WO2020105861A1 - Method for reusing plastic from and recovering valuable metals from plated waste plastic - Google Patents

Abstract

The present invention relates to a method for reusing plastic and recovering valuable metals using plated plastic and, more specifically, to a method for separating and recovering plated metals (nickel, copper, chromium) and separating and recovering plastic from by-products or plated waste plastic generated from a plating process, wherein the process is simple and metal impurities such as Na, Ca, etc. are easily removed as impurities such that high-purity plastic, copper, nickel, and chromium can be recovered.

Description

Method of recycling plastic and recovering valuable metals from plated waste plastics

The present invention relates to a method of recycling plastics and valuable metals using plated plastics, and more specifically, to separate and collect plated metals (nickel, copper, and chromium) from by-products or plated waste plastics generated in the plating process. , It relates to a method of separating and recovering plastics. The process is simple, and it is easy to remove metal impurities such as Na and Ca as impurities, and utilizes plated plastics that can recover high-purity plastics, copper, nickel, and chromium. It relates to a method of recycling plastics and recovering valuable metals.

Plating ABS plastic is not only high in hardness, but also glossy, and is widely used as exterior materials for automobiles, electrical and electronic products, and household products. The plastic silver plating layer is plated from the inside in the order of copper-nickel-chrome. When manufacturing a plated plastic exterior material using the properties of metal chromium with high hardness and excellent gloss as a surface material, the adhesion of chromium to the plastic is not good, so first plating copper and nickel on the plastic and then plating chromium on the surface ABS Manufacture plastic exterior materials.

On the other hand, in recent years, a large amount of waste-plated ABS plastic is inevitably generated as a large amount of waste automobiles and waste electrical and electronic products where plated ABS plastic was used as an exterior material. The waste-plated ABS plastic generated in such a large amount is a valuable secondary resource for Korea, a resource-poor country, because it contains useful metals such as chromium, nickel, and copper as well as plastics.

A technique that has been applied commercially for the recycling of waste-plated ABS plastic so far is to cut the waste-plated ABS plastic to an appropriate size and then pulverize to remove the plating layer from the ABS plastic surface and then recycle the plastic as raw material. However, in this method, as the pulverization is performed to remove the plating layer from the waste-plated ABS plastic, ① there are many fine plastic powders, so the plastic loss is serious, and the operating environment due to the fine powder is bad, ② the components of the plating layer There is a disadvantage that useful metals such as phosphorus copper, nickel, and chromium cannot be recovered.

To compensate for this disadvantage, in Korean patent 10-0658697 (registration date December 11, 2006, application number 10-2004-0040951), waste plating using hydrochloric acid solution (HCl solution) and ferric chloride solution (FeCl ₃ solution) A technique of peeling the plating layer from ABS plastic and recovering the plastic has been proposed, but there is a disadvantage in that a large amount of waste hydrochloric acid solution and waste ferric chloride solution occur, causing environmental problems. In addition, only plastics are recovered, and there is a disadvantage that useful metals such as copper, nickel, and chromium are not recovered from the plating layer.

Meanwhile, in Korean Patent Registration No. 10-1521554 (Registration Date May 13, 2015, Application No. 10-2013-0137910), nickel is leached and separated using a phosphorus-based extractant and a reducing agent, and copper is removed using an acidic etching solution. A method of selectively recovering high purity nickel oxide and copper oxide by extraction and separation is proposed. The method is complicated, and the use of a phosphorus extractant and an acid etching solution to leach and separate nickel and copper can damage plastics and make recycling difficult. Also, metal is being recovered, but plastic is not.

Therefore, as described above, the total recovery technology that simultaneously recovers and recycles useful metals such as copper, nickel, and chromium, as well as plastics as a main component from waste-plated ABS plastic, which is a useful resource, not only maximizes recycling of resources, but also poisonous chemicals It is required as an alternative that satisfies environmental protection simultaneously by suppressing the use and emission of drugs.

The present invention seeks to provide a method for efficiently recovering useful metal resources and plastics from plated waste plastics.

The present invention for solving the above problems relates to a method for recycling plastics and recovering valuable metals, comprising: a first step of separating a plastic material and a metal ion solution (etching treatment solution) after acid treatment of the plated waste plastics; Recovering ABS, PC and mixtures thereof from the separated plastic material, and recovering chromium metal, copper compound powder, and nickel carbonate powder from the metal ion solution.

In addition, the present invention has an object to provide a recycled plastic recovered by the above method.

In addition, the present invention has an object to provide a chromium metal recovered by the above method.

In addition, an object of the present invention is to provide a copper compound powder comprising copper chloride powder and / or copper carbonate powder recovered by the above method.

In addition, there is an object to provide a copper metal recovered from the copper compound powder.

In addition, the present invention has an object to provide a nickel carbonate powder recovered by the above method.

In addition, there is an object to provide a nickel metal recovered from the nickel carbonate powder.

