Disclosure of Invention
The invention mainly aims to provide a method and a system for recovering gold-containing wastewater, and aims to realize efficient recovery of gold in the gold-containing wastewater.
In order to achieve the purpose, the recovery method of the gold-containing wastewater provided by the invention comprises the following steps:
carrying out electrolysis operation on the first gold-containing wastewater to obtain metal gold;
mixing the electrolyzed first gold-containing wastewater with the electrolyzed second gold-containing wastewater to obtain mixed wastewater;
and carrying out adsorption operation on the mixed wastewater by adopting gold adsorption resin to obtain gold-loaded resin.
Optionally, in the step of performing an electrolysis operation on the first gold-containing wastewater to obtain metallic gold, the method comprises the following steps:
and (3) introducing the first gold-containing wastewater into an electrolytic bath, electrolyzing by taking an insoluble electrode as an anode and a titanium mesh as a cathode at the electrolytic voltage of 1.2V-2.0V, and depositing on the surface of the cathode to obtain the metallic gold.
Optionally, in the step of mixing the electrolyzed first gold-containing wastewater and the second gold-containing wastewater to obtain a mixed wastewater, the method comprises:
and mixing the electrolyzed first gold-containing wastewater and the electrolyzed second gold-containing wastewater in a mass ratio of 1:1 to 2:1, and stirring to obtain mixed wastewater.
Optionally, in the step of performing an adsorption operation on the mixed wastewater by using a gold-adsorbing resin, the method includes:
and continuously introducing the mixed wastewater into a resin adsorption tank containing the gold adsorption resin, wherein the introduction flow range of the mixed wastewater is 2-5 times of the volume of the gold adsorption resin per hour.
Optionally, the number of times of adsorption operation on the mixed wastewater by using gold adsorption resin is defined as N, and the value range of N is 2-4.
Optionally, before the step of performing the electrolysis operation on the first gold-containing wastewater, the method further comprises:
filtering the first gold-containing wastewater to remove coarse particle impurities in the first gold-containing wastewater;
and/or before the gold-adsorbing resin is adopted to perform adsorption operation on the mixed wastewater, the method further comprises the following steps:
filtering the mixed wastewater to remove coarse particle impurities in the mixed wastewater;
and/or after the step of carrying out adsorption operation on the mixed wastewater by adopting gold adsorption resin to obtain gold-loaded resin, the method further comprises the following steps:
and when the gold content in the adsorbed mixed wastewater is detected to be less than a preset value, replacing the gold adsorption resin.
The invention also provides a recovery system of the gold-containing wastewater, which is applied to the recovery method of the gold-containing wastewater, and the recovery system of the gold-containing wastewater comprises the following steps: a first gold-containing wastewater collection tank for containing a first gold-containing wastewater; a second gold-containing wastewater collection tank for containing a second gold-containing wastewater; an inlet of the electrolysis device is communicated with an outlet of the first gold-containing wastewater collection tank; an inlet of the liquid storage tank is communicated with an outlet of the electrolysis device and an outlet of the second gold-containing wastewater collecting tank; and the resin adsorption tank is internally provided with gold adsorption resin, and the inlet of the resin adsorption tank is communicated with the outlet of the liquid storage tank.
Optionally, the electrolysis device comprises an electrolysis cell, a cathode, an anode and a diaphragm, wherein the cathode, the anode and the diaphragm are all arranged in the electrolysis cell, the diaphragm divides the electrolysis cell into an anode chamber and a cathode chamber, the anode is arranged in the anode chamber, and the cathode is rotatably arranged in the cathode chamber.
Optionally, the resin adsorption tank is provided with a plurality of, and is a plurality of resin adsorption tank sets up in series, and is a plurality of among the resin adsorption tank along the liquid flow direction lie in the resin adsorption tank foremost resin adsorption tank communicate in the liquid storage pot.
