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View Full Version : Where is the derockers?



digger68
10-20-2012, 11:55 AM
I had the chance to look over a derocker this fall and was impressed with it. This derocker can handle 4' boulders and all of the big rocks get washed very well. The problem with a trommel-grizzly setup is that the very large boulders dont get washed good enough. The derocker seems to solve this issue. The owners will not have the derocker going untill next season so I didnt get to see it operate. It looked to me that it would classify only to 2" material. That being the case I can see needing to somehow classify down to at least 3/4" before running thru the sluices.
Why are derockers not being used more in Alaska? Is it a cost issue? This derocker was bought in Canada for over $150,000. I see that Canadian miners use them alot. There is a couple of videos of derockers on youtube that are worth watching. Thought I would see what everyone thought about them and maybe get to learn more about them.

chickenminer
10-20-2012, 12:22 PM
This derocker can handle 4' boulders and all of the big rocks get washed very well.

Well ... If you have a need to sluice 4' boulders, it might be the tool for you.




I see that Canadian miners use them alot.

Maybe an overstatement. I believe you will see far more traditional trommel and/or shaker screen plants.

outnaboutnak
10-20-2012, 01:06 PM
They do look impressive, as I saw them for the first time on GR. I would say cost and availability probably the two biggest factors. Trommels and shakers are much cheaper and much more plentiful.

digger68
10-20-2012, 02:35 PM
Chickenminer it is not about sluicing 4' boulders. It is about getting all the large rocks that would normally slid off of the grizzly washed free of the gold they are holding. Most trommels do not like 2' boulders going thru them. Most grizzlys dont wash these large boulders well enough to get the gold off of them.

chickenminer
10-20-2012, 07:53 PM
Most grizzlys dont wash these large boulders well enough to get the gold off of them.

Agreed. I hate grizzlies.

Like I said ... if you need to sluice 4' boulders it might be just the ticket. Don't take it quite so literal .....
if your pay material is full of large boulders, it could be an alternative method that may suit perfectly.

tenderfootminer
10-22-2012, 09:43 PM
i run 3ft. rocks over my shaker and come off clean as a whistle,but if your pay is full of them might be worth it.My trommel also spits out clean "boulders" just don't want to run them all day. That said I don't use any grizzly I just don't run rocks the size of the loader bucket.I ran alot of old piles this year that where just large rocks thrown out of the old wooden sluices.I did quite well on them but glad i ran them through the shaker not the trommel as it is pretty rough on things but clean as can be when they come out.