The present invention is very eco-friendly as it can efficiently recover and recycle useful plastics and metals from the discarded industrial waste, plated waste plastics.

1 is a schematic diagram sequentially showing a method of recycling plastics and recovering valuable metals using plated waste plastic according to the present invention.

Figure 2 is a schematic diagram showing the separation of the plastic and valuable metal by using the etching solution from the plated plastic according to the present invention.

Figure 3a is a schematic diagram for separating the plastic using the specific gravity selection from the mixed plastic according to the present invention.

3B is a photograph of ABS material plastic and PC material plastic obtained and recycled by specific gravity selection in Example 2. FIG.

4 is a schematic diagram for separating the etchant (Ni, Cu) and Cr from which the valuable metal is leached according to the present invention.

5 is a schematic view of separating Cu and Ni using an ion exchange resin from an etching solution (Ni, Cu) in which the valuable metal according to the present invention is leached.

Figure 6 is a schematic diagram for recovering the separated Cu by using the ion exchange resin according to the present invention as a Cu compound or by adding Na ₂ CO ₃ to copper carbonate.

7 is a schematic view of recovering nickel into nickel carbonate powder by adding Na ₂ CO ₃ to Ni separated using the ion exchange resin according to the present invention.

The present invention is specifically described below.

The present invention recovers high-value plastics (eg, acrylonitrile-butadiene-styrene (ABS) plastics, PC (polycarbonate) plastics, PC and ABS synthetic plastics, etc.) from plated waste plastics, and furthermore, copper metal , Nickel metal and chromium metal is an eco-friendly invention to recover and recycle.

The present invention is an acid treatment of the waste plastic plated with a metal containing copper, nickel, and chromium with an etching solution to form plastic suspended matter, metal ions and chromium precipitates that are not soluble in the acid from the waste plastic, and then separate and separate each of them. Plastic, copper, nickel and chromium can be recovered respectively by treatment.

Specifically, the present invention is a first step of producing an etching treatment solution by acid treatment of the plated waste plastic with an etching solution; A second step of removing and recovering a plastic float from the etching treatment liquid; A third step of filtering and removing the chromium metal as a precipitate by filtering the etching treatment liquid from which the suspended solids have been removed, thereby obtaining a leaching liquid; Four steps to adjust the pH of the leach solution; 5 steps of ion-exchanging the pH-adjusted leachate with an ion exchange resin to obtain an ion exchange treatment solution from which copper ions in the leachate are removed; 6 steps of recovering copper ions adsorbed on the ion exchange resin as a copper compound solution, and reacting the ion exchange treatment solution with sodium carbonate to produce and obtain nickel carbonate; And washing and drying the obtained nickel carbonate to obtain a nickel carbonate powder; a process including the same may be performed (refer to the schematic process schematic diagram of FIG. 1).

In step 1, the etching solution may include 10.00 to 25.00% by weight of sulfuric acid, 5 to 15% by weight of etching aid, and residual water, preferably 10.00 to 20.00% by weight of sulfuric acid, 7 to 12% by weight of etching aid, and At this time, if the concentration of the sulfuric acid is less than 10% by weight, the remaining amount of water may not readily dissolve metals such as copper and nickel contained in the waste plastic. In addition, if the concentration of the etching aid is less than 5% by weight, metals such as copper and nickel may not be dissolved well, and there may be a problem that the processing time increases, and when it exceeds 15% by weight, the process cost increases. There may be. In addition, if the concentration of the etching aid is less than 5% by weight, metals such as copper and nickel may not be well dissolved, and there may be a problem that the process time increases, and if it exceeds 15% by weight, there may be a problem that the process cost increases. It is possible to use within the above range.

And, the etching aid is a peroxide; Sodium sulfate (Na ₂ SO ₃ ); Alternatively, hydrogen peroxide and sodium sulfate may be included in a weight ratio of 1: 1 to 1.5, and preferably in a weight ratio of 1: 1 to 1.2.

The acid-treated step of the etching treatment solution includes a plastic suspension, a leaching solution containing nickel ions and copper ions, and a precipitate, wherein the plastic suspension is ABS (acrylonitrile-butadiene-styrene) plastic, PC (polycarbonate) Material plastics, PC and ABS synthetic plastics (hereinafter referred to as "PC / ABS plastics") and other unavoidable impurities. In addition, the leachate may contain other unavoidable impurities in addition to nickel ions and copper ions, and the precipitate may contain chromium metal and other unavoidable impurities.

The etching treatment solution of the acid-treated step 1 is 3 to 12% by weight of nickel (Ni), 6 to 14% by weight of copper (Cu), 0.10 to 2.5% by weight of chromium (Cr) and the remaining amount in scrap except liquid It may include a plastic float, preferably, 3.50 ~ 10.50% by weight of nickel in the scrap, 6.80 ~ 12.60% by weight of copper, 0.12 ~ 2.2% by weight of chromium, and a residual amount of plastic float, more preferably scrap It may include 3.58 to 10.20% by weight of nickel, 6.90 to 12.00% by weight of copper, 0.14 to 1.70% by weight of chromium, and a residual amount of plastic suspension.

