a : something that is formed by casting inside a mildew or kind: for example (one) : a replica (as of the statue) in metallic or plaster : casting (two) : a fossil copy of the small print of the pure object by mineral infiltration b : an impression taken from an item with a liquid or plastic substance : mould They made a mask from the wax cast of her face.
from the site melancholy scrap and junk suggest throwing away or breaking apart as worthless in existent variety.
discard implies the letting go or throwing away of a thing that has become useless or superfluous however generally not intrinsically valueless.