A method for recovering gold (Ⅲ) in leaching solution of waste circuit board using tin disulfide

Abstract

The application discloses a method for recovering gold (III) in waste circuit board leaching solution by using tin disulfide, and belongs to the field of hydrometallurgy and precious metal recovery. The method recovers gold (III) in the solution by using tin disulfide, and gold (III) adsorption is carried out under mechanical stirring. The specific process of the method is as follows: tin sulfide dihydrate and thioacetamide are used as raw materials to prepare tin disulfide by a hydrothermal method, then a waste circuit board leaching solution with a certain concentration is prepared, a certain amount of tin disulfide is added into the leaching solution, and gold adsorption is carried out under mechanical stirring. The method can efficiently recover gold (III) in the aqueous solution, has good selectivity for the recovery of gold (III) in the acidic waste liquid, and has the advantages of energy saving and environmental protection, low cost, large load capacity and the like.

Description

TECHNICAL FIELD

[0001] The application relates to a method for recovering gold (III) in a waste circuit board leaching solution by using tin disulfide, and belongs to the field of hydrometallurgy and precious metal recovery. BACKGROUND

[0002] With the rapid development of science and technology and the continuous updating of electronic information technology, the output of electronic waste is increasing day by day, and the grade of valuable metals in the electronic waste is relatively high. Taking gold as an example, the gold grade in electronic waste is several tens of times or even hundreds of times of the gold content in common gold ores, and the electronic waste has high recycling value. It is of great significance to efficiently recover gold in electronic waste and realize resource utilization.

[0003] The waste electronic resources have relatively small volume and relatively high gold content, and the aqua regia gold leaching method is considered to be a good method for recovering gold in waste electronic resources, and has the advantages of mature theory and high leaching efficiency. In order to recover gold in waste electronic resources, the waste electronic resources are first leached, and then gold in the leaching solution is recovered by a suitable method. Common recovery methods include adsorption method, solvent extraction method, precipitation method and electrodeposition method, and the adsorption method has obvious advantages in terms of operability and safety. Common adsorbents include activated carbon, silica gel, resin, chitosan and various new and existing MOFs materials. Unfortunately, although traditional materials such as activated carbon have low cost, they have the disadvantages of low adsorption capacity and poor selectivity, which increases the subsequent purification and smelting cost. Although new materials can obtain satisfactory adsorption capacity and selectivity, the preparation cost and large-scale application efficiency of the new materials are still unknown. Therefore, it is the key to realize the recovery and utilization of gold in waste electronic resources to study a gold recovery method with good selectivity, fast adsorption rate and simple feasibility.

[0004] SnS2 is a sulfur-containing compound, and at present, the application of SnS2 mainly concentrates in the fields of solar cells, photoelectric detectors and photocatalysis, and the application of SnS2 to the recovery of gold in a solution has not been reported. Therefore, the application recovers gold in waste circuit board aqua regia leaching solution by using tin disulfide, and the tin disulfide has the advantages of high adsorption selectivity and adsorption capacity, simple material preparation method, low price and good performance. SUMMARY

[0005] The application aims to provide a method for recovering gold (III) in waste circuit board leaching solution by using tin disulfide with high selectivity, and the method has the advantages of high selectivity, fast adsorption rate and simple and feasible adsorption material preparation process. The method is to add tin disulfide into waste circuit board aqua regia leaching solution to stir and adsorb gold, and specifically comprises the following steps.

[0006] (1) gold in waste circuit board is leached by using 1:1 (v / v) aqua regia on a constant temperature electric hot plate.

[0007] (2) Put the obtained tin disulfide into the leaching solution obtained in step (1) to carry out gold adsorption under mechanical stirring.

[0008] Preferably, the pH value of the aqua regia leaching solution of the waste circuit board according to the application is 1-6.

[0009] Preferably, the mass / volume ratio of tin disulfide to leaching solution in the method according to the application is 0.01:100-0.1:100, unit: g:mL.

[0010] Preferably, the stirring and adsorption time according to the application is 1h-24h, and the temperature is 25-65℃.

[0011] Preferably, the tin disulfide according to the application is prepared by reaction of stannous chloride dihydrate and thioacetamide, and the preparation process specifically comprises the following steps:

[0012] (1) Stannous chloride dihydrate and thioacetamide are added into deionized water to be fully stirred and dissolved to obtain a mixed solution, the concentration of stannous chloride dihydrate in the mixed solution is 0.04mol / L, and the concentration of thioacetamide is 0.75mol / L.

[0013] (2) The mixed solution in step (1) is transferred to a high-pressure reaction kettle, the kettle is sealed and placed in an oven to react.

[0014] (3) After the reaction is completed, the reaction kettle is taken out and cooled to room temperature, and then the product is taken out, washed with anhydrous ethanol and deionized water, and dried to obtain the required tin disulfide.

[0015] Preferably, the reaction temperature in step (2) according to the application is 160℃.

