Only 75 Ways to Recover Gold?
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18:20:47 Tue
Oct 30 2007
Only 75 Ways to Recover Gold?
Time for a jaw-dropper - it sure was for me when I totted up how many different methods are known for recovering gold. I thought maybe 20, and was astounded to end up with 75! That's with the help of a lot of Forum members and from people from around the world - its an attempt at a WORLD LIST.

It should be of interest to everyone on the Forum interested in catching gold. The list will be published on the Internet shortly as a freebie article with a page devoted to each method, and technical refs etc.

Nope I'm not going to attempt to post all 75! Instead I have numbered them 1 to 75, and if the title of one intrigues you then either PM me with which numbers you want, and I'll email them to you; or post your requested and I will post it on this thread.

(Steppe - it sounds like a Juke Box, we just think of a number between 1 and 75 and you play it, right? - Ed). Er yeah sort of!

(How come its 75? - Ed). Well it should be, I am convinced, over 100 methods - please rack your brains and memories to see if the Forum can boost the number.

Of course having a World List is fun. It is also very worthwhile in an effort to find alternatives to mercury and cyanide problems among artisanal miners, and for all of us to catch MORE gold. It also seems to me that many neglected methods merit revisiting by inventors, experimenters and equipment makers in the light of new manufacturing materials and our better know-how these days of the many properties of gold.

Something did emerge.The World List is so huge and diverse - thanks to the efforts of many contributors and the power of Internet - that all of us can benefit and I for one am startled by the huge number of methods that I was totally unaware of!!! And its clear there are MANY MORE methods to be unearthed. This World List is not a final list at all, just a progress report!

I'd best explain how a method gets on the World List:
1 - the method must have a clear description
2 - the method must be plausible within the realm of science, and
3 - the method must have at least some data on its ability to recover gold of different sizes.

By the way, over 400 methods failed to meet these rather simple criteria and are omitted - maybe 10% merit fresh attention.

Also omitted are hand-held manually-driven gold recovery devices – pans, bowls, bateas, dulongs, lotoks etc. as they merit a list of their own! Maybe someone would like to try and make one?

The World List is arranged more-or-less chronologically to indicate the waxing and waning of different methods through time. Doing so was difficult, bearing in mind the time lag between a) the invention, b) the patent and c) the commercialisation.

So, here we go, just ask for any number between 1 and 75 if you want to see what weasel words are written. Some of the weasel words are really good, but there is quite a lot of padding and there sure must be plenty of corrections required - please help.

Prior to 1970
1: mercury – amalgamation of gold
2: cyanide – chemical leaching of gold
3: chlorine – chemical leaching of gold
4: iodine – chemical leaching of gold
5: bromine – chemical leaching of gold
6: thiocyanate – chemical leaching of gold
7: thiourea – chemical leaching of gold
8: nitric acid – chemical cleaning of gold
9: aqua regia – chemical leaching of gold
10: borax – smelting of gold
11: froth floatation – 1930s research in Idaho and USSR
12: riffled sluices – 1960s-1970s research in China and USSR
13: simple jigs – 1970s research in China
14: pan-am duplex jigs – Alaska tests
15: Knudsen bowl – Alaska tests
16: Gilkey bowl – Alaska tests
17: helix wheel (gold wheel) – 1900s research in Colorado
18: Wilfley shaking table – 1890s research in Colorado
19: shaking tables – 1960s-1970s research in China
20: shaking tables – 1960s research in USSR
21: pinched sluice – historical usage
22: Reichert cone – 1960s research in Australia
23: Humphrey spirals – 1940s research in Colorado

1970 - 1980
24: thiosulphate leaching – 1970s research in Canada
25: Duke’s E-tank – 1970s research in Georgia
26: Visman’s CWC – 1970s research in Yukon
27: Neffco bowl – 1970s research in Utah
28: Bartles’ crossbelt – 1970s research in Cornwall
29: Bartles-Mozley orbital tables – 1970s research in Cornwall

