KR20120055365A - Metal extracting and separating method of cu, zn, cd and ni from the leach liquor of the secondary metal resources by solvent extraction - Google Patents

Abstract

PURPOSE: A method for extracting and separating copper, zinc, cadmium, and nickel by solvent extraction from a leaching solution of secondary metal sources is provided to selectively extract and separate valuable metal from leachate using specific organic solvent. CONSTITUTION: A method for extracting and separating copper, zinc, cadmium, and nickel by solvent extraction from a leaching solution of secondary metal sources comprises the steps of: collecting leachate containing valuable metal(S100), adding hydroxyoxime based extractant to the collected leachate and selectively extracting copper(S200), adding cathionic organic extractant to a first filtrate to selectively extract zinc and cadmium(S300), and recovering nickel from a second filtrate(S400).

Description

Metal Extracting and Separating Method of Cu, Zn, Cd and Ni from the Leach Liquor of the Secondary Metal Resources by Solvent Extraction }

The present invention relates to a method for extracting and separating useful metals from a leachate, and more particularly, to extracting a solvent from an leachate which can extract and separate copper, zinc, cadmium, and nickel components from a leachate of industrial wastes by a solvent. The present invention relates to a method for extracting and separating copper, zinc, cadmium and nickel.

In modern times, with the rapid development of information and communication technology and the advancement of components, the replacement cycle of products is shortened, and the generation amount of waste electric and electronic products is increased, and in addition, industrial waste such as electronic scrap or printed circuit board The amount is increasing at the same time.

When these industrial wastes are buried or stored underground, leachate flows from them, and the leachate contains a large amount of heavy metals. In addition, industrial wastewater generated in the manufacturing process of electronic scrap or printed circuit boards contains a large amount of heavy metals, so if these leachate and industrial wastewater (hereinafter referred to as "leakage") are discharged as they are, serious environmental pollution occurs. Because it is generated, it is necessary to treat leachate specially.

The leaching liquid of industrial waste contains various useful metals such as gold, silver, copper, tin, zinc, cadmium and nickel, and these useful metals occupy an important position as raw materials of high-tech industries and have relatively added value. Due to its high level, there is an active plan to recover and recycle industrial waste without simply disposing it.

Accordingly, research and development on the technology of recovering useful metals from industrial waste is actively progressing.

Conventionally, since secondary resources such as industrial waste contain various metals, a method of extracting useful metals using acid and alkali and then separating and purifying them is used. Separation, sementation, and reduction precipitation methods are used for separation and purification. And the like are universally known.

However, the separation and purification technology as described above does not selectively remove impurities, and thus, is not only environmentally friendly as an environmental load type method due to a lot of energy consumption. In addition, high purity metals and metal compounds cannot be obtained, and useful metals are lost during the multi-step process.

In consideration of these problems, separation and purification techniques such as solvent extraction and ion exchange, which are environmentally friendly and obtain high purity raw materials, have been developed.In the case of solvent extraction, when the concentration of metal ions in the solution is high, the concentration of metal ions in the solution is increased. In the low case (lean solution), an ion exchange method is used.

In particular, a solvent extraction method has been proposed as a method for selectively separating various metal components contained in the leachate of industrial wastes using an organic solvent (extractant).

G. M. Ritcey and A. W. Ashbrook, Solvent extraction, Part II, Elsevier, Amsterdam, 1979.

In Document 1, G. Thorsen extracted and separated copper, zinc and cadmium at pH 1 ~ 2 using organic extractant, DEHPA (Diethylhexyl Phosphoric Acid), from the leachate of the residue generated in the cementation process.

Document 2 Proc. TMS Annual Meeting-EPD Congress’98, Minerals, Metals and Materials Soc./TMS, Warrendale, PA, USA, p. 289-300.

In Document 2, G. Owusu proposed a process for separating zinc, cadmium, cobalt and nickel, which selectively extracts zinc at pH 2.0 using 30% DEHPA and 4% Tributyl Phosphate (TBP) as an extractant. , cadmium was extracted and separated at pH 3.7.

[Reference 3] Minerals Engineering, vol. 16 (12), pp. 1371-1374 (2003).

In Document 3, K. Kongolo et al. Proposed a process for separating zinc, copper, cobalt, and iron from sulfuric acid leaching liquor produced in a copper smelter, and this process was performed by selective leaching of copper using LIX 984 and iron by precipitation. Removal, simultaneous leaching of cobalt and zinc by DEHPA, and selective deodorization with sulfuric acid solution.

