Primary crushers Primary crushers are heavy-duty machines, used to reduce the run-of-mine ore down to a size suitable for transport and for feeding the secondary crushers. There are two main types of primary crusher in metalliferous operations--jaw （颚式）and gyratory （旋回）. Jaw Crushers The distinctive feature of this class of crusher is the two plates which open and shut like animal jaws. Gyratory Crushers（旋回破碎机） The gyratory crusher consists essentially of a long spindle（轴）, carrying a hard steel conical grinding element（研磨体）, seated in an eccentric sleeve（轴套）. At any cross-section of the crushing chamber there are in effect （实际上、有效）two sets of jaws opening and shutting like jaw crushers.
Review of the last lesson Primary crushers Primary crushers are heavy-duty machines, used to reduce the run-of-mine ore down to a size suitable for transport and for feeding the secondary crushers. There are two main types of primary crusher in metalliferous operations--jaw and gyratory. Jaw Crushers The distinctive feature of this class of crusher is the two plates which open and shut like animal jaws. Gyratory Crushers The gyratory crusher consists essentially of a long spindle, carrying a hard steel
conical grinding element, seated in an eccentric sleeve. At any cross-section of the crushing chamber there are in effect two sets of jaws opening and shutting like jaw crushers.
Lesson4 Secondary Crushers 圆锥破碎机：结构与旋回破碎机相似，所不同的是，破碎腔由两个相互平行的正立截头圆锥组成，固定锥和运动锥表面有一段平行面，排矿粒度较细，通常作为中细碎设备使用。
圆锥破碎机：按照破碎腔的型式又可分为：标准型（给矿口大，平行区短）、短头型（给矿口小，平行区长）、中间型则（给矿口、平行区居中）。
辊式破碎机：破碎腔由两个相向转动的辊子组成，矿石在两辊之间受到挤压、破碎。可作为选煤厂破碎设备或中小型金属矿选矿厂细碎设备使用，其特点是能量利用率高、适用于脆性和粘性矿石，但处理能力较小，在大型金属矿中应用较少。