The machine, adopting excellent hard alloy steel or wearable steel as its blade, is durable and suitable for the coarse comminution of different types of hard material. With the rotary blade and fixed blade, the materials are cut into granules falling on the sieve. By adjusting the sieve, we can control the size of granules. The machine is equipped with cooling water system, so as to control the comminuntion temperature and guarantee the granule quality.