In addition, the scrap is nickel, copper, chromium, and other unavoidable traces of impurities (eg, calcium, cobalt, iron, potassium, magnesium, sodium, tin, zinc, metal, plastic, or other plastic materials) Etc.).

The second step is a step of recovering the plastic suspended solids from the etching treatment liquid, and the recovered plastic suspended solids may be recovered by plastics having different specific gravity (refer to the schematic process schematic diagrams of FIGS. 2 and 3).

Specifically, the 2-1 step of introducing and leaving the plastic suspended matter collected in the above step 2 in a solution having a specific gravity of 1.06 to 1.09; Step 2-2 of recovering the floating ABS material plastic from the neglected solution; Step 2-3 of adjusting the specific gravity of the solution from which the ABS material plastic is recovered to 1.16 to 1.18, and then recovering the floating PC and ABS synthetic plastic (PC / ABS plastic); And 2-4 steps of recovering the PC material plastic from the solution from which the PC and ABS synthetic plastics were recovered; respectively, the ABS material plastic, the PC material plastic, and the PC / ABS plastic may be recovered.

In other words, ABS material plastics have a specific gravity of 1.05 or less, PC material plastics have a specific gravity greater than 1.18, and PC / ABS usually have a specific gravity of about 1.10 to 1.15. And recovering.

And, in step 2, the solution of the specific gravity of 1.06 to 1.09 and the specific gravity of 1.16 to 1.18 in step 2-1 may use an aqueous sulfuric acid solution, and the specific gravity may be adjusted by adjusting the sulfuric acid concentration of the aqueous sulfuric acid solution. For example, an aqueous 12% by weight sulfuric acid solution has a specific gravity of about 1.08.

Next, step 3 filters the precipitated chromium metal (which is insoluble in the etching solution) from the etching treatment liquid from which the plastic suspended solids are removed and recovered, removes and removes the chromium metal from the etching treatment liquid, and recovers the leachate from which the precipitate is removed. It is a process to obtain. Here, the filtering may be performed by a general filtering method used in the art, and for a preferred example, the filtering of the steps may be performed using a filter press (refer to the schematic process schematic diagram of FIG. 4).

In addition, the leaching solution in three steps may include copper ions and nickel ions. The leachate may include 12,000 to 50,000 ppm of copper ions and 7,000 to 30,000 ppm of nickel ions, preferably 14,000 to 40,000 ppm of copper ions and 8,000 to 25,000 ppm of nickel ions, and more preferably 14,500 to 35,000 ppm of copper ions. And 8,500 to 25,000 ppm of nickel ions.

In addition, the leach solution may contain other metal impurities in addition to copper ions and nickel ions. For a specific example, the leachate is 50 ppm or less of calcium (Ca) ion, 10 ppm or less of cobalt (Co) ion, 5 ppm or less of chromium (Cr) ion, 100 ppm or less of iron (Fe) ion, 5 ppm or less of potassium (K) ion, magnesium ( Mg) 5 ppm or less of ions, 40 ppm or less of sodium (Na) ions, 50 ppm or less of zinc (Zn) ions, and the leachate is preferably 25 ppm or less of Ca ions, 5 ppm or less of Co ions, 4 ppm or less of Cr ions, Fe ions 50 ppm or less, K ion 4 ppm or less, Mg ion 3.5 ppm or less, Na ion 25 ppm or less, Zn ion 20 ppm or less, more preferably, the leachate is Ca ion 15 ppm or less, Co ion 2 ppm or less, Cr ion 2 ppm or less , Fe ion 30ppm or less, K ion 2ppm or less, Mg ion 2.5ppm or less, Na ion 22ppm or less, Zn ion 10ppm or less, and metal impurities.

Next, step 4 is a step of adjusting the pH before the ion exchange treatment of the leachate from which the precipitate has been removed. The leachate is strongly acidic with a pH of 0.7 or less, and it cannot be subjected to ion exchange treatment immediately. Therefore, NaOH is added to the leach solution to adjust the pH to 1.80 to 2.2, preferably to pH 1.90 to 2.1. At this time, if the pH is less than 1.8, the pH is too low, and there may be a problem that the copper adsorption amount of the ion exchange resin is low during the ion exchange treatment or the process time increases. When the pH exceeds 2.2, a part of nickel is adsorbed on the ion exchange resin. There may be a problem of nickel loss.

Next, step 5 is a process of obtaining an ion exchange treatment solution in which copper ions in the leach solution are removed by ion-exchanging the pH-adjusted leach solution with an ion exchange resin (refer to the schematic process schematic diagram of FIG. 5).

The ion exchange treatment can be carried out by a general method used in the art, preferably by using HIDA (iminodiacetic acid) ion exchange resin, a preferred embodiment, for example, 1.0 ~ 1L per etchant The copper ions can be separated from the leach by adsorbing copper ions on the ion exchange resin by circulating the etching solution in 1.5 L HIDA-based ion exchange resin for 1 to 4 hours, preferably 1.5 to 2.5 hours.

