为了区别于自磨机，通常把需要加金属介质(球或棒)的磨矿机称为常规磨矿机，如球磨机和棒磨机。要获得较高的磨矿效率和改善选矿经济效果，就必须根据选矿工艺对入选物料粒度的要求和原矿性质，按照各种磨矿机的特点，恰如其分地选用磨矿机。选矿厂常用的球磨机和棒磨机主要特点和适用范围如下。 (1)格子型球磨机。由于其特有的格子板和扇形室内的提升斗的存在，实现了低水平的强迫式排矿，已磨细的矿粒不至于在球磨机停留过久，能及时排出，过粉碎现象轻，磨矿速度快，效率高。 (2)溢流型球磨机。该磨机排矿的排料端中空轴径稍大于给料端中空轴径，造成磨矿机内矿浆面向排料端有一定倾斜度，当矿浆面高度高于排料口内径最低母线时，矿浆便溢流排出，属于非强迫的高料位排矿，排料速度慢，矿料在机内滞留时间长，介质的有效作用也较低，因此溢流型球磨机过磨严重，处理量也比同规格的格子型低。一般适用于细磨或两段磨矿中第二段磨矿。 (3)棒磨机。棒磨机内的介质是钢棒，故水平落下后与矿料面线接触，选择性粉碎矿石(即按粒度从大块到小块依次粉碎)，因此过磨轻，磨矿产物粒度均匀，适合于粗磨或要求磨矿产物过粉碎轻的重选厂。
In order to distinguish it from the mill, usually need to add metal dielectric (a ball or rod mill known as conventional mill, such as ball mill and roller mill. To obtain a higher grinding ore efficiency and improve the processing economic effect, it must be according to the ore dressing process of the selected material particle size requirements and the nature of the ore, according to various mill, appropriately selected mill. The main characteristics and application range of ball mill and rod mill are as follows.
(1) lattice type ball mill. Due to its unique grid plate and the fan-shaped indoor lifting hopper, the low level of forced discharging has finely ground ore grain is not as in a ball mill to stay too long, timely discharge, crushing phenomenon of light, grinding ore speed and high efficiency.
(2) overflow type ball mill. The grinding mill discharge of discharging end of the hollow shaft is somewhat larger in diameter than the feed end of the hollow shaft diameter, caused by wear in the ore pulp for discharging end has a certain inclination, when the pulp surface is higher than the height of a row of minimum diameter of discharging port bus, pulp and the overflow drain, belonging to the non forcing material bit row ore, discharging speed slow, aggregate in the machine a long residence time, effective function of the medium is low, so the overflow type ball mill too serious grinding, processing volume also than with the specifications of the lattice type low. Generally applied to fine grinding or grinding of the second section of the two grinding.
(3) rod mill. Rod mill in the medium is steel bar, so that the horizontal falls and ore burden line contact, the selective comminution ore (i.e. by size, from large to small in turn crushed), so too light grinding, grinding ore product of uniform size, suitable for coarse grinding or grinding products crushed lightly of gravity concentrator.