In order to solve trapezoidal coal loss mining close to roof and floor, Xintun Mine of Jizhong Energy Group adopted stacked beam support to enlarge the trapezoidal coal recycle. The practice showed that the loss coal height reduced from 3 m to 1 m after the new support, with an additional 1 2000 t coal, the roof maintenance difficulty decreased, the top support was improved, with promotional value.
