The Value of Waste PCB and Its Recycling Steps

Any item that is used for a long time will be damaged, especially electronic products. However, the damaged items are not completely waste, and the PCB can be recycled. In addition, with the advancement of science and technology, the number of electronic products has increased dramatically, thereby shortening their life cycle. Many products are discarded without damage, resulting in serious waste.

Products in the electronics industry are changing very fast, and the amount of waste PCBs that comes with it is also alarming. Each year, the UK has more than 50,000 tons of waste PCBs, while China's Taiwan has up to 100,000 tons. Recycling is the principle of saving resources and green production. In addition, certain substances on electronic products are harmful to the environment, so recycling is unavoidable.

The metals contained in PCBs include common metals: aluminum, copper, iron, nickel, lead, tin and zinc, etc.; precious metals: gold, palladium, platinum, and silver etc.; rare metals: rhodium and selenium, etc. The PCB also contains a large number of high molecular polymers directly or indirectly from petroleum products, and has a high calorific value. Using them can not only generate energy, but also produce related chemical products, many of which are toxic and harmful, and if discarded, they will cause huge pollution.

PCB Recycling Steps:

The PCB samples are composed of a variety of elements, and even if it cannot be used normally, the elements in them can be recycled. Therefore, how to recycle them, we introduce its steps:

1. Remove Paint

Because the surface of the PCB is coated with protective metal, the first step in recycling is to remove the paint first. The paint remover includes organic paint remover and alkaline paint remover. Organic paint remover is highly toxic and harmful to human body and the environment. Sodium hydroxide and corrosion inhibitor can be used to dissolve it.

2. Crush

After removing the PCB, it needs to be crushed. There are methods such as impact crushing, extrusion crushing and shear crushing. More commonly used is ultra-low temperature freezing and crushing technology, which cools hard materials and makes them brittle and pulverized, thereby completely separating metal and non-metal.

3. Separation

The crushed materials need to be sorted according to the characteristics of the density, particle size, magnetic permeability, and electrical conductivity of each component. Generally, there are dry and wet separation. Dry separation includes dry screening, magnetic separation, electrostatic, density and eddy current separation, etc. Wet separation includes hydrocyclone classification, flotation and hydraulic vibrating tables, etc. The material that is sorted out can be reused.