This is the starting point for understanding how cone crushers work – and how they can make your mine or quarry more productive.
Elsewhere on the site you can find detailed information about all aspects of crushing and screening, but to make sense of these it helps to understand the basics of cone crushing. That’s what you’ll find here!
The basic principle is straightforward: the material to be crushed (the feed), drops into the crushing chamber. The mantle is a moving part that gyrates in an eccentric motion. That is, it doesn’t remain completely centred – it swings slightly as it rotates, continually altering the gap between the mantle and the concave (the ring outside the mantle that stays fixed in place.) As the mantle moves, it crushes the material against the concave at the points where the gap is smallest (the stones in the feed are also compressed against each other – that’s known as interparticle crushing).
Sandvik CH cone crusher
As the feed is crushed, it falls and exits the crusher through the space at the bottom. The eccentric gyration of the mantle means that at any moment this space is narrowest at one point, and widest at the opposite point. The widest distance is known as the open side setting (OSS) and the narrowest, the closed side setting (CSS). These settings are important. The OSS is the largest distance between the concave and the mantle at the bottom of the crusher, so it determines the largest particle size of the outgoing product. As the smallest distance between the concave and the mantle, the CSS is the final crushing zone, and is vital for determining the product size, as well as energy consumption and crusher capacity.
It’s hard to overstate the importance of feed size in a cone crusher. It is vital that you know, as accurately as you can, the size distribution of the raw material. The Sandvik CH cone crusher can be calibrated to achieve specific results, maximize productivity and minimize wear, but any calculation will be undermined without a solid understanding of what is going in to the crusher. Sampling is a vital part of the crushing process, to ensure that you know the size distribution of the feed. It’s crucial that sampling is done regularly, especially when there are changes in blasting, mining or any other upstream processes.
Feed moving towards a crusher in the Sandvik-designed Deer Park quarry in Melbourne, Australia.
Are you aware of how fast the mantle in your cone crusher spins?
It can make between four and seven revolutions per second, so crushing material is compressed multiple times as it descends through the crusher