it took about 6 hrs, the material had built up for over a year, so it actually represents several hundred thousand tons of material concentrated down to about 2 ton.
My sluice isn't large enough, 20"w x 40" L, I'm making a larger one that can handle more material, 24"w x 6 ft long. I believe my recovery could have been better, my box was over loaded too often. I hook it up to a drain on a large tank where the heavies collect, and it can be hard to control the feed rate.
Look for an update in a couple months.
I'm on the similar project in Hungarian gravel pit. You can see me using a suction nozzle as I'm standing on the side of the tank. I'm using a 12" x 6' popandson style sluice + atached a short piece of a board covered with woolen baize. This set up is working great for me.
the simpler you can keep your setup, the better off youll be! but yes a fluidbed would work just fine if you know how to set it up and controll the fed rate so that you wont flood the system with to much material/water.lozenya has his system working for him and he can see how its going quickly/simply! hes still probly missing some of the fine gold, but for the most part, hes doing just fine!
Thanks Gold Maven,
I do not have a picture of cleaned pure gold yet.
I' am running this sluice also which placed close to the conveyor belt washer. It is working paralel with gravel pit machines day by day. So it generates a lots of concentrates to deal with.
When ready with the final clean up I will post picture.