Basics, guidelines, parameters, limits

[thegoldgopher]

I'm seeing an awful lot of sluices, all of diferent widths, depths, lengths, riffle configurations, and who knows what else under there that can't be seen. Is there a knowledgeable site where the abc's of sluicing are laid out?

It would seem that there is a length at which a sluice would become non-functional, having caught all or almost all of the gold. Making it any longer would institute a lot more cleanup work, and not for a lot of yeild. DAMHIKT.

The width would seem to be something good, as a wider sluice could run longer without cleanout and plugging. The channelling would have to be correct, though, to make the materials run evenly distributed throughout the entire width.

Width and length to me would seem to be the most important things, as I think you could have it too short or too wide.

I have seen very little on the principles of vibration or harmonics applied to sluice beds..

Other things that would allow gold to go over the end would be high water flow, inefficient trapping, too steep of an incline, or delaying of gold particles by obstructions or inefficient designs.

Is there a standard tried and true formula, or is it merely a combination of several things that when brought into concert run like a tuned car? I know for centuries, hollow logs, ceramic bowls, fiber matting, gravity, and many other concepts have had the end result of catching and holding gold. Maybe just get all the basics right, then dig where the gold is?

Just some thoughts .........

Steve

 

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[Goodyguy]

Steve,

The learning curve is steep. Sluice design is best when it is compatible with the mining conditions, such as; type of material being run, size of classification, speed of water flow, and size of gold most likely contained in the paydirt being fed. Not to mention ease of portability and whether the sluice is being used for major production or for sampling.

Typically a wider sluice would be used in fast water and a narrower sluice in slow water. Also if the water is too slow then a wider flair is needed at the head of the sluice to channel more water into a smaller space to increase water flow.


As far as a standard formula that fits all situations there is none. Each situation calls for a different setup to achieve maximum performance.

For instance.... Lets say that a location is known for producing only fine to flour gold. In that case slower water speed and no riffles would be recommended with a carpet or mat designed for capturing fine & flour gold up to small flakes. Classifying the material down to 1/8" to no more than 3/16" would be essential. However some plastic sluices with built in riffles and no mat or carpet will capture fine and flour gold if ran under proper setup conditions such as flow and angle and with proper classsification of the material being run.

Of course a sluice designed for a highbanker or trommel or dredge would each have it's own set of requirements for maximum performance.
And a self classifying fluid bed sluice still another design requirement.

IMPORTANT!!!
Classification of material entering any sluices gold recovery medium has a direct impact on it's performance and is of utmost importance.


GG~

 

[thegoldgopher]

IMPORTANT!!!
Classification of material entering any sluices gold recovery medium has a direct impact on it's performance and is of utmost importance.


GG~

My dredge head is progressing in its development. One of the main things I wanted to have on it was classification by some means to keep anything larger than say, a silver dollar, out of the hose and sluice. After a lot of thought, I keep coming back to parallel bars simply because of their likelyhood of clogging less. Any oversize would simply fall off, as there wouldn't be enough suction to hold it against the head, say as a sheet of perforated metal or any series of holes would. Your statement gives me a little validation that my original thought might be correct. One of the major considerations for this head is that it is uncloggable. I watch these underwater shows, and few have any restrictor bars, and people spend a lot of down time with clogged hoses, then beating on them with sledge hammers. What's up with that? I am also working on a couple of sluice designs (with a couple of secret additions), and if I can get the two to match up, it would be a beautiful combo.

 

[TAKODA]

That's some good advice from GG .

I would add .............. don't make it harder than it is .
You don't need the technological equivalent of a space
shuttle in a sluice in order to get all the shine your gona
get via the sluicing methodology .

 

[jcazgoldchaser]

You should, however, consult NASA with regards to any welding,...

 

[nickmarch]

This should be helpful:

http://www.hecklerfabrication.com/files/sluice-build-partIII-2.pdf

 

[Goodyguy]

This should be helpful:

http://www.hecklerfabrication.com/files/sluice-build-partIII-2.pdf

Good stuff Nick
I couldn't agree more with their findings. Everyone should read that report.



GG~

 

[goldog]

Where are you at ..gopher? Ya know, 'cuz goldog would like to chase a goldgopher...

How is the sluice working out? Any luck? You mention a dredge, is it a sluice for a dredge?

The PDF Nick supplied is interesting (thanks Nick!) Just don't let the sheer volume of information throw you off. Most hand sluices are similar in dimensions. Some a little larger or smaller depending on you particular application. Usually around a foot wide and 3.5 or 4.5' long. This is the kind you would just take out and shovel away for the afternoon. If you are building one weight and portability matter quite a bit. You'll be carrying it in and out of your spot each trip along with all your other gear.

For a dredge a lot more info would be needed to point you in the right direction. You are right about clog ups. Most nozzles have some amount (20-30%) of reduction to reduce the chance of clog-ups. But usually when you're on the best gold your hose will still get clogged. A grizzly (screen) is not usually used because it will collect cobbles due to the suction.

Classification on any sluice is a variable which needs specifics too. For a hand sluice I simply use a piece of expanded metal probably down to about 1/2". You'll need to strike a balance between optimum recovery and ease of use. Again depending on your conditions. For a dredge it is a whole different set of requirements.


I know the thread's been idle for a month but I thought an update was in order.

 

[Fullpan]

I will just add to goldog's comments above by saying experienced dredgers tend to use their fingers as a "variable" restriction at the suction nozzle. When
you've found a spot where you're trying to move as much material as possible through the system, dredgers find its much faster to "catch" over-size rocks with
their fingers at the last moment, rather than constantly removing partially blocked rocks from a grid or bars attached to the suction nozzle. Hope this helps!