dissolved by dissolving precious metals from waste catalysts and waste materials of electronic materials. In view of the fact that the acid concentration used in the recovery of 5 to 6 mol / dm ³ is considered, this is also an advantageous result from an industrial viewpoint. In addition, the low extraction rate in the region where the horizontal axis log [HCl] is small suggests that the extracted gold is recovered with water.

(4) Octanol (stock solution)
All experiments were performed in a batch process. The aqueous phase, a hydrochloric acid solution of the metal (Au, Pd, Pt) with a metal concentration ^1.0x10 -3 mol / dm ³ was adjusted to the concentration of hydrochloric acid (1.0x10 ^-1 ~5.0mol / dm ³⁾ Was used. Octanol (extractant of the present invention) was used as the organic phase. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

  In FIG. 4, the horizontal axis indicates the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis indicates the extraction rate of each metal. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 4, only gold is selectively extracted. Particularly in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ), the gold extraction rate shows a high value, which is used when gold is recovered by dissolving precious metals from waste catalysts and waste materials of electronic materials. Considering that the acid concentration is 5 to 6 mol / dm ³ , this is an advantageous result from an industrial viewpoint.

(5) 2-ethylhexanol (stock solution)
All experiments were performed in a batch process. The aqueous phase, a hydrochloric acid solution of the metal (Au, Pd, Pt) with a metal concentration ^1.0x10 -3 mol / dm ³ was adjusted to the concentration of hydrochloric acid (1.0x10 ^-1 ~5.0mol / dm ³⁾ Was used. As the organic phase, 2-ethylhexanol (extractant of the present invention) was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

  In FIG. 5, the horizontal axis represents the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis represents the extraction rate of each metal. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 5, only gold is selectively extracted. Particularly in the region where the hydrochloric acid concentration is high (5 mol / dm ³ ), the gold extraction rate shows a high value. This is the acid used for recovering gold by dissolving noble metals from waste catalysts and waste materials of electronic materials. Considering that the concentration is 5 to 6 mol / dm ³ , this is an advantageous result from an industrial viewpoint. In addition, the low extraction rate in the region where the horizontal axis log [HCl] is small suggests that the extracted gold is recovered with water.

(6) Dodecanol (stock solution)
All experiments were performed in a batch process. As the aqueous phase, a hydrochloric acid solution of Au having a metal concentration of 1.0 × 10 ⁻³ mol / dm ³ adjusted to each hydrochloric acid concentration (1.0 × 10 ^{−1 to} 5.0 mol / dm ³ ) was used. As the organic phase, dodecanol (extractant of the present invention) was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG. 6 together with the results of (2), (4) and (5) above.

  In FIG. 6, the horizontal axis indicates the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis indicates the gold extraction rate. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 6, the gold extraction rate is particularly high in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ). This is because gold is dissolved by dissolving noble metals from waste catalysts and waste materials of electronic materials. In view of the fact that the acid concentration used in the recovery of 5 to 6 mol / dm ³ is considered, this is also an advantageous result from an industrial viewpoint. In addition, the low extraction rate in the region where the horizontal axis log [HCl] is small suggests that the extracted gold is recovered with water.

(7) FIG. 7 shows the results of (2) and (3) above, that is, octanol (3.0 mol / dm ³ ) and 2-ethylhexanol (3.0 mol / dm ³ ). ], And the vertical axis represents C _{HCl, org} / C _{RN, 0} . Here, C _{HCl, org} indicates the concentration of metal ions in the organic phase after equilibration, and _{CRN, 0} indicates the initial concentration of octanol or 2-ethylhexanol. From FIG. 7, the extraction rate becomes almost zero when the hydrochloric acid concentration is close to 0 indicates that the extracted gold can be recovered with water.