Optionally, the system for recovering gold-containing wastewater further comprises a first filtering device, the first filtering device is disposed between the first gold-containing wastewater collection tank and the electrolysis device, an inlet of the first filtering device is communicated with an outlet of the first gold-containing wastewater collection tank, and an outlet of the first filtering device is communicated with an inlet of the electrolysis device;
and/or, the recovery system of gold-containing waste water still includes second filter equipment, second filter equipment set up in the liquid storage pot with between the resin adsorption tank, second filter equipment's import communicate in the export of liquid storage pot, second filter equipment's export communicate in the import of resin adsorption tank.
According to the technical scheme, the first gold-containing wastewater is subjected to electrolysis operation to obtain the metallic gold, the purity of the metallic gold is high, the content of the gold in the first gold-containing wastewater is reduced through the electrolysis operation, then the electrolyzed first gold-containing wastewater and the electrolyzed second gold-containing wastewater are mixed to obtain mixed wastewater, and finally gold-adsorbing resin is adopted to perform adsorption operation on the mixed wastewater to obtain the gold-loaded resin. The recovery method is simple to operate, can realize the efficient recovery of gold in the gold-containing wastewater, changes waste into valuable, and has high economic value. Meanwhile, compared with the existing treatment method, the treatment cost is greatly reduced, and no secondary wastewater is generated.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that all the directional indicators (such as up, down, left, right, front, and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the movement situation, etc. in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indicator is changed accordingly.
In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "connected," "secured," and the like are to be construed broadly, and for example, "secured" may be a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In addition, the technical solutions in the embodiments of the present invention may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination of technical solutions should not be considered to exist, and is not within the protection scope of the present invention.
The invention provides a method for recovering gold-containing wastewater, which is used for treating and recovering the gold-containing wastewater. The gold-containing wastewater comprises first gold-containing wastewater and second gold-containing wastewater, the content of gold in the first gold-containing wastewater is higher than that in the second gold-containing wastewater, under normal conditions, the first gold-containing wastewater is from a failed and scrapped gold plating solution and wastewater generated by first-stage washing, and the content of gold is in a range of 0.1g/L to 0.2 g/L; the second gold-containing wastewater is wastewater generated by the second-stage water washing or the third-stage water washing, wherein the content of gold is in a range of 2ppm to 3ppm, and the part of the gold-containing wastewater cannot be subjected to electrolytic operation to recover gold.
Referring to fig. 1, in an embodiment of the method for recovering gold-containing wastewater of the present invention, the method for recovering gold-containing wastewater includes the following steps:
step S10, carrying out electrolysis operation on the first gold-containing wastewater to obtain metallic gold;
step S20, mixing the electrolyzed first gold-containing wastewater and the electrolyzed second gold-containing wastewater to obtain mixed wastewater;
and step S30, carrying out adsorption operation on the mixed wastewater by adopting gold adsorption resin to obtain gold-loaded resin.
Specifically, the content of gold in the first gold-containing wastewater is high, and the metallic gold can be recovered by adopting electrolysis operation, namely, the first gold-containing wastewater is subjected to electrolysis operation, because the potential of gold is relatively positive, the gold is easily deposited on the surface of a cathode, the purity of the metallic gold obtained by deposition is high, the purity of the metallic gold is generally higher than 95%, the content of gold in the first gold-containing wastewater after electrolysis operation is greatly reduced, and generally, the content of gold in the first gold-containing wastewater after electrolysis operation can be reduced to 2ppm to 10 ppm. And then mixing the first gold-containing wastewater and the second gold-containing wastewater after the electrolysis operation to obtain mixed wastewater, wherein the mixed wastewater cannot be subjected to the electrolysis operation due to the low gold content, and the mixed wastewater can be subjected to adsorption operation by using gold adsorption resin to obtain gold-loaded resin which can be directly recycled, and the gold-loaded resin can also be recycled by an incineration metallurgy method or an acid pickling method.
