阅读说明：本技术 一种富集回收硫代硫酸盐溶液中的金(Au(S2O3)23-)的方法 (Enrichment recovery of gold (Au (S) in thiosulfate solution2O3)23-) of (b) ) 是由 字富庭 李烛娟 胡显智 陈云龙 于 2021-08-11 设计创作，主要内容包括：本发明公开一种富集回收硫代硫酸盐溶液中的金(Au(S-(2)O-(3))-(2)～(3-))的方法,属于贵金属回收技术领域。本发明所述方法以聚醚三元醇为萃取剂,通过将聚醚三元醇加入到(Au(S-(2)O-(3))-(2)～(3-))溶液中,可实现(Au(S-(2)O-(3))-(2)～(3-))溶液中金(Ⅰ)离子的分离与富集。本方法所述萃取剂的使用,最终使得(Au(S-(2)O-(3))-(2)～(3-))溶液中金(Ⅰ)直接被聚醚三元醇从体系中萃取出来,明显提高了(Au(S-(2)O-(3))-(2)～(3-))的富集回收率；本发明有效避免了吸附法中活性炭对金亲和力低以及硅胶粒度小难以分离等问题；本发明操作过程简单易控、试剂绿色无毒、成本低廉,是一种(Au(S-(2)O-(3))-(2)～(3-))的高效低碳回收方法,对硫代硫酸盐提金技术的产业化具有重要意义。(The invention discloses a method for enriching and recovering gold (Au (S) in thiosulfate solution 2 O 3 ) 2 3‑ ) Belonging to the technical field of precious metal recovery. The method takes polyether triol as an extracting agent and adds the polyether triol to (Au (S) 2 O 3 ) 2 3‑ ) In solution, (Au (S) 2 O 3 ) 2 3‑ ) And (3) separating and enriching gold (I) ions in the solution. The method uses the extractant to finally obtain (Au (S) 2 O 3 ) 2 3‑ ) Gold (I) in the solution is directly extracted from the system by polyether triol, and (Au (S) is obviously improved 2 O 3 ) 2 3‑ ) The enrichment recovery rate of (1); the invention effectively avoids the problems of low affinity of the active carbon to gold and small silica gel particle size in the adsorption methodTo problems such as separation; the invention has simple and easily controlled operation process, green and nontoxic reagent and low cost, and is (Au (S) 2 O 3 ) 2 3‑ ) The high-efficiency low-carbon recovery method has important significance for industrialization of thiosulfate gold extraction technology.)

1. Enrichment recovery of gold (Au (S) in thiosulfate solution₂O₃)₂ ³-) according to any of the preceding claims, characterized in that: adopts polyether triol asExtractant, p (Au (S)₂O₃)₂ ³-) gold (I) in the solution is enriched and recovered.

2. The enrichment of gold (Au (S) in a recovered thiosulfate solution according to claim 1₂O₃)₂ ³-) according to any of the preceding claims, characterized in that: by substituting thiosulfates (Au (S)₂O₃)₂ ³-) putting the gold leaching solution in a separating funnel, keeping the pH value of the gold leaching solution between 6 and 12, and adding polyether triol into the solution; and fully shaking the mixed solution for 5-10 min, standing for liquid separation, wherein obvious layering occurs after standing, and the gold leaching solution and the extracting agent are respectively arranged at the upper layer and the lower layer.

3. The enrichment recovery of gold (Au (S) in thiosulfate solution according to claim 1 or 2₂O₃)₂ ³-) according to any of the preceding claims, characterized in that: polyether triol and (Au (S)₂O₃)₂ ³-) the volume ratio of the solution is 1: 10-1: 50.

Technical Field

The invention relates to a method for enriching and recovering gold (Au (S) in thiosulfate solution₂O₃)₂ ^3-) Belonging to the technical field of hydrometallurgy and precious metal recovery.

Background

With the progress of times and the development of economy, the gold demand is increased year by year. However, at present, cyanide is used as a leaching agent in a main stream gold extraction method, namely a cyanidation method, is a highly toxic substance and has serious harm to the environment and the ecology. Therefore, non-cyanide gold extraction reagents and methods must be sought. Compared with the prior art, the thiosulfate method has the advantages of environmental protection, high leaching rate and the like, and is considered to be an ideal non-cyanide gold extraction technology. However, gold (Au (S) in the leachate obtained in this way₂O₃)₂ ^3-) Difficult to effectively recover, which limits the industrialization of the thiosulfate gold extraction technology.

