A new method for the adsorption and recovery of gold and palladium ions by PEI-based network polymers

Abstract

The present invention discloses a method for efficiently and selectively adsorbing and recovering gold and palladium ions. The adsorbent provided by the present invention is prepared by a solution polymerization method using polyethyleneimine and alkyl dialdehyde. The adsorbent has the advantages of simple synthesis process, economic and environmental protection, high thermal / chemical stability, and a wide range of applications; it has rapid adsorption performance, excellent selectivity, and a high adsorption capacity for both trivalent gold ions and divalent palladium ions; at 25°C, the adsorbent can adsorb 2575 mg / g and 497 mg / g for trivalent gold ions and divalent palladium ions, and the adsorption capacity can be further increased by increasing the adsorption temperature. The present invention solves the shortcomings of traditional adsorption materials, such as small adsorption capacity, slow adsorption rate, and poor selectivity, is conducive to batch treatment of wastewater, is suitable for large-scale production, and has good industrial application prospects.

Description

Technical Field

[0001] The invention belongs to the field of precious metal recovery, and particularly relates to a method for preparing an adsorbent by cross-linking polyethyleneimine with glyoxal or malondialdehyde or succindialdehyde or glutaraldehyde or adipaldehyde, and is used for adsorbing and recovering trivalent gold and divalent palladium ions in leaching liquid or wastewater. Background Art

[0002] Most precious metals have excellent physical and chemical properties such as good color, ductility, high temperature oxidation resistance, corrosion resistance, good conductivity, and high catalytic activity. As precious metals, gold and palladium are widely used in industrial applications. They can not only be used as decorations, but also in catalysis, electronics, medical treatment, aerospace, and military fields. In the production and use of precious metals, including waste electronic products, inactivated chemical catalysts, and mineral smelting, there is a certain amount of waste of precious metal resources. In addition, waste precious metals will affect water quality, affect plant growth, and even endanger human life and health. Therefore, the separation and recovery of precious metals is not only conducive to the effective utilization of resources and environmental protection, but also will bring huge economic benefits to society.

[0003] At present, the methods for recovering and separating metal ions mainly include chemical precipitation, but since chemical precipitation generally requires the addition of a large amount of chemical agents and precipitates in the form of precipitates. This determines that there will be a large amount of secondary pollution after chemical precipitation, such as the generation of a large amount of waste residues, and there is no better treatment and disposal method for these waste residues, so there are huge negative effects on its application in engineering and future sustainable development; ion exchange method, although the functional groups on the ion exchange resin can remove ions in the raw water, after a period of use, the saturation of the functional groups leads to a decrease in deionization efficiency, causing the disadvantage of water quality deterioration; membrane separation method, membrane treatment technology cannot concentrate the filtered product into dry matter; ionic liquid method, it is easy to absorb moisture in the air, which also greatly reduces its practical application ability; solid-liquid extraction method, almost all solid-liquid extractions must first pre-treat the raw materials, generally crushing the raw materials to make fine particles or flakes; adsorption method, etc. Among the above methods, the adsorbent of precious metal ions in the adsorption method is not only simple in preparation process, low in raw material price, and simple in separation process, but also widely used.

[0004] At present, the adsorbents used to recover precious metal ions in wastewater mainly include activated carbon, nano-metal oxides, SiO2, chitosan, lignin and resin. However, the adsorption capacity of the above adsorbents for gold ions is low. Therefore, a method for simultaneously recovering precious metal ions from wastewater is developed. 3+ and Pd 2+ Adsorbents with large adsorption capacity, fast adsorption rate and good selectivity are of great significance. Summary of the invention

[0005] In view of the problems in the prior art, the purpose of the present invention is to provide a new method for recovering gold and palladium ions by adsorption of PEI-based network polymers, which has the advantages of low cost, simplicity and high efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A new method for recovering gold and palladium ions by adsorption of PEI-based network polymers, characterized in that it comprises the following steps:

[0008] (1) Preparation of adsorbent:

[0009] A certain amount of polyethyleneimine and glyoxal or malondialdehyde or succinaldehyde or glutaraldehyde or adipaldehyde are weighed and dissolved in a solvent, reacted at 20-80° C. for 2-24 hours under stirring, centrifuged and filtered to remove the solution, repeatedly washed with N,N-dimethylformamide, anhydrous ethanol and deionized water to remove impurities, dried in a vacuum drying oven to constant weight, and ground to obtain the corresponding adsorbent powder.

