CN112143894A - Method for recovering copper from waste enameled wire - Google Patents

Abstract

The invention provides a method for recovering copper from waste enameled wires, which comprises the following steps: mechanically arranging the waste enameled wires, and performing surface layer spraying treatment on the mechanically arranged waste enameled wires; and cleaning the waste enameled wire subjected to surface layer spraying treatment to obtain the purified copper wire and the waste paint slurry. The invention achieves the purpose of separating the copper and the insulating paint in the waste enameled wire by combining the expansion with heat and the contraction with cold, physical impact and chemical paint removal, has high separation efficiency and good separation effect, ensures that the purity of the recovered copper can reach 95.2 wt%, and has good social and economic benefits.

Description

A method of recovering copper from waste enameled wire

technical field

The invention belongs to the technical field of environmental protection, and relates to a method for recycling waste enameled wires, in particular to a method for recovering copper from waste enameled wires.

Background technique

Enameled wire is the main raw material for products such as motors, electrical appliances and household appliances. Especially in recent years, the power industry has achieved sustained and rapid growth. The rapid development of household appliances has brought a broad field to the application of enameled wire, and the use of enameled wire is also increasing, followed by the production of a large number of waste enameled wire.

The waste enameled wire is composed of the dismantling of the copper coil of the electrical appliance and the defective varnished products. Therefore, the waste enameled wire is rich in copper resources, but due to the existence of the insulating varnish layer, the waste enameled wire cannot be used directly as a copper raw material.

Metal copper is widely used in electric power, machinery, electronics, electrical appliances, weapons, new energy and other industries. However, my country's copper resources are relatively scarce, and its external dependence is greater than 70%, which seriously limits the development of my country's copper industry chain. The recycling of waste copper resources has become an important means to make up for the shortage of copper resources in my country. It is of great practical significance to recycle the copper in waste enameled wires.

At present, the method for recovering copper from waste enameled wire is mainly thermal depainting method. CN 106024215 A discloses a waste wire recycling system and processing method. Unboxing, accommodating waste wires, and along the advancing direction of the conveyor belt are sequentially provided with station 1, station 2, station 3 and station 4. Station 1 is provided with a vacuum mixing device, and station 2 is provided with microwave heating There is a separation device on the third station, and a cleaning device on the fourth station.

CN 203944842 U and CN 104096842 A disclose a system and method for producing high-purity copper powder using waste enameled wire and enameled wire, the system includes a melting furnace for heating and pyrolyzing enameled wire, and a furnace tank for sealing pressure-maintaining enameled wire , trolley, crushing and air separation system, ball mill screening machine for processing copper powder, and transport rack for cooling, loading and unloading semi-finished copper powder, the trolley is equipped with a nitrogen conveying device, which is connected to the furnace through a nitrogen inlet pipe The tank body of the tank is connected to the furnace tank. The top of the furnace tank is connected with an air outlet pipe. The air outlet pipe is provided with an air outlet valve. A track is arranged between the trolley and the furnace door of the melting furnace. The trolley slides or rolls with the track In cooperation, an induced draft fan and a heat exchanger are arranged on the outer wall of the melting furnace, the gas outlet pipe of the furnace tank is connected with the inlet of the heat exchanger, and the inlet of the induced draft fan is connected with the outlet of the heat exchanger.

However, the above conditions all use pyrolysis and melting to separate the insulating paint film of the waste enameled wire. The equipment required for pyrolysis and melting is expensive, and the cost is high, and the generated tail gas contains a large amount of toxic and harmful gases, which is difficult to handle.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the object of the present invention is to provide a method for recovering copper from waste enameled wire, the method adopts the method of physical separation to separate the copper in the waste enameled wire from the insulating varnish, and the purity of the obtained copper wire is relatively high. High, can be directly used in the preparation of copper products.

For this purpose, the present invention adopts the following technical solutions:

The invention provides a method for recovering copper from waste enameled wire, the method comprises the following steps:

(1) Mechanically regularizing the waste enameled wire;

(2) Spray the surface of the mechanically regulated waste enameled wire;

(3) Cleaning the waste enameled wire after surface spraying treatment to obtain purified copper wire and waste paint slurry.

