Types Of Crushers Used At The Mining Site

Crushing rocks and ores is the first step in mineral processing where different types of hard materials from the mining site are being excavated and feed into special crushing equipment for size reduction. In this process the crushing equipment that is used brakes/crushes the ore or the rocks so that valuable minerals can be liberated from the rocks. Special crushing equipment consisted of several crushing machines is used to reduce the size of the materials, and depending on the requirements, there can be primary, secondary, tertiary, or quaternary crushing stage. The primary crushing is usually performed by the crushing equipment at the mining site. In general, the crushing machines can be classified in two categories: primary and secondary crushers.

Types Of Crushers Used At The Mining Site

The primary crushing equipment is consisted of heavy-duty machines which are used to reduce the materials to a manageable size so that the secondary crushing machines can complete the crushing procedure. These machines always work in open circuit. Most common primary crushing machines are: jaw crusher and gyratory crusher.

Jaw Crusher. The jaw crusher is definitely the most utilized crushing equipment at the mining sites. This machine brakes and reduce the size of the materials by a compression force when the rocks/ores are pressed against two plates. It is consisted of two vertical jaws, one which is in fixed position and another that can be moved back and forth by a special mechanism. After the crushing procedure, the rocks are small enough to move freely through the opening at the bottom of the jaw crusher. The jaws of this crushing equipment are usually made from cast steel or cast iron.

Gyratory Crusher. This crushing equipment is usually consisted of long spindle which comes with a steel made grinding element. This grinding element is known as the “head” and it is positioned in one eccentric sleeve. When the spindle rotates it creates a conical path in the fixed crushing chamber.

The secondary and tertiary crushing equipment is used once the materials have been crushed either by the jaw or the gyratory crusher. Most popular secondary or tertiary crushing machines are the following ones:

Cone Crusher. The cone crusher is similar to the gyratory crusher. The main difference is the short spindle which is supported instead of being suspended. When the rock enters the machine from the top opening, it becomes squeezed and wedged between the bowl liner and the mantle. Larger rock pieces are broken and then they fall to a lower position where they are broken again. The crushing procedure continues until the rock pieces are small enough to move freely through the bottom opening.

Roll Crusher. The roll crusher is another heavily used secondary crushing equipment. It crushes hard materials by creating compression force with its two rotating rolls. The rolls rotate around a shaft. The size of the rocks can be set by adjusting the gap between the rolls. The rock pieces are crushed by being drawn into the gap between the rotating rolls. The main advantages of this crushing equipment is that it crushes the materials to a perfect size, and it creates little amount of dust and other harmful particles.

Other secondary and tertiary crushing machines which are also used at the mining sites are: impact crusher, hammer mill, rotary coal breaker, and other less known crushing machines.