Grinding is a further process for crushed products, contributing to achieving mineral monomer dissociation and providing qualified raw mineral for beneficiation. Grinding is a necessary stage for most plants, and also the last stage for preparing minerals before beneficiation. Ball mill is the main equipment in grinding process. According to different discharge ways, ball mill is classified into overflow ball mill, in which grinding products overflows freely from the hollow journal in discharge port. Grid ball mill, grinding products are discharged from holes in discharge port’s grid liner, and then flows by a hollow journal. Peripheral type ball mill, in which products are discharged from simple peripheral holes in discharge port.
Grid ball mill is used for grinding kinds of ores and minerals, which widely applies in beneficiation, building and chemical industries. A particle of feeding minerals is less than 65mm, and the best feeding particle is less than 6mm. It has a better grinding effect in fine grinding than that of coarse grinding. Grid ball mill is composed with cylinder (liner, flange), feeding port ( end cover, hollow journal, feeder), discharge port ( grid liner, end cover, discharge hollow journal), main bearing and etc.
Minerals enter into ball mill by a feeder. When ball mill’s cylinder rotates, friction among cylinder, minerals, and steel balls raise the minerals and steel balls to a certain height. With the gravity force, minerals and steel balls fall down and are ground, and the ore is ground due to the impacts and grinding. At the same time, feeding port continuously gives minerals, and creates pressure to ore in a cylinder, promoting to move towards discharge port. Discharge holes in gird liner have a certain specification, and the inner wall of discharge’s end cover is divided into sector ventricular with a certain number by radiated ribs. Minerals whose particle size is less than the size of discharge holes enter into sector ventricular by holes in grid liner. When the sector ventricular rotates with cylinder, minerals in it enter into hollow journal in discharge port, and finally, minerals are discharged out of ball mill.