- To participate in the 911Metallurgist Forums, be sure to JOIN & LOGIN
- Use Add New Topic to ask a New Question/Discussion about Crushing.
- OR Select a Topic that Interests you.
- Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
Using Add Reply allows you to Attach Images or PDF files and provide a more complete input. - Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.
Crusher CSS Closed Side Setting Measurement VS P80 Product Size (8 replies)
The product size distribution depends on various machine, material characteristics and the operating conditions. If you are interested in mathematical modeling of crushers refer to Modeling and Simulation of Mineral Processing Systems by R.P. King, Department of Metallurgical Engineering, University of Utah, USA. The JKMRC's, Mineral Comminution Circuits, Their Operation and Optimisation Edited by Tim Napier-Munn is also an useful reference.
Thank you so much for your reply. I would like to inform you that we are going to design(basic design) a crushing and material handling for a plant. For designing of conveyor, screen and other needed crushers, we need to simulate product size of crusher. In this regard we will use Gaudin function(W= 100(D/A)^b). We have done bond work index and we have all the required information.
SMC Testing Pty Ltd has published a number of methods for predicting SAG mill feed size based on JKDWT / SMC data:
F80 = 0.2 x CSS x DWi^0.7
You may be able to use that relationship to estimate primary crusher product sizes. For secondary / tertiary crushing, your best bet would be to use programs like Plant Designer, Bruno, or AggFlow.
Just a quick note, crusher product will depending on the crusher feed, if you are using run of mine feed and can economically remove the fines it is something to consider, especially if they are prone to packing, fines will consume power without significant particle size reduction. if you are using cone or short heads have them choke fed for optimum performance. I would recommend a design that allows the restart of equipment under full load, or maintenance start (by-pass chutes or a way to unload the system) Plan for jammed crushers or screen O/Loads.
Nordberg's series C jaw crushers the cumulative passing of product can be described by the quation: Y =[dp/(1.423xCSS)]^0.898 where the closed-side setting CSS is expressed in same dimension unity that one for particle size see paper in: http://www.maden.org.tr/resimler/ekler/6f70126ad0b23f8_ek.pdf
If you look at the manufacturer's manuals; metso for instance, it says around 80% of your product progeny would pass the so-called CSS.
For Metso GP series crushers at different CSS, the product passing through css is 70% and maximum product siz is about 2 times the css. But normally, that is for medim hard ore like limestone. For other ore types soft and hard , the figures will be different ...less for hard ore and more for softer ore.
Is there any relation between crusher's CSS and product size distribution?
In some crushing references it was mentioned that 55 percent of crusher product are smaller than CSS.
Anyone has data on that?