Common MSW separation technology mainly includes screening, gravity separation, buoyancy separation, magnetic separation, power separation and so on. In recent years, some new garbage sorting technologies have emerged, such as image recognition sorting, variable weight sorting and so on. This paper introduces some common MSW separation technologies.
1. Screening
Screening is to mix the garbage with different particle sizes. Through the vibration of the screen, the garbage particles with a diameter smaller than the mesh hole are passed through the screen surface, while the large garbage with a diameter larger than the mesh hole will be retained on the screen, so as to achieve the sorting method of household garbage with different diameter sizes.
2. Gravity sorting
Gravity sorting is based on the different densities of different components in the solid waste. Through the comprehensive action of gravity, medium power and mechanical force, the solid waste is layered and separated to obtain products of different densities. According to the different sorting media, the gravity sorting of MSW can be divided into wind sorting, jigging sorting, shaking table sorting and heavy medium sorting.
3. Buoyancy sorting
Buoyancy separation is mainly carried out by means of liquid and surface treatment agent. Due to the different surface properties of each component of MSF, the adsorption energy is also different, so that some garbage can float on the surface of the liquid, and some at the bottom of the liquid, so as to achieve the purpose of sorting.
4. Magnetic sorting
Magnetic separation is a real separation method according to the different magnetic properties of each component of MSW. The household garbage into the magnetic separator, by the magnetic field attraction, household garbage magnetic particles are magnetized, adsorption on the magnetic separator cylinder left, non-magnetic particles and other waste discharge together.
5. Power sorting
Power separation is a separation method which makes use of the different electrical properties of each component of MSW in the electric field. Most of MSW belongs to semiconductor and non-conductor, so the power separation process of MSW is also the process of separating semiconductor and non-conductor.
6. Electrostatic separation
Electrostatic separation is a kind of separation method which makes use of the different electrostatic properties of domestic garbage. Electrostatic separation method is mainly used for plastic domestic waste, especially for polarized polyvinyl chloride, and the purity of separation can reach 99%.