Application of modified polyamine gel material in recovery of gold (I) in thiosulfate solution

Abstract

The invention discloses application of a modified polyamine gel material in recovery of gold (I) in a thiosulfate solution, and belongs to the field of hydrometallurgy and precious metal recovery. According to the invention, a polyamine gel material with abundant cationic groups is synthesized and is used as a material for adsorbing gold (I) in a thiosulfate solution; the material prepared by the method can be used under a wide pH condition, is easy to separate from a solution, can be recycled for multiple times, has the characteristics of stable adsorption material performance and simple adsorption process flow, and can efficiently recover gold (I) in a thiosulfate solution.

Description

Technical Field

[0001] This invention relates to the application of a modified polyamine gel material in the recovery of gold (I) from thiosulfate solution, belonging to the fields of hydrometallurgy and precious metal recovery. Background Technology

[0002] Thiosulfate, due to its non-toxicity, low price, ability to form stable complexes with gold, rapid leaching rate, and efficient processing of gold ores containing copper, arsenic, and carbonaceous materials—which are difficult to process using cyanide—exhibits unique technical and economic competitiveness and is considered the most promising alternative to cyanide. However, due to several technical bottlenecks, it has not yet been successfully industrialized. Among these, the difficulty in recovering gold from thiosulfate leaching solutions is a core challenge for the industrialization of this technology. Therefore, researching methods for recovering gold(I) from thiosulfate solutions is meaningful. Among numerous separation and enrichment methods, adsorption is considered a feasible and effective gold recovery method due to its low cost, eco-friendliness, and ease of operation. Currently, materials used for gold adsorption mainly include resins, activated carbon, silica gel, and covalent organic frameworks. However, most materials have limited adsorption capacity and selectivity for gold in thiosulfate solutions, while conventional ion exchange resins are expensive and have poor stability under certain conditions. Therefore, developing a novel adsorbent with high adsorption performance for gold(I) in thiosulfate solutions is of significant practical importance.

[0003] Hydrogels are a class of polymers with a three-dimensional network structure formed by cross-linking of the polymer backbone and hydrophilic functional groups through covalent bonds, ionic bonds, hydrogen bonds, or physical entanglement. Currently, the main synthetic methods for hydrogel materials are chemical cross-linking and physical cross-linking. However, the synthesized gels lack selectivity in complex thiosulfate solutions, have poor mechanical properties, and low loading capacity. There are no reports on using the gel materials to recover gold (I) from thiosulfate solutions. The material synthesized in this invention can meet the requirements for the recovery of gold (I) from thiosulfate solutions in terms of mechanical properties. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of gold recovery in the existing thiosulfate leaching method and to provide a method for recovering gold (I) from thiosulfate solution. The prepared adsorbent can be used under a wide range of pH conditions, has a large adsorption capacity, is easy to separate from the solution, and has good recycling performance.

[0005] To achieve the above objectives, the present invention is implemented according to the following technical methods: The preparation method of the modified polyamine gel of the present invention specifically includes the following steps: (1) Take a certain amount of linear polyamine and add it to the reaction vessel. Adjust the pH to 2-3, add a certain amount of formaldehyde and acetone, and react at room temperature for 1 hour. Adjust the pH of the solution to 8-9, add a certain amount of formaldehyde, and heat the reaction in a 65°C water bath for 45 minutes. Raise the temperature to 80°C, add a certain amount of glutaraldehyde, and continue the reaction for 3 hours to obtain a hydrogel. Soak the hydrogel in deionized water to remove residual impurities, wash, filter, and dry to obtain a dry gel. (2) Place the gel obtained in (1) in the modified solution, wash, filter and dry to obtain the modified polyamine gel.

[0006] Preferably, in step (1) of the present invention, the linear polyamine is selected as diethylenetriamine, triethylenetetramine, or tetraethylenepentamine.

[0007] Preferably, the amount of glutaraldehyde used in step (1) of the present invention is 5-15 mmol.

[0008] Preferably, the temperature in step (1) of the present invention is 25~60℃.