[0010] (2) Gold and palladium ion adsorption recovery experiment:

[0011] The powder is immersed in a certain volume of aqueous solution containing a certain concentration of gold or palladium ions, and shaken for a certain time at a certain acidity and temperature, and filtered to obtain an adsorbent enriched with metal ions and a residual solution after adsorption. The metal ion concentration of the solution before and after adsorption is tested by atomic absorption, and the adsorption rate and adsorption amount are calculated; the adsorbent is eluted with an acidic thiourea solution of a certain volume and concentration, and the adsorbent after desorption can be reused.

[0012] Preferably, in step (1), the number average molecular weight of the polyethyleneimine is 600 to 10000 g / mol.

[0013] Preferably, in step (1), the mass ratio of glyoxal or malondialdehyde or succinaldehyde or glutaraldehyde or adipaldehyde to polyethyleneimine is 0.40:1 to 10.68:1.

[0014] Preferably, in step (1), the solvent is water or N,N-dimethylformamide.

[0015] Preferably, in step (2), the acidity of the gold solution is H + The ion concentration is 10 -9 ~10 3 mol / L, pH of palladium solution is 10 -3 ~10 3 mol / L.

[0016] Preferably, in step (2), the time is 0 to 24 hours.

[0017] Preferably, in step (2), the gold ion concentration is 0 to 1200 mg / L, and the palladium ion concentration is 0 to 500 mg / L.

[0018] Preferably, in step (2), the temperature is 15-60°C.

[0019] Compared with the prior art, the present invention has the following technical effects:

[0020] The present invention provides a new method for recovering gold and palladium ions by adsorption of PEI-based network polymers, which can be used for Au in high and low concentration noble metal solutions. 3+ and Pd 2+ It can adsorb quickly, efficiently and selectively; the adsorbent used can be reused, reducing the cost of metal recovery.

[0021] The method has the advantages of high efficiency and selective adsorption of Au 3+ and Pd 2+ In the preparation process and application method of the adsorbent, the key performance indicators of the adsorbent are as follows: the adsorbent contains a multi-level pore structure of micropores, mesopores and macropores; the adsorbent is 10-100 mg / L Au at 25°C and pH = 1-9. 3+ The adsorption rate is over 99%. At 25℃ and pH=1, it can absorb 10-100mg / L Pd 2+ The adsorption rate exceeds 99%; the adsorbent is 10mg / L Au 3+ and Pd 2+ The adsorption equilibrium time of the solution was 10min and 20min respectively; the adsorbent was Au at 25℃ 3+ and Pd 2+ The maximum adsorption capacity was 2575mg / g and 497mg / g respectively; the adsorbent was 3+ , Pd 2+ , Cu 2+ 、Zn 2+ , Pb 2 + , K + Au in mixed solution 3+ and Pd 2+ The adsorption rates were 99.7% and 98.7% respectively; after three cycles of adsorbent, the adsorption rate of about 100 mg / LAu 3+ and Pd 2+ The adsorption rate is still close to 100%.

[0022] The method has the advantages of high efficiency and selective adsorption of Au 3+ and Pd 2+ In the preparation process and application method of the adsorbent, the adsorbent is 3+ The adsorption mechanism includes electrostatic attraction, chelation and redox.2+ The adsorption mechanisms include electrostatic attraction and chelation.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] (1) The present invention uses polyethyleneimine as a matrix and glyoxal or malondialdehyde or succinaldehyde or glutaraldehyde or adipaldehyde as a crosslinking agent to prepare the adsorbent by solution polymerization. The method has mild synthesis conditions, simple process, low raw material cost and is easy to industrialize. (2) The adsorbent has a strong affinity for Au 3+ and Pd 2+ It has a large adsorption capacity. (3) Adsorbent for Au 3+ and Pd 2+ It has a faster adsorption rate. (4) Adsorbent for Au 3+ and Pd 2+ It has excellent ion selectivity. (5) The adsorbent has a wide range of uses. (6) The adsorbent has stable performance and can be recycled. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below based on specific embodiments.

