Superfine grinding for the particles also had been researched and compared the effects from comminution by machine and gas stream , which were D90 < 8.856 u m and D900 < 2.509 u m separately .
同时对粉体进行了超细粉碎研究，研究了机械粉碎和气流粉碎的粉碎效果，机械粉碎可以得到D（90）＜8.856μm的产品；
d900