Rege-PA Posted February 26, 2017 Share Posted February 26, 2017 What is the smallest mesh gold that a dry washer can realistically, consistently recover? Any feed back appreciated. Link to comment Share on other sites More sharing options...
vanursepaul Posted February 26, 2017 Share Posted February 26, 2017 Rege, Don't know exactly how fine they can get..but it would be very fine. This depends more on the operator than the machine, I believe... Not everyone can set up a dry washer properly....but even people like me can get a good bit of fine gold. Link to comment Share on other sites More sharing options...
LukeOzDigger Posted February 26, 2017 Share Posted February 26, 2017 Small. The photo is a sample out of a hand built, hand operated drypuffer I made last year and it did have a huge angle on it too, it's all in the wrist :) Depends on the material, machine and You! Too many different variables. Link to comment Share on other sites More sharing options...
Hard Prospector Posted February 26, 2017 Share Posted February 26, 2017 Bellows/puffer drywashers will catch an impressive amount of fines so long as ; the material is classified down to -1/8, is "talcum powder dry" and the drywasher properly tuned Link to comment Share on other sites More sharing options...
Reno Chris Posted February 26, 2017 Share Posted February 26, 2017 As a real rough ball park number, I'd say that 20 mesh is about the number you are looking for. However, if there is not loads of clay in the material, Ive seen them recover a decent percentage (not close to 100 percent by any means) of stuff as small as 50 mesh by folks dry washing old hard rock mine dumps. The problem with clay is that small flakes will stick to little rocks by the dry clay and then roll right out of the dry washer attached to a rock. The more the clay and the more the clods, the lower your recovery is going to be. Dry with heavy clay will still give you a recovery that is not so good. You can see some of the gold in my photo below is pretty small. Link to comment Share on other sites More sharing options...
Hard Prospector Posted February 26, 2017 Share Posted February 26, 2017 The clay clods can be easily broken up by pounding it with a concrete tamp. Also using a cement mixer really breaks down the clods, just throw in some big chunks of iron stone or granite with the material. Link to comment Share on other sites More sharing options...
Reno Chris Posted February 26, 2017 Share Posted February 26, 2017 A patch I dry washed a couple years ago, I detected the piles and got a signal which seemed to come from a rock - not a piece of quartz, just a piece of country rock. I looked at the rock and it seemed clean, but it was the source of the target sound. I looked real close and at one end there was a tiny crack in the rock and a tiny pinch of dirt in the crack. I cleaned out the crack with my fingernail and sure enough, there was a little flake of gold in there that my SDC was sounding off on. That kind of thing can hardly be avoided when dry washing even if you smash all the clods. That is why its always good to go over your piles - both over size and the stuff that goes across the dry washer - with a metal detector to make sure you didn't miss anything big enough to detect. Link to comment Share on other sites More sharing options...
Rege-PA Posted February 26, 2017 Author Share Posted February 26, 2017 1 hour ago, Hard Prospector said: The clay clods can be easily broken up by pounding it with a concrete tamp. Also using a cement mixer really breaks down the clods, just throw in some big chunks of iron stone or granite with the material. I was wondering if some kind of pre treatment of the dirt would help to dislodge the clay, maybe some kind of vibration chamber or trommel with some rollers inside. Link to comment Share on other sites More sharing options...
vanursepaul Posted February 26, 2017 Share Posted February 26, 2017 There is a chemical..I can't remember the name, but you add it to the water like soap powder.. But you gotta have water and that means you aren't dry washing..what was I thinking... Link to comment Share on other sites More sharing options...
Hard Prospector Posted February 26, 2017 Share Posted February 26, 2017 Most seasoned desert drywashers, including myself, own a cement mixer for this very reason. I use it whenever I can "practically" get it to the site as it makes small work of caleche, clods or whatever conglomerate crap needs reducing. I use the hand crank model w/wheels as its more portable when I have to drag it to the spot. Once reduced to my satisfaction, i will just run the material right into the drywasher. If the area is mostly known for fine gold, I will classify to at least 1/4" then run it. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now