[0026] 1. Testing and Analysis

[0027] Au before and after adsorption in the embodiment of the present invention 3+ , Pd 2+ The concentration of the solution was analyzed using a Shimadzu AA-6880 atomic absorption spectrophotometer.

[0028] 2. Embodiment

[0029] Example 1

[0030] (1) Preparation of adsorbent

[0031] The experiment was carried out under the condition that the mass ratio of glyoxal:polyethyleneimine (Mn=10000) was 10.68:1. 200 mg of polyethyleneimine and 2 mL of glyoxal were dissolved in 8 mL of DMF, and the solution was fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0032] (2) The adsorbent was immersed in 528.3 mg / L Au at pH = 4. 3+In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining solution after adsorption were obtained by filtration. The metal ion concentration before and after adsorption was measured using AA-6880 (atomic absorption spectrophotometer). Au 3+ The adsorption rate was 90.0%. The adsorbent was immersed in 302.1 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining solution after adsorption were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 36.3%.

[0033] Example 2

[0034] (1) Preparation of adsorbent

[0035] The experiment was conducted under the condition that the mass ratio of malondialdehyde to polyethyleneimine (Mn=10000) was 10.68:1. 200 mg of polyethyleneimine and 2 mL of malondialdehyde were dissolved in 8 mL of DMF, and fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0036] (2) The adsorbent was immersed in 500 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate was 89.0%. The adsorbent was immersed in 300 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 hours, the adsorbent enriched with metal ions and the remaining solution after adsorption are obtained by filtration. The metal ion concentration before and after adsorption is measured using AA-6880 (atomic absorption spectrophotometer). Pd 2+ The adsorption rate is 37.1%.

[0037] Example 3

[0038] (1) Preparation of adsorbent

[0039] The experiment was carried out under the condition that the mass ratio of succinic dialdehyde to polyethylene imine (Mn = 10000) was 10.68:1. 200 mg of polyethylene imine and 2 mL of succinic dialdehyde were dissolved in 8 mL of DMF, and fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0040] (2) The adsorbent was immersed in 500 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate was 86.0%. The adsorbent was immersed in 300 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining solution after adsorption were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 44.1%.

[0041] Example 4

[0042] (1) Preparation of adsorbent

[0043] The experiment was conducted under the condition that the mass ratio of adipaldehyde to polyethyleneimine (Mn=10000) was 10.68:1. 200 mg of polyethyleneimine was dissolved in 8 mL and 2 mL of DMF of adipaldehyde, and the solution was fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0044] (2) The adsorbent was immersed in 528.3 mg / L Au at pH = 4. 3+In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. It is shaken at 25°C for 24 hours and filtered to obtain the adsorbent enriched with metal ions and the remaining solution after adsorption. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au 3+ The adsorption rate was 87.0%. The adsorbent was immersed in 302.1 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 44.0%.

[0045] Example 5

[0046] (1) Preparation of adsorbent

[0047] The experiment was carried out under the condition that the mass ratio of glutaraldehyde: polyethyleneimine (Mn=10000) was 10.68:1. 200 mg of polyethyleneimine and 2 mL of glutaraldehyde were weighed and dissolved in 8 mL of DMF. Ultrasonication was performed for 5 minutes to fully dissolve the solution to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0048] (2) The adsorbent was immersed in 85.8 mg / L Au at pH = 4. 3+ Solution and pH = 1 103.7mg / L Pd 2 + In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ and Pd 2+ The adsorption rates were 99.2% and 98.8%.

[0049] Example 6

[0050] (1) Preparation of adsorbent

[0051] The experiment was conducted under the condition that the mass ratio of glutaraldehyde:polyethyleneimine (Mn=10000) was 10.68:1. 200 mg of polyethyleneimine and 2 mL of glutaraldehyde were weighed and dissolved in 8 mL of water. Ultrasonication was performed for 5 minutes to fully dissolve the solution to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with anhydrous ethanol and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0052] (2) The adsorbent was immersed in 81.5 mg / L Au at pH = 4. 3+ The adsorbent was 10 mg and the solution volume was 20 mL. The mixture was shaken at 25 °C for 12 h and filtered to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Au 3+ The adsorption rate is 100%.