4 S. K. Sahu, A. Agarwal, B. D. Pandey and V. Kumar, Minerals Engineering, vol. 17, pp. 949-95, 2004.

Sahu et al. Proposed a process for separating copper, cobalt and nickel from sulfuric acid leaching liquor from Uranium Corporation of India Limited (UCIL), which extracts copper using LIX 84 diluted with kerosene as extractant. Then, cobalt and nickel were separated from the filtrate using Na-Cyanex 272.

However, the conventional solvent extraction process presented in the above documents is not selective in the extraction and separation of useful metals, or there are too many apparatuses used for extraction and separation, including solvent extraction apparatuses such as mixing tanks and agitation tanks. But there is a problem that the solvent extraction process is complicated.

The present invention was created in order to solve the above problems, it is easy to extract and separate useful metals, as well as extract and separate useful metals such as copper, zinc, cadmium and nickel with high purity accurately and efficiently from the leachate. The purpose is to provide a method for extracting and separating useful metals that can be solved.

Method for extracting and separating copper, zinc, cadmium and nickel from the leaching solution according to the present invention, the leaching solution collection step of collecting the leaching solution containing the useful metal (S100); A copper extraction step (S200) for selectively extracting copper by adding a hydroxyoxime extractant to the leaching solution collected through the leaching solution collection step (S100); Zinc and cadmium extraction step (S300) of selectively extracting zinc and cadmium by adding a cationic extractant to the first filtrate remaining after the copper is extracted through the copper extraction step (S200); The zinc and cadmium extraction step (S300) includes a nickel recovery step (S400) for recovering nickel from the remaining second filtrate after zinc and cadmium is extracted.

It is preferable to further include a washing step (S210) to remove the impurities mixed in the organic phase by adding an acid solution of pH 1.5 ~ 5.0 to the organic phase separated in the copper extraction step (S200).

It is preferable to further include a copper back extraction step (S220) for adding the sulfuric acid solution to the organic phase from which impurities are removed in the cleaning step (S210) to back extract copper into an aqueous solution.

It is preferable to further include a zinc back extraction step (S310) of adding the sulfuric acid solution to the organic phase separated in the zinc and cadmium extraction step (S300) to back extract zinc into an aqueous phase.

It is preferable to further include a cadmium back extraction step (S320) of extracting the cadmium back into the aqueous solution by adding hydrochloric acid solution to the remaining organic phase after the zinc is back extracted through the zinc back extraction step (S310).

It is preferable that at least one of LIX 84, LIX 64N, and LIX 984 is used as the hydroxy oxime extractant.

As the cationic extractant, at least one of DEHPA, Cyanex 272, Cyanex 301, and Cyanex 302 is preferably used.

According to the present invention, by selecting and using a specific organic solvent, useful metals such as copper, zinc, cadmium, and nickel contained in the leachate can be easily and efficiently selected and extracted and separated.

In addition, since the extraction and separation process of the useful metal is carried out simply and continuously, it is possible to improve the productivity according to the extraction and separation of the useful metal, as well as to reduce the economic cost.

In addition, it is possible to extract useful metals having high purity and to separate them, and thus, metals / compounds / powders having high added value can be manufactured as compared to conventional precipitation or sementation methods.

1 is a flow chart illustrating a method for extracting and separating copper, zinc, cadmium and nickel from the leachate according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in Figure 1, the method for extracting and separating copper, zinc, cadmium and nickel from the leaching solution according to the present invention comprises a leaching solution collection step (S100) for collecting the leaching solution; Copper extraction step of extracting copper (S200); Zinc and cadmium extraction step of extracting zinc and cadmium (S300); It includes a nickel recovery step (S400) for recovering nickel.

(1) leaching liquid collection step (S100)

In this step, the leachate of industrial wastes containing useful metals to be extracted is stably collected in a container, and the collected leachate contains copper, zinc, cadmium and nickel.

(2) copper extraction step (S200)

In this step, an organic solvent is added to the leachate collected through the leachate collection step 100 to selectively extract copper from the leachate. In this case, as the organic solvent for the extraction of copper, a hydroxyoxime based solvent is used, and in particular, at least one of LIX 84, LIX 64N and LIX 984 is preferably used.

It is preferable that the hydroxy oxime extractant is diluted in kerosene at a predetermined ratio. Since the hydroxy oxime extractant is a known technique, a detailed description of its effect will be omitted.

