PHYSICS. Resietncia of particles under ( 1-3 mm of diameter 41 granules; wear by friction among themselves, being placed in quantity in a tank where insufflated air at one end for your debugging; the flow of air produces the movement of particles ( rise into the air, falling by gravity ) and they friccionan. Wear makes them dust, and reduce its efficiency ( see articles on ZEOLITES and MOLECULAR sieve of CARBON )