Method for recovering gold in surface treatment liquid
By combining ion exchange resin pretreatment, photoelectric synergistic reduction, and nanofluid retention with titanate nanotube array electrodes and two-dimensional graphene/metal-organic framework nanofluidic channels, the low efficiency and pollution problems of traditional gold recovery methods have been solved, achieving a highly efficient and environmentally friendly gold recovery process.
Patent Information
- Application Number
- CN202511079876.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-04
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional methods for recovering gold by combining physical adsorption and photoelectrocatalysis suffer from low recovery rates, long processing times, and potential pollution.
By employing steps of ion exchange resin pretreatment, photoelectric synergistic reduction, nanofluid retention, and intelligent regeneration, combined with titanate nanotube array electrodes and two-dimensional graphene/metal-organic framework nanofluid channels, gold ions are reduced using photogenerated electrons and electric fields, and gold nanoparticles are exfoliated by pulsed laser. Automated control is achieved by integrating conductivity sensors and AI algorithms.
It achieves ultra-fast reduction and efficient retention of gold ions, increasing the recovery rate by 10 times, reducing energy consumption by 70%, and reducing environmental pollution through closed-loop resource utilization.
Smart Images
Figure CN120905727A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of recycling surface treatment liquid gold, and particularly relates to a method for recycling gold in a surface treatment liquid. BACKGROUND
[0002] Surface treatment liquid is widely used in industrial production, and contains various valuable metal components. Recycling the metals in the surface treatment liquid can not only reduce production costs, but also reduce environmental pollution.
[0003] In the field of wastewater gold recycling, traditional methods often use a combination of physical adsorption and photoelectrocatalysis. From the perspective of recovery rate, physical adsorption mainly relies on physical interactions between the adsorbent and gold ions, such as van der Waals forces and electrostatic attraction. However, these forces are relatively weak, and in complex wastewater environments, there are many competitive adsorption substances, such as other metal ions and organic impurities, which compete with gold ions for adsorption sites, resulting in a significant decrease in the selective adsorption capacity of the adsorbent for gold ions. Moreover, the adsorption capacity of the adsorbent is limited, and when saturation adsorption is reached, if desorption and regeneration cannot be effectively carried out in time, it will seriously affect the subsequent adsorption effect, making it difficult to achieve the ideal level of overall recovery rate.
[0004] In terms of time consumption, the physical adsorption process usually requires a long contact time to ensure that the adsorbent and gold ions in the wastewater are in sufficient contact and reach adsorption equilibrium; this is because the diffusion speed of gold ions in wastewater is slow, and the pore structure inside the adsorbent is complex, so gold ions need to diffuse for a long time to reach the adsorption site. In addition, in order to achieve efficient regeneration of the adsorbent, the desorption process also requires a large amount of time, usually requiring the use of a specific desorbent and long-time stirring or soaking; the photoelectrocatalytic reaction is also a relatively slow process, and the reduction and deposition of gold ions require a certain amount of time to complete, and in order to improve the reaction efficiency, the reaction conditions often need to be precisely controlled, such as adjusting the light intensity and bias voltage, which undoubtedly increases the complexity of the operation and the time cost. The entire recovery process involves multiple steps, each of which requires a certain amount of time to complete, resulting in a long overall recovery cycle, which cannot meet the needs of industrial production for efficient recovery.
[0005] Moreover, in the physical adsorption process, some adsorbents themselves have certain toxicity or are difficult to degrade, such as some heavy metal-containing adsorbents or organic synthetic adsorbents; during use, these adsorbents may leak or lose, entering water bodies or soil environments, causing potential harm to the ecological environment. SUMMARY
[0006] The present application aims at solving the problem of low recovery rate, time consumption and pollution in the traditional method of recovering gold from wastewater by combining physical adsorption and photoelectrocatalysis.
[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: a method for recovering gold from surface treatment liquid, comprising the following steps:
[0008] S1: pretreatment: removing macromolecular organic matter from gold-containing surface treatment liquid by ion exchange resin, and adjusting pH to 2-4;
[0009] S2: photoelectricity synergistic reduction: passing the pretreated solution into a photoelectricity catalysis reaction module, under the irradiation of ultraviolet-visible light and 0.5-2V bias, reducing gold ions in the solution into metal gold nanoparticles through gold-specific ligand modified on the surface of titanium salt nanotube array electrode (TNTAs);
[0010] S3: nanofluid interception: intercepting the metal gold nanoparticles through the two-dimensional graphene / metal organic framework (MOF) composite nanofluid channel integrated on the surface of the electrode, while allowing the treatment liquid to pass through;
[0011] S4: intelligent regeneration: when the online conductivity sensor detects that the gold ion concentration of the outlet liquid is ≤0.1ppm, starting the pulsed laser ablation device to peel off the intercepted gold nanoparticles and collect them.
[0012] As a further description of the above technical scheme:
[0013] The clamping groove is provided with a first clamping groove and a second clamping groove, the first clamping groove is located on the circumferential side of the overflow prevention surface, and the second clamping groove is located on the outer circumferential side of the first clamping groove.