The ion exchange treatment solution after the ion exchange treatment is performed may include a nickel ion content of 7,000 to 30,000 ppm, preferably a nickel ion content of 8,000 to 28,000 ppm, more preferably 8,500 to 26,000 ppm.

In addition, the ion exchange treatment liquid may contain a very small amount of impurities in addition to nickel ions. Specifically, the ion exchange treatment solution is 50 ppm or less of calcium (Ca) ion, 10 ppm or less of cobalt (Co) ion, 5 ppm or less of chromium (Cr) ion, 5 ppm or less of copper (Cu) ion, 100 ppm or less of iron (Fe) ion, potassium ( K) 5 ppm or less of ion, 5 ppm or less of magnesium (Mg) ion, 40 ppm or less of sodium (Na) ion, 50 ppm or less of zinc (Zn) ion, preferably 25 ppm or less of Ca ion, 5 ppm or less of Co ion, Cr ion 4 ppm or less, Cu ion 3 ppm or less, Fe ion 50 ppm or less, K ion 4 ppm or less, Mg ion 3.5 ppm or less, Na ion 25 ppm or less, Zn ion 20 ppm or less, more preferably Ca ion 10 ppm or less, Co ion 2 ppm or less, Cr ion 2 ppm or less, Cu ion 2 ppm or less, Fe ion 30 ppm or less, K ion 2 ppm or less, Mg ion 2.5 ppm or less, Na ion 8 ppm or less, Zn ion 10 ppm or less.

The recovery of the copper compound solution in step 6 is performed by pickling the ion-exchange resin adsorbed with copper ions with an acidic aqueous solution to obtain a solution containing CuCl ₂ or CuSO ₄ in the pickling solution pickled by the ion-exchange resin, and then filtering it. The copper metal can be recovered in the form of a copper compound of CuCl ₂ or CuSO ₄ by washing (refer to the schematic process schematic diagram of FIG. 6).

More specifically, the ion-exchange resin on which copper ions are adsorbed is pickled with an aqueous HCl solution at a concentration of 10 to 20% by weight, preferably HCl at a concentration of 10 to 15% by weight, to obtain an pickling solution containing CuCl ₂ , The ion exchange resin can be regenerated.

In addition, the ion exchange resin adsorbed by copper ions is pickled with an H ₂ SO ₄ aqueous solution having a concentration of 10 to 20% by volume, preferably an H ₂ SO ₄ aqueous solution having a concentration of 10 to 15% by volume, and an acid containing CuSO ₄ Obtaining a washing solution and regenerating the ion exchange resin; Generating and recovering copper carbonate (CuCO ₃ ) by mixing, stirring, and reacting sodium carbonate (Na ₂ CO ₃ ) in the pickling solution containing CuSO ₄ ; And washing and drying the recovered copper carbonate to obtain a copper carbonate powder; a copper compound may be recovered in the form of copper carbonate and copper metal may be recovered therefrom.

In addition, the reaction for the production of copper carbonate (CuCO ₃ ) is based on 100 parts by weight of the pickling solution containing CuSO ₄ , the addition of sodium carbonate to the copper content in the pickling solution in a molar ratio of 1: 1 to 1: 1.5, preferably The addition of sodium carbonate to the copper content in the pickling solution can be reacted by mixing in a molar ratio of 1: 1.2 to 1: 1.4. At this time, if the amount of sodium carbonate used is less than 1: 1 molar ratio, the amount of copper carbonate may be reduced because the amount is too small, and if the amount of sodium carbonate used exceeds 1: 1.5 molar ratio, the process cost may increase. .

The copper carbonate thus obtained may be recovered in powder form, and the copper content in the copper carbonate powder may be 20 to 30% by weight, preferably 22 to 27% by weight. In addition, the copper carbonate powder may include nickel, iron, potassium, and sodium in addition to copper, and preferably the copper carbonate powder may contain 100 ppm or less of nickel, 80 ppm or less of iron, 20 ppm or less of potassium, and 500 ppm or less of sodium in addition to copper. In addition, more preferably, it may contain 10 to 80 ppm of nickel, 0.1 to 55 ppm of iron, 0.5 to 15 ppm of potassium, and 10 to 340 ppm of sodium.

In addition, copper recovered in the form of a copper compound (the CuCl ₂ , CuSO ₄ or CuCO ₃ ) may recover copper metal by a general method used in the art.

The ion exchange treatment solution in which ion exchange treatment was performed in step 6 to remove copper ions from the leach solution includes nickel ions. The ion exchange treatment solution can react with sodium carbonate (Na ₂ CO ₃ ) to produce and obtain nickel carbonate. (See schematic process schematic diagram in FIG. 7).

