Ted Mooney, P.E. RET
- Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Extraction of gold from seawater
Q. What materials, equipment and process must one have and go through to extract gold from seawater.
Louis W [last name deleted for privacy by Editor]- Houston, Texas
2003
A. I have known of gold being got out off sea water but the cost outweighs the return , I do not know how it was done.
Ross [last name deleted for privacy by Editor]- Tauranga, New Zealand
A. Hi, Louis. I can't tell if your question is student homework, a concern about an investment scheme/scam that has been presented to you, or a serious engineering question. But if it was intended as a serious question, the issue is that practically extracting the gold from seawater hasn't been achieved, whereas everyone has known for decades that it's theoretically possible. The problem the incredibly low concentration of gold in seawater :-)
Could you please tell us your real world situation? Hopefully you'll get a better response than I have given you so far. Thanks!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
! This is the real world! Louis' question is a serious one. Ted, admit it. You don't know! Dwight [last name deleted for privacy by Editor]- Renton, Washington 2004 I thought I had admitted it Dwight. Exactly what phrasing do you want me to use to "admit" that I don't know how to practically get gold from seawater? :-) Why do you feel that Louis is an engineer trying to design a practical recovery system as opposed to, say, a potential victim investigating the reasonableness of an investment scam presented to him? Thanks. Ted Mooney, P.E. Striving to live Aloha finishing.com - Pine Beach, New Jersey |
Q. Hello Mr. Mooney and Louis,
I'd really like to know. Just what equipment and methods, and how much time would it take to extract gold from seawater? It may be infeasible for a company but how about a small-scale ocean-side operator with capital and just trying to, say, feed the family?
Sincerely,
- Pittsburgh, Pennsylvania
2005
A. Unfortunately, economy of scale works in the opposite direction, Paul. The smaller the operation, the more impractical. It's been estimated that there is a milligram of gold in a ton of seawater. That means you would have to process (at 100 percent efficiency) two million pounds of seawater to get one gram of gold -- 57 million pounds to get an ounce.
Some day there may be a technology to do it practically (maybe some kind of special magnetic force or laser force or some kind of genetically engineered gold-eating microbe to concentrate it) but the numbers seem daunting for the present.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. I am an artist working on a project about extracting gold from seawater, I understand from what has been said that it is impractical to attempt the extraction of gold from seawater especially on a small scale, however as an artist I am not concerned with practicalities, more with the philosophical and ethical issues.
I would like to build a small working model of the experiment to extract gold from seawater, however inefficient and impractical, if you could suggest I way I might build this I would be very grateful. My great grandfather HJ Snell developed a technique which I found referred to in an American Newspaper, unfortunately as far as I can find his research has been lost (I am still researching this though through various UK institutions).
Sir William Ramsey (Nobel prize winner) was retained by a syndicate, called the Industrial and Engineering Trust (Limited), to develop H J Snell's work. Shareholders included Lord Brassey, Lord Tweedale, Hon. Alban Gibbs, several manufacturers and Albert Sandeman, foremost owner of the Bank of England. The syndicate had the modest capital of £3,000 in £1 shares.
Ramsey made experiments and stated in a formal report that "there is no doubt Snell has proved that gold can profitably be obtained from sea water on a large scale, and the amount of the gold obtained is so large that whether the cost of the treatment is £1 a ton or even the outside figure of £8 a ton, which it could not exceed, it would not make very much difference."
So any practical (or impractical) help you can offer would be wonderful.
- Brighton, England
2005
A. "Gold From the Sea", a web page at http://www.goldfever.com/gold_sea.htm addresses the issue and includes a bibliography with 27 references. Good luck with it, Anna!
My wild guess based on hints in the literature is that a microbe or nanomachine will be engineered which can bioaccumulate gold. If such a creature could concentrate gold even to 1 ppm, that would make the concept a hundred times more practical; if it could concentrate gold to 100 ppm it would be 10,000 times more concentrated than seawater. We live at the cusps of genetic and micromachine revolution, so I think it will happen.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
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Ed. note May 2019: Sorry, the web page I mentioned no longer exists.
A. Allowing drops of sea water to float up through Mercury will result in the Gold entering the Mercury. However, some Mercury will dissolve into the sea water, so much so that you spend more money on Mercury than you make from the Gold. Also the process pollutes the ocean with Mercury.
Bart H [last name deleted for privacy by Editor]- Altadena, California
2006
Q. That sounds interesting, if I was trying to do this on a very small (table top) scale and the seawater was in a flask or bowl and wouldn't contaminate anything could you tell me exactly how I would set up that experiment practically? And how would one get the gold out of the mercury (I realize this wouldn't be practical for me to do but I need to know anyway, in case people ask me).
