Originally Posted by tossgeorge

And please also kindly consider that the moisture varies from surface to the inner.

Good question(s).

Moisture migrates throughout stored materials. Its influence on density cannot be accurately determined beyond the recommendation of some dewatering equipment suppliers that there will be an initial 2% drainage over the first couple of days ensilement.

If there is segregation during stacking then we could expect lower density because of larger voids but that is conjecture. I have seen 1.5m boulders which have lain together with hardly any voids.

DEM would be particularly useful in this application. Results of DEM would be somewhat statistical. Just like sampling results are highly statistical. Some old timers would say "It all depends on what you are trying to prove."■

As louis has said it is a good question BUT,

the issue is more of the wieght of the material

per cubic foot as density will be affected by

settling and compaction from the act of stacking

and simple gravity as well as particle separation. ■

What does the packing distribution look like, and what factors affect it?

http://www.simpas.unsw.edu.au/public...N1991187.pdf

How do do you estimate the overall density in a heap?

http://www.simpas.unsw.edu.au/public...B1991605.pdf

Both papers by are by Yu and Standish, University of Wollongong and are for the case of coal. ■

The bulk density depends on the size distribution, uniformly sized material tends to have a more consistent bulk density than material with a broad range of material sizes. It also depends on how the stockpile is loaded and the moisture content. If there is a broad range of material sizes and the stockpile is fed randomly off the end of a conveyor at reasonable height then there will be significant material size segregation through the stock pile (and this is a primary cause of rat holing) for instance. So there is no simple answer to your question. A simple experiment is one way and that is run the stockpile down so it is effectively empty and then load it to full capacity with no draw down and using a weightometer work out how much is in the stockpile. If it is important to know then this is a simple way of finding out

Cheers

Colin Benjamin

Gulf Conveyor Systems Pty Ltd

www.conveyorsystemstechnology.com ■