1980 - 1990
30: bioleaching – 1980s research in Wales and California
31: biooxidation – 1980s research in B.C. and California
32: agglomeration – 1980s research in Australia and China
33: oleophilic adhesion – 1980s research in Alberta
34: magnetic coated gold – 1980s research in Colorado
35: flat bar riffles – 1980s research in Yukon, 1990s in Mongolia
36: angle-iron riffles – 1980s research in Canada
37: expanded metal grating riffles – 1980s research in Canada
38: expanded metal mesh riffles – 1980s research in Canada
39: McCann’s small sluice – 1980s research in California
40: hydraulic riffles – 1980s research in NZ and Canada
41: Graefe’s E-tank – 1980s research in California
42: Cleaveland/IHC jig – 1980s research in USA and Holland
43: Lashley’s ASAT E-tower – 1980s research in New Mexico
44: Osterberg’s E-tower – 1980s research in California
45: Younge’s horizontal centrifuge – 1980s research in B.C.
46: Mozley MGS centrifuge – 1980s research in Cornwall
47: Kelsey centrifugal jig – 1980s research in Australia
48: Yunxi bowl – 1960s-90s research in Yunnan
49: KnelsonTM bowl – 1980s research in British Columbia
50: FalconTM C bowl – 1980s research in British Columbia
51: Lemmon’s vanner – 1980s research in the Yukon
52: Brosseuk’s helix cylinder – 1980s research in B.C.
53: GemeniTM table – 1980s research in Colorado
54: Mark-7 Reichert spirals – 1980s research in USA

1990 - 2000
55: bromine leaching – 1990s research in Indiana
56: gold-paraffin floatation – 1990s research in Brazil
57: Damn Fine SluiceTM – 1990s research in New Mexico
58: CleangoldTM sluice – 1990s research in Oregon
59: PyramidTM E-tank – 1990s research in California
60: GekkoTM in-line pressure jig – 1990s research in Australia
61: FalconTM SB bowl – 1990s research in British Columbia
62: ItomakTM bowl – 1990s research in Novosibirsk
63: BGS shaking table – 1990s research in UK
64: GoldtronTM machine – 1990s research in Utah
65: U-TechTM reverse polarity table – 1990s research in Arizona

2000 - 2007
66: HGP leaching – 2000s research in New Jersey
67: iGoli chlorine leaching – 2000s research in South Africa
68: tincture of iodine leaching – 2000s research in Japan
69: gold-binding proteins – 2000s research in Washington
70: phytomining – 2000s research in New Zealand
71: Loewen electrostatic sluice – 2000s research in Alberta
72: Popandson sluice – 2000s research in USA
73: reflux classifier – 2000s research in Australia
74: Ecologic E-tower – 2000s research in New Zealand
75: helix belt – 2000s research in Canada and USA

If I've missed off a method that should be on, then please do post! Some favourites are under different names than traditionally given.

And if you think I've spoiled the fun of discovering new/old methods then think again. This has opened up a Pandora's box of things to chase up and discover. We ain't seen nothin yet!


18:32:44 Tue
Oct 30 2007
Re: Only 75 Ways to Recover Gold?

Mercury reduction is not good enough

Worldwide, millions of artisanal gold miners use mercury as routine with appalling risk to human health and the environment [20]. The mercury issue, coupled with issues of poverty, wealth creation, child labour, human rights, land degradation and conflict with formal mining, has spawned artisanal mining projects worldwide.

One of the largest is the is the Global Mercury Project (GMP) on ‘Removal of Barriers to Introduction of Cleaner Artisanal Gold Mining and Extraction Technologies’ under the aegis of the United Nations Industrial Development Organization (UNIDO) [21]. Remarkably the GMP has not systematically investigated gravitational or chemical alternatives to mercury, and instead focussed mostly on mercury REDUCTION. Such projects are simple to do by consultants, socio-economists and ecologists with no prior knowledge of mineral separation; quick success assured by simple measures such as promoting retorts. ‘Reduction’ is only short-term local ‘sticking plaster’ liable to marginalise the technical scientific approach essential for mercury ELIMINATION, such as by Cleangold [22,23], the British Geological Survey [4,24], Projekt-Consult [25] and the Alaska Gold Forum. As a result the GMP Training Manual [26] is a fascinating anecdotal compilation devoid of a coherent roadmap for mercury elimination.