As I mentioned above I am an artist, I want to do a kind of performance where I talk about my great grandfather's work (see post above) and do an experiment as I talk.
Would the gold extracted by the mercury method constitute nanoparticles?
Thanks for any help advice anyone has!
- Brighton, England
A. Hi, Anna,
Many lab technicians and nurses who wear gold rings have learned to their sorrow that when mercury touches gold it forms an amalgam. Bart was suggesting that you could take a small hose & pump, and pump the water with gold in it to the bottom of a bowl of mercury. As the water floated upwards (water is lighter than mercury), the gold would contact the mercury and form an amalgam. I suspect that you would have to recirculate this water several times for all of the gold to contact mercury.
The gold and mercury can be separated by heating the amalgam but, in leaving the gold behind, this releases toxic mercury gas, so this information is for your general understanding not for actual practice.
Nanoparticles are particles of 1 to 100nm in diameter. Sorry, I don't know if the gold in the ocean might sometimes be in the form of nanoparticles, but I don't think it's important because you don't get the properties of nanoparticles until you somehow classify out the non nanometer sized particles. Once captured in the amalgam, the gold would not be particles at all.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Sirs,
I have been led to believe that gold can be profitably extracted from ground water.
The area has been assayed at approximately $0.75 US per gallon at todays spot price for gold and other precious metals. Simplified, the process requires a filter to trap the metals, a precipitant to concentrate them , then send it to a refinery.
Thus, my questions... Does this make sense? Is it possible to extract gold and other precious metals (& platinums) from common well water? If so how is it done?
Thank you for your response.
- Tishomingo, Oklahoma
2006
A. Hi, Mike. It makes no economic sense to me (with today's technology), as I've said a couple of times. If gold is worth about $400 per ounce then $.75 worth would be $.75/$400 = .001875 oz. of gold. Then if there was .001875 oz. of gold in a gallon (which is 128 oz.), the concentration would have to be .001875/128 = 14.7 ppm. This water would be considered toxic by the EPA on the basis of its gold concentration alone!
If this ground water was at the bottom of a gold mine, I guess it could have that much gold in it (maybe--I really don't know), but why would not the mining companies be extracting it?
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Is it possible to remove gold from sea water using electricity? I am thinking of investing in a process that will extract oxygen and hydrogen gas from sea water. I am curious about the ability to separate all metallic salts form the slurry that is left behind. Can it be done with electrical heat or is there a chemical process.
Patrick M [last name deleted for privacy by Editor]transportation - Sarasota, Florida
2006
Q. "As an interesting historical aside, extraction of gold from seawater was most famously tried by Fritz Haber. Haber is an interesting character - he was a Nobel laureate in chemistry (for his work on fixing nitrogen from the atmosphere), he is also sometimes referred to as the father of chemical warfare (as the organizer of the first gas attacks in the Great War). In the early 1920's Haber spent a lot of time working on an extraction process to remove gold from seawater, and surveying the oceans for dissolved gold. He hoped that the gold could be used to help pay off Germany's enormous reparations payments from the war. Ultimately, he found that there was nowhere near enough gold in seawater to make extraction economically feasible (by about a factor of 1000)."
Found this quote on a website. It shows that this topic has been looked into. True, the fact that we have more modern technology now increases the possibility of this process being plausible. But, will it be worth it?
- Osan, ROK
2007
A. My Dear Gold seeking friends,
I stumbled over this discussion and want to add a few things. If I am not mistaken the original idea of the discussion was to filter gold out of seawater to sustain a small family.
Even though, there might be a huge amount of gold in seawater, there are more efficient ways of getting your hands on gold (without paying for it in the jewelry shop or the bank). For example, people still make a living of panning for gold which you can find in many areas of the world, the only requirements for that would be a pan, patience, a sense of adventure and knowledge about the area you live in.
But even if you aren't living in an area where gold occurs, looking for minerals might be more profitable than filtering a couple thousand pounds of water for an ounce of gold. For example, a good sized sample of amethyst, a big agate or anything like it is very valuable for collectors (who pay good money up to a few thousand dollars for good specimens).
As conclusion, I would suggest to look for a way to filter gold from seawater as a hobby in your free time where you might get some dollar.
- Lunenburg, Nova Scotia, Canada
A. Magnetic Activated Carbon Particles for Gold Recovery
Is used to remove heavy metals and toxins from air and water.
