JP2019026925A - Valuable metal recycling method from copper scrap containing vinyl chloride - Google Patents

Abstract

To provide a valuable metal recycling method from a copper scrap containing vinyl chloride for easily recovering and recycling the valuable metal from a scrap such as a waste copper wire material containing vinyl chloride.SOLUTION: There is provided a valuable metal recycling method for a copper scrap containing vinyl chloride, by obtaining a roasted material by applying a scrap containing polyvinyl chloride and the valuable metal to a roasting process for roasting at a temperature of 350°C or higher and 1000°C or lower, obtaining a roasted article after washing by applying the roasted article to a water washing process for water washing, then recovering the valuable metal by applying the roasted article after washing to a melting and separating process for melting the roasted article after washing and separating the same into a metal containing the valuable metal and a slag.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for recycling scrap containing vinyl chloride and copper.

  At present, from the viewpoint of resource depletion, various items have been recycled, and metals that have been consumed in large quantities have also been recycled. In particular, wire materials that use high-purity copper as a conductor are used in large quantities as cables for power transmission and communication, so copper, which is a valuable metal, is recovered from copper scrap such as waste cables (waste copper wire). However, they have been reused as resources.

On the other hand, in coated copper wiring materials, polyvinyl chloride (hereinafter also referred to as “PVC” or simply “PVC”) is often used for coating from the viewpoint of insulation and durability, and contains a large amount of chloride (Cl) component. There are features.
It is known that careless incineration of materials containing PVC such as the above may result in the generation of harmful substances such as dioxins. Careful attention to recycling is necessary to avoid danger. Become.
However, in order not to generate harmful substances, it is not easy to separate and recycle the coated part of the coated copper wiring material by separating it from the copper wire part that is a conductor, for example, by human power. Since it takes a long processing time, it is not realistic.

  In addition, although it seems that the coated waste copper wiring material can be processed at once if it is melted in a high-temperature furnace such as a copper smelting furnace, the furnace will corrode if chlorine enters the copper smelting furnace. However, there were many problems such as that the coated waste copper wiring material could not be directly put into the copper smelting furnace.

As a technique regarding the processing of such scraps containing chloride, for example, methods disclosed in Patent Literature 1 and Patent Literature 2 can be cited.
That is, Patent Document 1 discloses that “a method of recovering metal from fly ash containing chlorine generated by combustion of waste as CaCl ₂ and containing a) shearing force of the fly ash in an oxidizing atmosphere. While heating, the chlorine and hydrogen chloride generated by the decomposition of CaCl ₂ react with the metal components contained in the fly ash. B) The metal chloride generated and volatilized is brought into contact with the absorbing solution. And c) a method for recovering metal from fly ash, wherein the dissolved metal is recovered separately from the recovered liquid obtained.

However, in Patent Document 1, the atmosphere is adjusted while applying a shearing force to decompose CaCl ₂ , and the chlorine and hydrogen chloride generated by the decomposition are reacted with the metal components contained in the fly ash and generated. It is necessary to go through a very complicated and long process in which the metal chloride is brought into contact with the absorbing solution and dissolved and recovered, and the dissolved metal is recovered separately from the obtained recovered solution. Such a complicated and long process is not suitable for processing requiring low cost of recycling.

  Patent Document 2 states that “in the treatment step of washing and desalting waste containing chlorine and heavy metals, the pH of the waste aqueous slurry (aqueous suspension) is in the range of 8.5 to 13”. Disclosed is a waste treatment method characterized by maintaining and washing with water to suppress elution of heavy metal salts and desalting.

However, in Patent Document 2, waste containing chlorine and heavy metals is directly washed and desalted, and the pH of the aqueous slurry of the waste (aqueous suspension) is in the range of 8.5 to 13 at that time. It is characterized by the fact that it is maintained in the water and washed with water, and the elution of heavy metal salts is suppressed for desalting. Such a technique cannot be applied to scrap containing chlorine for the purpose of copper recovery.
In other words, even if the coated copper wiring material is directly wet-treated, vinyl chloride cannot be decomposed. Therefore, water washing with a waste aqueous slurry pH maintained in the range of 8.5 to 13 is effective in removing chloride. has no effect.
As described above, many problems remain in the recycling method for recovering valuable metals from scraps containing valuable metals such as PVC and copper.

