Abstract: The treating capacity of the coal washery is found to be unmatchable after the mine output is augmented and the severe degradation of gangue material in water has led to overload of slurry treatment system and high consumption of medium. To tackle these problems,it is proposed to add a coarse coal pre-deshaling system. An introduction is made in the paper to the heavy medium shallow-bath separator-based deshaling process,selection of process equipment,process layout and its design features. After the technical transformation,a remarkable economic and social performance has been obtained,well achieving the expected result.