HP Cone Crusher Efficiency: A Technical Selection Guide
The HP-style cone crusher (one of the latest developments of this type of machine) combines high-powered chamber with hydraulic side setting regulation and automatic clearance of large foreign bodies to provide a crushing solution ideal for secondary and tertiary crushing of the ores and the products extracted from them across a broad range of mining sites. The paper gives an outline about cone crusher efficiency of HP type machines, the way that crushing chambers of different profiles influence product gradation and throughput, and the main selection factor for the cone crusher to perfectly match the conditions of your mining activity.
"HP" as a designation within cone crusher types
Within a broader perspective, "HP" was originally used by a specific manufacturer as a series of the models but it has now become generally applied to refer to a class of hydraulic, dense-powered density cone crushers with the following features:
Hydraulic setting of the crusher opening—the closed-side setting (CSS) can be altered while the crusher is running
The crusher allows automatic removal of large and non-metallic intruding foreign materials (tramp iron) without damaging the machine
Variation chamber of the machine design—identical crusher machine accommodates different crushing profiles (mantle and concave) with the help of these interchangeable pieces to produce products of the very fine, medium, up to coarse size.
The machine has the ability to process very fine material and at the same time to give a high reduction ratio. It is very powerful per unit ton so, when you compare old crusher designs and new high-power ones, it is clear that high powered design is far more effective in production.
The portfolio of Sanland includes the various series of cone crusher that share these design features. The American Technology range is a main part of it represented by the SH series with several others, such as SS, SG, SM, etc., available for different crushing tasks (secondary crushing, screening, etc.) within the circuit.
Why the Cone Crushers Are the Main Equipment for Secondary and Tertiary Crushing
After primary crushing that is typically done by a jaw or gyration crushers the feed is brought down in size to about 150-250 mm of maximum top size. From here onward till the end of the crushing circuit most of the work is done by cone crushers. It's because several features of the crushing process make it one the most effective ways to achieve crushing at the required final product size and still maintain high degree of economic efficiency:
Comminution under compression, which is most efficient at this material size range, is normally the preferred method of rock reduction in terms of kWh-per-tonne. Compression is typically 30-50% more economical in the crushing phase than an impact type crushing.
Cubical product shape resulting from particle crushing against each other in the cavity satisfies shape specifications set by the aggregate industry without needing further processing
Running the crushing process in a closed circuit with the screening done at an area which is downstream of the crusher leads to producing very close-graded products which sell at premium prices
The use of liners of suitable wear characteristics will lead to long operating lives which means lower cost of the operation and will make the operation more competitive on the market
Cavity Profile is the Key Decision Item
The cavity profile—the profile that defines where the material is crushed in the cone—is the major factor deciding the relation between the amount of throughput of a jaw crusher and the level of fines it produces. A cone series, such as Sanland's SG and SH, usually provides for several different chamber shapes, from Extra Coarse (with the largest size of the finished product but the highest throughput, used mainly in the secondary crushing operations) up through Coarse, Medium, to Fine with the very finest product (lowest throughput) and even up to Extra Fine for the fine products of sand, etc.).
Normally, the same crusher body can be fitted with three or even more types of these profiles meaning a user is able, without purchasing a new crushing unit, to switch a crusher machine from one type of job to another by simply re-configuring the chamber—a highly valuable characteristic regarding a capital efficiency.
Closed-Side Setting and Reduction Ratio
Closed-side setting (CSS) defines the minimum space between the mantle and the concave at the end of the gyration cycle. It is the primary factor determining product top size (in an overload-free cone crusher, product top size is approximately equal to the CSS multiplied by 1.2 to 1.7 [the multiplier depends on cavity profile and feed gradation]).
The reduction ratio—feed top size divided by product top size—typically ranges from 4:1 to 7:1 per cone crushing stage. Achieving a final product around 5-15 mm from a primary-crushed feed at 150-200 mm therefore typically requires two cone crushing stages operating in series.
Hydraulic Adjustment: Why It Matters
In older cone crusher models, it was necessary to stop the crusher and then manually adjust a threaded adjustment ring to increase or reduce the closed-side setting (CSS). Usually it took 30-60 minutes per adjustment and was done as late as possible. As a result, the crusher often ran for a long time at improper settings and the product size gradually changed as the wearing liners became thinner.
Today's hydraulic adjustment systems' - also featured in Sanland's SH series - enable the operator (or, for auto operations, the control system) to make minor CSS adjustments while the crusher is running, which can also be used to do regular fine-tuning in line with the wear of liners. This system helps in two major respects:
A product of consistent size throughout the life cycle of the liners - as a result, the efficiency of downstream screening is at maximum and oversize returns are minimal
Higher liner utilization - liners can be kept much closer to their actual wear points since the operator is constantly monitoring the actual CSS
automatic tramp-iron release
today;s hp-style cone crushers use pressure-relief cylinders on the bowl support. when a non-crushable item enters the crusher - usually a metal iron foreign object such as tooth from excavator bucket - the cylinders on the pressure-relief side will raise the bowl and the foreign object passes the crushing zone as crusher resumes normal operation without the operator's interference.
the sanland sh series employs special dual-action hydraulic tramp-release cylinders which let the tramp iron go through on either side of the bowl. that system is particularly efficient to handle "trumps" which single-action systems sometimes cannot release.
Factors to Be Decided: What to Order
The main points that should be settled when ordering a machine for a new operation or a plant revamping are as follows:
The work Index and Abrasion Index of feed - they are essential both for the lining-life prediction and power estimation.
Feed particle size - the crushing process will operate smoothly only if the size is limited to less or equal to 80% of the cavity opening.
Max. size of the final product - it is one of the decisive factors in choosing the crusher cavity configuration and setting of CSS.
Capacity wanted - is among the main parameters determining the size of a crusher being chosen
Processing system - open-circuit or closed-circuit with screen recirculation.
Elecctrical connection at the site - determines the choice of motor size of the equipment in the given frame.
Economy of Long-Term Costs
The major thing that most people misunderstand while talking about a cone crushing equipment's cost is assuming that the very first purchase is the main expense. Actually, the major cost is due to constant replacement and purchasing of consumables like wearing parts during the time the machine is being operated, approximately 15-20 years. Decisions during the selection phase only based on very low prices and with no regard to operating-cost factors will almost always be detrimental to profit because by the fifth working year you've already spent the saved money. The selection of one with proper cavity profile, suitable liner and a larger-capacity crusher is generally the most economical choice from the viewpoint of the whole life cycle of the crusher's equipment.
Contact Sanland for Your Mining Project
To discuss cone crusher selection for your specific project—whether you are planning a greenfield installation, upgrading existing equipment, or evaluating a replacement strategy—contact Sanland's engineering team:
Email: sales@sanland.com
China HQ: +86-24-2583-0521 ext. 8121 (Shenyang)
North America: +1-705-988-5866 (Sanland Canada, Val Caron, ON)