Then, the reaction product containing nickel carbonate is filtered, and after the nickel carbonate is separated, it is washed and dried to obtain NiCO ₃ in powder form. The obtained nickel carbonate may contain nickel in a high purity with a nickel content of 30 to 45% by weight, preferably 35 to 40% by weight.

In addition, the obtained nickel carbonate powder may include aluminum, calcium, cobalt, chromium, copper, iron, magnesium, and sodium in addition to nickel carbonate, specifically aluminum 15 ppm or less, calcium 180 ppm or less, cobalt 20 ppm or less, chromium 10 ppm or less , 40ppm or less of copper, 50ppm or less of iron, 20ppm or less of magnesium, and 450ppm or less of sodium, more preferably 1 to 12ppm of aluminum, 20 to 120ppm of calcium, 0.5 to 15ppm of cobalt, 0.1 to 6ppm of chromium, and 5 to 30ppm of copper , 5 ~ 40ppm iron, 1 ~ 12ppm magnesium and 20 ~ 350ppm sodium can contain only a very small amount.

High value-added plastics, such as ABS, PC, and PC / ABS, can be recovered and recycled from the plated waste plastics by the method described above. In addition, copper compounds such as chromium metal, copper chloride powder or copper carbonate powder and nickel carbonate powder can be recovered and recycled from the plated waste plastic, and copper metal and nickel metal can be recovered from the copper compounds and nickel carbonate powder. have.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are intended to help the understanding of the present invention, and should not be construed as limiting the scope of the present invention by the following examples.

[Example]

Example 1: Acid treatment (etching treatment)

In the schematic diagram constituting the method for recycling plastics and recovering valuable metals using the plated plastics according to the present invention as shown in FIG. 1, an experiment was conducted to separate the plastics and valuable metals by etching the plated plastics.

In Example 1, the step of separating the plastic and the valuable metal was performed using an etchant from the plated plastic (see FIG. 2).

In the experiment, an aqueous solution of sulfuric acid and aqueous hydrogen peroxide was mixed with water to prepare an etching solution containing 20% by weight of sulfuric acid, 10% by weight of hydrogen peroxide, and water of residual water. Etching (acid treatment) was performed for a time. At this time, the mixed sulfuric acid aqueous solution and hydrogen peroxide solution in the etching solution are shown in Table 1 below.

Then, after leaving the etching treatment solution which etched the plated plastic, the etching treatment solution contained plastic suspended solids, sediment chromium metal, and copper, nickel and other metal impurities dissolved in the etching treatment solution.

Then, the plastic from which the plating had been removed floated on top of the etchant and was recovered.

Table 1 shows the contents of plastic, chromium, nickel, and copper in the scrap except for the liquid phase of the etching treatment liquid.

division	Product Name	Weight before etching (g)	Weight after etching (g)	Weight reduction rate (%)	Content in scrap (% by weight)
Sample 1	Plastic scrap	2,000	1,608.8	19.56	-
	Scrap Ni weight	-	158.4	-	7.9
	Scrap Cu weight	-	226	-	11.3
	Residual Cr Weight	-	6.8	-	0.34
Sample 2	Plastic scrap	2,000	1,759.48	12.02	-
	Scrap Ni weight	-	72.55	-	3.62
	Scrap Cu weight	-	140.4	-	7.02
	Residual Cr Weight	-	27.54	-	1.38
Sample 3	Plastic scrap	2,000	1,570.14	21.49	-
	Scrap Ni weight	-	199.68	-	9.98
	Scrap Cu weight	-	227.01	-	11.35
	Residual Cr Weight	-	3.16	-	0.16
Synthesis	Plastic scrap	2,000	1,646.15	17.69	-
	Scrap Ni weight	-	143.55	-	7.17
	Scrap Cu weight	-	197.80	-	9.89
	Residual Cr Weight	-	12.50	-	0.63

Looking at Table 1, it can be seen that in Sample 1, 2Kg of plated plastic before etching was separated into 80.44% by weight of plastic, 7.9% by weight of nickel, 11.3% by weight of copper, and 0.34% by weight of chromium after etching.

In Sample 2, it can be seen that 2Kg of the plated plastic before etching was separated into 87.92% by weight of plastic and 3.62% by weight of nickel, 7.02% by weight of copper, and 1.38% by weight of chromium after etching.

In Sample 3, it can be seen that 2Kg of the plated plastic before etching was separated into 78.51% by weight plastic and 9.98% by weight nickel, 11.35% by weight copper, and 0.16% by weight chromium after etching.

And, looking at Table 1, it can be seen that when the weight ratio of the aqueous hydrogen peroxide solution is increased compared to the aqueous sulfuric acid solution in the etching solution, the chromium metal content increases and the nickel and copper content tends to decrease.

Example 2: Specific gravity sorting treatment of plastic suspended solids

In the plastics recovered in Example 1, ABS, PC / ABS, and PC plastics are generally mixed, and when melted and recycled at one time, the properties of each plastic are mixed to lower the value of the product.

