That was cool to see the zinc part just for an experiment. Thanks for keeping us entertained and trying different things so it's not the same video each time.
Thanks again for listening to the community and try the crazy ideas we are trowing arround sometimes. It's one of the thing I really appreciate about this chanel. You are close to us, take the time answer all our dumb, dumber and sometime not so dumb questions.
My spouse and I wish we’d have had this in HS chemistry, to follow along and balance out formulas during the process. I find your videos very relaxing and a great time to get my Nerd on. Thanks again!
I’m really impressed by you being able to experiment with an uncommon refining process and have it come out this well. Not perfect, but hey, we learned something, so thanks!
I would like to see him do a drop with electrolysis... it's similar to the gold cell but uses a carbon anode instead of gold, and the solution fades from gold-red to clear as it pushes it out. Like this it isn't "selective" (anything that will favor over hydrogen can be/is pushed out) but it doesn't contaminate the "drop" (plating). In fact you can keep it completely out of the solution by putting a bag around it like the silver cell. The only thing that will appear in it will be trace carbon that may have agitated loose. (Edit: Process is called "electrowinning")
Anyone else feel like any gold that doesn’t make it into the final yield directly affects you, like it’s your gold pouring into the waste container? Very engaging, I love watching
How fast the zinc reacted --> I know it can be dangerous to work with and really isn't appropriate for industrial scale for several reasons, but DAMN if that isn't one of the coolest reactions I've yet seen on this channel!! The reaction just took off!!!
That reacted with the zinc and dropped the gold out much faster and more dramatically then I though it would.i thought it was gonna take hours.very cool
Very interesting to watch. I could tell by the color of the precipitate that gold was contaminated. I was amazed at how it looked after the melt. It looked fake. It reminded me of gold I've seen in India, dull and plastic looking. I read a paper talking about this, and they recommended using Zn powder, bubbling N2 through the solution and fixing the pH between 2 and 4. This was a process to create ultra high purity for microelectronics.
In my experience, zinc will follow the gold no matter how many rinses, acid or water, are performed. In order to get that zinc out I’m going to have to refine it out. Including inquartation. If I tried to dissolve that bar as-is, filter and precipitate, then traces of zinc will still be present and make an ugly bar. The only way to get it out is to inquart.
I worked for a big gold refinery in Australia for a while. There we would inquart the gold with silver and a bit of copper, and wrap it in a lead parcel. This was then put in a furnace on a special dish that would absorb lead but not gold, silver or copper. Once it would come out we'd be left with a silver coloured bead. This would then be beat into an oblong shape and fed through rollers that made it into a strip, there were a couple of annealing steps along the way to assist with this shaping. These strips were then coiled around to keep the surface area but reduce the space they would take up. These were then boiled in nitric to remove the silver. All this in fact was just to do an assay on any gold the refinery received. With that in mind, thinking about your nitric acid boiling step, if there was any desire to speed it up and improve it, then some step to increase the surface area could be done. Since you do the step pouring the molten inquarted gold into water though, I guess that's the best and quickest way to increase the surface area. If you had some kind of press though, you could flatten these flakes to increase the surface area. Doing that though, I guess would increase the risk of a boil over with the nitric steps. In the refinery in Australia we would receive gold from a variety of sources. We'd get prospector nuggets, things that people had found with metal detectors, these were always interesting shapes. We would also get a lot of Indian jewellery that was of high purity. We would also get nuggets from the mines, samples that they had extracted chemically then melted into nuggets of alloy that were of unknown purity at that stage. We'd also get various gold bars and coins from mints around the world, Indian tola bars, South African krugerrand's and so on. All were treated to the same initial step, weighed when they first came on site, then a small piece taken and an assay ran, and then the whole lot was added to the gold refineries main purifying process. The storage room was incredible, it was a room full of pallets of stacked 14kg gold bars. I enjoyed working there, but it did get repetitive. It was officially a lab analyst job, but it felt more like I was a blacksmith, using a big hammer to pound the little beads into a perfect shape to be flattened and coiled up. All the garbage was collected and reduced with high heat into a black crud. This was also assayed to see how much gold was in it. If the gold was above a certain amount, we extracted it, if it was below that but above a secondary limit...it was sent to Africa on a ship to be extracted! If it was below this secondary limit, it was just binned as normal garbage. Periodically the paint on the walls from certain places was also removed and treated to a similar process as the garbage.
@@sreetips Ah! haha! Sheesh. Yeah, the gold refinery had these special rollers, we'd roll them through it twice, then anneal them, and roll them again. I guess the difference with the refinery is that they wanted to get the gold at that stage to 4 nines or higher in purity for the sake of the assay.