Mercury elimination by out-competing

For eliminating mercury by out-competing it, 15 candidates for Best Available Techniques (BAT) were identified. Most are cheap, pose little risk to the environment and human health, and none are overly complicated. This refutes the mantra that alternatives to mercury are too costly or too technical for ASM to adopt.

Chemical challengers to mercury

Four ‘chemical’ competitors to mercury are capable of immediate use as Best Available Techniques (BAT):
HGP leaching (#66). A non-toxic chemical leaching method able to compete directly with mercury on cost, efficiency and speed. Small units recently performed well in extensive tests in Ghana with artisanal gold miners compared with mercury –
Chlorine leaching (#3). A long-neglected chemical leaching method that performed adequately in basic tests by WWF in the Guianas, and forms the basis of MINTEK’s iGoli process (#67) that is gaining interest among artisanal and small-scale gold miners in Southern Africa as an alternative to mercury.
Borax smelting (#10). A traditional method of preparing dore gold from clean concentrate. However, artisanal miners in the Philippines seem to use borax smelting at an earlier stage as an alternative to mercury.
Nitric acid cleaning (#8). A method used by artisanal miners in Kyrgyzstan to free gold from sulphide ores. It is an alternative to mercury in some situations.
In the medium-term, tincture of iodine (#68) and phytomining (#70) may become viable.

Gravitational challengers to mercury

Eleven ‘gravitational’ competitors to mercury are capable of immediate use as Best Available Techniques (BAT):
Cleangold® Sluice (#58). A low-cost innovation that recovers 90% of very fine gold down to about 30. The device has performed well in demonstrations in North America, Guyana and the Philippines, and is capable of comprehensively out-competing mercury.
DFS sluice (#57). A simple in-stream sluice intended for recreational miners to recover fine gold.
PopandSon sluice (#72). A more recent innovation, recovering 90% of fine gold down to 50 micron with ‘tiny’ raised expanded metal mesh. It can be used as a high banker and has ‘dampers’ to reduce surging.
BGS shaking table (#63). A home-built over-the-shoulder hand-cranked gold recovery device that can compete with mercury in recovering >90% of very fine gold down to about 40 micron.
Duke’s E-tank (#25). A wash-plant recovering 90% of fine gold down to 50-60 micron and requiring very little water. The device seems ideal for larger artisanal operations, and can be made locally at low cost.
Graefe’s E-tank (#41). A wash-plant recovering 90% of fine gold down to 30 micron and requiring very little water. The device is small, ideal for small operations and can be made locally at moderate cost.
ASAT E-tower (#43). A tranquil elutriation tower, capable of recovering >95% of gold down to 20 micron and still catch useful amounts of 5 micron gold. Scaling up for industrial mining proved difficult and R&D ceased. However the original device seems ideal for artisanal miners and can out-compete mercury and reduce the case for cyanide.
Osterberg’s E-tower (#44). A tranquil elutriation tower intended to assist recreational miners to recover fine gold from black sand concentrates. It seems ideal for artisanal miners and can compete with mercury.
Ecologic E-tower (#74). A turbulent E-tower with an innovative pedal-powered water pump. The device is designed for recreational and artisanal miners to recover coarse and fine gold and is being marketed worldwide.
Neffco bowl (#27). This device is superior to other single-wall bowl centrifuges in recovering fine gold but no tests have been published. It is used by a few recreational miners on small offshore dredge platforms in Alaska and can be adapted to meet the needs of artisanal miners.
Younge’s horizontal centrifuge (#45). A simple motorised cylinder able to recover >90% of very fine gold down to at least 75 micron, yet requiring very little water. The device seems especially suitable for arid regions, and can be built in a simple workshop.
Helix wheel (gold wheel) (#17). A device widely used for decades by recreational miners and industrial miners, mostly for upgrading. Know-how transfer to artisanal miners is warranted – especially of the many types of small gold wheels made for recreational miners.

