... , Compared with traditional sands and coal filter material, ceramic sand filters have great advantages as follows:1. Shaped in sphere, ... cause by the filter as quartz sand or coal filters itself. 2. Chemical Composition of Ceramic Sand Filters Composition Content % Al2O3 18-25% ... resistance,%≤0.5- Compressive strength, N30-150- Water permeability,t/m2.h2-4- Gas permeability,m3/m2h.h1500-2000- Thermal ...