Japanese Patent Laid-Open No. 8-35018 JP 2002-18394 A

  Therefore, the present invention provides a scrap processing method for safely and easily recovering and recycling valuable metals from copper scrap such as waste copper wire containing PVC.

  The first invention of the present invention that solves the above problems is to obtain a roasted product by subjecting a scrap containing polyvinyl chloride and a valuable metal to a roasting step of roasting at a temperature of 350 ° C. or higher and 1000 ° C. or lower. Then, the roasted product is subjected to a washing step of washing with water to obtain a post-cleaning roasted product, and then the post-cleaning roasted product is melted and separated into a metal and slag containing the valuable metal. A valuable metal recycling method from copper scrap containing vinyl chloride, characterized in that the valuable metal is recovered through a process.

  The second invention of the present invention is a coating containing copper obtained by scraping or crushing a used waste-coated copper wire and subjecting it to specific gravity sorting by wet or air flow. It is a valuable metal recycling method from copper scrap containing PVC, which is characterized in that it exists.

  In the third invention of the present invention, when the scraps in the first and second inventions are subjected to the roasting process, any one or more of calcium carbonate, calcium oxide, calcium hydroxide, and calcium sulfate is added to the scrap. This is a valuable metal recycling method from copper scrap containing PVC.

  According to a fourth aspect of the present invention, from the copper scrap containing vinyl chloride, the washing time of the roasted product in the washing step of the first to third inventions is 30 seconds or more and 50 minutes or less. This is a valuable metal recycling method.

  According to a fifth aspect of the present invention, there is provided a valuable metal recycling method from copper scrap containing vinyl chloride, characterized in that the washing time in the fourth aspect is not less than 30 seconds and not more than 10 minutes.

  According to a sixth aspect of the present invention, the ratio of the roasted product to water in the water washing step of the first to fifth inventions is a weight ratio, and the water / roasted product is 2 or more and 30 or less. Is a valuable metal recycling method from copper scrap containing PVC.

  A seventh invention of the present invention is the copper scrap containing vinyl chloride characterized in that the ratio of the roasted product to water in the sixth invention is a weight ratio of water / roasted product of 3 or more and 10 or less. This is a valuable metal recycling method.

  The eighth invention of the present invention is a valuable metal recycling method from copper scrap containing vinyl chloride, characterized in that the scrap in the first invention contains 1.5% by mass or more of chloride.

  The ninth invention of the present invention is a method for recycling valuable metals from copper scrap containing vinyl chloride, characterized in that melting of the post-cleaning roasted product in the first invention is performed using a copper smelting furnace.

  According to a tenth aspect of the present invention, the scrap in the first aspect of the invention contains 1.5% by mass or more of chloride, and the total content of lead, cadmium and zinc is 1.0% by mass or more. This is a valuable metal recycling method from copper scrap containing polyvinyl chloride.

  ADVANTAGE OF THE INVENTION According to this invention, a chloride can be effectively isolate | separated from the scrap containing organic substances, such as a chloride, and valuables, such as copper, and recovery of resources and prevention of deterioration of an installation can be aimed at.

It is a process flow figure in the present invention. It is a process flow figure which isolate | separates the baking products and ash of the vinyl chloride containing copper scrap in this invention. It is a process flow figure which performs water washing after roasting of the vinyl chloride containing copper scrap in the present invention. It is a process flow figure which performs specific gravity separation before roasting of vinyl chloride content copper scrap in the present invention.

