The program called Gold Rush Alaska which is being aired on the Discovery Channel is well worth watching if you are curious about what it takes to do placer mining. In addition to the strenuous task of digging down to the gold bearing layer of sediment, the miners are challenged by the short mining season in Alaska (~100 days or 2400 hours) and the remoteness of the location.
There are several unit operations in play. The first operation using the trommel classifies or sorts the sediment by size. This results in cobbles and pebbles being excluded from the sand and silt. This is a classification process that uses gravity to roll the large rocks to a separate location.
The next step is more of a density driven process wherein the material stream is taken through a shaker station where sedimentation of the dense fines is accelerated by mechanical agitation and the resulting material flow is transferred to a sluice where the heavy gold particles and nuggets are agitated by the riffling action of the water and settle to the bottom. The less dense solids are washed out of the sluice and discharged to a waste pile.
All of the slurry flow is gravity driven, so the process train must begin uphill and work its way down. The sluice section is where the density separation occurs in earnest and this is where the gold will accumulate.
Periodically, the sluice section must be cleaned out and the resulting gold laden silt must be further processed to isolate the gold. The fellows in the program must use panning or a shaker table to isolate the dust and larger pieces of gold. This a definite disadvantage compared with miners in the past.
The buckets of silt isolated from the sluice would have been treated to amalgamation in times past. This selective dissolution of gold and silver could be used to accumulate the gold until the amalgam would begin to solidify. This process requires less skilled labor than panning or using a shaker table. The amalgam would eventually be placed in a retort and heated strongly to distill out the mercury leaving the non-volatiles behind.
The gold would then be sold and sent to a smelter for further refinement (i.e., parting) of the crude gold.
Without mercury, present day miners have a rather more complicated task in isolating the gold.
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February 7, 2011 at 10:50 am
Comments on Gold Rush Alaska Program on the Discovery Channel … | Gold Rush Alaska
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February 9, 2011 at 6:42 am
lbf
I think the show is very entertaining because of the characters involved (esp. Walter Brennan!!!). But, in truth, what they want to do is hard. It would be like setting up a pilot plant operation in the middle of Alaska, you need to bring all utilities, reactors, filters, dryers, piping, pumps, parts, etc…. up there. I don’t think that they thought everything through, from the episodes I have seen. I would have spoken to/hired someone who has been there/done that before I spent a dime.
February 9, 2011 at 4:23 pm
gaussling
An acquaintance has been doing this for a few years and the show matches with his descriptions very well. You need to acquire and stage the equipment well in advance so that when the thaw occurs, you can move onto the claim. A sluice operation requires plenty of water and earth moving equipment. It’s all about keeping the yards of dirt moving through the equipment. You must be prepared to do as much mechanic work as possible, as the show suggests. And you need to have worked out how you isolate the gold fines. The fellows on the show didn’t do so well on this part. The shaker table dates back to the 19th century and is evidently a good method for isolating the fines. But you need to know how to use it properly, which is a problem for the boys on the show.
February 12, 2011 at 7:09 am
neil
Remember, it is a reality TV show and you can probably guess as to the outcome.
February 15, 2011 at 9:50 am
claude
I like the show and no I dont believe its all real.But it is entertaining.However the big fuss over killing a bear is overrated.I live in northern ontario and i can tell you that bears are not harmless cudly creatures.They may not go around attacking people but they are a nuisance and the more of them that get shot the better.
May 16, 2011 at 3:33 pm
gaussling
Hi Claude,
Has the thaw started yet?
January 13, 2012 at 7:05 pm
witchno1
What happened to the big cleanup.Get out there and rake and scrape and struggle like everyone else.No one deserves to be idle rich these days…NO ONE.
February 26, 2013 at 7:53 pm
Brian Tomlinson
Fire todd he screws up every thing he touches
He drives me nuts with his stupid comments like if we break the plant then we break it
Your fired.
February 27, 2013 at 8:37 am
gaussling
I think what Todd breaks is more than made up for by his sheer tenacity. The cash from the cable show probably helps too.
July 2, 2013 at 1:44 pm
Fred Kadett
For Dave Turin:
I think you’re a great miner. (As far as I can see from the show). Meticulous, knowing, leader (there I say).
You’re buddy Todd Hoffman is not. He is neither a leader, nor a miner:
His abilities in the Klondike are poorly. He has no idea what he is doing, really, except spitting quotes.
Bought a quarter of a million dollars trommel, which was untested. Best in the world, claim untested builder. (And you warned him). It was delivered some 7 weeks late & than the motor was found to be too small for the plant.
Later, when teaming up with you, he managed to flush a significant amount of gold out of the box. They harvested 107 ounces, but how much did they (=Todd) flush? (Say 10%. That is still 10 ounces.) And you were doing brilliantly before?
I’m fine where I am. In a city. Doing what I do. But stay strong in the Klondike.
Jan