KR102035296B1 - The method for recovering of gold from gold-absorbed ion exchange resin - Google Patents

Abstract

The present invention relates to a method for recovering gold from a god-adsorbed ion exchange resin from leaching liquid or waste liquid of a gold-containing material and, more specifically, to a method for recovering gold from a gold-adsorbed ion exchange resin which pyrolyzes a god-adsorbed ion exchange resin and then recovers gold powder by leaching and reducing steps instead of a conventional method of using detaching liquid in a god-adsorbed ion exchange resin to detach and recover gold. And the present invention has an advantage of recovering gold powder by reducing most of gold in leaching liquid by supplying a proper amount of a reducer to gold leaching liquid to leach most of gold contained in an ion exchange resin by a leaching process of residuals remaining in a pyrolysis process of a god-adsorbed ion exchange resin. And the present invention has an advantage of recovering high-purity gold powder by a step of washing gold powder recovered in a reducing step and recovering gold powder of high purity of 99.95% or higher by repeatedly performing a leaching step, a reducing step, and a washing step to further improve purity of recovered gold powder.

Description

The method for recovering of gold from gold-absorbed ion exchange resin}

The present invention is a method for recovering the gold from the leachate of the gold-containing raw material or the ion-exchange resin adsorbed gold from the waste liquid, the conventional method for desorbing and recovering the gold by using a desorption solution to the ion-exchange resin adsorbed gold and In another aspect, the present invention relates to a method for recovering gold from a gold adsorption ion exchange resin, characterized in that the gold powder is recovered by pyrolysis, and then leaching and reducing.

Gold is the most malleable and ductile among the metals, and has the characteristics of inertness and high electrical conductivity, so it is a precious metal widely used in the electrical and electronics industry such as plating terminals, printed circuits, and semiconductors, and it does not recycle industrial waste containing gold. Disposal will result in huge losses.

As a method for recovering gold from industrial wastes containing gold, industrial ions such as plating terminals, printed circuit boards (PCB) substrates or semiconductors are pulverized by conventional pretreatment methods, and gold ions are removed using acid or alkali desorption liquids. A method of adsorbing gold from an leachate or a waste liquid from which is separated by using an ion exchange resin and then recovering the gold through a substitution method or a reduction method is adopted.

Various types of ion exchange resin devices have been developed as a method for adsorbing gold from leachate from which gold is separated by pretreatment of industrial waste containing gold. Looking at the various ion exchange resin devices that are being developed in this way, by providing a compact precious metal recovery device in Patent Document 1, maximize the utilization of the space, by preventing the solidification of the ion resin to recover the precious metal precious metal recovery rate The ion resin tower for recovering precious metals having a structure as shown in FIG. 1 is known as a means for increasing the amount, and in Patent Document 2, the surface area of the ion exchange resin to which the precious metal is adsorbed can be increased to significantly increase the recovery rate of the precious metals and recover the precious metals. A noble metal ion exchange resin flow recovery device as shown in FIG. 2 is known so that time can be shortened and the size of the noble metal recovery device can be reduced.

As a method of recovering gold using the ion exchange resin devices as described above, a method of recovering a noble metal element from an electronic waste by using a chelating resin is disclosed in Patent Document 3, but as shown in FIG. It is known to recover the precious metal element from the electronic waste by using a chelate resin by desorption using the eluent, and to selectively recover the gold from the printed circuit board scrap in Patent Document 4, as shown in Figure 4 copper leaching After the step (S300) and then the gold leaching step (S400) of adsorbing and recovering the gold through the step (S500) is known how to recover the gold, depending on the type of leachate or waste liquid of the gold-containing raw material The type of desorption liquid used depends on the type of ion exchange resin adsorbed. Therefore, there is a possibility that the desorption rate of gold will be lowered accordingly, and it will be difficult to secure a stable recovery rate.

Accordingly, the present inventors have made it possible to leach most of the gold contained in the ion exchange resin through the pyrolysis step of the ion exchange resin adsorbed gold in order to improve the above disadvantages, and powder most of the gold from the leach solution. The present invention has been completed by allowing the recovery of the gold powder at a high recovery rate by reducing it to a state.

Patent Document 1: Domestic Patent Publication No. 10-1436861 (September 05, 2014 announcement) Ion resin tower for precious metal recovery Patent Document 2: Domestic Utility Model Publication No. 20-0474133 (August 23, 2014) Precious Metal Ion Exchange Resin Flow Collector Patent Document 3: Korean Patent Application Publication No. 10-2001-0067641 (published Jul. 13, 2001) A method for recovering precious metal elements from electronic waste using a chelating resin Patent Document 4: Domestic Patent Publication No. 10-1229766 (February 05, 2013 announcement) Method for selectively recovering gold from printed circuit board scrap

In order to solve the above problems, the present invention is characterized in that the leaching of most of the gold contained in the ion exchange resin through the pyrolysis step of the ion-exchange resin adsorbed gold and the leaching step of the residue after pyrolysis. A method for recovering gold from gold adsorption ion exchange resins is a subject.