On the other hand, by adding the above-mentioned organic solvent to the leaching solution, and then stirred for a certain time, the aqueous phase and the organic phase is formed, these two phase (phase) is in phase contact with each other. At this time, the aqueous phase and the organic phase is located above the organic phase due to the density difference and the aqueous phase is located below, the organic phase contains a copper component, the aqueous phase contains zinc, cadmium and nickel components.

When the organic phase located above the two phase liquids is removed, the copper component in the leachate is naturally separated from the zinc, cadmium and nickel components in the aqueous phase.

(2-1) washing step (S210)

In this step, an acid solution having a pH of 1.5 to 5.0 is added to the organic phase separated in the copper extraction step (S200) to remove impurities incorporated into the organic phase. That is, not only copper but also various impurities are mixed in the organic phase separated in the copper extraction step (S200). In this step, a dilute acid solution having a pH of 1.5 to 5.0 is used to remove impurities mixed in the organic phase. The organic phase is washed.

(2-2) copper back extraction step (S220)

In this step, sulfuric acid (H ₂ SO ₄ ) solution is added to the organic phase from which impurities are removed in the washing step (S210), and copper is extracted back into the aqueous phase. For this, the ratio of the organic phase and the aqueous phase (O / A ratio) is approximately 1. Set to 1, and then back extract copper from the organic phase to the aqueous phase using sulfuric acid solution. Copper extracted back to the aqueous phase through this step is produced as a copper compound, copper metal or copper powder through a method such as crystallization, electrowinning or hydrogen reduction.

(3) zinc and cadmium extraction step (S300)

In this step, copper is extracted through the copper extraction step (S200), and an organic solvent is added to the remaining first filtrate to selectively extract zinc and cadmium simultaneously. That is, when the organic phase is separated and removed from the two phases in the copper extraction step (S200), the filtrate of the aqueous phase (hereinafter referred to as “first filtrate”) is left in the container, and this step includes zinc and cadmium remaining in the first filtrate. It is to extract.

On the other hand, as the organic solvent to be added to the first filtrate, a cationic organic solvent, in particular DEHPA, Cyanex 272, Cyanex 301, Cyanex 302 is used, and when at least one of these cationic extractant is added Zinc and cadmium are extracted into the organic phase from the first filtrate, and nickel remains in the aqueous phase in the first filtrate.

And it is preferable to use the thing of the dilute state in kerosene extractant.

(3-1) Zinc back extraction step (S310)

In this step, sulfuric acid solution is added to the organic phase separated in the zinc and cadmium extraction step (S300) to extract zinc back into the aqueous phase. That is, in the zinc and cadmium extraction step (S300), the first filtrate is separated into an organic phase and an aqueous phase (hereinafter referred to as “second filtrate”). In this step, zinc is added by adding about 10% sulfuric acid solution to the organic phase. Back extract into aqueous phase.

(3-2) cadmium back extraction step (S320)

In this step, zinc is back extracted through the zinc back extraction step (S310), and hydrochloric acid (HCl) solution is added to the remaining organic phase to back extract cadmium. In other words, about 10% hydrochloric acid solution is added to the remaining organic phase after the zinc back extraction step (S310) to extract back the cadmium from the organic phase into the aqueous phase.

When an aqueous solution containing zinc or cadmium is obtained by the above steps, zinc and cadmium in metal or compound form are separated from the aqueous solution by electrolysis or the like.

(4) nickel recovery step (S400)

In this step, zinc and copper are extracted through the zinc and cadmium extraction step (S300), and nickel is recovered from the remaining second filtrate. That is, after the zinc and cadmium separation step (S300) is applied to the first filtrate remaining in the aqueous solution remaining after the copper extraction step (S200), a second filtrate in the aqueous solution is finally left, and the second filtrate is electrolyzed by nickel Recover.

Hereinafter, some experiments performed to confirm the validity of the present invention described above will be described.

≪ Example 1 >

First, a leachate having a composition of 1.0 g / L copper, 0.1 g / L zinc, 0.1 g / L cadmium, and 0.1 g / L nickel is prepared to separate metal ions from the leach solution of the electronic scrap. 50 ml of each organic extractant was added to the separatory funnel so that the O / A ratio was 1, and the mixture was shaken vigorously. At this time, 10% LIX 84 diluted with kerosene, which is a hydroxyoxime extractant, was used as the organic extractant.

The mixture of leachate and organic extractant reached equilibrium within 2.0 minutes at pH 2.0, from which the organic phase was separated and washed with dilute acid at pH 3.5 to remove impurities incorporated or extracted in the organic phase, followed by O / A Copper was back-extracted into the aqueous phase using a sulfuric acid solution at a concentration of 200 g / L at ratio 1. After 5 minutes, 99% of copper was stripped off and recovered.