[0009] Another object of the present invention is to provide the application of the modified polyamine gel prepared by the method in a method for recovering gold (I) from a thiosulfate solution.

[0010] The beneficial effects of this invention are: (1) The material prepared by the present invention is easy to separate from the solution.

[0011] (2) The adsorbent of the present invention has a small amount of adsorbent and a high adsorption capacity for gold (I), with a cumulative loading of 91.8 kg / t.

[0012] (3) The adsorbent of the present invention undergoes five adsorption cycles. Even after desorption and cycling, it still exhibits good adsorption of gold, demonstrating excellent recycling performance.

[0013] (4) The adsorbent of the present invention can have good adsorption performance for gold (I) over a wide pH range. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to specific examples, but the scope of protection of the present invention is not limited to the content described.

[0015] Example 1 (1) Add 0.05 mol diethylenetriamine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol formaldehyde and 0.125 mol acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 10 mmol glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0016] (2) Adjust the temperature to 25℃, stir the obtained gel magnetically in a 1mol / L phosphoric acid solution for 3h, wash, filter and dry to obtain modified polyamine gel.

[0017] Prepare 100mL of Au(S2O3)2 3- The solution had a gold concentration of 50 mg / L and a sodium thiosulfate concentration of 0.1 mol / L. The pH was adjusted to 10. 0.5 g of the material obtained in step (2) was added to the solution and mechanically stirred for 12 h to adsorb. The supernatant was then taken. After oxidation, drying and volume adjustment, the gold concentration of the sample was finally analyzed and the adsorption rate was measured to be 95.46%.

[0018] Example 2 (1) Add 0.05 mol tetraethylenepentamine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol formaldehyde and 0.125 mol acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 10 mmol glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0019] (2) Adjust the temperature to 25℃, and stir the obtained gel magnetically in a 1mol / L hydrochloric acid solution for 3h. Wash, filter and dry to obtain modified polyamine gel.

[0020] (3) Prepare 100mL Au(S2O3)2 3- The solution had a gold concentration of 50 mg / L and a sodium thiosulfate concentration of 0.1 mol / L. The pH was adjusted to 9. 0.1 g of the material obtained in step (2) was added to the solution. After mechanical stirring and adsorption for 12 h, the supernatant was collected. After oxidation, drying, and volume adjustment, the gold concentration of the sample was finally analyzed, and the adsorption rate was measured to be 68.41%.

[0021] Example 3 (1) Add 0.05 mol diethylenetriamine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol formaldehyde and 0.125 mol acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 10 mmol glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0022] (2) Adjust the temperature to 25℃, and stir the obtained gel magnetically in a 1mol / L hypophosphite solution for 3h. Wash, filter and dry to obtain modified polyamine gel.

[0023] (3) Prepare 100mL Au(S2O3)2 3- The solution contained 50 mg / L gold and 0.1 mol / L sodium thiosulfate, and the pH was adjusted to 10. 0.2 g of the material obtained in step (2) was added to the solution, and the supernatant was collected after mechanical stirring for 12 hours. After oxidation, drying, and volume adjustment, the gold concentration of the sample was finally analyzed, and the adsorption rate was found to be 79.61%.

[0024] Example 4 (1) Add 0.05 mol of triethylenetetramine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol of formaldehyde and 0.125 mol of acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol of formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 10 mmol of glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0025] (2) Adjust the temperature to 60℃, and stir the gel obtained in step (1) magnetically in a 0.2mol / L 3-amino-1,2,4-triazole solution for 3h. Wash, filter and dry to obtain modified polyamine gel.

[0026] (3) Prepare 100mL Au(S2O3)2 3- The solution had a gold concentration of 25 mg / L and a sodium thiosulfate concentration of 0.1 mol / L. The pH was adjusted to ~10. 0.2 g of the material obtained in step (2) was added to the solution, and the supernatant was collected after mechanical stirring and adsorption for 12 h. After oxidation, drying, and volume adjustment, the gold concentration of the sample was finally analyzed, and the adsorption rate was found to be 83.29%.