[0053] Example 7

[0054] (1) Preparation of adsorbent

[0055] The experiment was conducted under the condition that the mass ratio of glutaraldehyde:polyethyleneimine (Mn=1800) was 10.68:1. 200 mg of polyethyleneimine and 2 mL of glutaraldehyde were dissolved in 8 mL of DMF and fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0056] (2) The adsorbent was immersed in 528.3 mg / L Au at pH = 4. 3+ In the metal solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are filtered. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate was 91.03%. The adsorbent was immersed in 302.1 mg / L Pd 2+In the metal solution, the adsorbent is 10 mg and the solution volume is 20 mL. Oscillate at 25 ° C for 24 hours, filter to obtain the adsorbent enriched with metal ions and the remaining solution after adsorption. Use AA-6880 (atomic absorption spectrophotometer) to measure the metal ion concentration before and after adsorption. Calculate the Pd 2+ The adsorption rate is 56.0%.

[0057] Example 8

[0058] (1) Preparation of adsorbent

[0059] The experiment was conducted at a mass ratio of glutaraldehyde to polyethyleneimine (Mn = 600) of 10.68:1. 200 mg of polyethyleneimine and 2 mL of glutaraldehyde were weighed and dissolved in 8 mL of DMF. Ultrasonication was performed for 5 minutes to fully dissolve the solution to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0060] (2) The adsorbent was immersed in 528.3 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25°C for 24 hours, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The concentration of the solution before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). The Au 3+ The adsorption rate was 91.0%. The adsorbent was immersed in 302.1 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 44.1%.

[0061] Example 9

[0062] (1) Preparation of adsorbent

[0063] The experiment was carried out under the condition of glutaraldehyde: polyethyleneimine (Mn=10000) with a mass ratio of 8:1. 200 mg of polyethyleneimine and 1.5 mL of glutaraldehyde were weighed and dissolved in 8 mL of DMF. Ultrasonication was performed for 5 minutes to fully dissolve the solution to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0064] (2) The adsorbent was immersed in 100 mg / L Au at pH = 4. 3+ In the metal solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining solution after adsorption were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Au 3+ The adsorption rate is 99.8%.

[0065] Example 10

[0066] (1) Preparation of adsorbent

[0067] Example According to the different mass ratio of glutaraldehyde: polyethyleneimine (Mn=10000) of 4.21:1, 0.79mL of glutaraldehyde and 200mg of polyethyleneimine were weighed and dissolved in 8mL of DMF, and ultrasonicated for 5min to fully dissolve to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500rmp for 10h. The product was taken out and placed in a centrifuge for centrifugation at 6000r / min for 8min, and the supernatant was removed by suction. The product was washed with DMF, anhydrous ethanol and water for 3 times, then filtered and dried. The filtered sample was placed in a vacuum freeze drying box and vacuum dried for 24h to obtain a powder product.

[0068] (2) The adsorbent was immersed in 100 mg / L Au at pH = 4. 3+ In the metal solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining solution after adsorption were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Au 3+ The adsorption rate is 100%.

[0069] Embodiment 11

[0070] (1) Preparation of adsorbent

[0071] Example: 0.7 mL of glutaraldehyde and 500 mg of polyethyleneimine were weighed and dissolved in 8 mL of DMF at a mass ratio of 1.5:1. The mixture was fully dissolved by ultrasonication for 5 min to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 h. The product was taken out and placed in a centrifuge for centrifugation at 6000 r / min for 8 min, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol, and water, and then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 h to obtain a powder product.

[0072] (2) The adsorbent was immersed in 100 mg / L Au at pH = 4. 3+ In the metal solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate is 99.4%.