Therefore, it can be understood that in the technical scheme of the invention, the first gold-containing wastewater is subjected to electrolysis operation to obtain the metallic gold, the purity of the metallic gold is higher, the content of the gold in the first gold-containing wastewater is reduced by the electrolysis operation, then the electrolyzed first gold-containing wastewater and the electrolyzed second gold-containing wastewater are mixed to obtain mixed wastewater, and finally the mixed wastewater is subjected to adsorption operation by adopting the gold adsorption resin to obtain the gold-loaded resin. The recovery method is simple to operate, can realize the efficient recovery of gold in the gold-containing wastewater, changes waste into valuable, and has high economic value. Meanwhile, compared with the existing treatment method, the treatment cost is greatly reduced, and no secondary wastewater is generated.
It should be noted that, the gold-adsorbing resin is a strong base anion exchange resin, such as a strong base anion exchange resin with a polystyrene structure, which can adsorb gold efficiently.
Further, in step S10, the method includes: and (3) introducing the first gold-containing wastewater into an electrolytic bath, electrolyzing by taking an insoluble electrode as an anode and a titanium mesh as a cathode at the electrolytic voltage of 1.2V-2.0V, and depositing on the surface of the cathode to obtain the metallic gold.
The first gold-containing wastewater is used as an electrolyte and is introduced into an electrolytic cell, an insoluble electrode is used as an anode, the insoluble electrode can be an inert metal electrode, such as a lead electrode or a titanium electrode, of course, a graphite electrode and a titanium mesh are used as a cathode, and the electrolytic voltage is controlled to be 1.2V, 1.4V, 1.6V, 1.8V or 2.0V, so that the high-efficiency electrolytic operation can be carried out. If the electrolytic voltage is lower, the electrolytic rate is slower, and the gold is harder and is not easy to fall off from the surface of the cathode, and if the electrolytic voltage is higher, the electrolytic rate is faster, and the gold is easy to fall off from the surface of the cathode and enter the electrolyte. It is understood that when the electrolysis operation is carried out, the anode generates oxygen gas, and the surface of the cathode is deposited to obtain metal gold with higher purity.
It should be noted that, because oxygen is generated by the electrolysis operation, the components such as cyanide ions and citrate ions in the first gold-containing wastewater can be decomposed or absorbed, thereby avoiding resource waste and realizing the reuse of the wastewater.
Further, in step S20, the method includes: and mixing the electrolyzed first gold-containing wastewater and the electrolyzed second gold-containing wastewater in a mass ratio of 1:1 to 2:1, and stirring to obtain mixed wastewater.
Because the content of the gold in the second gold-containing wastewater is lower than that in the electrolyzed first gold-containing wastewater, a proper proportion of the gold in the second gold-containing wastewater and the electrolyzed first gold-containing wastewater is selected in order to ensure that the adsorption efficiency of the mixed gold and the electrolyzed first gold-containing wastewater is higher, for example, the mass ratio of the electrolyzed first gold-containing wastewater to the electrolyzed second gold-containing wastewater is 1:1, 1.5:1 or 2: 1.
Further, in the step of step S30, the method includes:
the mixed wastewater is continuously introduced into a resin adsorption tank 50 containing the gold-adsorbing resin, and the introduction flow rate of the mixed wastewater is in the range of 2 to 5 times the volume of the gold-adsorbing resin per hour.
The flow rate of the mixed wastewater is controlled to be 2 times, 3 times, 4 times or 5 times of the volume of the gold adsorption resin per hour, so that the gold in the mixed wastewater can be more effectively adsorbed, the gold adsorption efficiency is improved, and the yield of the gold-loaded resin is improved. The gold content in the mixed wastewater after resin adsorption is low or even no gold is contained, and the mixed wastewater can be directly discharged to a sewage treatment station for unified treatment.
