Abstract: The refuse product of the heavy medium separation system of the washery is found to be relatively low in ash.To tackle this problem,and in the light of the specific conditions of the plant,exploratory experiment is made on the separation of the raw coal of Ding,Wu and Geng groups using the structurally optimized gravity-fed 3-product H.M.cyclone with ultracoarse magnetite power as medium solids.Test result shows that under the prerequisite of ensuring the quality of clean coal product,the use of ultracoarse magnetite power as dense medium in place of the magnetite power of standard size can lead to a rise of refuse ash by 8~10 percentage points and an increase of yield of middling product by 2 percentage points.