Therefore, it is necessary to separate the plastics of ABS, PC / ABS, PC, etc. to increase the product value of recycled plastics.

The mixed plastics (ABS, PC / ABS, PC) as shown in FIG. 3 are prepared by preparing two solutions having a specific gravity of 1.07 and a specific gravity of 1.18 by adjusting the concentration of sulfuric acid, and then using these, ABS, PC / ABS in the mixed plastic. , PC was separated.

Specifically, when the plastic suspended solids are introduced and left in an aqueous sulfuric acid solution having a specific gravity of 1.07, the ABS material plastics float, and the PC material plastics and PC / ABS plastics having a specific gravity exceeding 1.07 precipitate. From this, the ABS material, which is a floating material, was obtained by separating and obtaining plastic, and then filtering the precipitate.

Next, the precipitate was charged and left in an aqueous sulfuric acid solution having a specific gravity of 1.07.

As a result, the PC / ABS plastic was suspended, and the PC material plastic precipitated.

Table 2 below is a table showing the results of adjusting the specific gravity of the solution. Looking at the table, it can be seen that only ABS is floating at a specific gravity of 1.07, and PC / ABS and PC settle. At a specific gravity of 1.18, it can be seen that ABS and PC / ABS float and PC precipitates.

In other words, only pure ABS can be recovered at a specific gravity of 1.07, and PC / ABS can be recovered at a specific gravity of 1.18 after ABS removal and the rest of the PC can be recovered.

And, after the final recovery, drying, processing and recycling of the final ABS material plastic and PC material plastic is shown in Figure 3b.

importance	ABS	ABS / PC	PC
1.07	floating	Sedimentation	Sedimentation
1.18	floating	floating	Sedimentation

Example 3: Recovery of chromium metal

After removing the plastic as a floating material in Example 1, the chromium metal was recovered as follows from the etching treatment solution (Samples 1 to 3).

As shown in Fig. 4, in the case of chromium metal, it is insoluble in sulfuric acid, which is a main component of the etching treatment solution, and thus exists in a metal form rather than ions. In the case of nickel and copper, it is dissolved in sulfuric acid and mixed with ions in the etching treatment solution.

As shown in FIG. 4, the etchant was filtered (filtered) to separate the precipitated chromium metal from the etchant.

And, Table 3 below shows the results of the component analysis of the etching treatment solution after filtering. Looking at Table 3, after filtering, it can be seen that there are almost no chromium components in the etching treatment solution.

Sample name	Sample 1	Sample 2	Sample 3
Ni (ppm)	14800	10400	16600
Ca (ppm)	12	2	3
Co (ppm)	One	0	0
Cr (ppm)	One	2	0
Cu (ppm)	21500	17000	15300
Fe (ppm)	One	29	2
K (ppm)	One	2	0
Mg (ppm)	2	0	0
Na (ppm)	9	5	22
P (ppm)	Trace	0	0
Sn (ppm)	Trace	0	0
Zn (ppm)	One	2	One

Example 4: Ion exchange treatment (separation of copper and nickel)

In Example 3, each of the etching treatment solutions (samples 1 to 3) containing chromium-free copper ions and nickel ions was subjected to ion exchange treatment to separate copper and nickel using ion exchange resin.

Since the etching solution containing copper and nickel is strongly acidic having an initial pH of 0.7 or less, copper and nickel cannot be separated using an ion exchange resin in this state. Therefore, the pH of the etching solution was adjusted to 2 by adding it to the etching solution using caustic soda.

Next, 5 L of the etching treatment solution adjusted to pH 2 was circulated in 5 L of iminodiacetic acid-based ion exchange resin for 2 hours to adsorb copper on the ion exchange resin.

Then, the results of analyzing the components of the ion-exchange treatment solution that passed through the ion-exchange resin are shown in Table 4 below.

When comparing Table 3 and Table 4, the copper ions of 10000ppm or more present in the etching solution in Table 3 are adsorbed to the ion exchange resin and the ion exchange treatment solution passed there is almost copper ions in the ion exchange treatment solution as shown in Table 4. It was confirmed that it does not.

Sample name	Sample 1	Sample 2	Sample 3
Ni (ppm)	14700	10100	16100
Ca (ppm)	10	2	3
Co (ppm)	One	0	0
Cr (ppm)	One	2	0
Cu (ppm)	One	0	One
Fe (ppm)	One	25	2
K (ppm)	One	2	0
Mg (ppm)	2	0	0
Na (ppm)	8	5	20
P (ppm)	Trace	0	0
Sn (ppm)	Trace	0	0
Zn (ppm)	One	2	One

Example 5: Copper recovery from ion exchange resin

As shown in Fig. 6, copper adsorbed on the ion exchange resin was recovered as a copper compound solution and copper carbonate was prepared by adding sodium carbonate to the recovered copper compound.