And another object of the present invention is to provide a method for recovering gold from the gold adsorption ion exchange resin, characterized in that by reducing the amount of reducing agent in the gold leachate, it is possible to reduce most of the gold in the leachate to recover as a gold powder. .

In addition, in the present invention, the gold powder recovered in the reduction step is capable of recovering the gold powder of higher purity through the washing step, and in order to further improve the purity of the recovered gold powder, the leaching step, the reducing step and the washing step are repeated several times. Another object of the present invention is to provide a method for recovering gold from a gold adsorption ion exchange resin, wherein the gold powder having a high purity of 99.95% or more can be recovered by performing repeatedly.

The present invention for solving the above problems is a method for recovering the gold from the ion-exchange resin adsorbed gold from the leaching liquid or waste liquid of the gold-containing raw material, the thermal decomposition step of the gold-adsorbed ion exchange resin (S100); Leaching step (S200) for leaching the gold contained in the residue after pyrolysis in the pyrolysis step (S100); A reduction step (S300) of recovering the gold powder by adding and reacting a reducing agent to the gold leaching solution generated in the leaching step (S200); A washing step (S400) of washing the gold powder generated in the reducing step (S300) with a nitric acid solution and then using pure water to improve the purity of the gold powder; The method for recovering gold from the gold adsorption ion exchange resin, characterized in that it comprises a drying step (S500) of recovering the dried gold powder by removing the moisture of the gold powder generated by the washing step (S400) It is a means of resolution.

And the step of pyrolysis (S100), pyrolysis for 2 to 8 hours at a temperature of 900 ~ 950 ℃, the reduction step (S300), characterized in that ascorbic acid in the ratio of 3 to 5 compared to the theoretical theoretical amount do.

According to the present invention, an amount of a reducing agent is added to the gold leach solution so that most of the gold contained in the ion exchange resin is leached out through the leaching of the residues remaining during the pyrolysis of the ion exchange resin to which gold is adsorbed, thereby reducing most of the gold in the leach solution. The advantage is that it can be recovered as gold powder.

In the present invention, the gold powder recovered in the reduction step is capable of recovering the gold powder of higher purity through the washing step, and in order to further improve the purity of the recovered gold powder, the leaching step, the reducing step and the washing step are repeated. It is an advantage that high purity gold powder of 99.95% or more can be recovered.

1 is a schematic view showing a conventional ion resin tower for the recovery of precious metals.
Figure 2 is a schematic diagram showing the internal state of a conventional precious metal ion exchange resin flow recovery device.
Figure 3 is a process block diagram showing a process for recovering the precious metal using a conventional ion exchange resin device.
Figure 4 is a process block diagram showing a process for recovering gold using a conventional ion exchange resin device.
Figure 5 is a process block diagram showing a process for recovering gold from the gold adsorption ion exchange resin according to the present invention.

With reference to the accompanying drawings, a method for recovering gold from the gold adsorption ion exchange resin according to the present invention will be described only the parts necessary to understand the technical configuration of the present invention, the description of the other parts scatter the gist of the present invention. Note that it will be omitted so as not to fall short.

According to a feature of the present invention for solving the above and the problems, through the pyrolysis step of the ion-exchange resin adsorbed gold, most of the gold contained in the ion-exchange resin can be leached, most of the gold from the leaching liquid By reducing to, it is possible to recover the gold powder at a high recovery rate.

In the meantime, as a method for recovering gold from the leachate of a gold-containing raw material or an ion exchange resin in which gold is adsorbed from waste liquid, a solution obtained by separating gold ions using an acid or alkali desorption solution is obtained. The gold is recovered through the process, and the type of ion exchange resin varies depending on the type of leaching liquid or waste liquid of the gold-containing raw material, and the type of desorbent used depends on the type of adsorbed ion exchange resin. . Accordingly, there is a possibility that the desorption rate of gold is lowered, and it is difficult to secure a stable recovery rate.

5 is a process block diagram showing a process for recovering gold from a gold adsorption ion exchange resin according to the present invention, which recovers gold from an ion exchange resin that adsorbs gold from a leach solution or waste liquid of a gold-containing raw material. A flowchart illustrating the method is shown.