In the invention, the waste enameled wire is mechanically regulated, so that the surface of the waste enameled wire is fully exposed; then the surface layer of the mechanically regulated waste enameled wire is sprayed to separate the insulating paint and copper in the waste enameled wire; finally, a simple cleaning method is used. , clean the residual insulating paint in the waste enameled wire after surface spraying treatment to obtain purified copper wire and waste paint slurry.

The method provided by the invention is simple to operate, and the insulating paint and copper in the waste enameled wire can be separated only by the method of physical separation, and the copper has high purity and recovery rate, no secondary pollution, and good social and economic benefits.

Preferably, the mechanical regularization in step (1) is to regularize the waste enameled wire into a single-layered waste enameled wire. The method of mechanical regularization includes winding the waste enameled wire on the surface of any fixing piece in a single-layer winding manner or laying the waste enameled wire on the surface of any fixing piece in a single-layer tiling manner. The method of mechanical regularization is not limited to the above-mentioned single-layer winding and single-layer tiling, and the methods that can make the single-layer arrangement of the waste enameled wire are all methods of the mechanical regularization of the present invention. The fixing members are commonly used fixing members in the field, including but not limited to fixing rods and/or fixing plates, which can be reasonably selected by those skilled in the art according to process requirements.

Preferably, the method for surface spraying treatment in step (2) includes the following steps: firstly use hot water to spray the mechanically regulated waste enameled wire, and then use a paint remover to spray the hot water sprayed waste enameled wire.

The surface spraying treatment of the present invention is not a simple spraying treatment, but firstly, the surface layer is sprayed with hot water, and then the surface layer is sprayed with a paint remover.

Hot water spraying the waste enameled wire can make the copper in the waste enameled wire thermally swell, and can also preliminarily remove the insulating paint in the waste enameled wire. Then the waste enameled wire is sprayed with paint remover. The thermal conductivity of copper is high, and cold shrinkage occurs under the spray of the paint remover, and the insulating paint on the waste enameled wire is quickly separated from copper under the action of the spray. That is, the surface spraying described in the present invention does not achieve the purpose of separating copper and insulating paint by simply physical shock, but achieves separation of copper and insulating paint in waste enameled wires through the combination of thermal expansion and cold contraction, physical shock and chemical paint removal. purpose of paint.

Preferably, the temperature of the hot water is 60-80°C, such as 60°C, 65°C, 70°C, 75°C or 80°C, preferably 70-80°C.

Preferably, the spraying pressure of the hot water spraying is 5-60MPa, such as 5MPa, 10MPa, 15MPa, 20MPa, 25MPa, 30MPa, 35MPa, 40MPa, 45MPa, 50MPa, 55MPa or 60MPa, preferably 30- 50MPa.

Preferably, the spraying time of the hot water spraying is 5-30 minutes, for example, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes or 30 minutes, preferably 10-20 minutes.

The greater the brushing pressure and the longer the brushing time, the better the effect of physical impact, but the consumption of hot water also increases. The present invention does not rely solely on the physical impact of spray brush to separate the insulating paint and copper in the waste enameled wire, but achieves the separation of copper and insulation in the waste enameled wire through the combination of thermal expansion and cold contraction, physical impact and chemical paint removal Therefore, it does not need an excessively high spraying pressure. When the spraying pressure during hot water spraying is 5-60 MPa, the separation effect to be achieved by the present invention can be achieved.

Preferably, the paint remover is composed of functional components, methyl cellulose, paraffin wax and deionized water.

Preferably, the functional component comprises any one or a combination of at least two of dichloromethane, trichloromethane, ethyl acetate, triethyl phosphate, tributyl phosphate, vegetable oleic acid, triethanolamine or benzyl alcohol , typical but non-limiting combinations include dichloromethane and chloroform, ethyl acetate and triethyl phosphate, triethyl phosphate and tributyl phosphate, tributyl phosphate, benzyl alcohol and The combination of vegetable oleic acid, the combination of benzyl alcohol, triethyl phosphate and ethyl acetate, the combination of dichloromethane, chloroform, ethyl acetate and vegetable oleic acid, ethyl acetate, triethyl phosphate, tributyl phosphate, Combination of vegetable oleic acid and benzyl alcohol, triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine or dichloromethane, chloroform, ethyl acetate, triethyl phosphate, tributyl phosphate, vegetable oil The combination of acid, triethanolamine and benzyl alcohol is preferably a combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine.