Specifically, in order to desorb the copper adsorbed on the ion exchange resin of Example 4, a strong acidic solution having a concentration of 10% by volume or more is required. For example, in the case of a solution recovered by desorbing copper adsorbed on the ion exchange resin using an aqueous HCl solution having a concentration of 10% by volume or more, the solution is recovered as a solution of CuCl ₂ , and an ion exchange resin using an aqueous organic acid solution having a concentration of 10% by volume or more. Desorption of the copper adsorbed to the recovered solution can be recovered in the form of organic copper.

In Example 5, the 10% by volume concentration of H ₂ SO ₄ accommodated was passed through an ion exchange resin adsorbed by copper to desorb copper and regenerate the ion exchange resin to recover the CuSO ₄ solution.

Next, the recovered CuSO ₄ solution was able to recover a high purity CuSO ₄ solution free of other impurities as shown in Table 5.

Sample name	Sample 1	Sample 2	Sample 3
Ni (ppm)	10	8	8
Ca (ppm)	Trace	Trace	Trace
Co (ppm)	Trace	Trace	Trace
Cr (ppm)	Trace	Trace	Trace
Cu (ppm)	20100	16500	14400
Fe (ppm)	Trace	3	Trace
K (ppm)	Trace	2	One
Mg (ppm)	Trace	Trace	Trace
Na (ppm)	2	2	One
P (ppm)	Trace	Trace	Trace
Sn (ppm)	Trace	Trace	Trace
Zn (ppm)	Trace	Trace	Trace

Next, Na ₂ CO ₃ was added to the recovered CuSO ₄ solution and synthesized with copper carbonate. The pH of the CuSO ₄ solution was lower than 1, so that the amount of Na ₂ CO ₃ added was compared to the copper content in the pickling solution containing CuSO ₄ . Copper carbonate was prepared by adding at a molar ratio of 1: 1.5 rather than a theoretical 1: 1 molar ratio.

The prepared copper carbonate was washed 3 times using 1 L of distilled water and dried in an oven at 60 ° C. for 8 hours to obtain copper carbonate powder. Then, the components of the obtained copper carbonate were analyzed, and the results are shown in Table 6 below. Looking at Table 6, it can be seen that copper carbonate having a high purity of 25% by weight or more of Cu was produced.

Sample name	Sample 1	Sample 2	Sample 3
Ni (ppm)	81	52	55
Cu (ppm)	251500	252200	250200
Fe (ppm)	14	51	2
K (ppm)	5	7	10
Na (ppm)	210	320	152

Example 6: Preparation of nickel carbonate powder (nickel recovery)

As shown in FIG. 7, Na ₂ CO ₃ was added to the separated ion exchange treatment solution using an ion exchange resin to synthesize and obtain nickel carbonate.

In Example 4, after the ion exchange treatment, Na ₂ CO ₃ was added to the ion exchange treatment solution (samples 1 to 3) to prepare NiCO ₃ . The amount of Na ₂ CO ₃ ratio is theoretically 1: NiCO ₃ was synthesized and prepared by adding a proportion of 1.5: 1 instead of 1 ratio.

Next, NiCO ₃ obtained by filtering was washed three times with 1 L of distilled water, and then dried in an oven at 60 ° C. for 8 hours to obtain NiCO ₃ powder.

Then, the components of the obtained nickel carbonate powder were analyzed and are shown in Table 7 below. Looking at Table 7, it can be seen that a high purity NiCO ₃ powder having a Ni content of 35 wt% or more in the nickel carbonate powder was obtained.

Product Name	unit	Sample 1	Sample 2	Sample 3
Ni	weight%	36.0	36.4	35.8
Al	ppm	12	11	8
Ca		108	107	87
Co		14	5	10
Cr		5	2	One
Cu		25	27	17
Fe		29	35	27
Mg		9	8	8
Na		240	320	178

Through the above embodiment, it is possible not only to recycle high value-added useful plastics (ABS, PC, PC / ABS) from waste plastics plated with the method of recycling plastics and recovering valuable metals of the present invention, but also chromium, copper and nickel. It was confirmed that it can be recovered and recycled.

Claims (17)

1. A first step of producing an etching treatment solution by acid treatment of the plated waste plastic with an etching solution;

   A second step of removing and recovering a plastic float from the etching treatment liquid;

   A third step of filtering and removing the chromium metal as a precipitate by filtering the etching treatment liquid from which the suspended solids have been removed, thereby obtaining a leaching liquid;

   Four steps to adjust the pH of the leach solution;

   5 steps of ion-exchanging the pH-adjusted leachate with an ion exchange resin to obtain an ion exchange treatment solution from which copper ions in the leachate are removed;

   6 steps of recovering copper ions adsorbed on the ion exchange resin as a copper compound solution, and reacting the ion exchange treatment solution with sodium carbonate to produce and obtain nickel carbonate; And

   Washing and drying the obtained nickel carbonate to obtain a nickel carbonate powder;

   A method of recycling plastics and recovering valuable metals from plated waste plastic, characterized by performing a process comprising a.
2. The method of claim 1, wherein the etchant in the first step comprises 1 to 15 to 25.00% by weight of sulfuric acid, 5 to 15% by weight of etching aid containing at least one selected from peroxide and sodium sulfate, and the balance of water,

