Trommels

[murph52]

Hi --are their any people interested in trommels on this site ? if so I would be happy to show photos and discuss any problems !

[Steve Herschbach]

Hi murph52,

Heck, yeah, I'm interested!

[AceHand]

Howdy Murph,
We've got a small one that's getting modified over the next few weeks. I'm always interested.
Tom

[murph52]

ok well lets start at this one


I built this back in the 90s with a good friend of mine and only sold it a couple of years back


this was on the day we sold it and the smoke you can see in the background was from fires over 100 miles away



and here it is on our dam so many years ago

[murph52]

the Green Machine was powered by an 8kva 3phase gen set --it had an inner and outer barrel attached to one another the inner was 1/4 hole.
the pump was a flexi pump with an a electric motor and pumped at 1100ltrs a min in 3'' layflat
On board was a high pressure pump for the spray bar --130 foot lbs of pressure
We had a primary sluice backed up with a small jig and then a secondary sluice off the jig
the jig fed a small oscillating table which collected down to 40 micron gold
it had a conveyor taking the dirt from the hopper and then upwards to the back of the barrel
The concentrates ( 1/4 minus ) then went into a warman sand pump and then gravity fed into the jig

[Reno Chris]

So tell a bit about the up and down sides of operating a trommel - not just your unit in particular but more in general.

What are their advantages?

What are their dis-advantages?

When would you need one vs other times when they are unnecessary?

I see them built in all sizes from much larger than the "green machine" to much smaller. How would one choose a proper size to buy?

This could be an interesting discussion!

Chris

[Brian Berkhahn]

I would like to know who is the manufacture of this trommel..






Here's a video of the trommel in operation.
http://www.erinventures.com/trommel_0001.wmv

[kiwijw]

Thats a tease. How about showing some gold it recovered.
I guess the use & size of a trommel depends on weather you are doing it for a living & so need to process bulk material in a given time to increase your return of gold. The numbers game thing. In that case then the bigger the better & the bigger the excavator to feed it.
If you are a hobby type miner then size & expence come into it along with accessability to an area. Generaly you need to be able to drive right to where you want to work it & the hobbiest is more likely going to be shoveling into it to feed it. So for the hobbiest the disadvantages are size & weight & accessability to areas. Another disadvantage is that you need to lift your shovel of material quite high to get it into the hopper. Over a day that would be quite tiring. Advantage are that you can work areas away from a river as you can pump water to it. But then again you can do the same thing with a highbanker/banjo. The screen in a trommel will probably break up clays a bit quicker than a highbanker/banjo. But you can adjust the steepness of the top hopper of a highbanker/banjo to let the water jets really nail the clay.
For the hobbiest I think the highbanker/banjo is hard to beat. With a trommel you probably need two motors, one to drive the trommel screen & one to pump the water. The highbanker/banjo is lighter & more easily moved about.
But then blokes like building things & seeing them work in operation so in my opinion, to the hobbiest a trommel is just another addition to his arsenal of gold getting "toys" & really has no advantage over a highbanker/banjo. Sure you are still shoveling into it but you dont have to lift it so high.

JW

[murph52]

Well Reno now that you have asked i will explain as best I can .

What are their advantages? well in my case it was the old story CLAY!! and lots of the sticky stuff as well !
The twin barrel system was a godsend in the fact that as the high pressure water spray bar cut the clay and the fine gold into suspension it fell into the cavity between the two barrels,never coming into contact with any clay balls again. This i would say is the best way of treating the puggy clay question !

What are their dis-advantages?
I would say two things lack of real portability and most times having to cart the dirt to the unit .This is the reason I use a Banjo/Highbanker these days as you can pack them into the spot and run a long layflat hose to the gold bearing ground. I have seen pics of this kind of unit being used with 200 yds of layflat


I see them built in all sizes from much larger than the "green machine" to much smaller. How would one choose a proper size to buy?
Well i suppose thats like "how long a piece of string" you would have to look at many things -- the Green Machine was a two man operation but was a handful for one man ! ----the smaller ones that one man could handle ,or woman oops, are great for moving a lot of dirt in a short time as against ,panning,blue bowl,ect.

[chickenminer]

When I was looking at building a washplant I looked at both shaker plants and trommels. The shaker plants I observed operating did not impress me with there ability to clean heavy sediment material in a short distance. Not so with the trommels I saw!
So I built a trommel plant. Barrel is 48" dia., piece of the Alaska pipeline.
One of the best things I ever did to make mining easier and increase recovery.