Preferably, the mass ratio of the triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine is (1-2):(1-2):(1-2):(1-2), for example Can be 1:1:1:1, 1:1.5:1:1, 1:1:1.5:1, 1:1:1:1.5, 1:1.5:1.5:1, 1:1.5:1:1.5, 1:1:1.5:1.5, 1:1.5:1.5:1.5, 1.5:1:1:1, 1.5:1:1.5:1, 1:2:2:1, 1:1:2:1, 1: 2:1:1, 1:2:2:1 or 2:1:2:1, preferably 2:1:2:1.

Preferably, the mass ratio of the functional component, dispersant, paraffin and solvent is (4-6):(0.5-2):(0.5-1.5):(2-3), for example, it can be 4:0.5: 0.5:2, 4.5:0.8:0.8:2.2, 5:1:1:2.5, 5.5:1.5:1.2:2.7, 6:2:1.5:3 or 6:0.5:0.5:3, preferably 6:0.5: 0.5:3.

Preferably, the paint remover is sprayed at a temperature of 10-25°C, such as 10°C, 12°C, 15°C, 18°C, 20°C, 22°C or 25°C, preferably 15-20°C.

The temperature of the paint remover of the present invention is 10-25 DEG C when sprayed, which is lower than 60-80 DEG C of the hot water spray. It can be thermally expanded and contracted, thereby improving the effect of surface spraying.

Preferably, the spraying pressure of the paint remover is 5-20 MPa, such as 5 MPa, 8 MPa, 10 MPa, 12 MPa, 15 MPa, 18 MPa or 20 MPa, preferably 10-20 MPa.

Preferably, the spraying time of the paint remover is 5-30min, such as 5min, 8min, 10min, 12min, 15min, 18min, 20min, 24min, 25min, 27min or 30min, preferably 10-20min .

The greater the brushing pressure and the longer the brushing time, the better the effect of physical impact, but the consumption of hot water also increases. The present invention does not rely solely on the physical impact of spray brush to separate the insulating paint and copper in the waste enameled wire, but achieves the separation of copper and insulation in the waste enameled wire through the combination of thermal expansion and cold contraction, physical impact and chemical paint removal Therefore, it does not need an excessively high spraying pressure. When the spraying pressure during hot water spraying is 5-60 MPa, the separation effect to be achieved by the present invention can be achieved.

Preferably, the cleaning in step (3) is cleaning with deionized water.

Preferably, the cleaning temperature in step (3) is 15-30°C, such as 15°C, 18°C, 20°C, 24°C, 25°C, 27°C or 30°C, preferably 20-25°C.

Preferably, the method also includes post-processing steps after step (3):

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice;

Step (4) and step (5) are in no particular order.

Preferably, the filtrate obtained in step (4) is returned to step (3) to clean the waste enameled wire after surface spraying treatment.

Preferably, the average length of the purified copper rice obtained in step (5) is ≤5mm, such as 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm.

The smaller the average length of the purified copper rice is, the more favorable the subsequent utilization of the copper rice is. The present invention makes the purified copper wire cut and broken into purified copper rice with an average length of ≤5mm through conventional cutting and crushing operations, reducing the amount of waste enameled wire. The difficulty of reusing copper.

Preferably, after step (5), a step (6) of treating the purified copper rice is further included: the purified copper rice obtained in step (5) is ball-milled to obtain copper powder.

Preferably, the time of the ball milling in step (6) is 30-200 min. For example, it can be 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, 130min, 140min, 150min, 160min, 170min, 180min, 190min or 200min.

The method of ball milling includes, but is not limited to, wet ball milling and/or dry ball milling. The material of the grinding ball used in the ball milling includes any one or a combination of at least two of zirconia, alumina or silicon carbide. The size can be selected according to the needs of the process, and will not be repeated here.

The copper powder obtained after the ball milling of the present invention passes through sieves with different mesh numbers to obtain copper powder with different particle sizes.

As a preferred technical solution of the method of the present invention, the method comprises the following steps:

(1) Mechanically arrange the waste enameled wire into a single-layer waste enameled wire;

(2) First, use hot water at 60-80°C to spray the mechanically regulated waste enameled wire for 5-30min, and the spraying pressure during brushing is 5-60MPa; The waste enameled wire after water spraying is 5-30min, and the spraying pressure is 5-20MPa;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 15-30°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order;

(6) The purified copper rice obtained in the ball milling step (5) is obtained to obtain copper powder.

