The screening reject is in fact the coarse fraction during a screening operation, the one whose particle size is too large to pass the mesh.
Often these rejects are considered "undesirable" in relation to the fraction of the fines which pass through the mesh, and which is often intended either to be marketed or to be admitted in a subsequent treatment process.
These refusals can also then be subjected to a subsequent separation of the type, for example aeraulic separation (to further eliminate films and plastic bags) or even ballistic to separate the stones, or even magnetic (by permanent magnet of the magnetic pulley or overband type) to separate ferrous metals. These subsequent refinings are often carried out in order to be able to market these refusals in another processing sector.
Depending on the desired particle size, these refusals, once refined, can also be sent to a grinding phase in order to produce a finer product which can thus be marketed in ad hoc sectors.
The ultimate goal of all these screening and treatment phases is to recover all these products as much as possible in order to reduce the percentage of final non-recoverable waste.
the refusal is the fraction of the incoming flow which does not cross the screening surface, the fraction which crosses this surface being the "passer"