To solve the above problems, various methods have been studied, including a displacement method, an electrodeposition method, an adsorption method, and the like. The displacement method has high recovery efficiency and high speed, but is greatly influenced by coexisting impurity ions, and high-cost impurity removal pretreatment is needed, so that the use of the displacement method is limited; the electro-deposition method has high recovery speed, but the method has high requirement on the concentration of the gold in the precious solution and is not suitable for recovering the gold with low concentration; the adsorption method mainly uses active carbon, resin and new synthetic materials, has certain recovery efficiency, but has complex process and high cost, and is difficult to use on a large scale. It is therefore of great importance to find other more efficient gold recovery methods.

The solvent extraction method has wide application in various fields such as waste utilization, metal separation and enrichment and the like, for example, a process for efficiently enriching and recovering noble metals such as platinum and palladium by using the solvent extraction method (patent number CN 104004921A). However, reports of solvent extraction methods for gold recovery in thiosulfate systems are rare. One of the main reasons is that solvent extraction is generally used in clarified liquors containing high concentrations of gold, but thiosulfate systems (Au (S)₂O₃)₂ ^3-) The concentration of gold in the actual gold leaching solution is generally low, and a proper extracting agent is difficult to find, so that the solvent extraction method recovers (Au (S)₂O₃)₂ ^3-) The gold (I) in (A) has little application in practice.

Disclosure of Invention

The invention aims to provide a method for enriching and recovering (Au (S)) in thiosulfate solution with simple operation and high efficiency₂O₃)₂ ^3-) The method of (1).

The invention is realized by the following technical scheme; using polyether trihydric alcohol as extractant to react with thiosulfate solution (Au (S)₂O₃)₂ ^3-) And (5) enriching and recovering the gold (I).

The method comprises the following specific operation steps: by substituting thiosulfates (Au (S)₂O₃)₂ ^3-) The gold leaching solution is placed in a separating funnel, the pH value of the gold leaching solution is kept between 6 and 12, and polyether triol is added into the solution; fully shaking the mixed solution for 5-10 min, and standing for liquid separation; obvious layering appears after standing, and the gold leaching solution and the extracting agent are respectively arranged at the upper layer and the lower layer; sampling raffinate and stock solution, analyzing the concentrations of the raffinate and the stock solution, and calculating the extraction rate.

Preferably, the polyether triols and (Au (S) in the process of the invention₂O₃)₂ ^3-) The volume ratio of the solution is 1: 10-1: 50.

Preferably, the polyether triol of the present invention has a density greater than (Au (S)₂O₃)₂ ^3-) And (3) solution.

The extraction principle of the invention is that the polyether triol and the thiosulfate solution are mutually insoluble, the distribution coefficients of the gold (I) ions in the two solvents are different, and the distribution coefficient of the gold (I) ions in the polyether triol is larger than that of the gold (I) ions in the thiosulfate (Au (S)₂O₃)₂ ^3-) During extraction, gold (I) ions are extracted from a thiosulfate solution (Au (S)₂O₃)₂ ^3-) Transferring the product to polyether triol to complete the extraction and separation process; compared with other organic extracting agents, the polyether triol has the obvious advantages of no toxicity, difficult volatilization, small reagent dosage, difficult volatilization and the like, and has a larger application prospect in a thiosulfate system.

The invention has the beneficial effects that: the extraction agent used in the invention is nontoxic, the cost of the reagent is low, the operation is simple, and the recovery rate of gold is high; the extraction speed is fast, and the applicability and the flexibility are high.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.

Example 1

In this example, polyether triol is used as an extractant to enrich and recover thiosulfate solution (Au (S)₂O₃)₂ ^3-) The gold (I) in (2) comprises the following steps:

(1) the preparation volume is 100mL, the gold (I) ion concentration is 50mg/L, S₂O₃ ^2-Au (S) having an ion concentration of 0.1mol/L₂O₃)₂ ^3-The simulant was placed in a separatory funnel and the pH was maintained at 7.

(2) And (2) adding 1mL of polyether triol into the solution in the step (1) for extraction reaction for 5min, and standing and separating liquid after the reaction is finished to obtain raffinate.

After the extraction experiment was completed, two 5mL portions of raffinate were added with 3mL of 30% H₂O₂Oxidizing for more than 15min, adding 2mL of 1:3HCl, heating on an electric heating plate, clarifying the solution, adding 3 drops of 10% KCl, and drying; the dried sample is subjected to constant volume to 25mL by using 5% aqua regia, and the gold concentration of the sample is analyzed by using AAS (alkaline ammonium sulfate) to obtain the extraction rate of 48%.