The numerical range described in the present invention not only includes the above-mentioned exemplified point values, but also includes any point value between the above-mentioned numerical ranges that are not exemplified. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list them. The specific point value included in the above range.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The method provided by the present invention is simple to operate, and the separation of insulating paint and copper in the waste enameled wire can be realized only by the method of physical separation, and the purity of copper can reach 95.2wt%, the recovery rate is as high as 98.5%, and there is no secondary pollution. , with good social and economic benefits;

(2) The surface spraying treatment of the present invention does not achieve the purpose of separating copper and insulating paint through simple physical impact, but achieves separation of copper in waste enameled wires through the combination of thermal expansion and cold contraction, physical impact and chemical paint removal. With the purpose of insulating paint, the separation efficiency is high, the separation effect is good, the purity of the recovered copper is high, and it has industrial application potential.

Detailed ways

The technical solutions of the present invention are further described below through specific embodiments.

Example 1

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) First, use hot water at 70°C to spray the single-layer-wound waste enameled wire for 40 minutes, and the spraying pressure is 40MPa; then use a paint remover at 18°C to spray the waste enameled wire after hot water spraying. 15min, the brushing pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine of 1:2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22° C. to obtain purified copper wire and waste paint slurry.

Example 2

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) Lay the waste enameled wire on the surface of the fixed plate in a single-layer tiling manner;

(2) First, use hot water at 65°C to spray the single-layer-wound waste enameled wire for 20 minutes, and the brushing pressure is 50MPa; then use a paint remover to spray the waste enameled wire after hot water spraying at 20°C. 10min, the spraying pressure is 10MPa; the paint remover is composed of functional components with a mass ratio of 4.5:1:0.8:2.5, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 1 : the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine of 2:2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 25°C to obtain purified copper wire and waste paint slurry.

Example 3

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) Lay the waste enameled wire on the surface of the fixed plate in a single-layer tiling manner;

(2) First, use hot water at 75°C to spray the single-layer-wound waste enameled wire for 30 minutes, and the spraying pressure is 10MPa; 20min, the brushing pressure is 18MPa; the paint remover is composed of functional components with a mass ratio of 5:1.5:1.2:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine of 2:2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 20°C to obtain purified copper wire and waste paint slurry.

Example 4

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) Lay the waste enameled wire on the surface of the fixed plate in a single-layer tiling manner;

(2) First, use hot water at 80°C to spray the single-layer winding waste enameled wire for 5 minutes, and the spraying pressure during brushing is 5MPa; then use paint remover at 10°C to spray the waste enameled wire after hot water spraying. 30min, the spraying pressure is 20MPa; the paint remover is composed of functional components with a mass ratio of 4:0.5:0.5:2, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 1 : the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine of 1:1:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 30°C to obtain purified copper wire and waste paint slurry.

Example 5

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) Lay the waste enameled wire on the surface of the fixed plate in a single-layer tiling manner;

(2) First, use hot water at 60°C to spray the single-layer-wound waste enameled wire for 30 minutes, and the spraying pressure is 60MPa; then use a paint remover at 25°C to spray the waste enameled wire after hot water spray 5min, the spraying pressure is 5MPa; the paint remover is composed of functional components with a mass ratio of 5.5:2:1.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine of 2:1:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 10°C to obtain purified copper wire and waste paint slurry.

Example 6

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) First, use hot water at 70°C to spray the single-layer-wound waste enameled wire for 40 minutes, and the spraying pressure is 40MPa; then use a paint remover at 18°C to spray the waste enameled wire after hot water spraying. 15min, the brushing pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of 1:2 triethyl phosphate, tributyl phosphate and ethyl acetate;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order.

Example 7

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) First, use hot water at 70°C to spray the single-layer-wound waste enameled wire for 40 minutes, and the spraying pressure is 40MPa; then use a paint remover at 18°C to spray the waste enameled wire after hot water spraying. 15min, the brushing pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of triethyl phosphate, tributyl phosphate and triethanolamine of 1:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order.