In the method for recovering gold from the gold adsorption ion exchange resin according to the present invention, as shown in Figure 5, in the method of recovering gold from the ion exchange resin adsorbed gold from the leaching liquid or waste liquid of the gold-containing raw material,

Pyrolysis step (S100) of the gold-adsorbed ion exchange resin;

Leaching step (S200) for leaching the gold contained in the residue after pyrolysis in the pyrolysis step (S100);

A reduction step (S300) of recovering the gold powder by adding and reacting a reducing agent to the gold leaching solution generated in the leaching step (S200);

A washing step (S400) of washing the gold powder generated in the reducing step (S300) with a nitric acid solution and then using pure water to improve the purity of the gold powder;

It characterized in that it comprises a drying step (S500) to recover the dried gold powder by removing the water of the gold powder generated by the washing step (S400).

The method for recovering gold from the gold adsorption ion exchange resin according to the present invention will be described below in detail for each step.

(1) pyrolysis step (S100)

This step is a step of pyrolyzing the components other than gold of the ion-exchange resin adsorbed gold, preferably pyrolyzed at a temperature of 900 to 950 ° C. for 2 to 8 hours. When the pyrolysis condition is less than the above-defined range, there is a concern that components other than gold adsorbed on the ion exchange resin may not be sufficiently removed, and when the pyrolysis condition exceeds the above-defined range, In addition to the increase in the consumption of the process, the efficiency of the process is lowered due to the delay of pyrolysis time.

Therefore, if the pyrolysis of the ion exchange resin adsorbed gold in the above thermal decomposition conditions to remove the components other than the gold adsorbed on the ion exchange resin, it is possible to efficiently leach the gold in the leaching step (S200) of the subsequent process step Can be.

(2) leaching step (S200)

This step is a step for leaching most of the gold contained in the residue remaining after the pyrolysis in the pyrolysis step (S100) of the pre-process step using aqua regia, 500 to 1000 weight of aqua regia relative to 100 parts by weight of the residue containing gold It is preferred to add gold, stir and then leach out the residue from the residue.

When the amount of aqua regia added to the residue containing gold falls below the range of the amount defined above, there is a fear that the gold is not sufficiently leached from the residue, and the amount of the aqua remnant is If the range is exceeded, since the leaching amount of gold does not increase in proportion to the increase of the amount of aqua regia, the consumption of the aqua regia is not only increased, but the efficiency of the leaching process due to the use of the aqua regia becomes low.

(3) reduction step (S300)

In this step, ascorbic acid as a reducing agent is added to the gold leachate produced in the leaching step (S200), and as a step of recovering gold powder by reacting, it is preferable to add ascorbic acid in a ratio of 3 to 5 relative to the theoretical amount of gold.

In the above, when the amount of the reducing agent is less than the range of the addition amount defined above, there is a fear that the gold powder may not be produced sufficiently from the gold leachate, and when the amount of the reducing agent exceeds the range of the addition amount defined above, the reducing agent Since the amount of gold powder produced does not increase in proportion to the increase of the input amount of, the consumption of the reducing agent increases.

(4) cleaning step (S400)

This step is a small amount of copper (Cu) or silver which is mixed in the gold powder by washing the gold powder produced in the reduction step (S300) by stirring in a nitric acid solution of 30-65% purity, then stirring by washing with pure water Impurities such as (Ag) are removed to improve the purity of the gold powder.

The amount of the nitric acid solution and the pure water is preferably 500 to 1000 parts by weight based on 100 parts by weight of the gold powder. When the amount of the nitric acid solution and the pure water is less than the amount used above, the impurity component mixed in the gold powder If the amount of the nitric acid solution and the pure water exceeds the amount defined above, there is a concern that the efficiency of the cleaning process may be lowered by using an excess amount of the cleaning liquid.

(5) drying step (S500)

In this step, the gold powder generated by the washing step (S400) is put into a dryer, dried at a temperature of 100 to 110 ° C. for 2 to 4 hours to remove moisture, thereby recovering the dried gold powder. As a result, about 99.9 A high recovery rate of gold powder can be recovered.

If the drying conditions are less than the above-mentioned conditions, there is a fear that the water contained in the gold powder may not be sufficiently removed, and if the drying conditions exceed the above-mentioned conditions, the drying process according to overdrying There is a concern that the efficiency of the efficiency is lowered.

In particular, the present invention 99.95 by repeatedly performing the leaching step (S200), reduction step (S300) and washing step (S400) in order to further improve the purity of the gold powder recovered in the drying step (S500). It is possible to recover high purity gold powder of more than%.

Hereinafter, a method for recovering gold from the gold adsorption ion exchange resin according to the present invention will be described in more detail with reference to the following examples. However, the following examples are only examples for describing the present invention in more detail, and the present invention is not limited to the following examples.