The number of times of adsorption operation of the mixed wastewater by adopting the gold adsorption resin is defined as N, and the value range of N is 2-4. The mixed wastewater is subjected to multiple adsorption operations, so that the gold in the mixed wastewater can be more fully and effectively adsorbed onto the resin, and the gold adsorption efficiency and the yield of the gold-loaded resin are improved. Generally, the adsorption operation times are 2, 3 or 4, so that the gold in the mixed wastewater can be effectively adsorbed, and the cost of the adsorption operation can be saved.
Referring to fig. 2, before step S10, the method further includes:
and step S01, filtering the first gold-containing wastewater to remove coarse particle impurities.
Generally, the first gold-containing wastewater is filtered by using a cotton core, and the pore size of the cotton core is 1 μm, so that coarse particle impurities in the first gold-containing wastewater can be effectively removed to prevent the coarse particle impurities from influencing the subsequent electrolysis operation.
Further, before step S30, the method further includes:
and step S21, filtering the mixed wastewater to remove coarse particle impurities.
Here, the mixed wastewater is usually filtered by using a 1 μm cotton core to remove coarse particles of impurities in the mixed wastewater, so as to prevent the coarse particles of impurities from affecting the subsequent resin adsorption operation.
Further, after step S30, the method further includes:
and step S40, when the content of gold in the adsorbed mixed wastewater is detected to be less than a preset value, replacing the gold adsorption resin.
After the resin adsorption operation, the content of gold in the mixed wastewater is greatly reduced, the gold-adsorbing resin gradually reaches a saturated state along with the continuation of the adsorption process, when the content of gold in the gold-adsorbing resin is less than a preset value, the gold-adsorbing resin is saturated, and the gold-adsorbing resin needs to be replaced at the moment, wherein the preset value is generally 1 ppm.
The invention also provides a recovery system 100 of the gold-containing wastewater, which is applied to the recovery method of the gold-containing wastewater.
Referring to fig. 3, in an embodiment of the recycling system 100 for gold-containing wastewater of the present invention, the recycling system 100 for gold-containing wastewater includes: a first gold-containing wastewater collection tank 10, the first gold-containing wastewater collection tank 10 being configured to contain a first gold-containing wastewater; a second gold-containing wastewater collection tank 20, the second gold-containing wastewater collection tank 20 being configured to contain second gold-containing wastewater; an inlet of the electrolysis device 30 is communicated with an outlet of the first gold-containing wastewater collection tank 10; a liquid storage tank 40, wherein the inlet of the liquid storage tank 40 is communicated with the outlet of the electrolysis device 30 and the outlet of the second gold-containing wastewater collection tank 20; and a resin adsorption tank 50, wherein the resin adsorption tank 50 is filled with gold-adsorbing resin, and the inlet of the resin adsorption tank 50 is communicated with the outlet of the liquid storage tank 40.
Here, first gold-containing wastewater collection tank 10 is used for collecting first gold-containing wastewater, second gold-containing wastewater collection tank 20 is used for collecting second gold-containing wastewater, the export of first gold-containing wastewater collection tank 10 is communicated with the import of electrolytic device 30 through the pipeline, can carry the first gold-containing wastewater in first gold-containing wastewater collection tank 10 to electrolytic device 30 in and carry out the electrolysis operation like this, obtain metallic gold at electrolytic device 30's negative pole surface deposition, metallic gold's purity is not less than 95%, like this, can reduce the content of gold in first gold-containing wastewater through the electrolysis operation, make the content of gold in the first gold-containing wastewater after the electrolysis treatment be less than 10 ppm. The outlet of the electrolysis device 30 and the second gold-containing wastewater collection tank 20 are both connected to the inlet of the storage tank 40 through pipelines, and the outlet of the storage tank 40 is connected to the resin adsorption tank 50 through pipelines, so that the first gold-containing wastewater and the second gold-containing wastewater after electrolysis operation are conveyed to the storage tank 40 to be mixed, generally, the two are mixed in a mass ratio of 1:1 to 2: 1. The two are mixed and then conveyed into a resin adsorption tank 50, and gold adsorption resin in the resin adsorption tank 50 adsorbs gold in the mixed wastewater to obtain gold-loaded resin which can be directly recovered. When the resin adsorption is saturated, the gold-adsorbing resin in the resin adsorption tank 50 is replaced, generally, when the gold content in the adsorbed mixed waste water is detected to be less than 1ppm, the resin adsorption is saturated, and at this time, the gold-adsorbing resin needs to be replaced, and the adsorbed mixed waste water can be directly discharged for treatment.