Example 8

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) First, use hot water at 70°C to spray the single-layer-wound waste enameled wire for 40 minutes, and the spraying pressure is 40MPa; then use a paint remover at 18°C to spray the waste enameled wire after hot water spraying. 15min, the brushing pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 2 : the combination of triethyl phosphate, ethyl acetate and triethanolamine of 2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order.

Example 9

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) First, use hot water at 70°C to spray the single-layer-wound waste enameled wire for 40 minutes, and the spraying pressure is 40MPa; then use a paint remover at 18°C to spray the waste enameled wire after hot water spraying. 15min, the spraying pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, methyl cellulose, paraffin and deionized water, and the functional components are in a mass ratio of 1 : the combination of tributyl phosphate, ethyl acetate and triethanolamine of 2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order.

Example 10

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) Use hot water at 70°C to spray the single-layer winding waste enameled wire for 55 minutes, and the spray pressure during spraying is 40MPa;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order.

Example 11

The present embodiment provides a method for recovering copper from waste enameled wire, the method comprising the following steps:

(1) winding the waste enameled wire on the surface of the fixed rod in a single-layer winding manner;

(2) Use paint remover to spray the waste enameled wire after hot water spraying at 18°C for 55min, and the spraying pressure is 15MPa; the paint remover is composed of functional components with a mass ratio of 6:0.5:0.5:3, Methyl cellulose, paraffin and deionized water, the functional component is the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine in a mass ratio of 2:1:2:1;

(3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 22°C to obtain purified copper wire and waste paint slurry;

(4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment;

(5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm;

Step (4) and step (5) are in no particular order;

(6) The purified copper rice obtained in step (5) is treated by ball milling, and then the obtained copper powder is sieved to obtain copper powder with particle sizes of 50 mesh, 100 mesh, 200 mesh, 325 mesh and 600 mesh.

Comparative Example 1

This comparative example provides a method for recovering copper from waste enameled wire, and the method is the same as Example 1 except that the waste enameled wire is not subjected to mechanical regularization treatment.

Since the waste enameled wire is not mechanically regulated, the waste enameled wire is piled up in a disorderly manner, and the effect of surface spraying treatment is not good. Therefore, the method provided in Comparative Example 1 cannot effectively separate the copper and insulating paint in the waste enameled wire, and the obtained purified copper The purity of the copper in the wire is poor.

The purity of copper and the recovery rate of copper in the purified copper wires obtained in Examples 1-11 and Comparative Example 1 were measured, and the obtained results are shown in Table 1.

Table 1

Purity of copper/wt% Copper recovery/% Example 1 95.2 97.3 Example 2 94.3 96.8 Example 3 94.5 98.5 Example 4 94.1 98.1 Example 5 93.9 97.6 Example 6 93.5 97.2 Example 7 93.8 96.9 Example 8 93.6 97.1 Example 9 93.1 97.4 Example 10 72.2 95.5 Example 11 77.8 98.4 Comparative Example 1 85.5 94.2

As can be seen from Table 1, the method provided in Examples 1-9 can separate the copper in the waste enameled wire from the insulating paint, and the purity of copper in the purified copper wire obtained is 93.1-95.2wt%, and the method provided in Examples 1-9 does not. It will cause loss of copper, and the recovery rate of copper is as high as 98.5%.

In Example 10, only hot water was used to spray and brush the mechanically regulated waste enameled wire, and the effects of thermal expansion and cold contraction, physical impact and chemical paint removal could not be achieved; Similarly, in Example 11, only paint remover was used. Painting the mechanically regulated waste enameled wire also fails to achieve the combined effect of thermal expansion and contraction, physical impact and chemical paint removal. Therefore, the purity of copper in the purified copper wire obtained in Example 10 is 72.2wt%, which is lower than 95.2wt% in Example 1; the purity of copper in the purified copper wire obtained in Example 11 is 77.8wt%, low 95.2 wt% in Example 1.

Compared with Example 1, the method provided by Comparative Example 1 does not carry out mechanical regularization treatment to the waste enameled wire, the waste enameled wire is piled up in a disorderly manner, and the effect of surface spraying treatment is not good. Therefore, the method provided by Comparative Example 1 The copper in the waste enameled wire cannot be effectively separated from the insulating paint, and the purity of the copper in the purified copper wire obtained is poor, which is 85.5 wt %, which is lower than 95.2 wt % in Example 1.