[0016] The application has the following beneficial effects:

[0017] (1) The gold recovery method in the leaching solution of the waste circuit board according to the application has high selectivity, simple process, low cost, and high gold recovery rate.

[0018] (2) The prepared tin disulfide (SnS2) adsorption material has large loading capacity and fast adsorption rate, has adsorption effect in the range of acidic adsorption solution, and has a wide pH range of adsorption solution.

[0019] (3) The method according to the application has certain theoretical significance for selectively recovering gold from the circuit board leaching solution, realizes one-step separation of gold and other metals with high efficiency and low cost, and has certain industrial application value.

[0020] (4) The low melting point of tin can selectively dissolve gold in any ratio in a molten state under certain temperature conditions, so after adsorbing gold, only a certain redox treatment is needed to make the gold into a single state, so that the separation and purification of gold can be realized. In addition, it also has good stability in an acidic environment, low toxicity (used as a food packaging box), low price and other advantages, so it should have good application prospects for gold recovery.

[0021] (5) The tin disulfide prepared by the method has a two-dimensional layered structure, can provide more effective sites for Au(III) adsorption, and the unique void structure can provide favorable conditions for selective loading of Au(III). DETAILED DESCRIPTION

[0022] The application will be further described in detail below in conjunction with specific embodiments, but the scope of protection of the application is not limited to the content described.

[0023] Example 1

[0024] In this embodiment, tin sulfide dihydrate and thioacetamide are used as raw materials to prepare tin disulfide by a hydrothermal method, which is used for selective adsorption and recovery of Au(III) in waste circuit board aqua leaching solution. The specific steps include the following:

[0025] (1) 3.5 mmoL tin sulfide dihydrate and 52.5 mmoL thioacetamide are added to a 100 mL beaker, 70 mL of deionized water is added, and stirring is performed until dissolution.

[0026] (2) The mixed solution is transferred to a high-pressure reaction kettle and sealed, and the reaction kettle is placed in a 160℃ oven for 12h.

[0027] (3) After the reaction is completed, the reaction kettle is cooled to room temperature, and then the product is washed with anhydrous ethanol and deionized water for 3-5 times, and finally transferred to a beaker and dried at 80℃ for standby.

[0028] 0.01 g of tin disulfide obtained in step (3) is placed in 100 mL of waste circuit board leaching solution (the solid-liquid ratio of tin disulfide to leaching solution is 0.01:100 (g:mL)), and the concentration of AuCl4 - in the leaching solution is 28 mg / L; before adsorption, the pH is adjusted to 3.0, and the adsorption is carried out at room temperature (25℃) with stirring at 180 r / min for 24h, the gold recovery rate is 100%, the gold loading capacity is 280 kg / t, and the rest such as Cu 2+ , Al 3+ , Zn 2+ , Ni 2+ , Ca 2+ , Fe 3+ and other metal ions have no obvious change in concentration before and after adsorption.

[0029] Example 2

[0030] (1) 3.5 mmol of stannous chloride dihydrate and 52.5 mmol of thioacetamide were added to a 100 mL beaker, 70 mL of deionized water was added and stirred until dissolved.

[0031] (2) The mixture was transferred to a high-pressure reaction kettle and sealed, and the reaction kettle was placed in a 160°C oven for 12 h.

[0032] (3) After the reaction was completed, the reaction kettle was removed and cooled to room temperature, and then the product was washed 3-5 times with anhydrous ethanol and deionized water, and finally transferred to a beaker and dried at 80°C for standby.

[0033] 0.03 g of tin disulfide obtained in step (3) was taken into 100 mL of waste circuit board leaching solution (the solid-liquid ratio of tin disulfide to leaching solution was 0.03:100 (g:mL)), wherein the concentration of AuCl4 - in the leaching solution was 30 mg / L; before adsorption, its pH was adjusted to 1.0, and adsorption was carried out at 35°C with stirring at 180 r / min for 12 h, the gold recovery rate was 100%, the gold loading capacity was 100 kg / t, and the concentrations of other metal ions such as Cu 2+ , Al 3+ , Zn 2+ , Ni 2+ , Ca 2+ , Fe 3+ , etc. had no obvious change before and after adsorption.

[0034] Example 3

[0035] (1) 3.5 mmol of stannous chloride dihydrate and 52.5 mmol of thioacetamide were added to a 100 mL beaker, 70 mL of deionized water was added and stirred until dissolved.

[0036] (2) The mixture was transferred to a high-pressure reaction kettle and sealed, and the reaction kettle was placed in a 160°C oven for 12 h.

[0037] (3) After the reaction was completed, the reaction kettle was removed and cooled to room temperature, and then the product was washed 3-5 times with anhydrous ethanol and deionized water, and finally transferred to a beaker and dried at 80°C for standby.

