In the era of rapid technological development, electronic products are updated extremely quickly, which has led to a sharp increase in the number of waste circuit boards. Waste circuit boards contain various valuable metals such as copper, aluminum, gold, and silver, as well as toxic and harmful substances like lead, mercury, and cadmium. Improper handling of waste circuit boards will not only cause a great waste of resources but also bring serious pollution to the environment. Therefore, efficiently and environmentally friendly recycling of valuable metals from waste circuit boards has become an urgent issue to be solved.
Among numerous waste circuit board recycling technologies, magnetic separation technology occupies a pivotal position due to its unique advantages. As the core equipment for realizing magnetic separation technology, magnetic separators can efficiently separate magnetic metals from other substances in waste circuit boards based on the differences in material magnetism. Its working principle is based on the fact that different substances are affected by different magnetic forces in a magnetic field. Generally speaking, a magnetic separator mainly consists of a magnetic system, an ore feeding device, a separation device, and concentrate and tailings discharge devices. After waste circuit boards undergo pre-treatment processes such as crushing and screening, they are fed into the magnetic separator. In the magnetic field generated by the magnetic separator, strongly magnetic metal particles such as iron, cobalt, and nickel are quickly attracted by strong magnetic forces, gather in areas with higher magnetic field intensity, and are finally collected as magnetic products; while substances such as plastics, glass, resins, and some non-magnetic metals, due to being affected by very small or almost no magnetic forces, move along different paths under the action of their own gravity, water flow force, or other mechanical forces, thereby achieving separation from magnetic metals and becoming non-magnetic products.
Magnetic separators play an extremely critical role in the waste circuit board recycling process and have an irreplaceable important function. In the early stage of waste circuit board recycling, magnetic separators can effectively remove iron components and metal powders. For example, in waste circuit boards such as computer motherboards and mobile phone circuit boards, there are a large number of iron screws, iron sheets, and other components used for fixing and connecting. If these iron substances are not separated in time, they will cause serious wear to other equipment in the subsequent recycling process, greatly affecting the service life and operational stability of the equipment. Through the preliminary screening of magnetic separators, most of the iron substances can be efficiently separated, providing purer raw materials for subsequent recycling processes and significantly reducing the cost of subsequent purification.
Magnetic separators are crucial for improving metal recovery rates. Relevant research data shows that in the process of waste circuit board treatment, magnetic separators can recover about 70% - 95% of iron materials. In some large-scale waste circuit board recycling factories, the adoption of advanced multi-stage magnetic separation processes combining permanent magnet separators and electromagnetic separators can increase the recovery rate of iron metals in waste circuit boards to more than 90%. This not only enables a large amount of iron resources that might otherwise be discarded to be fully recycled and utilized, reducing reliance on primary iron ore resources, but also brings considerable economic benefits to enterprises. At the same time, the degree of separation between metals and non-metals in the material after magnetic separation is significantly improved, creating more favorable conditions for the subsequent use of other separation technologies to further recover non-ferrous metals such as copper and aluminum and the comprehensive utilization of non-metallic materials, which greatly improves the resource utilization rate in the entire waste circuit board recycling process.
In practical applications, the collaborative cooperation between magnetic separators and other separation technologies can further improve the efficiency and quality of waste circuit board recycling. In common waste circuit board recycling production lines, magnetic separators are usually used in conjunction with equipment such as eddy current separators and electrostatic separators. The materials after iron substances are removed by magnetic separators are sent to eddy current separators. Eddy current separators use the eddy current effect generated by alternating magnetic fields in non-ferrous metals to efficiently separate non-ferrous metals such as aluminum and copper from the materials. Subsequently, the remaining materials enter the electrostatic separator, which achieves accurate separation of non-metallic materials such as plastics and resins from a small amount of residual metals according to the different electrical properties of material particles in a high-voltage electric field. Through the synergy of these multiple separation technologies, various components in waste circuit boards can be comprehensively and efficiently separated and recycled, greatly increasing the metal recovery rate in waste circuit boards, and at the same time realizing the effective recovery and utilization of non-metallic materials, which significantly reduces the generation of waste and the harm to the environment.
With the continuous progress and innovation of science and technology, magnetic separators are also continuously developing and optimizing in the field of waste circuit board recycling. In terms of equipment research and development, new types of magnetic separators are constantly emerging, and their performance has been significantly improved. Some manufacturers have developed magnetic separators with higher magnetic field intensity and more uniform magnetic field distribution, which can more effectively separate metal particles with weaker magnetism, further improving the accuracy of metal recovery. At the same time, to meet the needs of recycling enterprises of different scales, the specifications and models of magnetic separators are increasingly diversified, ranging from small laboratory equipment to large-scale industrial production equipment, and enterprises can flexibly choose suitable magnetic separators according to their actual production scale and process requirements.
In terms of intelligent control, modern magnetic separators have introduced advanced automatic control systems. Sensors are used to monitor parameters such as material properties, flow rate, and magnetic field intensity in real-time, and based on these data, the working parameters of the magnetic separator, such as magnetic field intensity, ore feeding speed, and drum rotation speed, are automatically adjusted, so that the magnetic separator is always in the best working state, ensuring the stability and reliability of the magnetic separation effect. Intelligent control also enables remote monitoring and operation. Staff can monitor and adjust the operation of the magnetic separator anytime and anywhere through terminal devices such as computers or mobile phones, which greatly improves the efficiency of production management and reduces labor costs.
Magnetic separators have an indispensable important position in waste circuit board recycling. They can not only efficiently recover iron metals, reduce subsequent processing costs, but also work in collaboration with other separation technologies to significantly improve the overall recycling efficiency and resource utilization rate of waste circuit boards. With the continuous development and innovation of technology, magnetic separators will play a more important role in the field of waste circuit board recycling, making greater contributions to promoting the development of resource recycling and environmental protection causes. We have reason to believe that with the help of advanced recycling technologies such as magnetic separators, waste circuit boards, a "urban mineral resource", will be more fully and reasonably developed and utilized, achieving a win-win situation between economic development and environmental protection.