[0027] Example 5 (1) Add 0.05 mol diethylenetriamine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol formaldehyde and 0.125 mol acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 10 mmol glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0028] (2) Adjust the temperature to 60℃, and stir the obtained gel magnetically in a 0.2mol / L 3-mercapto-1,2,4-triazole solution for 3h. Wash, filter and dry to obtain modified polyamine gel.

[0029] (3) Prepare 100mL Au(S2O3)2 3- The solution had a gold concentration of 25 mg / L and a sodium thiosulfate concentration of 0.1 mol / L. The pH was adjusted to 10. 0.2 g of the material obtained in step (2) was added to the solution. After mechanical stirring and adsorption for 12 h, the supernatant was taken. After oxidation, drying and volume adjustment, the gold concentration of the sample was finally analyzed, and the adsorption rate was measured to be 73.62%.

[0030] Example 6 (1) Add 0.05 mol diethylenetriamine to the reaction vessel, adjust the pH to 2-3, add 0.25 mol formaldehyde and 0.125 mol acetone, and react at room temperature for 1 h; adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and react at 65℃ for 45 min; raise the temperature to 80℃, add 5 mmol glutaraldehyde, and continue to react for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain gel.

[0031] (2) Adjust the temperature to 25℃, and stir the obtained gel magnetically in a 0.2mol / L aminotrimethylenephosphonic acid solution for 3h. Wash, filter and dry to obtain modified polyamine gel.

[0032] (3) Prepare 100mL Au(S2O3)2 3- The solution had a gold concentration of 25 mg / L and a sodium thiosulfate concentration of 0.1 mol / L. The pH was adjusted to ~10. 0.2 g of the material obtained in step (2) was added to the solution, and the supernatant was collected after mechanical stirring and adsorption for 12 h. After oxidation, drying, and volume adjustment, the gold concentration of the sample was finally analyzed, and the adsorption rate was found to be 84.52%.

[0033] The specific embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for preparing a modified polyamine gel material, characterized in that: The polyamine gel was modified by placing it in a modifying agent, and then washed, filtered, and dried to obtain the modified polyamine gel. The modifying reagent is an aqueous solution of hydrochloric acid, phosphoric acid, hypophosphoric acid, aminotrimethylenephosphonic acid, 3-amino-1,2,4-triazole, or 3-mercapto-1,2,4-triazole; wherein the concentration of hydrochloric acid is 1 mol / L; the concentration of phosphoric acid is 1 mol / L; the concentration of hypophosphoric acid is 1 mol / L; the concentration of aminotrimethylenephosphonic acid is 0.2 mol / L; the concentration of 3-amino-1,2,4-triazole is 0.2 mol / L; and the concentration of 3-mercapto-1,2,4-triazole is 0.2 mol / L.

2. The method for preparing the modified polyamine gel material according to claim 1, characterized in that: The polyamine gel is a diethylenetriamine gel, a triethylenetetramine gel, or a tetraethylenepentamine gel.

3. The method for preparing the modified polyamine gel material according to claim 1, characterized in that: The preparation process of the polyamine gel is as follows: (1) Take 0.05 mol of linear polyamine and add it to 100 ml of deionized water. Adjust the pH of the solution to 2-3, add 0.25 mol of formaldehyde and 0.125 mol of acetone, and react at room temperature for 1 h. (2) Adjust the pH of the solution to 8-9, add 0.25 mol formaldehyde, and heat the solution in a water bath at 65°C for 45 min; heat to 80°C and add 5-15 mmol glutaraldehyde; continue the reaction for 3 h to obtain hydrogel; soak in deionized water to remove residual impurities, wash, filter, and dry to obtain polyamine gel.

4. The method for preparing the modified polyamine gel material according to claim 1, characterized in that: The linear polyamines are diethylenetriamine, triethylenetetramine, or tetraethylenepentamine.

5. The application of the modified polyamine gel material prepared by the method according to any one of claims 1 to 4 in the recovery of gold (I) from thiosulfate solution.