Raised Expanded Metal. Does size really matter?

[ihatethese]

Like the title says, does size matter? I've read the popandson pdf stating 1",3/4",1/2",3/8", but doesnt say if anyother sizes were tried. I've seen videos of people using all kinds things for riffles, and all sizes or EM . My question is, does it really matter, so long as the cells are clearing how they're supposed to and you arnt blasting water/air through the sluice? Any one with expirence?

 

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[arizau]

Like the title says, does size matter? I've read the popandson pdf stating 1",3/4",1/2",3/8", but doesnt say if anyother sizes were tried. I've seen videos of people using all kinds things for riffles, and all sizes or EM . My question is, does it really matter, so long as the cells are clearing how they're supposed to and you arnt blasting water/air through the sluice? Any one with expirence?

A loose quote from Freddy Dodge: Different riffle sizing promotes different flow characteristics....if the gold will not settle in one area, maybe it will settle in another area.

 

[Assembler]

A loose quote from Freddy Dodge: Different riffle sizing promotes different flow characteristics....if the gold will not settle in one area, maybe it will settle in another area.

Just asking the question so by changing the sizing that included both the height and spacing out from each other will effect the drop out?

There may not be to many charts out there showing this kind of effect so is it best to play around with the riffles for different drop out?

 

[ihatethese]

A loose quote from Freddy Dodge: Different riffle sizing promotes different flow characteristics....if the gold will not settle in one area, maybe it will settle in another area.

This is why there are 2 different kinds of Hungarian-style riffles for Highbankers or dredging, but EMs riffles are tiny in comparison and usually greater in number. I guess a better question would be what difference size makes. Is it just that the smaller size provides more dropout zones?

As I should have stated in my original posting, this is pretty much exclusively flour gold ground intended to be mined, and everything will be classified to 3/16" inch.

 

[ihatethese]

"All operational instructions are based on a 12
�
wide sluice. Ratio the feeds and flows if yoursluice is a different width.Usually, run it at 1-1/2
�
slope per foot of length. This is a good middle ground for slope andwill support a significant feed rate. Then the only variables are water flow rate, gravel feedrate, and feed composition (size and percentage of heavy material).Dial-in your operation for the gold conditions.The sluice will capture -300 gold at moderate rates of flow and feed. But, if your site only hasgold down to 150 mesh, you can dramatically increase flow and feed, and still get a highpercentage recovery of this larger gold. So, some initial testing is in order."
This is from the study, and from what I'm understand is the flow rate of water/feed is what controls the recovery rates based on size of the gold targeted. Changing the flow changes the collection, and there is no real reporting as to if there was any significant difference in recovery among the sizes or if one size worked better.

 

[southfork]

From personal experience classification flow rate and length of sluice give the gold a chance to drop. We all love nuggets / big gold but in reality, in most areas just the fines are left. And you need to slow down to capture micro gold. My son and me have been reworking tailing and capturing gold lost in the past. The pickers drop easy it's the fines that pay our bills.

 

[russau]

As it was stated before , the bigger gold drops out quickly and the fine gold takes some work in getting the correct riffle/carpet/ water flow and the right sluice angle combinations working together to trap the fine gold ! This is why I used to bring with me LOT'S of different mats riffle setups when I traveled around the Country with my trailer ! I was a rolling hardware store ! BUT when your a day or two away from home ,IF you didn't have it you were DONE !

 

[southfork]

I have ribbed rubber v mat under header box grizzly then two different types of indoor outdoor mats in the sluice. Over the top of that low profile expanded metal then low-profile steel riffles to top things off. This for my 12-volt 2000 GPH bilge pump High Banker catch pickers and super fine gold.

 

[N-Lionberger]

I use larger expanded in my highbanker and my dredges.

 

[ihatethese]

I use larger expanded in my highbanker and my dredges.

What inparticularly do you like about the larger over the smaller?