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IDdesertman

Bucket Dredge Pics - 1940's to 1960's

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20 minutes ago, Morlock said:

I wonder how you would set up it up to dredge for ores of nobium, uranium and tantalum.

Those ores aren't particularly heavy compared to gold. Seems you'd have modify the process in order to capture those ores as opposed to gold.

Nobium is not that heavy, but tantalum and uranium are both pretty heavy, both much heaiver than lead and it can be caught pretty easy in a dredge, tantalum's specfic gravity is around 16.6, uranium is around 18.7, most anything with a specfic gravity of over 10 or 11 can be caught in a dredge pretty easy.

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7 minutes ago, Au Seeker said:

Nobium is not that heavy, but tantalum and uranium are both pretty heavy, both much heaiver than lead and it can be caught pretty easy in a dredge, tantalum's specfic gravity is around 16.6, uranium is around 18.7, most anything with a specfic gravity of over 10 or 11 can be caught in a dredge pretty easy.

While the metallic forms are heavy, I can't imagine those ores also being heavy. It just seems you wouldn't be able to run the dredge the exact same way for the ores as you would for gold.

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I agree there would have to be some modifications, water flow, riffle type, etc.,  but most blacksands caught in dredges easily only have a specific gravity of 5 to 6 as in the case of magnetite and hematite, and most all of these rare-earth minerals ore would be in the form around the size of sand, I'm sure not much of it was in big chucks, even when these dredges were dredging gold the material going through the sluices was screened down to no bigger than 3/4" to 1" and sometimes smaller depending on the gold being recovered.

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Morlock, now you have me wondering how diamond dredges manage to separate relatively lightweight diamonds from heavier mud.  Maybe they're designed to catch the lightweight diamonds that wash over the top, and allow the heavy gunk out the bottom?  I'd never thought of that before, how to intentionally recover lighter target minerals.

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8 minutes ago, Saul R W said:

Morlock, now you have me wondering how diamond dredges manage to separate relatively lightweight diamonds from heavier mud.  Maybe they're designed to catch the lightweight diamonds that wash over the top, and allow the heavy gunk out the bottom?  I'd never thought of that before, how to intentionally recover lighter target minerals.

Diamonds, sapphires and many other precious stone or caught on a "greased" slick plate/table in which they readily stick to, diamond, etc. are hydrophobic, meaning they resist being wetted, and as such stick to a greased surface easily.

 

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35 minutes ago, Au Seeker said:

Diamonds, sapphires and many other precious stone or caught on a "greased" slick plate/table in which they readily stick to, diamond, etc. are hydrophobic, meaning they resist being wetted, and as such stick to a greased surface easily.

 

http://www.greasetable.com

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Here's some serious equipment. Not sure of the location on this one...

DM123631.jpg

DM123636.jpg

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I wonder what it is?  Looks like something comes out the bottom and tailings go out the left...  Also can't tell if it is self propelled or towed...

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18 hours ago, chrisski said:

I wonder what it is?  Looks like something comes out the bottom and tailings go out the left...  Also can't tell if it is self propelled or towed...

Perhaps a trommel?  If it is a trommel, though, I can't understand the reason for the huge Pitman arm.  Whatever it is, the axle/I-beam cross member that supports the track appears to be a temporary affair scabbed together just to get the contraption from one site to another.  It must have been towed by a Cat or winch. 

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20 hours ago, chrisski said:

I wonder what it is?  Looks like something comes out the bottom and tailings go out the left...  Also can't tell if it is self propelled or towed...

 

2 hours ago, Saul R W said:

Perhaps a trommel?  If it is a trommel, though, I can't understand the reason for the huge Pitman arm.  Whatever it is, the axle/I-beam cross member that supports the track appears to be a temporary affair scabbed together just to get the contraption from one site to another.  It must have been towed by a Cat or winch. 

The upper section is definitely a type of trommel, you can see the barrel shape of it at the top and also a drive motor at the right rear.

But what I can't seem to understand in that most trommels deposit the concentrates into a sluice, but I see no sluices, instead I see a possible centrifuge at the center bottom,

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Here's one more pic of the above contraption... found a note on the this slide that reads " Dredge near Sonoita, Arizona. June 1961".

DM123635.jpg

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Here are a few pics of a different dredge. This one is the Natoma #6. Another article I read about it said that it was the last working dredge in California. Operated near Folsom, CA through 1962. These pics were taken July, 1959. 

DM183724.jpg

DM183726.jpg

DM183727.jpg

DM183728.jpg

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DM183729.jpg

DM183730.jpg

DM183731.jpg

DM183734.jpg

DM183736.jpg

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On ‎5‎/‎15‎/‎2018 at 5:57 PM, IDdesertman said:

Here's one more pic of the above contraption... found a note on the this slide that reads " Dredge near Sonoita, Arizona. June 1961".

DM123635.jpg

I wonder if this is similar to the dry land dredge that operated in the San Domingo Area? Never seen a picture of a dry land dredge.  Google does not have one.  There's Dry Blowers, but not a propelled drege.

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