[0014] As a further description of the above technical scheme:
[0015] The gold-specific ligand in S2 is a thiol group (-SH) or a thiosulfate group (-S2O3), which is modified on the surface of the TNTAs electrode through self-assembled monolayer technology, and the binding constant thereof with gold ions is ≥10 5 L / mol.
[0016] As a further description of the above technical scheme:
[0017] The wavelength of ultraviolet-visible light in S2 is 355-385nm, the light intensity is 50-500mW / cm 2 , the bias is 1V, and the reaction time is 15-30 minutes.
[0018] As a further description of the above technical scheme:
[0019] The surface charge density of the nanofluid channel in the S3 is -20 to -50 mV, which prevents the negatively charged impurity ions in the solution from entering the inside of the channel by electrostatic repulsion.
[0020] As a further description of the above technical solution:
[0021] In the S4, the laser wavelength of the pulsed laser ablation device is 355-1064 nm, the pulse width is 1-20 ns, and the energy density is 1-5 J / cm², which is used to strip the metal gold nanoparticles in a non-thermal melting state and maintain the nanoscale particle size distribution.
[0022] As a further description of the above technical solution:
[0023] Further comprising:
[0024] Electrode regeneration step: After the intelligent regeneration, the permeability of the nanofluid channel is restored by ultrasonic cleaning, and the cleaning liquid is deionized water or dilute hydrochloric acid.
[0025] As a further description of the above technical solution:
[0026] The collected metal gold nanoparticles are directly used to prepare 3D printing conductive ink or catalyst carriers, and the particle size distribution is 5-50 nm, and the specific surface area is ≥50 m 2 / g.
[0027] As a further description of the above technical solution:
[0028] In the S4, the recovery system automatically switches the operation mode according to the conductivity sensor signal: when the gold ion concentration is >0.1 ppm, the continuous recovery mode is maintained; when the gold ion concentration is ≤0.1 ppm, the intermittent cleaning mode is switched to and the laser stripping is started.
[0029] As described above, due to the adoption of the above technical solution, the beneficial effects of the present application are:
[0030] 1、In the present application, by combining photo-generated electrons (UV-Vis light excitation) and electric field assistance (low voltage 0.5-2V), gold ions are reduced to gold nanoparticles at a speed 10 times faster than traditional methods, and energy consumption is reduced by 70%.
[0031] 2、In the present application, a two-dimensional graphene / MOF composite nanofluid channel (pore size 0.5-2 nm) is used, which can effectively intercept gold nanoparticles (purity ≥99.9%) through size screening and surface charge effect, while allowing small molecules to pass through.
[0032] 3、The integrated conductivity sensor and AI algorithm in the application dynamically adjust light intensity, voltage and flow rate, realize continuous recovery and automatic cleaning switching, pulse laser strips gold layer and is directly used for 3D printing ink or catalyst, forms a closed loop resource, and reduces environmental pollution. BRIEF DESCRIPTION OF DRAWINGS
[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.
[0034] Fig. 1 A flow chart of the steps of a method for recovering gold in a surface treatment liquid.
[0035] Fig. 2 A graph of experimental data of a method for recovering gold in a surface treatment liquid. DETAILED DESCRIPTION
[0036] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.
[0037] In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0038] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.
[0039] It should be noted that: similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.
[0040] In the description of the embodiments of the present application, it should be noted that the terms "upper", "inner", etc. indicate the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the product of the present application is used, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.
[0041] In the description of the present application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "arrangement", "installation", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0042] Please refer to Figs. 1-2 The present application provides a technical solution: a method for recovering gold in surface treatment liquid, comprising the following steps:
[0043] S1: pretreatment: removing macromolecular organic matter from gold-containing surface treatment liquid by ion exchange resin, and adjusting pH to 2-4;
[0044] S2: photoelectricity synergistic reduction: passing the pretreated solution into a photoelectricity catalytic reaction module, under ultraviolet-visible light irradiation and 0.5-2V bias, reducing gold ions in the solution into metal gold nanoparticles through gold-specific ligand modified on the surface of titanium oxide nanotube array electrode (TNTAs);
[0045] S3: nanofluid interception: intercepting the metal gold nanoparticles by using two-dimensional graphene / metal organic framework (MOF) composite nanofluid channels (pore size 0.5-2nm) integrated on the surface of the electrode, while allowing the treatment liquid to pass through;
[0046] S4: intelligent regeneration: when the outlet liquid gold ion concentration detected by the online conductivity sensor is ≤0.1ppm, starting the pulsed laser ablation device to peel off the intercepted gold nanoparticles and collect them.
[0047] The gold-specific ligand in S2 is a thiol group (-SH) or a thiosulfate group (-S2O3), which is modified on the surface of the TNTAs electrode by self-assembled monolayer technology, and its binding constant with gold ions is ≥10 5 L / mol.
[0048] The ultraviolet-visible light wavelength in S2 is 355-385nm, and the light intensity is 50-500mW / cm 2, the bias is 1V, and the reaction time is 15-30 minutes.
[0049] The surface charge density of the nanofluid channel in S3 is -20 to -50 mV, which prevents the negatively charged impurity ions (such as CN, Cl-) in the solution from entering the inside of the channel through electrostatic repulsion.
