Abstract: The raw coal mined form Qingshan coal mine containing a lot of white mineral,which can quick become fine mud when it is in the water,caused the coal slurry very difficult to treat. To solve the sedimentation problem of coal slurry,analyzed the sedimentation property of slurry containing fine mud. The research results showed that the combined use of MgCl₂ and nonionic polyacrylamide can enhance the sediment effect.