07:18:20 Wed
Oct 31 2007
Whuttabout Electrowinning?
I looked thru your list and got quite an education all over again.
Thanks for all of your superb efforts..!!

The closest citation you offered to what I know as "electrowinning" was deep inside the murky proprietary habercorp website.

Electrowinning has been tinkered with for many years but seems to be recognized mostly outside the US...
...funny, because I first saw and old sourdough hooking his arcwelder to steel wool underwater in Fairbanks 1968.

Here's a company in Australia that sells electrowinning units..
they're actually pretty simple and can be built out of boards and baked mud if necessary.

If you have a bunch of parallel holes in the ground you can rig up in-situ electrowinning in muddy water that has flooded the shafts... but don't rely on low voltage DC only. Even in-situ electrowinning responds dramatically better if you can tune-in the resonant harmonic to the target molecules amid the rest of the dross in the hole..
..much like tuning in a shortwave radio antenna.
It helps to have experience building ham radio equipment and amplified antenna systems to get the feel what's required for superheterodyne high efficiency electrolytic chemical cells.

ASM's might figure out how to combine>
an old truck
an old diesel arcwelder
an electrowinning tank
...then end up with a tank-truck water purifier that gets 50mpg while it's making it's own gold from concentrates on the way to the biodiesel seller.

In the past couple years a few busy-minds have been visualizing a convergence between environmental cleanup technologies, and mining technologies.. some goldbrickers have already landed contracts to clean up toxic mess and they end up making a mint reprocessing the winnings off their electrodes.

18:26:18 Wed
Oct 31 2007
Re: Drywashers
There are a couple of different drywasher types that I know of.

Puffers using bellows.
Fan vibrators supposedly with static electricity. (never used one so the static aspect is unknown to me.)

Recovery is so-so.

Countless centrifugal bowl variants from 5 gallon buckets using water injection to spinning horizontal auto tires.

Recoveries are claimed to roughly 50 micron for classifides.

Powered rockers and thier variants.

Micron Wave Table.™ see Action Mining Services Inc.
supposedly recovers to 5 micron

00:31:35 Thu
Nov 1 2007
Re: Drycrusher ----> woodfired?
so, ya metalspray the inside of one of these windhexe-pulverizers with a mix of superduplex stainless & powdered industrial diamonds [borrowed from the grrrlz in Yellowknife].....
this will toughen it up enuff to grind schist and granidiorite [or whuttever] ---->

...then ya tinker with powering the big-windy pulverizer gizmo with a turbo wood-immolater like this ---->

...then you can melt dore-bars for door-stops to hand out as holiday gifts, while heating a 100' building at -50F.....(;-P)

01:20:41 Thu
Nov 1 2007
Re: Only 75 Ways to Recover Gold
Well I can think of the Gemini table which was probably invented in the 1980s and the Goldfields Goldtron table. How about the Ross box from the 1970s?

I think are bunches more manufactured gizmos that have been marketed.
Geo Jim

03:10:41 Thu
Nov 1 2007
Re: Only 75 Ways to Recover Gold
What about using a sheep fleece to separate the gold? Seems that is from antiquity, but may have captured more gold than the others combined. Just a thought.

18:02:35 Thu
Nov 1 2007
Re: Only 75 Ways to Recover Gold?
I dont see any wheels on your list. Was this an oversight or am I not reading you criteria for making the top 75 list correctly?
:confused:Geo Jim

03:06:25 Fri
Nov 2 2007
Re: Only 75 Ways to Recover Gold?
Geo_Jim -

Thanks for checking the list.
Lets see...

Wheels are there, as 'gold wheels' = 'helix wheels', see number 17! And they are good too!

Well I can think of the Gemini table which was probably invented in the 1980s and the Goldfields Goldtron table. How about the Ross box from the 1970s?

Gemini Table is #53.
Goldfields Goldtron is #64.
Ross Box and Pearson Box are treated as #36 angle iron riffles, as in the Yukon tests.

I think are bunches more manufactured gizmos that have been marketed.

I quite agree - I think there are about 400 or so in my files. However many are variations inside the list of 75 such as the vast array of gold wheels past and present. Others are excluded as they are too vague or have as yet unsubstantiated claims.

