Chemical Extraction of Gold from Ore
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- Опубликовано: 24 май 2023
- I demonstrate a complete, end to end, micro gold extraction process from gold ore using hydrochloric and nitric acids, and using zinc to precipitate the gold from solution. I estimate the yield of the ore.
Keywords: gold ore, gold prospecting, gold extraction, rock grinding, rock crushing, aqua regia, chemical extraction.
I worked as an assay chemist in a gold refinery long ago. Your comparing of the color and translucency of the solution after the stannous test was new to me. What we would do instead is cook a tiny crucible on a Bunsen burner. Let it cool and get its weight. Then we would precipitate our AR with Au solution with sodium sulphite. Testing only a drop at time to see that all gold dropped out of solution. Then we would filter the Au precipitate out using ashless filter paper and fold up the paper with Au and put it in the crucible we just found the weight of. Then we should burn the paper in the crucible till only the gold was left. Then let it cool and weigh again. The difference in weight is the amount of gold that was in the solution. If the amount of gold is only a stain then you will need a very sensitive scale. So your visual test may have some benefits in trace amount analysis. But be aware the purple color comes from colloidal gold in suspension. Over time that colloidal gold will sink to the bottom of the test tube changing the translucency of the solution. ❤❤❤❤ Very exciting things you are doing. Thank you for your video.
Hi Randy, thanks for the excellent and useful comment. -- Dave
HCL can and often will by itself, put gold into solution. There are other substances in ore (manganese for one) that will mimic nitric. it looks like some iron and possibly copper went into solution during your prewash op. I'd suggest at least testing with stannous after a dose of urea. Neodymium magnets will pull gold - I used to use one to remove BS, then I started seeing gold sticking to the mag, so I went with a low power mag instead. Thanks for the update, glad to see your progress :)
I do test the HCl wash water and I haven't found any gold yet, but I'll keep my eye out for that problem. I've always worried about the magnet pulling out gold. Any easy way to test this? Thanks so much! -- Dave
@@orophilia excellent - i figured you would, but other visitors to your awesome channel might not :) I've found about 10% of the gold i've found in the Mojave is magnetic enough to get picked up with a strong magnet, typically larger pieces, but I suppose it depends on the purity and content of the individual piece. If we ever meet up, i'll show you some of the gold we have found that is magnetic.
@@AUMINER1 I'm sure we'll meet up so keep the 'lode' gold handy. 😊
I see 'gold' on my neo-D magnet regularly however I assume it is all pyrite, pyrolite, chalcopyrite, etc. The 'gold' crystals that the magnet picks up seem very cubic in shape so I just discard all of it. I would recommend continuing to use the magnet and if in doubt gather some of the gold bits and blast them with a jet lighter. Chances are they will go brown and release the smell of sulfuric acid. That's Fools Gold for ya!
Very precise and detailed. Congratulations. This is for patient people.
Great tip with the watch glass. I am using it now. Thanks.
Great video, have a wonderful day!
Thank you for the video. Very informative very well put together.
first, put your magnet in something like a zip lock bag for easy cleaning,,second, yes you can remove gold while removing the magnetics if you scrape the bottom of the pan ..try to avoid scraping lastly, where is your soap Sir?.. you need a surfactant to break water tension, otherwise no matter how careful you are panning, you Will have float gold, float right out of your pan😊
All good comments. Thanks. -- Dave
@@orophiliayou pan away 30% or more precious metals. Look at the dry mud.
@@somsackvongsa7077 Thanks for the comment. How do you know that I pan away 30%+ of the precious metals? It's interesting that you can tell this from the video.
@@orophiliaHi Prof
Could you explain the way of electrolysis to extract gold from rock, please?
@@AO6.3 I'm sorry, I've never tried electrolysis.
thank you so much
you make the niftiest gadgets ever!
Good presentation
Thank you so much for.the update,pls work.on cabonacioucious metals after grinding
VERY NICE VIDEO SIR GOOD JOB
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Is adhering to the weights you mentioned important in the gold extraction process? ( I do not mean the 3:1 weight for preparing aqua regia )
What is the reason that prompted you to add 10 milliliters of water with nitric acid and hydrochloride?
