Municipal Solid Waste Sorting is a method of waste management. In its crude form it is done by scavengers on refuse dumps and in its most advanced form by computer guided machines in a plant. It is a process in which the wastes are separated into their various constituents which are paper and cardboards, metals, textiles, vegetable matter, plastics/rubbers. These constituents can then be further processed to produce other finished goods such as refuse derived fuel, fertilizer or as a land filling agent.
The sorting machine sorts waste by utilizing the physical and/or chemical properties of the waste. To effect the sorting of the wastes, processes like magnetic separation, air classification, density separation, etc, are used with different levels of sophistication introduced in their operation. Mechanical waste sorting is the process of using machines to sort wastes into their various components. These machines use various mechanisms in a prescribed or predetermined sequence, to sort the waste while being interconnected by conveyors.
Modern material recovery facilities (MRFs) usually make use of electronics like colour sensors, seismic sensors, eddy current separators, and other means with the main purpose of improving the sorting efficiency. With mechanical waste sorting greater quantities of waste derived fuel can be extracted from the waste stream. These high energy components of the waste stream can be incinerated to produce energy to power electricity generating plants. Also, the putrescible vegetable matter obtained from the sorting process can be used to generate biogas or syngas which can also be used to generate electricity in addition to natural gas as integration to an existing gas power plant.