Keep the comments coming..

03:37:33 Fri
Nov 2 2007
Re: Whuttabout Electrowinning?

Sorry slow in replying to your excellent posts - we are running about like headless chickens here, gathering stuff for start up of winter shaft sinking.

Electrowinning! Yep it needs to be added to the list. (How could you miss such a good one? - Ed). Er I'm only a geologist not an electrician. Electrowinning now I shall study closely indeed.

Puffers using bellows. Fan vibrators supposedly with static electricity. Ooops well spotted! I er um forgot to put them in the list. Odd, as I have looked at about 2,000 and even tested 10 with lead shot. (Steppe - are you goin senile or what? - Ed). Its the 'what' not the 'senile' m'thinkgs. Must add drywashers. Oh, VERY BIG REQUEST EVERYONE - if anyone knows or has ideas on the % gold recovery of say Keene drywashers please let me know. We did tests with lead shot and 100% recovery of course. But what about finer gold? Any opinions? It really is odd that no tests seem to been published - they are good machines!

Countless centrifugal bowl variants from 5 gallon buckets using water injection to spinning horizontal auto tires. Most of the main ones are in the list but the Butler horizontal auto tire was missed off, although I did look at a lot of info on it. I could not find an actual user of it - anyone tried it? Anyone like to share info on it? Yep it should be added to the list.

Powered rockers and thier variants. Oops again - should be on the list. Which one would you suggest as a good or typical example?

Micron Wave Table.™ see Action Mining Services Inc. supposedly recovers to 5 micron Yes it should also be on the list. I have read their stuff carefully and just forgot - actually I dithered as I could find no clear basis for the 5 micron claim in terms of test method or test result. Has anyone direct user experience I can quote from?

Well done for improving the list everyone. The idea is to publish the list as it is, warts and all, as a free pdf download, and then do an updated better list next year.

Meantime, anyone else who wants bits to study - please post or PM and I will either post here or email.


02:56:41 Sun
Nov 4 2007
Re: Whuttabout Electrowinning?
Did I miss the "Gold Pan", I think it should be on the list, if I didn't miss seeing it?


19:05:28 Sun
Nov 4 2007
Re: Only 75 Ways to Recover Gold?
Au_Seeker - good question about gold pans! I took the decision to arbitarily exclude from the list all manually held gold recovery devices, as there are so many its a separate list. More importantly, I could not find any reliable information of what % recovery that they can make for gold of different sizes. So there should be a separate list for hand-held devices including for starters:

North American modern small plastic pans
North American traditional large metal pans
North American patented pans of past and present

Anyone want to start such a list?

05:43:04 Tue
Nov 6 2007
Re: Only 75 Ways to Recover Gold?
Well, I tried the "tincture" of Iodine method outlined in your article, and would like to report back that it certainly does work as outlined.

However, it does not work as well as pure iodine.

But, the material I used was some that had been hanging around here for some time. It was all of the stuff that you pick up with your snuffer over time, but that is to small to really mess with. Mixed with Black sand, garnet, lead, just your general concentrates. I did not prepair the material in any way with regard to cleaning. I am certain that the material contained sulfides as I have heated material from the same area before preping for other processes.

OK, so no pre-cleaning of the material, no agitation, just soaked over night. As well, I was unable to find any pure ascorbic acid locally. I purchased the most generic brand I could find in the vitamine isle at Wal-Mart. After reading through the labels of about 50 bottles, this one was tainted with the least amount of "filler" substances. I think acutally what sold me on it was that it had no Rose Hips, which pretty much ever other bottle had. They all seem to contain all of the rest of the following ingredients though; Corn Starch, Cellulose Gel, Hydroxypropyl Cellulose, Stearic Acid, Magnesium Stearate, Silicon Dioxide.

So, along with the precipitated gold, there is all of the cellulose residue too. But, it certainly does work as advertised. The microfine gold was certainly leached, and then I was able to retreive it out of solution. The larger visible pieces were not brought into solution, but were brightened. I think if I had agitated, rather than just letting the bottle sit, the outcome would have been much better. As well, cleaning the material first, either by cooking off or with chemical I am sure would have improved the action.