These are good questions. I'm not a chemist, so I don't have good answers at this time, but I will do some research.
Tapwater is chlorinated, and together with HCL it will dissolve some gold. Distilled water solves this problem.
As AU miner points out, you should check your black sands for gold as well, as gold does tend to stick to it.
The free Cl from the chlorination is the problem and why HCL alone does not pose a problem.
Thanks for the great advice. I've been wondering about the tap water. -- Dave
You are absolutely wrong there. Adding the miniscule amount of chlorine contained in tap water to hcl produces....nothing. Where you can get into trouble is rinsing with tap water and then using nitric acid. Nitric + the chloride in tap water can dissolve gold because you've accidentally made aqua regia. Hcl will not dissolve gold alone. Ever.
What kind of plane is that flying overhead at 4 minutes and 33 seconds?
It's a general aviation prop plane.
This is why I collect concentrates (sluice, cyclonic separator, etc) and then fire the stuff with Bismuth.
I hate dealing with the fussy end points of panning, chemicals, etc. Let Fire sort that shizat out! :D
If you don't want to run a propane mini-furnace then have a look at Microwave Metal Melting. I'm trying it these days for fun.
Hi Sean. Yes, I've smelted gold ore many times, either as crushed or concentrated and it does work well. Even better if your cons are clean enough to cupel directly with Bismuth. -- Dave
السلام عليكم ورحمة الله وبركاته كيف حالكم أحبتي وأصدقائي واخوتي خبراإ. اني عربي. لا يفتهم لي.. بعظ. شروحات لسبب الغه هل يمكن توضح في ترجمه علا خطوات في عربي وكل تفاصيل. خطوات وشكرا
👏 ok very good
I believe the issue you're having with precipitation of gold is the DeNox step which is something worth avoiding.
The best method (from SREETIPS) is to microdose the HNO3 just until the gold dissolves. You DO NOT want excess or else you have to do the whole DeNox thingy.
With this amount of gold you might start with 0.5ml HNO3 and boil it until the acid action stops and then add a tiny bit more. Alternately dilute the Nitric Acid stock soln.
The use of Sodium Metabisulfite works well to form the ppte however I might be biased as this is a common pool chemical that I can easily obtain.
My problem with dropping the gold was my misunderstanding of what was happening and my inexperience with chemistry. It takes a few tries. Also, the very small quantities of gold in these rocks (less than a milligram) caused some confusion until I discovered what to look for. -- Dave
What is the temperature of of Hot plate?
I keep the plate at about 9C, which makes the beaker about 70C.
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"How dense are these rocks?" They are mostly quartz, so they have a density of about 2.5 g/cc.
A tiny pan like that is a toy.
Use your 14 inch pan and purchase a larger round basin to pan into
More accurate , much quicker and much easier , all due to having larger surface area , especially the pan base.
Yeah, I hate that small pan. I accidently left a couple of my nice pans at the cabin.
I think you lost the ultrafine when panning.
That is quite possible. I've been working on retaining the very fine gold and I'll have more on that subject coming.
@@orophilia You lost most of the gold on this.
With all the gadgets ive seen you made, you should make a gold floating machine from an old drill.
Panning followed by flotation will give you same results as cyanide.
Its the best of the professional types of gold extraction.
You need hydrochloric acide in solution you need urea to kill the nitric . You need zinc or aluminium just that a mouth hou much gold is in solution. Metals that are more reactive have a
greater tendency to lose electrons and get oxidized. When a more reactive metal is placed in the solution of a salt of a less reactive metal, it loses electrons and oxidizes.
• The electrons that are released by the more reactive metal are accepted by the cation of the less reactive metal present in the solution and the less reactive metal is reduced to the metal. As a result, the more reactive metal enters the solution as a cation, whereas the less reactive metal's cations are converted to metal. So more reactive metals displace less reactive metals from their salt solutions.
Yes, thanks!
@@orophilia I see your solution and I can tell you you don’t kill the nitric. If nitric no more in solution then when you add zinck you can see gold rite away and gold comes from solution and stays ! !!! Why I say kill nitric and add zinck or aluminum just that much Hou much is gold in solution . And if you have gold solution becomes brown . That you can see wery wel on the sun . Gold reflects sun lite and you see specific gold color