Rock Crushing Overview
It is common to use multiple crusher types within a project and set them up as stations in a circuit format. In many cases, primary, secondary, and tertiary, and quaternary stations are installed to reduce the rock to the desired size, shape, and consistency.
Knowing just how fine you need your final output to be, along with the feed requirements of your tertiary or final reduction crushing station, will help you determine how much reduction needs to take place within this stage. Compression-style jaw, cone, impact crushers, and gyratory crushers are most often appropriate as primary crushing equipment types.
Impact-style crushers include VSIs, as well as horizontal shaft impactors (HSIs) These types of machines break apart material by the impacting forces of certain wear parts known as blow bars and impact plates. Impact rock crushers can also require frequent part changes and can create a large amount of dust that can be an issue on some worksites.
1. Primary Crushing
A primary crusher is the driving force of the success of your plant. As the first stage in a crushing circuit following extraction from a mine site, (or in the case of recycled asphalt production, delivery to the RAP processing plant via truck transport), primary crushing reduces material to a size and shape that can be handled by the secondary crusher.
Typically, the minimum setting on most primary crushers will be about 4 to 6 inches, as noted above. Compression-style jaw, cone, impact crushers, and gyratory crushers are most often appropriate as primary crushing equipment types, though there can be overlap between primary and secondary crushers as far as suitable types.
2. Secondary Crushing
In secondary crushing, reduction ratios become an essential consideration. Knowing just how fine you need your final output to be, along with the feed requirements of your tertiary or final reduction crushing station, will help you determine how much reduction needs to take place within this stage.
Cone crushers are often placed within the secondary crushing station because they are versatile in terms of feed, closed side setting, speed, and throw. With cone crushers, though, it is essential to operate them at consistent choked settings to keep productivity up.
3. Tertiary/Quaternary/Final Reduction Crushing
The goal of the tertiary (third), quaternary (fourth) or final reduction stage of the crushing process is to size and shape rock or other material into a marketable product. Again, there may be overlap between stages in terms of which crusher styles work best.
Stedman Machine
Every Stedman crusher is engineered for a maximum feed size, target output size, and total capacity. These can be used as a cement crusher, mineral crushers, and many more. Every size reduction project requires evaluation of the complete process to maximize production and keep operating costs low.
Kemper Equipment
Jaw crushers are also known as rock breakers and are used to break up larger, harder materials. They tend to do well with many different types of materials and dont display as much wear and tear as impact-style rock crushers.
Kemper gyratory crushers feature a conical head and concave surface (often lined with manganese steel) and break apart material by compression through what is known as eccentric movement. Similar to jaw crushers, they are often utilized in primary aggregate crushing stations, though they may also be used in secondary applications.
Impact-style crushers are best used with less abrasive rock types, like limestone. These machines break apart material by the impacting forces of certain wear parts, like blow bars and impact plates. Some operations use impact crushers to achieve a cubical product after using another type of rock crusher.
ELRUS Aggregate Systems
ELRUS is a manufacturer of crushing equipment for the aggregate, mineral, mining and recycling industries. Our product line includes: ELRUS jaw crushers, Sandvik cone and impact crushers in a range of sizes and configurations including: portable, modular and stationary to suit individual requirements.
Metso Outotec
Metso Outotec is a frontrunner in sustainable technologies, end-to-end solutions and services for the aggregates, minerals processing and metals refining industries. We improve customers energy and water efficiency, increase their productivity, and reduce environmental risks with our product and process expertise.
Eagle Crusher
Eagle Crusher is a worldwide leader in the manufacture of a complete line of heavy-duty impact crushers, portable crushing and screening plants, jaw crushers, cone crushers, hammermills, and conveyors for the recycle concrete, asphalt, aggregate, and sand and gravel industries. The company provides innovative, quality products and exceptional aftermarket service and support.
