Enamelled copper wire is the key material for the manufacture of electromagnetic windings of motors, electrical appliances and telecommunication instruments. The copper used is of high purity and is the main source of miscellany copper recovery. In 2010, the output of our country's copper lacquer wire reaches 1.24 million tons, the dosage of lacquer wire is close to 200 thousand tons, become the world first big country of lacquer wire manufacturing. By 2019, global copper production will reach 20.6 million tons, and China's consumption will reach 11.55 million tons, showing an annual growth trend.
Domestic copper resource supply is insufficient, and more than 70% of copper resources need to be imported.
With the increasing demand for copper products and the contradiction between the shortage of copper concentrate resources, recycled copper has been paid more and more attention, and has become an important supplement to the supply of copper raw materials.
Recovery and treatment of waste enamelled copper wire
The main process includes comminution - air separation - secondary comminution - electrostatic separation - dust collection, etc., which has the disadvantages of unstable separation effect, large copper loss, low processing efficiency and so on. It is difficult to meet the modern industrial requirements of automation and assembly line production.
The direct contact between copper wire and air during incineration process oxidizes, making copper loss large and low quality. At the same time, peroxic combustion will produce a large number of harmful gases and dioxins, which is easy to cause secondary environmental pollution.
Batch pyrolysis method
After the scrap copper wire is broken, it is heated into the tank for cracking. Because the tank is produced by alternating heating and cooling of A/B tank, each furnace must have the process of heating and rapid cooling and cooling, so the equipment energy consumption is large and the labor intensity is high.
Continuous pyrolysis recovery method
Continuous pyrolysis method can realize the continuous and large-scale recovery production of scrap copper wire, so as to improve the energy utilization rate, shorten the production cycle, and reduce the production cost and labor cost. Pyrolysis tail gas into the environmental protection tail gas purification system, can eliminate the impact of smoke, dioxins and other harmful substances on the environment. Through online monitoring, the emission values of all indicators are lower than the relevant national emission standards
By comparison, it can be seen that continuous pyrolysis recovery method has many advantages over mechanical method, direct incineration and batch pyrolysis method, and has broad application and development space!
In view of this situation, Dingli Technology has achieved high efficiency and environmental protection lacquer removal of enamelled wire and recycling of copper resources through technological breakthrough, and successfully developed complete sets of technology and key equipment for continuous pyrolysis recovery of enamelled wire.
The key technology of enamelled copper wire continuous pyrolysis equipment
1. Continuous anaerobic pyrolysis technology
The continuous pyrolysis equipment of enamelled wire adopts the emptying and sealing method to recover the continuous pyrolysis of waste enamelled wire in anaerobic environment. After the replacement, the material enters the pyrolysis furnace for continuous pyrolysis. After the pyrolysis is completed, the pyrolysis gas enters the purification system for purification. After the product is pyrolyzed, it is cooled by the cooling system and discharged for subsequent treatment.
FIG. 1 Pyrolysis furnace treatment process
1. Pyrolysis tail gas clean treatment technology
The tail gas treatment process is shown in Figure 2. The tail gas generated in the pyrolysis process is treated successively by continuous collection, secondary combustion, etc., and then discharged. To achieve a reasonable and efficient clean treatment of pollutants such as volatile organic compounds (VOCs), fly ash, dust, heavy metals and acid gases in exhaust gas. The dioxins in the tail gas were completely decomposed and the secondary generation was inhibited by the treatment process of rapid full combustion and quench cooling. After treatment by the exhaust gas purification system, the exhaust gas can be discharged up to the standard.
FIG. 2 Pyrolysis tail gas treatment process
1, intelligent automatic process control technology
The enamected-wire continuous pyrolysis equipment carries out continuous feed-pyrolyzation-cooling-discharge process under a stable pyrolysis temperature and cooling environment. All production lines adopt a visual intelligent monitoring system to realize continuous production, overcoming the problems of long production cycle, high energy consumption and high labor intensity in traditional batch pyrolysis production. The operation of the entire production line equipment is controlled by computer integrated automation, and monitored by visual intelligent system to improve the efficiency of production operation.
Equipment and system for continuous low temperature pyrolysis of enamelled copper wire
The equipment for continuous anaerobic pyrolysis of waste enameled copper wire has been successfully put into 4 sets (sets) in Anhui Chujiang High-tech Electric Materials Co., LTD., all of which have achieved continuous normal production and good operation.
a single set of equipment in a capacity of 20000 tons or more
copper recovery rate of 99.5% or higher
tons of processing costs 200 yuan or less
annual production of about 1 billion yuan a single set of equipment
After monitoring, the average concentration of particulate matter is 10~15mg/m³, SO2 is not detected, the average of NOx is 100mg/m³, and all exhaust emission indicators are in line with national emission standards.G. 3 shows the comparison of waste enamelled wire before and after equipment treatment. After treatment, the enamelled wire paint is obviously charred, and a small part of the carbon attached can be removed by twisting the copper wire and wind separation.
Key technology of efficient and environmental protection recycling of waste enamelled copper wire and large-scale continuous intelligent equipment
FIG. 3 Comparison of waste enamelled copper wire before and after treatment
The continuous intelligent equipment for efficient and environmentally friendly recovery of waste enameled copper wire developed by Top Technology has broken through the bottleneck of efficient recovery of rare and precious metal resources, deep purification of pyrolysis tail gas and recycling of waste heat and other key technologies, and improved the harmless and high-value utilization of pyrolysis products. We have obtained 8 patents, and through the evaluation of scientific and technological achievements, the overall technology has reached the international advanced level, and some technologies have reached the international leading level.