Although used for similar tasks, the crushing and screening machines are completely different and work in different way. The crushing and screening machines come in a variety of forms and sizes, and can be seen on every major construction or mining site. Construction or mining contractors use specially designed crushing and screening machines for specific tasks, like breaking or separating different types of medium to hard materials. The focus in the following text will be on describing the crushing and screening machines and for what applications they are generally used.
Like the name suggests, the crushing equipment is generally used for crushing/breaking different kinds of materials, like stones, rocks, ores, etc. These machines come with simple structure that contains several parts, but are very powerful and highly efficient. Because the crushing procedure involves several stages, more than one crushing machine is involved in the process. Depending when the crushing machine is being used, all crushing machines are categorized in there major groups: primary, secondary, and tertiary. The basic crushing procedure is performed by the primary crushers, and if the material needs to be crushed further, secondary or tertiary crushing machines are used. Most commonly used crushing machines are: jaw crusher, cone crusher, gyratory crusher, and the roll crusher. All these machines are used as primary crushers. Other machines which are less known but are also used for crushing are: hammer mill, impact crusher, rotary coal breaker, etc.
The crushing and screening equipment usually is used together on the job site, because the materials that need to be crushed also need to be screened. The process of screening, or also called mechanical screening, involves separating different materials by their size. This procedure can be either wet or dry. The screening machines are different depending on whether they are mobile or static. Additionally, these machines can be further classified depending on whether their screens are horizontal or inclined. A typical screening machine is consisted of several parts: drive, screen media, and a deck. The drive creates vibration while the screen media is responsible for the separation. The deck holds the drive and the screen media. Once the materials are being crushed, a screening machine is used for making final separation of the materials. The crushed materials are separated by their size as they pass through several screens with different openings. Generally, the screen at the top has large openings, while the other screens have smaller slots or openings.
Many well-known and reputable manufacturers design and produce different kinds of crushing and screening machines. Some of them are the following ones: Neyrtec, Terex Pegson, Attila, Lorso Parisini etc.