During the past decades, great strides have been achieved in coal mining and processing technology.  There is still some valuable coal in some aged gob piles and even prep plant refuse piles due to inefficient mining and processing methods employed years ago.  Recovering coal from these gob/refuse piles has become economically feasible with the prices of this commodity going up.  The FGX dry coal processing by its nature is a deshaling method which provides effective separation between rock and coal.  More importantly, FGX is a simple process with low operating cost, usually US $0.5-0.6 per raw ton.  Thus,  the FGX dry separation has received considerable  favor for  recovering coal from gob  or  refuse piles.  On the other hand, since gob/refuse piles are notoriously harmful to community environment and quality of life, removal of these waste piles by FGX also contributes to building a better environment.