(Example 1)

Pyrolysis was carried out in an electric furnace at 950 ° C. for 2 hours at 950 ° C. with gold adsorbed, and 500 parts by weight of aqua regia was added to 100 parts by weight of the residue produced after pyrolysis to generate a leachate containing gold. 100 parts by weight of gold powder to remove gold (Cu) or silver (Ag), which are impurities contained in the gold powder, is recovered by adding ascorbic acid and reducing it at a ratio of 1: 3 relative to the theoretical amount. 30 to 65% of nitric acid solution was added to 500 parts by weight, followed by stirring for 30 minutes, and then gold powder was added to 500 parts by weight of pure water, followed by stirring for 30 minutes to wash the nitric acid solution. After removing the gold powder was recovered, the gold recovery is as described in Example 1 in Table 1 below.

(Example 2)

Pyrolysis was carried out in an electric furnace at 900 ° C. for 8 hours in which gold was adsorbed, and 1000 parts by weight of aqua regia was added to 100 parts by weight of the residue generated after pyrolysis to generate a leaching solution containing gold, and then gold to this leaching solution. 100 parts by weight of gold powder to remove traces of copper (Cu) or silver (Ag), which are impurities contained in the gold powder, was recovered by adding ascorbic acid at a ratio of 1: 5 to the theoretical amount to reduce the gold powder. 30 to 65% of nitric acid solution was added to 1000 parts by weight, followed by stirring for 30 minutes. Then, gold powder was added to 1000 parts of pure water, stirred for 30 minutes to wash the nitric acid solution, and then dried at a temperature of 110 ° C. for 2 hours. After removing the gold powder was recovered, the gold recovery is as described in Example 2 in Table 1 below.

(Comparative Example 1)

Pyrolysis was carried out in an electric furnace at 800 ° C. for 2 hours at 800 ° C., after which the residue was leached into aqua regia, and then the leachate was reduced to recover gold powder. ] Is as described in Comparative Example 1.

Process conditions of the method for recovering gold in Comparative Example 1 were carried out under the same conditions as in Example 1 to recover the gold powder.

(Comparative Example 2)

Pyrolysis was carried out in an electric furnace at 700 ° C. for 8 hours at 700 ° C., and the residue was leached into aqua remnants after pyrolysis, and then the leachate was reduced to recover gold powder. ] Is as described in Comparative Example 2.

Process conditions of the method for recovering gold in Comparative Example 2 were carried out under the same conditions as in Example 2 to recover the gold powder.

division Pyrolysis Temperature (℃) Gold recovery rate (% by weight) Example 1 950 99.98 Example 2 900 99.15 Comparative Example 1 800 88.38 Comparative Example 2 700 72.14

Therefore, as can be seen from the experimental results presented in [Table 1], the recovery rate of gold increased as the pyrolysis temperature increased. At the thermal decomposition temperature of 700 ° C., the recovery rate of gold was the lowest at 72.14 wt%, and most of the gold was recovered at 950 ° C. at 99.98 wt%.

As described above, in the method of recovering gold from the leachate of the gold-containing raw material of the present invention or the ion-exchange resin adsorbed gold from the waste liquid, the comparison of the gold recovery rate according to the thermal decomposition temperature of the ion-exchange resin adsorbed gold is shown in [Table 1]. As described, in the case of Examples 1 and 2, it was confirmed that the recovery rate of the gold powder is much higher than that of Comparative Examples 1 and 2.

As described above, a method for recovering gold from a gold adsorption ion exchange resin according to a preferred embodiment of the present invention has been described, but this is merely described, for example, and various changes without departing from the technical spirit of the present invention. And those skilled in the art will appreciate that changes are possible.

Claims (3)

In the method of recovering gold from the ion-exchange resin adsorbed gold from the leaching liquid or waste liquid of the gold-containing raw material,
Pyrolysis step (S100) of the gold-adsorbed ion exchange resin;
Leaching step (S200) for leaching the gold contained in the residue after pyrolysis in the pyrolysis step (S100);
A reduction step (S300) of recovering gold powder by adding and reacting a reducing agent to the gold leach solution generated in the leaching step (S200);
A washing step (S400) of washing the gold powder generated in the reducing step (S300) with a nitric acid solution and then using pure water to improve the purity of the gold powder;
Method for recovering gold from the gold adsorption ion exchange resin, characterized in that it comprises a drying step (S500) of recovering the dried gold powder by removing the moisture of the gold powder produced by the washing step (S400).
The method of claim 1,
The thermal decomposition step (S100),
A method for recovering gold from a gold adsorption ion exchange resin, characterized in that pyrolysis at a temperature of 650 ~ 950 ℃ for 2 to 8 hours.
The method of claim 1,
The reduction step (S300),
A method for recovering gold from a gold adsorption ion exchange resin, characterized in that ascorbic acid is added at a ratio of 3 to 5 of the theoretical amount of gold.

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