... ,antistatic 4.polyester mine grid 400-400kN/m for long-wall recovery system roof support,hock mining geogrid,Shandong Hock MiningMine ... protection of the blast areaSlice mining longwall facesDeclining longwall faces for roof supportMine Grid Characteristics:Large square, flexible and light, ... ,Polyester Geogrid,Biaxial Geogrid. mine grid 400-400kN/m for longwall recovery system,rib and roof support