Volume Loss in Gravel Processing 1

[indbuilder]

I'm working on a project where we need to reduce the fines content of a stockpile of owner-supplied material. I'm looking for some advice in determining how much volume will be lost to processing gravel through a vibrating screen. For example, if I start with a 1000 cy pile of 2" minus material, and a grading report shows that 20% passes through a 3/4" screen, if I run the pile through a 3/4" vibrating screen, will I end up with 800 cy of 2" minus?

 

[GeoPaveTraffic]

Was the 20% passing the 3/4" screen determined by volume or weight? It was probably done by weight. If you remove 20% by weight from the pile then you may end up with more than 800 cy in your example. However, you will also have some breakage and loss due to handling that could take you down below that figure.

All of this will depend on the type of rock, actual gradation, handling, etc.

Hope this helps.

 

[indbuilder]

Thanks for the reply and assistance. Yes, the gradation report on the stockpile shows percentage passing by weight. I have a fairly good guess as to how much the material will shrink in compaction, but I am not sure how to estimate how much is lost in screening.

 

[aggman]

There is a lot of published information in regards to calculating screen efficiency's, percent passing and etc. I would contact Metso Minerals or Telesmith and they will lead you in the right direction. They will probably even have information on there website that you could download. Typically any aggregate handbook can walk you through the calculations. There is more to it than can be explained over this site.