"Activated carbon finds use in the extractive metallurgy of gold. In 1999, the amount of activated carbon purchased for gold recovery in the US and the rest of the world was estimated to be 4000 and 7000 metric tons... Activated carbon has been recommended by the EPA as one of the best available technologies for water and wastewater treatment. Activated carbon is also used in the food, automotive, chemicals, and pharmaceutical industries ... This technology has been demonstrated to work in proof-of-concept experiments."
http://www.business.utah.edu/display.php?&pageId=1936
"For example, in a laboratory-scale test, conventional activated carbon with a particle size of 6x12 mesh (3.35 mm x 1.40 mm) adsorbed 60% of the gold in cyanide solution after 8 hours of contact time. A magnetic activated carbon with a particle size of minus 200 mesh (74 mm), under the same experimental conditions, adsorbed more than 96% of the gold in about 15 minutes and 99% of the gold in less than 2 hours."
http://www.umpic.utah.edu/opps2.html
"Gold is recovered from the gold-bearing solution in the carbon process in which pellets of activated carbon, made from charred coconut husks, are added to the slurry and the gold-bearing ions are adsorbed onto the pellet surface. The pellet load is moved through a number of linked tanks containing slurry in a direction opposite to the slurry movement.
Pellets, loaded with gold, are removed and gold is stripped from them by washing in a solution of hot cyanide. Carbon used in the process is recycled. An electric current is passed through the new solution and the gold is deposited on a steel wool cathode."
http://www.australianminesatlas.gov.au/info/factsheets/gold.jsp
The research is just beginning and recovering gold from water may be possible in the future.
- Wayne, New Jersey
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Ed. note May 2019: The three web pages Derek referenced no longer exist.
Thanks, Derek -- although I am not quite seeing the connection yet.
As you say, activated carbon has been used in many industries almost forever. In the electroplating industry we have linked it to ion exchange media to help it serve as a wastewater effluent polishing material, and we've linked it to various stabilizing materials like cellulose filter aid to try to limit the dustiness of conventional activated carbon. The efficiency improvement that the licensing office at utah.edu claim sounds interesting, and being able to gather it with magnetism sounds like another nice plus, but I am not understanding in your links how it makes recovery of gold from seawater any closer. Maybe you can comment on the specific relationship between this development and recovering gold from seawater? Thanks again!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. Here is a thought based on one of the last comments: De-desalinization plants are being built like CRAZY and from what I understand the process is practically much the same as RO units? So the water is simply filtered to the extreme and those filtered elements have to be disposed which unfortunately I am just guessing they dump all BACK into the sea that is already becoming too high in saline. I am thinking that since all that GOLD surely is IN that which is disposed of and now at a much increased concentration 'per pound' as they say it ought to more practical than ever before to extract gold from THAT ... and at the same time it could become a requirement to NOT dump the salt back into the sea! Could possibly be a win win win situation? The people get their water, the ocean has all these little salt removing operations going 24/7 that just might make an appreciable difference at some point AND some enterprising Alchemist get either rich in the process or have a lot of fun trying!
Doug Chenay- Costa Mesa, California
Personally, I think the extracted salt should go back into the sea, not onto land. While many bays, estuaries, and brackish areas are becoming too salty due to reduced fresh water inflow, I haven't heard that the ocean itself is getting too salty -- but certainly the land is.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. I think it is a promising prospect
Allen mhanduelectronics - Harare, Zimbabwe
January 28, 2008
A. It seems to me that the cost of separation of gold from seawater will determine the ultimate maximum price of gold. Considering the increase in price of copper and silver: a separation of those elements from seawater may well make the process of separation more practical for gold as a separation byproduct. Copper is about 100,000 times more concentrated in seawater than gold. The value of gold today is about 2000 times the value of copper. So, one dollar of gold would be separated for each $50 of copper. Perhaps this conversation should be more about the separation of copper from seawater.
dumbill
- San Jose, California
That sounds true, Bill, only if the selected recovery technology recovers copper, silver, and nickel concurrently. But we are saying that it may become practical with some future technology, and we don't know whether that technology recovers the 3 metals together or only the gold. I mentioned a microbe that might accumulate gold, but we don't know whether it will bioaccumulate copper and silver; maybe not, since these can tend to be biocides. But your posting is certainly great food for thought. Thanks!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
A. In theory it is possible to electro plate the metals out of the slurries then smelt out the gold (or if you're smart the copper chrome and other metals).
Jay Chuck- Quincy, Massachusetts
A. After giving this some thought.
You use eddy current, powered by a water mill mounted on the ocean floor to force gold in seawater into a nonporous receptacle .The concentration of gold increase with time, then all one would need is a constant flow of sea water like the Gulf Stream or tow the whole rig behind a ship.