The present invention roasts scraps containing chlorides such as PVC and valuable metals such as copper, and effectively removes chlorides by washing the roasted material obtained after roasting, and then melts the valuable metals. Are to be collected and applied to recycling.
Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

The scrap containing chloride and valuable metals is not particularly limited. That is, it is only necessary to contain an organic substance containing chloride and a valuable metal such as copper. Specifically, waste wires and coated copper wires are cut short, crushed, and then subjected to flotation using wet or air flow to pre-treat so that some of the copper contains organic matter In addition, it is possible to recover valuable metals more efficiently by selecting those having a high proportion of valuable metal components and those having a high proportion of organic matter by a method such as specific gravity sorting.
Further, scraps containing expensive noble metals such as Au and Ag can be similarly processed.

  Here, in the case of scraps of waste electric wires, the grade of chloride contained may be 1.5% by mass or more, and scraps of such high chloride grades must be smelted at the time of melting the scrap. Because it corrodes, it cannot be put directly into the furnace. For this reason, it is preferable to adjust so that the chlorinated article level in the processed material put into the furnace is at most 1.0% by mass or less.

Further, depending on the scrap, scraps in which impurities such as lead (Pb), cadmium (Cd), and zinc (Zn) coexist with chloride other than the waste electric wire may be processed.
When they coexist, they are contained in chlorides or other forms, but in the present invention, the scrap is roasted to advance Pb, Cd and Zn, and further washed with water to increase the removal rate. The method was used. Moreover, by separating the roasted scrap into metal and ash and washing only the metal with water, the removal rate of Pb, Cd and Zn can be further increased and efficiently removed.
Hereinafter, each step will be described in detail.

<Roasting process>
The method for roasting scrap containing chloride is not particularly limited, but an apparatus capable of efficiently roasting scrap and sending it to the next process so as not to cool the scrap after roasting as much as possible is preferable. For example, a rotary kiln may be used. A rotary kiln is preferable because it can be heated while mixing scraps and is easy to roast the scraps uniformly.

The heating method is not particularly limited, and electricity, coke, pulverized coal, heavy oil, or the like may be used. In particular, pulverized coal and heavy oil are preferable because they are inexpensive.
The roasting temperature is not particularly limited, but is preferably 350 ° C. or higher and 1000 ° C. or lower when a relatively large amount of organic material is contained such as a coated copper wire. Below 350 ° C., organic substances are difficult to decompose and burn, and there is a high possibility that they will remain unburned. On the other hand, if it exceeds 1000 ° C., there is no problem with roasting, but it is not preferable because the temperature is excessively high and the fuel cost becomes high.
A more preferable roasting temperature is 500 ° C. or higher and 900 ° C. or lower, and in this range, roasting can be performed more efficiently.

Furthermore, when roasting using a rotary kiln, the rotation speed depends on the scale of the apparatus and the processing capacity, but in a kiln that is frequently used for industrial purposes with an inner diameter of about 2.5 to 3 m, about 1 to several rpm is about. good. If the rotational speed is too slow, for example 0.2 rpm or 0.3 rpm or less, it is difficult to uniformly roast the scrap, which is not preferable. On the other hand, if the rotational speed is too high, for example, exceeding 5 rpm or 6 rpm, the scrap rises and is discharged from the kiln before it can be sufficiently roasted.
Moreover, it is preferable to make the diameter of the discharge port thinner than the kiln body. By reducing the diameter of the discharge port, the flow rate of the exhaust gas increases and it becomes easier to separate ash and relatively large metal components.

  Moreover, scraps after roasting may separate metal and ash and put only the metal into the smelting furnace. By doing so, Cl contained in the ash does not enter the smelting furnace, and energy for melting the ash can be saved, which is even more preferable.

<Washing process>
Chloride is removed to some extent by scrap baking in the roasting process, but chloride remains in the roasted product (scrap after roasting) and is put in this state in a smelting furnace. This can damage the furnace. Therefore, a method of removing chloride by washing the roasted product with water was used.

The washing method is not particularly limited. By using a water tank and a stirrer without using a special device, the investment cost can be suppressed, and as a result, the processing can be performed at low cost.
The washing conditions are not particularly limited. However, the washing time is from 30 seconds to 50 minutes, more preferably from 30 seconds to 10 minutes.
In addition, it is preferable that the ratio of water to the roasted product is a weight ratio and the water / roasted product is set to 2 or more and 30 or less so that the water can be efficiently washed.
More preferably, it is more preferable that the ratio of water to the roasted product is a weight ratio and the water / roasted product is set to 3 or more and 10 or less, so that water can be washed more efficiently.