(8) 1,1-octanediol (3.0 mol / dm ³ )
All experiments were performed in a batch process. As the aqueous phase, a hydrochloric acid solution of Au having a metal concentration of 1.0 × 10 ⁻³ mol / dm ³ adjusted to each hydrochloric acid concentration (1.0 × 10 ^{−1 to} 5.0 mol / dm ³ ) was used. As the organic phase, a toluene solution of 1,1-octanediol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The concentration of hydrochloric acid in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

  In FIG. 8, the horizontal axis represents the hydrochloric acid concentration log [HCl] in the aqueous phase, and the vertical axis represents the gold extraction rate. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 8, the gold extraction rate is particularly high in the region where the hydrochloric acid concentration is high (5.0 mol / dm ³ ). This indicates that the precious metal is dissolved from the waste catalyst or the waste material of the electronic material to dissolve the gold. In view of the fact that the acid concentration used in the recovery of 5 to 6 mol / dm ³ is considered, this is also an advantageous result from an industrial viewpoint.

(9) 1,1-octanediol (3.0 mol / dm ³ )
All experiments were performed in a batch process. As the aqueous phase, a nitric acid solution of Au having a metal concentration of 1.0 × 10 ⁻³ mol / dm ³ adjusted to each nitric acid concentration (1.0 × 10 ^{−1 to} 5.0 mol / dm ³ ) was used. As the organic phase, a toluene solution of 1,1-octanediol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The nitric acid concentration in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

In FIG. 9, the horizontal axis indicates the nitric acid concentration log [HNO ₃ ] in the aqueous phase, and the vertical axis indicates the gold extraction rate. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 9, the gold extraction rate is particularly high in the region where the nitric acid concentration is high (5.0 mol / dm ³ ). This is because gold is dissolved by dissolving noble metals from waste catalysts and waste materials of electronic materials. In view of the fact that the acid concentration used in the recovery of 5 to 6 mol / dm ³ is considered, this is also an advantageous result from an industrial viewpoint.

(10) 1,1-octanediol (3.0 mol / dm ³ )
All experiments were performed in a batch process. As the aqueous phase, a sulfuric acid solution of Au having a metal concentration of 1.0 × 10 ⁻³ mol / dm ³ adjusted to each sulfuric acid concentration (1.0 × 10 ^{−1 to} 5.0 mol / dm ³ ) was used. As the organic phase, a toluene solution of 1,1-octanediol (extractant of the present invention) adjusted to a concentration of 3.0 mol / dm ³ was used. 10 cm ³ each of the aqueous phase and the organic phase were put into an L-shaped tube and shaken in a thermostatic bath at 30 ° C. for 24 hours. After 24 hours, the aqueous phase was collected. The metal concentration in the aqueous phase was quantified using an atomic absorption photometer. The sulfuric acid concentration in the aqueous phase after equilibration was quantified by neutralization titration. The experimental results are shown in FIG.

In FIG. 10, the horizontal axis represents the sulfuric acid concentration log [H ₂ SO ₄ ] in the aqueous phase, and the vertical axis represents the gold extraction rate. The definition of the extraction rate is the same as the extraction rate in Experiment 1 (1).

As shown in FIG. 10, the gold extraction rate is particularly high in a region where the sulfuric acid concentration is high (5.0 mol / dm ³ ). This is because gold is dissolved by dissolving noble metals from waste catalysts and waste materials of electronic materials. In view of the fact that the acid concentration used in the recovery of 5 to 6 mol / dm ³ is considered, this is also an advantageous result from an industrial viewpoint.

Claims (3)

Formula (I): R ¹ OH [wherein R ¹ is a linear or branched alkyl group or alkenyl group having 6 to 20 carbon atoms]; and Formula (II): R Effective at least one selected from compounds represented by ² OH (OH) [wherein R ² is a linear or branched divalent saturated hydrocarbon group having 4 to 13 carbon atoms] Gold extractant as an ingredient.   A method for extracting gold, comprising extracting gold from an aqueous solution containing gold using the extractant according to claim 1.   A method for recovering gold, comprising extracting gold from an aqueous solution containing gold using the extractant according to claim 1 and then back-extracting gold from the organic phase containing gold and the extractant using water. Method.

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