- Danielsville, Georgia
Q. I'm told that sea-water extraction of uranium has had some provisional work done, which has not been vigorously pursued basically because uranium from mining is so cheap, but that the principle is proven and as it is simple technology - ways of further reducing costs are clear:
www.taka.jaea.go.jp/eimr_div/j637/theme3%20sea_e.html
Synthesis of adsorbent for uranium in seawater
jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-en/2006/4_5.html
4-5 Confirming Cost Estimations of Uranium Collection from Seawater
The technology basically consists of hanging an absorbent membrane in an ocean current, and pulling it up when it is saturated.
They indicate that probable costs look like around $200/pound, which would be roughly $12/ounce. Now, uranium is more concentrated than gold, but this looks promising. What do you think?
- Chicago, Illinois
April 23, 2008
A. This thread is old and may be dead, but it seems to me you have a better chance of extracting gold from blood of cadavers than sea water.
I am no scientist, but actually an economist and CPA. It seems to me that if a practical way to extract gold from seawater is developed, the price of gold would instantly plummet due to the huge amounts of newly recoverable gold available. Therefore, the expense to research and develop the method would instantly render the goal worthless.
- Brooklyn, New York
Hi, Steven and thanks. But, I don't agree with your conclusion. While making gold easier to obtain would reduce its cost, and would thus devalue jewelry, it would not render the goal worthless. Although gold is used in jewelry, it's also used in electronics and for its excellent corrosion protection, etc., and designers would love to apply it almost everywhere but are terribly limited by its cost. Yes, we reduced the value of the aluminum cap on the Washington Monument when we figured out how to make aluminum cheaply, but we didn't render aluminum worthless. Thanks for a thought-provoking discussion.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
! Interesting topic.
I think a lot of people are after a way that you could get gold without doing much physical work, working smarter not harder. Also if it doesn't need constant supervision you can have it as a second income without it taking up any more of our dwindling time.
From the sounds of it the value of gold won't plummet because it doesn't seem that there is much there anyway so the market won't be flooded.
As stated, there are far better ways of getting gold, panning has already been mentioned but that takes effort! And hunting around for other minerals takes research and time and effort.
I, like the rest of the world, would like my gold for nothing, after all it is free if you can just pick it up!
Ideally I would set up my rig in a tidal region, this way fresh, gold filled seawater will be delivered daily and all the gold depleted seawater will be removed just as quickly. This would cost me nothing.
If electrolysis could be shown to work to pull out gold, silver, platinum or anything worthwhile then I can worry about how to separate it later (as a side note, wasn't most manganese pulled out of seawater by electrolysis?).
I can run a few solar panels to charge this, so apart from an initial outlay there are no running costs.
As for efficiency, 100% would be nice but as I would only come to check the equipment once every couple of months (to make sure it hadn't been stolen) the actual efficiency could be as low as 1%, as long as the precious metals were slowly being deposited and my net worth was slowly going up I would not be too concerned.
Even if I could show a small fraction of gold recovery I would be able to make more money on eBay selling the plans than I would from the actual gold recovery.
Fortunately I live on a beach and own a solar panel but at the moment I am going to try and use it to extract the copper from cupronickel coins and see if I can't get rich that way.
Then of course there is always the gold and silver to be recovered from computer and electronic parts. After that I might try to get something from seawater.
I, like everyone else on this thread, await the advancement of technology and hope I can get in first before the rest of you take it all.
Mark
- Redcliffe, Queensland, Australia
December 1, 2008
A. I am a doctor at a University and I am attempting another doctorate in order to get my professorship in chemistry.
I have found a way of isolating gold from sea water using a biodegradable ion and a electronic synthesizer that will solidify and attach itself to any metal in the sea water and convert it into a rough ore (if left for a certain amount of time).
This ore can be separated by the elements using their different boiling points; the final products are silver and any other metal that is common in sea water.
The good news that I have made the process 10 pence cheaper than the total price of the yield, I will be publishing the paper in 3 months time as there is still problems with the variables of pure sea water and its corrosive properties.
- Cardiff, U.K.
A. Getting gold from sea water is simple and can be extracted at much lower cost than conventional cost. Its technology of extraction is carrier transported immobilized liquid membrane.
Jabin herald thomson- Chennai, Tamil Nadu , India
A. "Geothermal brines are passed through a bed of an anionic resin selective to the removal ... 4778597, Process for the separation and recovery of boron compounds from a geothermal brine .... Gold No 0.2. Silver 2.6 0.5. Zinc 1500 500. Lead 650 110 .... The boron-enriched solution can be heated to evaporate water and ..."
www.freepatentsonline.com/5236491.html
- Salt Lake City, Utah
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