A crusher is a general name for a heavy-duty device designed to crush rocks and minerals into smaller rocks, gravel or dust. The equipment may be used in a wide range of contexts across various industries. Types of materials crushed in crushers include clay, coal, lime, potash, salts and fertilizer.
A cage crusher uses large internal hammers to crush materials. They include a cage at the top of the device used to filter out rocks of particular sizes that do not need to be crushed. The cage may be adjusted in order to allow rocks of different sizes to pass through. Cage crushers are used in advanced coal processing to make coke, a type of fuel derived from coal and petroleum. They are also used to carry out fine grinding of industrial materials such as salt and lime and to crush wet salt at solar salt plants.
A roll crusher uses one or more rollers with rows of sharp and hard teeth attached to them. As the rollers turn they crush and cut rocks and minerals into the desired size. Speed and timing of these rollers may be adjusted to suit the specific purposes of the operator. Roll crushers are used to reduce oversized ash into smaller units so it may be stored in silos. They are also used in oil refineries to crush different types of coke, in chemical plants to crush hot chemicals and in nickel processing plants to crush raw nickel with high moisture content.
Impact crusher uses a massive metal plate to crush materials to the desired size. An impact crusher has a bigger reduction ratio than crushers that use hammers. Impact crushers are used to crush limestone, chamotte, calcium carbide, quartz, slag and coal, among other materials. It is found in the cement, fireproof material manufacturing, building, ceramics and glass industries.
There are also crushers currently in use in industry considered green devices. For example, green crushers are used in petroleum plants to crush petroleum-derived coke. Because it is more environmentally friendly, use of these devices often results in a lighter environmental impact as well as fewer fines associated with the violation of environmental regulations.