To sum up, the method provided by the present invention is simple to operate, and the separation of insulating paint and copper in waste enameled wires can be realized only by the method of physical separation, and the purity of copper can reach 95.2wt%, and the recovery rate can reach 98.5%. secondary pollution, with good social and economic benefits.

Further, the present invention achieves the purpose of separating copper and insulating paint in waste enameled wires through the combination of thermal expansion and contraction, physical impact and chemical paint removal, with high separation efficiency, good separation effect, and high purity of recovered copper, which has industrial application potential.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a method for recycling copper from waste enameled wire, is characterized in that, described method comprises the steps: (1) Mechanically regularizing the waste enameled wire; (2) Spray the surface of the mechanically regulated waste enameled wire; (3) Cleaning the waste enameled wire after surface spraying treatment to obtain purified copper wire and waste paint slurry. 2 . The method according to claim 1 , wherein the mechanical regulation in step (1) is to regulate the waste enameled wire into a single-layer arranged waste enameled wire. 3 . 3. method according to claim 1 and 2, is characterized in that, the method for described surface spraying treatment of step (2) comprises the steps: first use hot water to spray the waste enameled wire after mechanical regulation, then use paint removal The waste enameled wire after spraying with hot water. 4. The method according to claim 3, wherein the temperature of the hot water is 60-80°C, preferably 70-80°C; Preferably, the spraying pressure of the hot water spraying is 5-60 MPa, preferably 30-50 MPa; Preferably, the spraying time of the hot water spraying is 5-30 minutes, preferably 10-20 minutes. 5. method according to claim 3, is characterized in that, described paint remover is made up of functional component, methyl cellulose, paraffin and deionized water; Preferably, the functional component comprises any one or a combination of at least two of dichloromethane, trichloromethane, ethyl acetate, triethyl phosphate, tributyl phosphate, vegetable oleic acid, triethanolamine or benzyl alcohol , preferably the combination of triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine; Preferably, the mass ratio of the triethyl phosphate, tributyl phosphate, ethyl acetate and triethanolamine is (1-2):(1-2):(1-2):(1-2); Preferably, the mass ratio of the functional component, dispersant, paraffin and solvent is (4-6):(0.5-2):(0.5-1.5):(2-3), preferably 6:0.5:0.5 :3; Preferably, the temperature of the paint remover during spraying is 10-25°C, preferably 15-20°C; Preferably, the spraying pressure of the paint remover is 5-20MPa, preferably 10-20MPa; Preferably, the spraying time of the paint remover is 5-30 minutes, preferably 10-20 minutes. 6. The method according to any one of claims 1-5, wherein the cleaning described in step (3) is to use deionized water for cleaning; Preferably, the temperature during the cleaning in step (3) is 15-30°C, preferably 20-25°C. 7. The method according to any one of claims 1-6, wherein the method further comprises a post-processing step after step (3): (4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate; (5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice; Step (4) and step (5) are in no particular order. 8. method according to claim 7, is characterized in that, step (4) gained filtrate returns to step (3) to clean the waste enameled wire after surface layer spraying treatment; Preferably, the average length of the purified copper rice obtained in step (5) is less than or equal to 5mm; Preferably, after step (5), a step (6) of treating the purified copper rice is further included: the purified copper rice obtained in step (5) is ball-milled to obtain copper powder. 9 . The method according to claim 8 , wherein the ball milling time of step (6) is 30-200 min. 10 . 10. The method according to any one of claims 1-9, wherein the method comprises the steps of: (1) Mechanically arrange the waste enameled wire into a single-layer waste enameled wire; (2) First, use hot water at 60-80°C to spray the mechanically regulated waste enameled wire for 5-30min, and the spraying pressure during brushing is 5-60MPa; The waste enameled wire after water spraying is 5-30min, and the spraying pressure is 5-20MPa; (3) Use deionized water to clean the waste enameled wire after surface spraying treatment at 15-30°C to obtain purified copper wire and waste paint slurry; (4) filter step (3) gained waste paint slurry, obtain waste paint solid and filtrate, gained filtrate returns to step (3) to wash the waste enameled wire after surface spraying treatment; (5) sequentially cutting and crushing the purified copper wire obtained in step (3) to obtain purified copper rice with average length≤5mm; Step (4) and step (5) are in no particular order; (6) The purified copper rice obtained in the ball milling step (5) is obtained to obtain copper powder.