[0050] In S4, the laser wavelength of the pulsed laser ablation device is 355-1064 nm, the pulse width is 1-20 ns, and the energy density is 1-5 J / cm², which is used to strip the metal gold nanoparticles in a non-thermal melting state and maintain the nanoscale particle size distribution.
[0051] A method for recycling gold in a surface treatment liquid, further comprising:
[0052] Electrode regeneration step: after the intelligent regeneration, the permeability of the nanofluid channel is restored by ultrasonic cleaning (40 kHz, 5 min), and the cleaning liquid is deionized water or dilute hydrochloric acid (pH=3).
[0053] The collected metal gold nanoparticles are directly used for preparing 3D printing conductive ink or catalyst carrier, and the particle size distribution is 5-50 nm, and the specific surface area is ≥50 m 2 / g.
[0054] In S4, the recovery system automatically switches the operation mode according to the conductivity sensor signal: when the gold ion concentration is >0.1 ppm, the continuous recovery mode is maintained; when the gold ion concentration is ≤0.1 ppm, the intermittent cleaning mode is switched to and the laser stripping is started.
[0055] Working principle: first, remove macromolecular organic matter and adjust the pH through pretreatment; then, in the photoelectricity cooperative reduction step, under specific light and bias, the gold ions are reduced to metal gold nanoparticles by the gold specific ligand modified on the surface of the TNTAs electrode; then, the two-dimensional graphene / MOF composite nanofluid channel is used to intercept the gold nanoparticles, and the treatment liquid is allowed to pass through; in the intelligent regeneration step, the system automatically switches the operation mode according to the online conductivity sensor signal: when the gold ion concentration of the outlet liquid is >0.1 ppm, the continuous recovery mode is maintained; when the concentration is ≤0.1 ppm, the intermittent cleaning mode is switched to and the pulsed laser ablation device is started, and the intercepted gold nanoparticles are stripped in a non-thermal melting state by using laser with specific parameters and collected, so as to realize the recycling of gold and the intelligent regeneration of the device.
[0056] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.
Claims
1. A method for recovering gold from a surface treatment liquid, characterized by, The method comprises the following steps: S1： Pre-treatment: removing macromolecular organic substances from the gold-containing surface treatment solution by ion exchange resin and adjusting the pH to 2-4; S2: photoelectricity synergistic reduction: passing the pre-treated solution into a photoelectricity catalytic reaction module, and reducing gold ions in the solution into metal gold nanoparticles by specific ligands on the surface of titanium nanotube array electrodes (TNTAs) under ultraviolet-visible light irradiation and 0.5-2V bias; S3: nanofluid interception: intercepting the metal gold nanoparticles by using two-dimensional graphene / metal organic framework (MOF) composite nanofluid channels integrated on the surface of the electrodes, while allowing the treatment solution to pass through; S4: intelligent regeneration: when the online conductivity sensor detects that the gold ion concentration of the outlet liquid is ≤0.1ppm, starting a pulsed laser ablation device to strip the intercepted gold nanoparticles and collecting them.
2. The method of recovering gold from a surface treatment solution according to claim 1, wherein The gold-specific ligand in S2 is a thiol group (-SH) or a thiosulfate group (-S2O3) modified on the surface of the TNTAs electrode by self-assembled monolayer technology, and the binding constant with gold ions is ≥ 10 5 L / mol.
3. The method of claim 1, wherein, In the photoelectric synergistic reduction step, the wavelength of the ultraviolet-visible light in S2 is 355-385 nm, the light intensity is 50-500 mW / cm 2 , the bias is 1 V, and the reaction time is 15-30 minutes.
4. The method of claim 1, wherein the surface treatment liquid is a solution of gold chloride. The surface charge density of the nanofluid channel in S3 is -20 to -50mV, which prevents negatively charged impurity ions in the solution from entering the inside of the channel by electrostatic repulsion.
5. The method of claim 1, wherein the surface treatment liquid is a solution of gold chloride. In S4, the pulsed laser ablation device has a laser wavelength of 355-1064nm, a pulse width of 1-20ns, and an energy density of 1-5J / cm², which is used to strip the metal gold nanoparticles in a non-thermal melting state and maintain their nanoscale particle size distribution.
6. The method of recovering gold from a surface treatment solution according to claim 1, wherein Further comprising: Electrode regeneration step: after the intelligent regeneration, the permeability of the nanofluid channel is restored by ultrasonic cleaning, and the cleaning liquid is deionized water or dilute hydrochloric acid.
7. The method of claim 1, wherein the surface treatment liquid is a solution of gold chloride. The collected metal gold nanoparticles are directly used for preparing 3D printing conductive ink or catalyst carrier, with a particle size distribution of 5-50 nm, a specific surface area of ≥50 m 2 / g.
8. The method of claim 1, wherein the surface treatment liquid is a solution of gold chloride. In S4, the recovery system automatically switches the operation mode according to the conductivity sensor signal: when the gold ion concentration is >0.1ppm, the continuous recovery mode is maintained; when the gold ion concentration is ≤0.1ppm, the intermittent cleaning mode is switched to and the laser stripping is started.