Example 2

In this example, polyether triol is used as an extractant to enrich and recover thiosulfate solution (Au (S)₂O₃)₂ ^3-) The gold (I) in (2) comprises the following steps:

(1) the preparation volume is 100mL, the gold (I) ion concentration is 50mg/L, S₂O₃ ^2-Au (S) having an ion concentration of 0.1mol/L₂O₃)₂ ^3-The simulant was placed in a separatory funnel and the pH was maintained at 9.

(2) And (2) adding 5mL of polyether triol into the solution in the step (1) for extraction reaction for 10min, standing and separating liquid after the reaction is finished to obtain raffinate, and leaving an organic phase in a separating funnel.

After the extraction experiment was completed, 5m was takenTwo portions of L raffinate, 3mL of 30% H₂O₂Oxidizing for more than 15min, adding 2mL1:3HCl, heating on an electric heating plate, clarifying the solution, adding 3 drops of 10% KCl, and drying; the dried sample was made to a constant volume of 25mL with 5% aqua regia, and the sample gold concentration was analyzed by AAS to obtain an extraction rate of 50.7%.

Example 3

In this example, polyether triol is used as an extractant to enrich and recover thiosulfate solution (Au (S)₂O₃)₂ ^3-) The gold (I) in (2) comprises the following steps:

(1) the preparation volume is 100mL, the gold (I) ion concentration is 50mg/L, S₂O₃ ^2-Au (S) having an ion concentration of 0.1mol/L₂O₃)₂ ^3-The simulant was placed in a separatory funnel and the pH was maintained at 11.

(2) And (2) adding 3mL of polyether triol into the solution in the step (1) for extraction reaction for 10min, and standing and separating liquid after the reaction is finished to obtain raffinate.

After the extraction experiment was completed, two 5mL portions of raffinate were added with 3mL of 30% H₂O₂Oxidizing for more than 15min, adding 2mL1:3HCl, heating on an electric heating plate, clarifying the solution, adding 3 drops of 10% KCl, and drying; the dried sample is subjected to constant volume to 25mL by using 5% aqua regia, and the gold concentration of the sample is analyzed by using AAS (alkaline ammonium sulfate) to obtain the extraction rate of 68%.

Comparative example 1

In this example, polyether triol is used as an extractant to enrich and recover thiosulfate solution (Au (S)₂O₃)₂ ^3-) The gold (I) in (2) comprises the following steps:

(1) the preparation volume is 100mL, the gold (I) ion concentration is 50mg/L, S₂O₃ ^2-Ion concentration of 0.1mol/L (Au (S)₂O₃)₂ ^3-) The simulant was placed in a separatory funnel and the pH was maintained at 11.

(2) And (3) mixing 3mL of polyether triol and 3mL of absolute ethyl alcohol, adding the mixed solution into the solution obtained in the step (1) for extraction reaction for 10min, and standing and separating the solution after the reaction is finished to obtain raffinate.

Extracting fruitAfter the experiment was completed, two 5mL portions of raffinate were added with 3mL of 30% H₂O₂Oxidizing for more than 15min, adding 2mL of 1:3HCl, heating on an electric heating plate, adding 3 drops of 10% KCl after the solution becomes clear, drying, fixing the volume of the dried sample to 25mL by using 5% aqua regia, and analyzing the gold concentration of the sample by using AAS to obtain the extraction rate of 27%.

Comparative example 2

In this example, polyether triol is used as an extractant to enrich and recover thiosulfate solution (Au (S)₂O₃)₂ ^3-) The gold (I) in (2) comprises the following steps:

(1) the preparation volume is 100mL, the gold (I) ion concentration is 50mg/L, S₂O₃ ^2-Ion concentration of 0.1mol/L (Au (S)₂O₃)₂ ^3-) The simulant was placed in a separatory funnel and the pH was maintained at 11.

(2) And (3) mixing 3mL of polyether triol and 3mL of acetone, adding the mixed solution into the solution obtained in the step (1) for extraction reaction for 5min, and standing and separating the solution after the reaction is finished to obtain raffinate.

After the extraction experiment was completed, two 5mL portions of raffinate were added with 3mL of 30% H₂O₂Oxidizing for more than 15min, adding 2mL1:3HCl, heating on an electric heating plate, clarifying the solution, adding 3 drops of 10% KCl, and drying; the dried sample was made to a constant volume of 25mL with 5% aqua regia, and the sample gold concentration was analyzed by AAS, yielding an extraction rate of 23.5%.

The comparison shows that under the same conditions, the polyether triol serving as the extractant selected by the invention has the best extraction efficiency, and the effect of the complex phase extractant is not good.

While the present invention has been described in detail with reference to the specific embodiments thereof, the present invention is not limited to the embodiments described above, and various changes can be made without departing from the spirit of the present invention within the knowledge of those skilled in the art.