I am going to run through this a few more times, cleaning the material in various ways to see if I can improve the process. Maybe I can even get a picture or some video of the operation and the results.

Based on what I just did and observed though, this is something you should try for yourself, and possibly offer as the alternative to the mercury you are attempting to eliminate.

BTW, the Iodine I used is only a 1% titratable, 3.3% V/V. $11.00US/gal that I have had around for awhile. Use the stuff on my horses & livestock. I think in the article they talked about a 10% solution they were using. This in it's self makes the results I noted more impressive.

12:53:29 Tue
Nov 6 2007
Re: Only 75 Ways to Recover Gold?
Dan_Wasson - wow its great that you just got on and did this test, and marvellous you got a good result! I'm only the messenger boy who found out about the method, and never actually got around to doing it - bravo!

This Forum and its Forumologists continue to amaze me!

And to explain to everyone else what the hubbub is about, here is a new method of recovering fine gold, by chemical leaching NOT with too nasty/tricky cyanide but with TINCTURE OF IODINE the good stuff yer Ma put on your grazed knee with the infamous lie that all parent say. "Now be brave and stand still dear, this won't hurt! Yipes I can still remember. Oh yeah and the other chemicals - VITAMIN C, grandly called ascorbic acid in its pure form.

Dan, for the benefit of us all, can you please just set out the steps you used, and also how fine was the gold do you think you leached - microfine sounds VERY fine to me.

(Steppe, this Forum is gettin way out of line. Dan is catching gold with a first aid kit and vitamin pills, and you are using sunshine). Well now you mention it, we DO need a new First Aid Kit up at the mine, and wow there is gonna be loads of tincture of iodine enough for a grazed elephant and enough vitamin C to trigger a drugs alert in the Tour de France.

Can everyone gung-ho on this one please?
Dan says it works (my guess he is the first to try it outside of Japan) and flagged up some do's and don'ts - anyone else fancy a go at this?

Could be a rush on Vit C and Ticture of Iodine, better stock up!

To get the method, PM me with your email address and I will send you the original scientific article and a one-page pot-boiler I concocted.

05:51:10 Fri
Mar 28 2008
Re: Only 75 Ways to Recover Gold?
Looks like #67 is in the news, thought I’d post it…

Mercury-free gold extraction process makes African footprint

18:44:15 Fri
Mar 28 2008
Re: Only 75 Ways to Recover Gold?
Huntfish - thanks for the update. That's the iGoli Method from MINTECH in South Africa. If anyone would like to license it, cheap, then I guess they'll be pleased to provide you with the kit and training. It looks very good for fine hard rock ores.

But, I still think we've a long way to go with gravity and nice thing about gravity is that it's free, so far.


16:10:45 Sat
Mar 29 2008
Re: Only 75 Ways to Recover Gold?
If you would put all of that info into an e-book, I'd buy it in a heartbeat. I want it all.....
No time to say more right now...

16:31:58 Sat
Mar 29 2008
Re: Only 75 Ways to Recover Gold?
Zooka - well, indeed it should have been an e-book. With so many pics and drawings, a 'real' e-book was a non-no, so now it is now an ACROBAT book, each Chapter an ACROBAT file. You are guilty of having helped, so as punishment you get a freebie draft CD. Just hang on a little while. I have to finish the draft CD for Monday as then I go rock-tapping in a really remote region for a biggish client until end-June. Sometime in that long interval you - and others - will get a freebie draft CD by snail-mail. Should have cool postage stamps on it too.

21:35:30 Sat
Mar 29 2008
Re: Only 75 Ways to Recover Gold?
Steppe: Where is trommels and highbankers? Should they not be listed? Dredges? Banjos?


02:17:54 Sun
Mar 30 2008
Re: Only 75 Ways to Recover Gold?

LeTrap sluice?


12:59:35 Sun
Mar 30 2008
Re: Only 75 Ways to Recover Gold?
Eu_citizen....ah a tricky question...
Steppe: Where is trommels and highbankers? Should they not be listed? Dredges? Banjos?