Further, when the scrap contains calcium, it is preferable because water-soluble calcium chloride (CaCl ₂ ) is generated and the chloride is easily removed. Therefore, a method of intentionally mixing and roasting calcium compounds other than chlorides such as calcium carbonate, calcium oxide, calcium hydroxide, calcium sulfate, and calcium carbide to scrap and generating CaCl ₂ may be used.

  Calcium is added in a shortage so that the contained chloride is equal to or more than the equivalent to react as calcium chloride. Even if it is added so as to be in excess, even if a part of the chloride is exhausted as a gas, It is preferable because it is easy to fix as calcium chloride.

  Moreover, it is also possible to provide a separation step after roasting in which a calcium compound is added and the roasted product obtained by roasting is separated into metal and other ash, and only the metal is subjected to a water washing treatment. By separating and washing only the metal in this way, the amount of washing treatment can be greatly reduced, and thus valuable metals can be recovered efficiently and inexpensively.

It is preferable to perform the water washing in the water washing treatment twice or more. By performing washing with water twice or more, the chloride content can be greatly reduced.
Moreover, after rinsing with flowing water for the first time, a method of rinsing with stirring in a water tank may be used. Furthermore, the method of rinsing the roasted product with water may be washed while rinsing the water in a shower. By making the water into a shower like this, it is preferable because the roasted product can be washed more uniformly and reliably with a small amount of water.
Furthermore, when performing multiple times of water washing, if the water washing method used as a countercurrent is used, the amount of water required for washing can be reduced. Further, it can be efficiently washed with water by adding ultrasonic waves.
By washing with water in this way, chloride components can be removed efficiently and reliably, and scrap with reduced chloride content is less likely to damage equipment when recovering valuable metals by melting and separating, reducing recovery costs To help.

<Melting / separation process>
The method for melting and separating is not particularly limited. Since scraps after washing, which may cause damage to the melting furnace and smelting furnace, are preferably melted and separated after drying.
For melting and separation, a copper smelting furnace can be used as it is, which is preferable. If an existing copper smelting furnace can be used for the melting furnace, the capital investment cost becomes unnecessary, and valuable metals such as copper can be efficiently recovered. Specifically, it is preferable to use a converter in a copper smelting furnace because it can be used as it is without modification.

  When it is processed in the melting furnace, it is separated into molten slag and metal, and the metal accumulates downward due to the difference in specific gravity. There are no particular limitations on the shape and heating method of the melting furnace. A device that can recover metal at low cost, such as high thermal efficiency and low running costs and equipment costs, should be selected. Moreover, it does not specifically limit about a heating system, You may use electricity, coke, pulverized coal, heavy oil, etc. In particular, pulverized coal and heavy oil are inexpensive and preferable.

  EXAMPLES Hereinafter, although an Example, a comparative example, and a reference example are shown and this invention is demonstrated more concretely, this invention is not limited to a following example at all.

First, as a scrap, used coated copper wiring was crushed with a crusher, and then mixed, separated by 1.00 kg, and used as samples of test numbers 1-1 to 1-28. Thereafter, each sample was roasted under the conditions shown in Table 1 while flowing air using a small rotary kiln. The rotation speed was 2 rpm. The processing flow is shown in FIG.
Each sample after roasting was washed with water under the conditions shown in Table 1, and then dried in vacuum at 100 ° C. for 3 hours.
The dried sample was melted at 1200 ° C. to separate slag and copper metal, cooled, and recovered copper.

Note that an ICP emission spectroscopic analyzer was used for analysis of the copper content in the sample.
Moreover, the chlorine removal rate 1, the chlorine removal rate 2, and the copper recovery rate were calculated using the following formulas (1) to (3).

