Abstract: an excessively high consumption of medium is a problem that troubles Chaili Coal Preparation Plant. For tackling this problem,a series of measures is adopted based on the result of analysis of the existing operating conditions and the cause leading to the high consumption of medium. The measures taken include improvement of the water spraying system of medium draining screen,strengthening the management of operation of magnetic separator and more intensive overall system management and control. Practice shows that the adoption of the measures has brought about favorable economic result because of the drastic reduction of medium consumption per ton of raw coal treated from 1. 86 kg/t to 0. 86 kg/t and,hence,cut-down of operating cost.