TROMMELS - NOPE - disqualified.
Trommels were of course on THE LIST, but got taken off when I realised that trommels don't recover gold, but prepare the gravel ready for 'gold recovery by some other device. So, a trommel WILL boost gold recovery but should not actually catch gold in the trommel. A friend of mine did catch some nuggets in a trommel once, by mistake or good luck, the nuggets jammed in the mesh!

Trommel-like machines (trommeloids!) are on the list such as Helix Cylinders and Younge's Horizontal Centrifuges but that would be stretching the term 'trommel' way too far.

HIGHBANKERS er yes and no.
Have a look again at the list. There are several small (and large) sluices on the list that are often used as highbankers. The term 'highbanker' is too wide to put on the list.

Steppe, LeTrap sluice? Skip
When I concocted the LIST OF 75, there was very little info on gold recovery by manual methods (pans, lotoks, bateas, LeTrap etc) and so these are - for the moment - off the list. Now several can be added from the good efforts of members of the Forum.

My guess is that the total can creep up to over 100 if we check out more gizmos, more patents, more regions of the world.

That's the next step Steppe

17:09:23 Sun
Mar 30 2008
Re: Only 75 Ways to Recover Gold?
Steppe look again he asked for the Letrap SLUICE.:devil:

How about the blue/green bowl(s)?

As for the lad who got the nugget into the mesh, it seems logical a 'centrifugal force' would work on it when it's rotating. So if a nugget in right size on the nugget it would/could get squeezed in to the mesh.:smile:

04:48:38 Wed
Apr 2 2008
Re: Only 75 Ways to Recover Gold?
How about "ion exchange resins" or did I miss that as being under a different name?

18:10:07 Fri
Apr 4 2008
Re: Only 75 Ways to Recover Gold?

Steppe look again he asked for the Letrap SLUICE.
Good suggestion. If anyone has a test or enough info on % gold recovery for several mesh sizes that would be excellent. Can anyone help?

[SIZE=-i]How about the blue/green bowl(s)?
Another good suggestion.
Can anyone help with info on % gold recovery of the blue bowl for gold of different mesh sizes?

This thread has a QUESTION MARK - "Only 75 Ways to Recover Gold?" - the idea being to make the list longer and more detailed.

Kurt - How about "ion exchange resins" or did I miss that as being under a different name? Well this is a tricky one. For chemical methods, often its a two-step:
#1: Dissolve the gold somehow
#2: Precipitate the gold somehow
Ion exchange resins are in category #2. The "75 methods" tends to emphasize category #1, as this is the most critical. Once gold is dissolved (leached) into solution, then precipitating it is U-S-U-A-L-L-Y rather more straightfoward. So, ion-exchange resins are an EXCELLENT method for recovering gold.


07:57:15 Sun
Apr 6 2008
Re: Only 75 Ways to Recover Gold?
This may be included above but Dr. Jon Howarth has done research on bromine -- probably the Indiana stuff mentioned above. He is available to help me with it.

In discussing it he recommended roasting the sulfides on a sheet of tin over a wood fire to about 900F as one method to drive off the Sufides and drop the gold from the iron, making it susceptible to leaching, but he said that fine grinding and gravity separation would be the best choice if it would work on the ore. The grinding may not totally release the gold from the iron without the roasting, however I have read that some find microfine grinding to work in place of the leaching also.

His patent - I listed on the Iodine thread also.

He has a few others he has done or worked with others on also.

02:12:32 Sat
May 3 2008
Re: Only 75 Ways to Recover Gold?
I have two dry washers, both home made from plans published by Sam Raddings. In volume 1 the standard size unit is discrbed. I have electrofied the puffer with a 12 Volt moter that will work all day on a lawn tractor battery. The unit will process as much material as I am capable of shoveling. Many time I have ran the tailings through a high banker and have yet to find any meaningful size or quantity of gold. I know this isn't a scientific report but I'll put my unit up against whatever you want to bring to the party. The trick in dry washing is to 1) do not flood the tray. If you do simply shovel back into the hopper the overflow and run it again slower. and 2) the dirt must be dry and I mean dry. If it isn't dusty it isn't going to separtate. In volume 2 Sam discribes a small sampling unit that works as well but will handle only a small amount of material but the unit weighs only about 6 or 7 pounds and is great for sampling one of the hundreds of dry washes we have here in Arizona. Both of my units are puffers as their is no pleasure in going out into our buitiful desert to listening to a leaf blower screeming!
Hope this helps on your project and I am excited to read the final document on all 75 or 100 or how many methods you end up with.
Ray Carroll