Table 1 shows the measured chlorine removal rate 1, chlorine removal rate 2, and copper recovery rate.
By the treatment method of the present invention, chlorine can be effectively removed from scrap, and copper can be recovered at a high recovery rate. The present invention can be processed by simple methods such as roasting and washing without using a special apparatus, and can be processed industrially efficiently.

Using the same scrap as in Example 1 above, the coated copper wiring and the like were finely crushed with a crusher, and then mixed, separated by 1.00 kg, and used as samples of test numbers 2-1 to 2-22. Thereafter, each sample was roasted under the conditions shown in Table 2 while flowing air using a small rotary kiln.
Each sample after roasting was washed with water under the conditions shown in Table 2, and then dried in vacuum at 100 ° C. for 3 hours. The processing flow is shown in FIG.
The dried sample was melted at 1200 ° C. and separated into slag and copper metal. After cooling, the copper metal was recovered. The chlorine removal rate 1, the chlorine removal rate 2 and the copper recovery rate were calculated by the same method as in Example 1. (The following examples are also the same.)

Table 2 shows the measured chlorine removal rate 1, chlorine removal rate 2, and copper recovery rate.
It has been found that by the treatment method of the present invention, chloride can be almost removed even from scrap containing 1.5% or more of chloride, and copper can be recovered at a high recovery rate.

The same coated copper wiring as in Example 1 was finely crushed and mixed with a crusher, and then 1.00 kg was separated and used as samples of test numbers 3-1 to 3-36. Thereafter, each sample was roasted under the conditions shown in Table 3 while flowing air using a small rotary kiln.
Each sample after roasting was washed with water under the conditions shown in Table 3, and then dried in vacuum at 100 ° C. for 3 hours.
The sample after drying was melted at 1200 ° C., and slag and valuable copper metal were separated and cooled to recover copper. The processing flow is shown in FIG.

Table 3 shows the chlorine removal rate 1, the chlorine removal rate 2, and the copper recovery rate.
It can be seen that most of the chloride can be removed from the scrap containing lead, zinc and cadmium in addition to the chloride by the treatment method of the present invention, and copper can be recovered at a high recovery rate.

As the scrap, the same coated copper wiring as in Example 1 was finely crushed with a crusher and then mixed, and a part was subjected to specific gravity selection by a known method by a wet method.
Next, test numbers 4-1 to 4-7, 4-10, and 4-11 are samples from which specific gravity selection was not performed, and test numbers 4-8, 4-9, 4-12, and 4-13 are From the samples subjected to specific gravity sorting, 1.00 kg each was separated and used as samples of test numbers 4-1 to 4-13.

Thereafter, calcium carbonate (CaCO ₃ ) was added for test numbers 4-1 to 4-9. Regarding test numbers 4-10 to 4-13, calcium carbide (CaC ₂ ) was added and roasted under the conditions shown in Table 4 while flowing air using a small rotary kiln.

In test numbers 4-9, 4-11, and 4-13 after roasting, specific gravity selection by dry method was performed, and only the metal content was washed with water.
Moreover, test numbers 4-1 to 4-8, 4-10, and 4-12 after roasting were washed with water as they were without performing specific gravity sorting.
Washing with water was carried out under the conditions shown in Table 4, followed by drying at 100 ° C. in vacuum for 3 hours.

  The dried sample was melted at 1200 ° C. to separate slag and copper metal, and then cooled to recover copper. The processing flow was performed in FIG. 3 and FIG.

Table 4 shows the chlorine removal rate 1, the chlorine removal rate 2, and the copper recovery rate.
It can be seen that by the method of positively adding calcium, it is possible to remove most of the chloride from the scrap and to recover the copper at a high recovery rate.

The same scrap as in Example 1 was used as the scrap, and the coated copper wiring and the like were finely crushed with a crusher and then mixed and separated by 1.00 kg to obtain samples of test numbers 5-1 to 5-45.
Thereafter, the test numbers 5-1 to 5-14 were roasted under the conditions shown in Table 5 while flowing air using a small rotary kiln as it was. FIG. 4 shows a processing flow.