[0073] Example 12

[0074] (1) Preparation of adsorbent

[0075] Example: The conditions of different mass ratios of glutaraldehyde: polyethyleneimine (Mn=10000) were 0.83:1. 0.39 mL of glutaraldehyde and 500 mg of polyethyleneimine were dissolved in 8 mL of DMF, and fully dissolved by ultrasonication for 5 minutes to obtain solution A. Solution A was placed in a reaction tube at 40°C and stirred evenly at a speed of 500 rpm for 10 hours. The product was taken out and placed in a centrifuge and centrifuged at 6000 r / min for 8 minutes, and the supernatant was removed by suction. The product was washed three times with DMF, anhydrous ethanol and water in sequence, then filtered and dried. The filtered sample was placed in a vacuum freeze drying oven and vacuum dried for 24 hours to obtain a powder product.

[0076] (2) The adsorbent was immersed in 100 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate is 86.5%.

[0077] Example 13

[0078] (1) Preparation of adsorbent

[0079] The embodiment is carried out under the condition that the mass ratio of glutaraldehyde:polyethyleneimine (Mn=10000) is 0.40:1. 0.39mL glutaraldehyde and 1038mg polyethyleneimine are dissolved in 8mL DMF, and fully dissolved by ultrasonication for 5min to obtain solution A. Solution A is placed in a reaction tube at 40°C and stirred evenly at a speed of 500rmp for 10h. The product is taken out and placed in a centrifuge for centrifugation at 6000r / min for 8min, and the supernatant is removed by suction. The product is washed three times with DMF, anhydrous ethanol and water in sequence, then filtered and dried. The filtered sample obtained is placed in a vacuum freeze drying box and vacuum dried for 24h to obtain a powder product.

[0080] (2) The adsorbent was immersed in 100 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate is 89.2%.

[0081] Embodiment 14

[0082] The adsorbent prepared in Example 5 was immersed in 85.8 mg / L Au at pH = 1-9. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate is 95% to 100%. The adsorbent prepared in Example 5 is immersed in 103.7 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 12 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 98% to 100%.

[0083] Embodiment 15

[0084] Use 0.1-3M hydrochloric acid solution to prepare 97.1 mg / L Au 3+The adsorbent prepared in Example 5 was immersed in the solution, the adsorbent prepared in Example 5 was immersed in the solution, the adsorbent was 10 mg, and the solution volume was 20 mL. The mixture was shaken at 25°C for 12 hours, and the adsorbent enriched with metal ions and the adsorbed residual solution were filtered. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Au was calculated. 3+ The adsorption rate is 48% to 100%. Use 0.1-3M hydrochloric acid solution to prepare 105.0 mg / L Pd 2+ The adsorbent prepared in Example 5 was immersed in the solution, the adsorbent was 10 mg, and the solution volume was 20 mL. The mixture was shaken at 25 ° C for 12 h, and the adsorbent enriched with metal ions and the adsorbed residual solution were filtered. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Pd was calculated. 2+ The adsorption rate is 44% to 100%.

[0085] Example 16

[0086] The adsorbent prepared in Example 5 was immersed in 8.30 mg / L Au at pH = 4. 3+ Solution and pH = 1 9.18 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. Oscillate at 25°C for 1, 2, 3, 4, 5, 10, 20, 30, 45, and 60 min, and filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Among them, the calculated Au 3+ The adsorption rate of Pd 2+ The adsorption rate reached 99.7% in 4 min.

[0087] Embodiment 17

[0088] The adsorbent prepared in Example 5 was immersed in 523.9 mg / L Au at pH = 4. 3+ Solution and pH = 1 565.5 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. Oscillate at 25°C for 0, 10, 30, 60, 90, 120, 180, 360, 720, 1080 min, and filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. Use an atomic absorption spectrophotometer (AA-6880) to measure the metal ion concentration before and after adsorption. Calculate Au 3+The adsorption rate of Pd can reach 72% in 10 minutes, and the equilibrium is reached in 90 minutes, with an adsorption rate of 99.2% and an adsorption amount of 1040 mg / g. 2+ The adsorption rate can reach 68% of the adsorption equilibrium in 10 minutes, and the adsorption amount is 424 mg / g; it can reach 94% of the adsorption equilibrium in 90 minutes, and the adsorption amount is 588 mg / g.

