Washing involves immersing the crushed coal in a liquid of high specific gravity in which coal floats and can be recovered while the heavier rock and minerals sink and are discarded.
(Washing; involves; immersing the crushed coal in a liquid of high specific gravity) (the heavier rock and minerals; are discarded; ) (coal floats; can be recovered; T:while the heavier rock and minerals sink and are discarded) (the heavier rock and minerals; sink; )
Washing the heavier rock and minerals coal floats the heavier rock and minerals
involves are discarded can be recovered sink
immersing the crushed coal in a liquid of high specific gravity
T:while the heavier rock and minerals sink and are discarded