  About test numbers 5-15 to 5-45, specific gravity selection by airflow was performed. That is, the main component of the synthetic resin after removing the metal component to some extent was roasted under the conditions shown in Table 5 while flowing air using a small rotary kiln.

In the specific gravity selection by airflow, the heavy metal component is the main component, the main component is the synthetic resin, and the main component is relatively large. The main component is the synthetic resin, which is relatively small. The sample used in the examples is relatively small if it is mainly composed of synthetic resin.
A comparatively small thing mainly composed of this synthetic resin is characterized by containing a relatively large amount of finely pulverized metal components.

  Each sample after roasting was subjected to water washing treatment under the conditions shown in Table 5 as it was for test numbers 5-1 to 5-28, and then dried at 100 ° C. in vacuum for 3 hours.

  Test Nos. 5-29 to 5-45 were separated into a main metal component and other ash, and only the main metal component was washed with water under the conditions shown in Table 5, and then in vacuum at 100 ° C. for 3 hours. And dried.

  The dried sample was melted at 1200 ° C. to separate slag and copper metal, and then cooled to recover copper.

Table 5 shows the chlorine removal rate 1, the chlorine removal rate 2, and the copper recovery rate.
In particular, for the sample No. 5-43 to 5-45 in which the water was showered and washed with water for the first time, the amount of water could be reduced, the water could be washed in a short time, and copper could be recovered more efficiently.
Thus, it turns out that a chloride is effectively removed from scrap by wash | cleaning using flowing water, such as using a shower twice or using a shower.

  As described above, the treatment method of the present invention can almost remove chloride from scrap, and copper can be recovered at a high recovery rate. Furthermore, the present invention does not use a special apparatus, and is simple such as roasting and washing with water. It can be processed by a simple method and can be processed at low cost.

Claims (10)

A scrap containing polyvinyl chloride and a valuable metal is subjected to a roasting step of roasting at a temperature of 350 ° C. or higher and 1000 ° C. or lower to obtain a roasted product,
Next, after obtaining the roasted product after washing by subjecting it to a washing step of washing the roasted product,
The post-cleaning roasted product is subjected to a melting / separation step for melting and separating the metal containing valuable metals and slag,
A method of recycling valuable metals from copper scrap containing vinyl chloride, wherein the valuable metals are recovered.   2. The PVC according to claim 1, wherein the scrap is a coating containing copper obtained by cutting or crushing a used waste-coated copper wire and subjecting to wet gravity or specific gravity selection by airflow. Valuable metal recycling method from contained copper scrap.   3. When the scrap is subjected to a roasting process, at least one of calcium carbonate, calcium oxide, calcium hydroxide, calcium sulfate, and calcium carbide is added to the scrap. Of valuable metals from copper scrap containing a large amount of PVC.   The valuable metal recycling from the copper scrap containing vinyl chloride according to any one of claims 1 to 3, wherein the rinsing time of the roasted product in the rinsing step is 30 seconds or more and 50 minutes or less. Method.   The method for recycling valuable metals from copper scrap containing PVC according to claim 4, wherein the washing time is 30 seconds or more and 10 minutes or less.   6. The ratio according to claim 1, wherein the ratio of the roasted product to water at the time of washing in the water washing step is a weight ratio, and the water / roasted product is 2 or more and 30 or less. A method for recycling valuable metals from copper scrap containing PVC.   The method for recycling valuable metals from copper scrap containing vinyl chloride according to claim 6, wherein the ratio of the roasted product to water is a weight ratio, and the water / roasted product is 3 or more and 10 or less.   The said scrap contains 1.5 mass% or more of chlorides, The valuable metal recycling method from the copper scrap containing the vinyl chloride of Claim 1 characterized by the above-mentioned.   The method for recycling valuable metal from copper scrap containing vinyl chloride according to claim 1, wherein the post-cleaning roasted material is melted using a copper smelting furnace. The copper containing vinyl chloride according to claim 1, wherein the scrap contains 1.5% by mass or more of chloride, and the total content of lead, cadmium and zinc is 1.0% by mass or more. Valuable metal recycling method from scrap.

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