[0089] Embodiment 18

[0090] The adsorbent prepared in Example 5 was immersed in 134.6 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 120 mL. After shaking for 4 h at 15, 25, 35 and 45 °C, the adsorbent enriched with metal ions and the remaining adsorbed solution were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Au 3+ The adsorption rates were 59.6%, 83.7%, 96.9% and 98.4%, and the adsorption amounts were 962, 1352, 1565 and 1589 mg / g, respectively. The adsorbent prepared in Example 5 was immersed in 301.5 mg / L Pd 2+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 15, 25, 35 and 45 ° C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution were obtained by filtration. The metal ion concentration before and after adsorption was measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rates were 83.0%, 84.8%, 85.6% and 87.9%, and the adsorption amounts were 500, 512, 516 and 530 mg / g, respectively.

[0091] Embodiment 19

[0092] The adsorbent prepared in Example 5 was immersed in 5-100 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Au is calculated. 3+ The adsorption rate is 99% to 100%. The adsorbent prepared in Example 5 is immersed in 5 to 500 mg / L Pd 2+In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25 °C for 24 h, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880). Pd 2+ The adsorption rate is 98% to 100% under the condition of 10 to 100 mg / L, and the adsorption amount can reach 555 mg / g.

[0093] Embodiment 20

[0094] The adsorbent prepared in Example 5 was immersed in 135.6 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg, and the solution volume is 5, 10, 15, 20, 25, 30, 40, 50, 60, 80, 100, 120 mL. Oscillate at 25 ° C for 24 hours, filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. Use an atomic absorption spectrophotometer (AA-6880) to measure the metal ion concentration before and after adsorption. Calculate Au 3+ The maximum adsorption capacity reaches 2575 mg / g.

[0095] Embodiment 21

[0096] The adsorbent prepared in Example 5 was immersed in a C Au 3+ = 100.7 mg / L Au 3+ , K + 、Zn 2+ , Pb 2+ , Cu 2+ In the aqueous solution of metal ions, Au: other metal ions (molar ratio) = 1:1, the adsorbent is 10 mg, and the solution volume is 20 mL. Oscillate at 25 ° C for 1 hour, filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. Use an atomic absorption spectrophotometer (AA-6880) to measure the metal ion concentration before and after adsorption. Calculate Au 3+ The adsorption rate is 99.7%, K + The adsorption rate of Zn is 0.3%. 2+ The adsorption rate of Pb is 0.6%. 2+ The adsorption rate is 0%, Cu 2+ The adsorption rate was 5.0%. The adsorbent prepared in Example 5 was immersed in a C Pd 2+ = 98.4 mg / L Pd 2+ , K + 、Zn 2+ , Pb 2+ , Cu 2+In the solution, Pd: other metal ions (molar ratio) = 1:1, the adsorbent is 10 mg, and the solution volume is 20 mL. Oscillate at 25 ° C for 4 hours, filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. Use an atomic absorption spectrophotometer (AA-6880) to measure the metal ion concentration before and after adsorption. Calculate Pd 2+ The adsorption rate is 99.2%, K + The adsorption rate of Pb is 0.6%. 2+ The adsorption rate of Zn was 2.3%. 2+ The adsorption rate is 0%, Cu 2+ The adsorption rate is 0%.

[0097] Embodiment 22

[0098] The adsorbent prepared in Example 5 was immersed in a C Pd 2+ =95.0mg / L, C Au 3+ = 99.7 mg / L Au 3 + , Pd 2+ , K + 、Zn 2+ , Pb 2+ , Cu 2+ In the aqueous solution of metal ions, Au: other metal ions (molar ratio) = 1:1, the adsorbent is 10 mg, and the solution volume is 20 mL. Oscillate at 25 ° C for 4 hours, filter to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. Use an atomic absorption spectrophotometer (AA-6880) to measure the metal ion concentration before and after adsorption. Calculate Au 3+ The adsorption rate of Pd was 99.7%. 2+ The adsorption rate of K + The adsorption rate of Zn was 2.0%. 2+ The adsorption rate of Pb is 1.1%. 2+ The adsorption rate of Cu 2+ The adsorption rate is 0%.