   The etching aid is a peroxide; Sodium sulfate (Na ₂ SO ₃ ); Or hydrogen peroxide and sodium sulfate 1: 1 to 1.5, characterized in that it contains a weight ratio of plastic recycling and valuable metals recovery method from the plated waste plastic.
3. The method of claim 1, wherein the acid-treated step of the etching treatment solution includes a plastic suspension, a leaching solution containing nickel ions and copper ions, and a precipitate,

   The sediment is a method of recycling plastics and valuable metals from plated waste plastics, characterized in that it contains chromium metal.
4. The method according to claim 3, wherein the etching treatment liquid is 3 to 12% by weight of nickel (Ni) in scrap, excluding liquid, 6 to 14% by weight of copper (Cu), 0.10 to 2.5% by weight of chromium (Cr), and remaining amount A method of recycling plastics and recovering valuable metals from plated waste plastics, characterized by containing plastic floats and other inevitable traces of impurities.
5. The method of claim 1, wherein the second step is that the plastic suspension recovered from the etching treatment solution includes ABS (acrylonitrile-butadiene-styrene) plastic, PC (polycarbonate) plastic, PC and ABS synthetic plastic, and other inevitable impurities. It is a method of recycling plastic and recovering valuable metals from plated waste plastics.
6. According to claim 1, Step 2-1 of putting and leaving the plastic suspended solids collected in step 2 in a solution having a specific gravity of 1.06 to 1.12;

   Step 2-2 of recovering the floating ABS material plastic from the neglected solution;

   Step 2-3 of adjusting the specific gravity of the solution from which the ABS material plastic is recovered to 1.16 to 1.18, and then recovering the floating PC and PC / ABS synthetic plastic; And

   Step 2-4 to recover the PC material plastic from the solution from which the PC and PC / ABS synthetic plastics were recovered;

   A method of recycling plastics and recovering valuable metals from plated waste plastics, characterized by separating and recovering ABS material plastic, PC material plastic, and PC and ABS synthetic plastic, respectively.
7. [3] The method of claim 1, wherein the filtering of the three stages uses a filter press to recover chromium metal in the leachate.
8. The method of claim 1, wherein the fourth step is a method of recycling plastics and recovering valuable metals from plated waste plastics, characterized in that pH is adjusted to 1.8 to 2.2 by adding NaOH to the leachate.
9. The method of claim 1, wherein the recovery of the copper compound solution in step 6 is

   The ion-exchange resin with copper ions adsorbed is pickled with an aqueous HCl solution at a concentration of 8 to 20% by weight to obtain a pickling solution containing CuCl ₂ , and the plastic is reused from plated waste plastics characterized in that the ion-exchange resin is regenerated. And valuable metal recovery methods.
10. The method of claim 1, wherein the recovery of the copper compound solution in step 6 is

    Pickling an ion exchange resin with copper ions adsorbed thereon with an aqueous solution of H ₂ SO _{4 at a} concentration of 8 to 20% by weight to obtain an pickling solution containing CuSO ₄ and regenerating the ion exchange resin; And

    Generating and recovering copper carbonate (CuCO ₃ ) by mixing, stirring, and reacting sodium carbonate (Na ₂ CO ₃ ) in the pickling solution containing CuSO ₄ ; And

    Washing and drying the recovered copper carbonate to obtain copper carbonate powder;

    A method of recycling plastics and recovering valuable metals from plated waste plastics, further comprising a process comprising a.
11. That the mixture to 1.5 molar ratio according to claim 11, wherein the sodium carbonate in acid tax including the CuSO ₄ (Na ₂ CO ₃₎ the mixture is prepared acid tax content of the copper containing CuSO ₄ Sodium carbonate 1: 1 to 1 Method for recycling plastics and recovering valuable metals from plated waste plastics.
12. 12. The method of claim 11, wherein the copper content in the obtained copper carbonate powder is 20 to 30% by weight, and plastic recycling and valuable metals are recovered from the plated waste plastic.
13. The method of claim 1, wherein the sixth step is a method of recycling plastics and recovering valuable metals from plated waste plastics, characterized in that the sodium carbonate in the ion exchange treatment solution is mixed at a molar ratio of 1: 1 to 1: 1.5.
14. The method of claim 1, wherein the nickel content in the nickel carbonate powder of step 7 is 30 to 45% by weight, and the method of recycling plastics and recovering valuable metals from the plated waste plastics.
15. A copper compound regenerated from waste plastic plated by the method of claim 1, wherein the copper compound comprises copper chloride powder or copper carbonate powder.
16. A nickel carbonate powder regenerated from waste plastic plated by the method of claim 1.
17. A plastic recycled from waste plastic plated by the method of claim 1, wherein the recycled plastic comprises at least one selected from ABS plastic, PC plastic and PC / ABS synthetic plastic.

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