Radiometric Detection & Removal of Stone/Shale is a dry coal beneficiation technology for coarse Indian coals.  RAMDARS is a completely dry process and does not use water or add moisture to processed coal.

RAMDARS works on the principal of differential attenuation of gamma rays for different density particles.  The material is fed to RAMDARS system in monolayer by vibratory feeder onto a flat conveyor belt.  The detection system collects data from each passing particle, viz. its apparent density and its loading height with the help of high resolution and ultra fast response nucleonic gauges and laser sensors. The output of these signals is fed to a processor where the signals are processed to signal the presence of stone / shale on the belt based on a complex mathematical algorithm. Once detected, the processor activates the ejection mechanism.  This system is suitable for handling particles between 50 – 200 mm.