[0099] Embodiment 23

[0100] The adsorbent prepared in Example 5 was immersed in 104.6 mg / L Au at pH = 4. 3+ In the solution, the adsorbent is 10 mg and the solution volume is 20 mL. After shaking at 25°C for 24 hours, the adsorbent enriched with metal ions and the remaining adsorbed solution are obtained by filtration. The metal ion concentration before and after adsorption is measured using an atomic absorption spectrophotometer (AA-6880) to calculate Au 3+The adsorbent enriched with metal ions was washed three times with water, and 20 mL of 0.5 M thiourea and 1 M HCl solution was added and shaken at 25 °C for 24 h, and the desorbed metal ion solution was obtained by filtration. The metal ion concentration after desorption was measured using an atomic absorption spectrophotometer (AA-6880) to calculate Au 3+ The above steps were repeated for three cycles. The results showed that the adsorption rates of the three cycles were 99.3%, 98.8% and 99.8%, and the desorption rates of the three cycles were 99.3%, 98.7% and 94.2%.

[0101] Embodiment 24

[0102] The adsorbent prepared in Example 5 was immersed in a 109.1 mg / L Pd2+ solution with a pH of 1, with 10 mg of adsorbent and a solution volume of 20 mL. The mixture was shaken at 25°C for 24 h and filtered to obtain the adsorbent enriched with metal ions and the remaining adsorbed solution. The metal ion concentrations before and after adsorption were measured using an atomic absorption spectrophotometer (AA 6880). Pd 2+ The adsorbent enriched with metal ions was washed three times with water, 20 mL of 0.5 M thiourea and 1 M HCl solution was added, and the mixture was shaken at 25 °C for 24 h. The desorbed metal ion solution was obtained by filtration. The metal ion concentration after desorption was measured using an atomic absorption spectrophotometer (AA6880) to calculate the Pd 2+ The above steps were repeated for three cycles. The results showed that the adsorption rates were 99.7%, 99.4% and 99.4% respectively, and the desorption rates were 99.2%, 100% and 100% respectively.

[0103] The above examples only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but the technical scope thereof is not limited to the above embodiments. For those skilled in the art, various improvements and implementations can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A novel method for recovering gold and palladium ions by adsorption of PEI-based network polymers, characterized in that: The steps include: (1.1) Preparation of adsorbent: Weigh a certain amount of polyethyleneimine and glyoxal or malondialdehyde or succinaldehyde or glutaraldehyde or adipaldehyde and dissolve them in a solvent, react at 20-80°C for 2-24 hours under stirring, centrifuge and filter to remove the solution, repeatedly wash with N,N-dimethylformamide, anhydrous ethanol and deionized water to remove impurities, dry in a vacuum drying oven to constant weight, and grind to obtain the corresponding adsorbent powder; (1.2) Gold and palladium ion adsorption experiment: The powder is immersed in a certain volume of aqueous solution containing a certain concentration of gold or palladium ions, and shaken for a certain period of time at a certain acidity and temperature. The adsorbent enriched with metal ions and the residual solution after adsorption are obtained by filtration. The metal ion concentration of the solution before and after adsorption is tested by atomic absorption, and the adsorption rate and adsorption amount are calculated. The adsorbent is eluted with an acidic thiourea solution of a certain volume and concentration. The adsorbent after desorption can be reused.

2. The novel method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim 1, characterized in that: in step (1.1), the number average molecular weight of the polyethyleneimine is 600-10000 g / mol.

3. A new method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim (1), characterized in that: in step (1.1), the mass ratio of glyoxal or malondialdehyde or succindialdehyde or glutaraldehyde or adipaldehyde to polyethyleneimine is 0.40:1~10.68:

1.

4. A new method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim (1), characterized in that: in step (1.1), the solvent is water or N,N-dimethylformamide.

5. A novel method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim (1), characterized in that: In step (1.2), the acidity of the gold solution is H + The ion concentration is 10 -9 ~10 3 mol / L, pH of palladium solution is 10 -3 ~10 3 mol / L.

6. The novel method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim 1, characterized in that: in step (1.2), the time is 0 to 24 hours.

7. The novel method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim 1, characterized in that: in step (1.2), the gold ion concentration is 0-1200 mg / L, and the palladium ion concentration is 0-500 mg / L.

8. The novel method for recovering gold and palladium ions by adsorption of a PEI-based network polymer according to claim 1, characterized in that: in step (1.2), the temperature is 15-60°C.