[0038] 0.05 g of tin disulfide obtained in step (3) was taken into 100 mL of waste circuit board leaching solution (the solid-liquid ratio of tin disulfide to leaching solution was 0.05:100 (g:mL)), wherein the concentration of AuCl4 -concentration of AuCl4- is 48 mg / L; the pH is adjusted to 2.0 before adsorption, the adsorption is carried out at 45°C with stirring at 180 r / min for 8 h, the recovery rate of gold is 100%, the gold loading capacity is 96 kg / t, and the concentrations of Cu 2+ , Al 3+ , Zn 2+ , Ni 2+ , Ca 2+ , Fe 3+ and other metal ions do not change significantly before and after adsorption.

[0039] Example 4

[0040] (1) 3.5 mmol of stannous sulfide dihydrate and 52.5 mmol of thioacetamide are added to a 100 mL beaker, 70 mL of deionized water is added, and the mixture is stirred until dissolved.

[0041] (2) The mixture is transferred to a high-pressure reaction kettle and sealed, and the reaction kettle is placed in a 160°C oven for 12 h.

[0042] (3) After the reaction is completed, the reaction kettle is removed and cooled to room temperature, and then the product is washed with anhydrous ethanol and deionized water for 3-5 times, and finally transferred to a beaker and dried at 80°C for standby.

[0043] 0.08 g of tin disulfide obtained in step (3) is placed in 100 mL of waste circuit board leaching solution (the solid-liquid ratio of tin disulfide to leaching solution is 0.08:100 (g:mL)), wherein the leaching solution contains AuCl4 - at a concentration of 60 mg / L; the pH is adjusted to 4.0 before adsorption, the adsorption is carried out at 55°C with stirring at 180 r / min for 1 h, the recovery rate of gold is 55%, the gold loading capacity is 41.25 kg / t, and the concentrations of Cu 2+ , Al 3+ , Zn 2+ , Ni 2+ , Ca 2+ , Fe 3+ and other metal ions do not change significantly before and after adsorption.

[0044] Example 5

[0045] (1) 3.5 mmol of stannous sulfide dihydrate and 52.5 mmol of thioacetamide are added to a 100 mL beaker, 70 mL of deionized water is added, and the mixture is stirred until dissolved.

[0046] (2) The mixture is transferred to a high-pressure reaction kettle and sealed, and the reaction kettle is placed in a 160°C oven for 12 h.

[0047] (3) After the reaction is completed, the reactor is removed and cooled to room temperature, then the product is washed with anhydrous ethanol and deionized water for 3-5 times, and finally transferred to a beaker and dried at 80°C for standby.

[0048] Take 0.10 g of the tin disulfide obtained in step (3) and put it into 100 mL of the waste circuit board leaching solution (the solid-liquid ratio of tin disulfide to leaching solution is 0.10:100 (g:mL)), wherein the leaching solution contains AuCl4 - with a concentration of 96 mg / L; before adsorption, the pH is adjusted to 6.0, and the adsorption is carried out at 65°C with stirring at 180 r / min for 24 h, the gold recovery rate is 90%, the gold loading capacity is 86.4 kg / t, and the concentrations of the remaining metal ions such as Cu 2+ , Al 3+ , Zn 2+ , Ni 2+ , Ca 2+ , Fe 3+ , etc. do not change significantly before and after adsorption.

[0049] The specific embodiments of the present application are described in detail above, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the present application.

Claims

1. A method for recovering gold(III) from leaching solutions of waste circuit boards using tin disulfide, characterized in that: Tin disulfide was added to the aqua regia leaching solution of waste circuit boards to stir and adsorb gold. The pH value of the aqua regia leachate from the waste circuit boards is 1~6.

2. The method for recovering gold(III) from the leaching solution of waste circuit boards using tin disulfide according to claim 1, characterized in that: The mass ratio of tin disulfide to the volume of the leaching solution is 0.01:100 to 0.1:100, in g:mL.

3. The method for recovering gold(III) from the leaching solution of waste circuit boards using tin disulfide according to claim 1, characterized in that: In step (4), the stirring and adsorption time is 1 h to 24 h, and the temperature is 25 to 65℃.

4. The method for recovering gold(III) from the leaching solution of waste circuit boards using tin disulfide according to any one of claims 1 to 3, characterized in that: The preparation of tin disulfide by reacting stannous dihydrate with thioacetamide includes the following steps: (1) Add stannous sulfide dihydrate and thioacetamide to deionized water and stir thoroughly to dissolve to obtain a mixture. The concentration of stannous sulfide dihydrate in the mixture is 0.04 mol / L and the concentration of thioacetamide is 0.75 mol / L. (2) Transfer the mixture obtained in step (1) to a high-pressure reactor, seal it, and place it in an oven for reaction; (3) After the reaction is completed, the reaction vessel is taken out and cooled to room temperature. Then the product is taken out and washed and dried with anhydrous ethanol and deionized water to prepare the desired tin disulfide.

5. The method for recovering gold(III) from the leaching solution of waste circuit boards using tin disulfide according to claim 4, characterized in that: The reaction temperature in step (2) is 160℃.