It should be noted that, the gold-adsorbing resin is a strong base anion exchange resin, such as a strong base anion exchange resin with a polystyrene structure, which can adsorb gold efficiently.
The recovery system 100 of the gold-containing wastewater can efficiently recover gold therein, has high economic benefit, does not generate secondary wastewater, and can partially recycle the treated wastewater to change waste into valuable. And the used equipment has small volume, small occupied area, easy maintenance and less electric energy consumption.
Further, the electrolysis device 30 includes an electrolysis cell, a cathode, an anode and a diaphragm, wherein the cathode, the anode and the diaphragm are all disposed in the electrolysis cell, the diaphragm divides the electrolysis cell into an anode chamber and a cathode chamber, the anode is disposed in the anode chamber, and the cathode is rotatably disposed in the cathode chamber.
Here, the cathode is rotatably provided to the cathode chamber so that the cathode is kept rotating during the electrolysis operation, which makes it possible to more sufficiently contact with the electrolyte so that gold can be more sufficiently adsorbed to the surface of the cathode to improve the yield of gold. Generally, a low-power motor is arranged at the top or the side part of the electrolytic cell, and an output shaft of the motor extends into a cathode chamber of the electrolytic cell and is in transmission connection with the cathode, so that the driving motor can drive the cathode to rotate.
Optionally, the cathode is a mesh structure, such as a titanium mesh, which can increase the specific surface area of the cathode, so that more gold is deposited on the surface of the cathode, thereby further improving the yield of gold.
Alternatively, a plurality of resin adsorption tanks 50 are provided, the plurality of resin adsorption tanks 50 are arranged in series, and the resin adsorption tank 50 positioned foremost in the plurality of resin adsorption tanks 50 in the liquid flow direction communicates with the liquid reservoir tank 40. Here, a plurality of resin adsorption tanks 50 are provided, that is, the mixed wastewater is subjected to multiple adsorption operations, so that gold in the mixed wastewater can be more sufficiently and effectively adsorbed onto the resin, and the gold adsorption efficiency and the yield of gold-loaded resin can be improved. Generally, the resin adsorption tanks 50 are provided with 2, 3, or 4, so that gold in the mixed wastewater can be adsorbed more effectively, and the cost of the adsorption operation can be saved.
Further, the recycling system 100 for gold-containing wastewater further includes a first filtering device 60, the first filtering device 60 is disposed between the first gold-containing wastewater collection tank 10 and the electrolysis device 30, an inlet of the first filtering device 60 is communicated with an outlet of the first gold-containing wastewater collection tank 10, and an outlet of the first filtering device 60 is communicated with an inlet of the electrolysis device 30.
The first filtering device 60 is configured to filter the first gold-containing wastewater before the electrolysis operation, so as to effectively remove coarse impurities in the first gold-containing wastewater, thereby preventing the coarse impurities from affecting the subsequent electrolysis operation.
Further, the recovery system 100 for gold-containing wastewater further includes a second filtering device 70, the second filtering device 70 is disposed between the liquid storage tank 40 and the resin adsorption tank 50, an inlet of the second filtering device 70 is communicated with an outlet of the liquid storage tank 40, and an outlet of the second filtering device 70 is communicated with an inlet of the resin adsorption tank 50.
The second filtering device 70 is arranged to filter the mixed wastewater before the resin adsorption operation, so as to effectively remove coarse particle impurities in the mixed wastewater, thereby preventing the coarse particle impurities from influencing the subsequent resin adsorption operation and prolonging the service life of the gold adsorption resin.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.