In almost all cases, mined rock needs to be crushed and sized before it becomes commercially viable. 聚合 need to be crushed and sized before they can be used to build roads, 桥梁和建筑物, and mineral ore needs to be crushed and sized before it can be refined to concentrate the materials.
破碎 is the process of reducing large lumps of material into smaller sizes suitable for further handling downstream. 它通常包括一个或多个阶段，包括:
- 初次破碎
- 二次破碎
- 三次破碎
- 第四纪破碎
初次破碎
初级破碎是破碎过程的第一个阶段. 在这个阶段, 被炸过的原料或未开采的原料, mined or otherwise extracted from the ground is crushed to a size that can be easily transported by a conveyor belt and handled by downstream processing equipment.
初级破碎机可以处理大的饲料块大小和 通常包括 颚式破碎机和回转式破碎机, but Impact Crushers may also be used as primary crushers if the material is easily crushed and not abrasive.
初级破碎阶段后, further stages of crushing may be required to better control the size of the output and/or refine the shape of the product. This is where downstream crushing with secondary, tertiary and quaternary stages comes in.
二次破碎
二次破碎 (or intermediate crushing) accepts the material from the primary crushing stage and reduces it even further, whether for final product sizing or in preparation for final product sizing in the tertiary or quaternary stages.
第三纪和第四纪破碎
The 第三纪和第四纪破碎阶段 are used for the final sizing of products. 因为最终菠菜网最稳定正规平台_最全菠菜网大全的质量要求是严格的, it is important to include a properly designed and engineered crusher system for the job.
二级破碎机的类型
二级破碎机通常包括(但不限于)圆锥破碎机, 水平轴冲击器, 锤磨机和辊磨机. 有时候,一个 颚式破碎机 可以用作二次破碎机吗.
圆锥破碎机
圆锥破碎机 是压缩式破碎机吗, which reduce material as it advances downward through the chamber (with the help of gravity and the weight above) by means of squeezing the material between a moving piece of steel (mantle) and a stationary piece (liner). 偏心旋转导致主轴和机头晃动.
Rock is fed into the open top and gravity pulls it through the tapered crushing chamber. 随着腔体变得更紧, the material gets smaller until it is small enough to pass through the cavity at the bottom of the crusher.
The gradation is controlled by adjusting the distance between the stationary concave and the moving mantle at their closest points. However, adjusting the closed-side setting tighter reduces the throughput capacity of the machine.
圆锥破碎机适用于硬到中硬物料. 它们在磨料中表现良好，运行成本相对较低. 在二次应用中, 它们通常提供6:1的还原比, 通过8:1的减速比可以实现粗糙的应用.
水平轴冲击器
卧式轴冲击式破碎机 设有装有锤头的水平旋转转子. 当物料进入破碎腔时, it is fractured at its weakest point upon its initial impact with the hammers on the spinning rotors.
The fractured pieces are then flung toward the breaker plates inside the chamber, 它们在哪里再次断裂，垂直于第一次断裂. Additional breakage occurs from the inter-particle collisions with the other material in the chamber.
Gradation changes are made by either changing speed of the rotating rotor and the gap setting between the adjustable curtains and the rotor. 更快的速度导致更精细的输出, 同时调节窗帘也影响整体的减少.
These impact-type crushers offer reduction ratios of 8:1 to 10:1 in secondary crushing applications. 它们是理想的软到中硬，轻微研磨材料.
锤磨机
锤磨机 特征摆动锤连接到一个旋转转子. 类似于水平轴冲击器, 物料在摇摆锤的冲击下破碎.
The shattered particles break against the breaker plates lining the crushing chamber and are carried across a grate surface, 在那里它们被磨成更小的尺寸. Openings in the grating allow the release of appropriately sized material to ensure controlled product sizing.
这些破碎机提供的减速比高达20:1. They are adept at handling less abrasive materials in aggregate and industrial applications.
辊破碎机
辊破碎机 可用于初级、二级、三级或四级破碎阶段. They are compression machines and work by crushing rock between a single or pair of rotating rolls equipped with teeth.
取决于配置(单卷), 双辊, 三卷或四卷), the material is crushed between the roll bodies and teeth on the two rolls or, 在单辊破碎机和三辊破碎机的顶部阶段, 辊子和压板之间.
取决于设计, 辊破碎机 have a reduction ratio of 6:1 (single roll and the top stage of the Triple Roll) and 4:1 (双辊s). 他们是伟大的处理软到中硬, 稍具磨蚀性的材料，可干可湿且有粘性.
三级和四级破碎机的类型
用于精细上浆, tertiary or even quaternary crushing stages may follow the primary and secondary stages. 圆锥破碎机是三级和四级破碎机中最常见的类型, though 竖轴冲击器 and 辊破碎机 can also be used depending on the application.
短头圆锥破碎机
Short-head 圆锥破碎机 are specified for many tertiary and quaternary crushing applications. 短头圆锥破碎机的工作原理与标准圆锥破碎机完全相同, 但它们的特点是破碎腔较小, 使它们成为精细粉碎应用的理想选择.
The closed-side setting on a Short-head 圆锥破碎机 can be adjusted tighter than a standard cone to improve final product size and shape. 短头圆锥破碎机提供减少比约4:1.
竖轴冲击器
Vertical Shaft Impact Crushers have a rotating vertical shaft with a table or rotor at the top. 岩石通过机器中心的进给管进入转子. 转子加速岩石，把它抛向一边. 然后岩石撞击固定的表面(金属鞋或岩架). 岩石破裂，从底部掉了出来.
These types of crushers are usually applied as tertiary or quaternary crushers with less than 2” (75 mm) feed or smaller. Some 竖轴冲击器 can be used as secondary crushers with larger feed.
立轴冲击器是非常具体的应用. They are sensitive to abrasive materials and can experience very high maintenance and operating costs. 其中一些机器配备了岩石架，以减少磨损成本. The rock shelves improve the maintenance costs but sacrifice in the amount of reduction achieved.
选择合适的二级破碎机
Each of the crushing stages plays an important role in the production process, whether it be material reduction for further handling downstream or final product sizing.
Selecting the right crusher for each stage of the crushing process depends on an understanding of the material to be crushed and the site’s production goals. 在初级破碎阶段，通常会发现颚形和旋回, 而锥, 冲击器和辊式破碎机是最常用于二级, 第三纪和第四纪破碎阶段.
知道哪个破碎机最适合每个阶段, 以及确保适当大小的破碎机的任务, will help a site achieve optimum crushing efficiency and overall profitability.