14:17:13 Sat
May 3 2008
Re: Only 75 Ways to Recover Gold?
Here's another idea that came from Hal Farmer of Australia and was published in the Popular Mining Mag of the 80's and 90's.
It's a 10.5 in by 3 foot pvc trommel with 3/8s holes and bands of miners moss secured around it. This trommel sits above a catch tank and when the machine is in operation, centrifical force drives the heavies outward and into and thru the moss to be captured both by the moss and below by the tank. The m/moss is removable for cleanup. Moss is installed rough side inward and is fastened with fabricated metal pieces on the ends. The drive appears to be conventional trommel construction. There's a couple of pix.
The whole article is called "A Revolving Gold Pocket Creator" and is in Vol 5 of the Popular Mining Encyclopedia sold by Action Mining, page 63. I bought the series a few years ago for about $150 and have never regretted it.
Hal passed away a few years ago and was quite a character. He wrote a lot of articles for the mag and peppered them with mildly racy cartoons with mining themes. Most of his ideas dealt with universal mining problems and his Aussie style solutions.
I would be glad to copy and send this info via snail mail as I, alas, do not have a scanner. baub

08:01:55 Thu
Sep 25 2008
Re: Only 75 Ways to Recover Gold?

I am a new user to this forum and find it quite interesting. I am an American living in the Philippines and former Alaska resident (Palmer, Wasila). I am doing research to find the best method for high extraction of gold from ore found here in the PI. All small scale minors here use either the mercury then cyanide method or the cyanide/carbon method. All mills here are pretty much hand made from local materials. I am very interested in understanding which method is the best to try here. I am expecting that because everything is low tech here, that introducing some technology may return a higher net gold.
I have been researching centrifuge's like Falcons etc. Also the wave tables look promising. In you post on 75 ways to recover gold, you mention that you will have the article posted somewhere. Is this article available now? I would certainly like to research the different methods to see what can be utilized. I am hoping that newer technology could be used to get the Filipino miners away from chemicals if we can equal or increase the return.

Thank you in advance


14:08:38 Thu
Sep 25 2008
Re: Only 75 Ways to Recover Gold?
What about (or did I miss them?):


solvent extraction using Butyl Diglyme

07:05:27 Sun
May 24 2009
Re: Only 75 Ways to Recover Gold?
I am looking for the article of Leaching with the tincture of iodine method and Vitamine C (asorbic acid) I need some help with this! did many searches on the forum but can't find it.:confused:


14:08:47 Sun
May 24 2009
Re: Only 75 Ways to Recover Gold?
Gold Finder, try this:

07:13:25 Mon
Jun 1 2009
Re: Only 75 Ways to Recover Gold?
Thanks Jim,
Just what I was looking for.

07:24:17 Mon
Jun 1 2009
Re: Only 75 Ways to Recover Gold?
How about blood, sweat, and tears?:devil:

14:26:21 Fri
Sep 17 2010
Re: Only 75 Ways to Recover Gold?
Baub, if possible seend-me a article "revolving gold pocket creator'' ,will be great !

16:46:21 Sat
Dec 4 2010
Re: Only 75 Ways to Recover Gold?

I'm just going over the posts I missed while out West getting dirty. Could you give me some more info about what you want? My memory is getting a little shaky.



23:09:50 Tue
Mar 29 2011
Re: Only 75 Ways to Recover Gold?
Hello steppegold, I was told on another blog to join Alaska Gold Forum and look for your method of Iodine leaching for gold. I can't find your method, could you post it again if you get the time.
Thanks much

Only 75 Ways to Recover Gold?
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