<Example 2>

Next, the first filtrate of the aqueous phase after the organic phase was removed contained zinc, cadmium, and nickel, from which zinc, cadmium, and nickel were extracted and separated, respectively.

To this end, first, 50 ml of the first filtrate containing zinc, cadmium, and nickel is mixed with 7.5 ml of cyanex 302, a cationic extractant, and 50 ml of an organic extractant consisting of 1.5% isodecanol diluted with kerosene. Zinc and cadmium were extracted into the organic phase. As a result, 80% zinc and 100% cadmium were extracted into the organic phase within 2 minutes at an O / A ratio of 1 and equilibrium pH 2.64. Back extraction was performed in an aqueous solution of 99% or more.

In addition, by the above process, the cadmium-containing organic phase was removed and the pH of the solution was increased to 3.0 at O / A ratio 1 for the second filtrate of the remaining aqueous phase. As a result, zinc was extracted as an organic phase. 4% sulfuric acid was added at an O / A ratio of 1, and 99% of zinc was extracted as an aqueous solution.

When the aqueous solution of zinc and cadmium was obtained by the above process, zinc and cadmium were recovered from these aqueous solutions by electrolysis, respectively.

<Example 3>

Example 3 is the same as that of Example 1, except for extracting copper from the leachate, except for extracting and separating zinc, cadmium and nickel from the first filtrate remaining after copper is extracted.

Equilibrium with O / A ratio 1 in a first filtrate containing zinc, cadmium, and nickel with 50 ml of an organic extractant consisting of 10 vol.% Cyanex 302, a cationic extractant, and 2% isodecanol diluted by kerosene. After 5 minutes at pH 3.8, zinc was extracted as 98.9%, cadmium as 99.0% organic phase, and no nickel was extracted.

Experiments to extract and separate zinc and nickel, respectively, from the cadmium-free filtrate were performed in the same manner as in Example 1.

As described above, the present invention can not only selectively and efficiently extract and separate copper, zinc, cadmium, and nickel contained in the leachate through a series of processes, but also greatly reduce the number of processes for extraction and separation.

Claims (6)

In the method for extracting and separating copper, zinc, cadmium and nickel from leaching liquid of industrial waste, etc.,
Leachate collection step of collecting the leachate containing the useful metal (S100);
A copper extraction step (S200) for selectively extracting copper by adding a hydroxyoxime extractant to the leaching solution collected through the leaching solution collection step (S100);
Zinc and cadmium extraction step (S300) of selectively extracting zinc and cadmium by adding a cationic extractant to the first filtrate remaining after the copper is extracted through the copper extraction step (S200);
Extracting copper, zinc, cadmium and nickel from the leachate, characterized in that it comprises a nickel recovery step (S400) for recovering nickel from the remaining second filtrate after zinc and cadmium extraction step (S300) And how to separate.
The method according to claim 1,
Copper, zinc, cadmium and leach from the leaching solution characterized in that it further comprises a cleaning step (S210) to remove the impurities mixed in the organic phase by adding an acid solution of pH 1.5 ~ 5.0 in the organic phase separated in the copper extraction step (S200) How to extract and separate nickel.
The method according to claim 2,
Copper, zinc, cadmium, and nickel from the leachate further comprising a copper back extraction step (S220) for adding copper to the aqueous phase by adding sulfuric acid solution to the organic phase from which impurities are removed in the cleaning step (S210). How to extract and separate.
The method according to claim 1,
A zinc back extraction step (S310) of adding zinc sulfate to the aqueous phase by adding a sulfuric acid solution to the organic phase separated in the zinc and cadmium extraction step (S300);
The zinc is extracted back through the zinc extraction step (S310) by adding a hydrochloric acid solution to the zinc back extraction and the remaining organic phase cadmium back extraction step (S320) further comprises a cadmium back extraction from the leaching solution, characterized in that the copper, zinc To extract and separate cadmium and nickel.
The method according to claim 1,
The hydroxyoxime-based extractant is a method for extracting and separating copper, zinc, cadmium and nickel from the leachate, characterized in that at least one of LIX 84, LIX 64N and LIX 984.
The method according to claim 1,
Wherein the cationic extractant is at least one of DEHPA, Cyanex 272, Cyanex 301, and Cyanex 302. Extracting and separating copper, zinc, cadmium, and nickel from the leachate.

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