Yes Mr Sreetips. Plus, for poor rookie refiners like me, I can use selective separation by using Zn or Al. Being Al something that pops out everywhere in my house. If we run out of SMB or any other reason. First, diluted NH3 boil However as alternative you can use pure HCl with highly concentrated H2O2, no Nitric (it is needed extra care here because it is very likely not all Au will go in solution in the first boil). Add small pieces of clean Zn or Al until everything drops. You go selectively separating the metallic salt, first with HCl, clean, HCl with low concentration H2O2. If Ag is present, after the first round of separation with HCl only, use in. 1:1 proportion high concentration HCl with NH4Cl, it will dissolve everything up to Ag. There are intricacies and further refining is needed to achieve better purification and it there are PGMs present. Just is just an abridged overview of this option if we lack of NH3 and SMB, or we want to save either or. There is also another alternative that involves boil in H2SO4 and a follow up boil in H2SO4 + H2O2 (I used this method this week to recover gold from sundry integrated electronic components). Not talking to much because it is dangerous and most refining communities have banned either the topic or the topic and the person who raised the topic. Points to consider: volume of waste generated, level of certainty that you do have all Au and up recovered. At the very end when, supposedly, you have only Au (and PGMs) in solution, one boil with a bit of Nitric is recommended to ensure the leftover salt (please noticed I use salt very loosely to refer to precious metals in cement or powder state. Some of them are salt, other are not even close, just to make annotations easier when making annotations of the experiment in execution) is pure gold
@@sreetips if we are within a controlled stage of the process, it should not: Au + HNO3 + 4Cl -> AuCl4 + NO2 + 2H2O And then we filter and add Zinc: AuCl4 + Zn -> Au + Zn(2+ ionized) + 4Cl Again filter, boil the pure Au with water a couple of times, then boil the pure Au with HCl. There should not get outside this scenario. We might want to evaluate the scenario of we have any known contamination during either equation. For the first equation, if there is Ag on the left side alone or alloyed, the right side is completely different. For every other scenario I did not achieve any scenario where pure Au is extracted. Also, I did not calculated the scenarios having PGM. There are ionizations I do not remember the expression (like with ionized Zn above which results in minus 2 electrons when exchanging places with Au).
@@sreetips well, just to make sure, gold i AR is gold(III) with the formula AuCl4- , however the - sign should be upper-script like the Z2+ and my phone does not have the feature. Also, when Zn is added to goldIII), a redox reaction takes place. Zn acts as a reducing agent and reduces gold(III) ions to metallic gold as per the formula above.
@@sreetips just for reference, the formula for adding SMB to gold(III) is: AuCl4- + 3Na2S2O5 + H2O -> Au + 3NaHSO4 + 4HCl We have somewhat similar scenario if no contamination is present.
I still highly recommend pouring into coin molds over bar molds, the coins just look better in a big pile, one of these days im gonna come across a nice wooden chest to drop em all in so i can do my blackbeard impression 😂
I like to use zinc instead of stump out because its way less fumes. It also depends on what I'm doing. I don't have a nice set up or fume hood so unfortunately everything I do is backyard buggie! Lol. I'm going to build a tiny work shed because it gets so cold in New England that is hurts my reactions and things take so much longer because any heat used needs to be done super super slow so no glass or beaker gets broke. I love your channel Sir! You are #1 in Professional Gold Refinement Sir! Thank you so much for all you do! God Bless you & the Wife!🙏
Another great video! Can I just give one small critique. That extra light you've added is great and all but it's way too warm. Videos go looking from a nice pro garage lab setup to looking like someone refining gold in their living room. Not a big deal but I think a nice bright cool light would make a huge difference. Just my two cents anyway.
I wanted to mention a few days back how interesting it was that you added a watch in the background to see elapses wall-clock time on some of the sped-up clips. Nice touch !
This is one of the coolest precipitations I’ve seen on this channel! So freakin cool! I like the way you experiment, Sreetips. Keep it up! Keep playing and learning! This is awesome. 🙂😎👍
The way it sloughs off the zinc strip was BEAUTIFUL! It builds up then falls off and more builds up etc... I had no idea you could use zinc to precipitate gold! How does that chemistry work i wonder? How many different ways to precipitate gold?
This is the method that many prospectors use to precipitate gold from AR although it carries the risk of also dropping out other metals if not removed first.
You did that exactly the way I hoped you would every step of the way. Nothing at all to even be mad about. It was very very cool to see how that would work to try using zinc to cement gold, and I woulda been Kinda upset if you refined a third time because the curiosity in me needed to know if that would be at all a viable method of getting gold out of solution. I wonder if some sort of equation could get that process to work without any contimation. Like if you used the exact amount of zinc required and not a speck more, would the final Product be threw mines fine? I dunno but damn was that cool to see and especially how the zinc was replaced by gold so efficiently that the shape or the zinc sheet was still there only it was actually gold flakes that took its place. Overall this is one of the best and most interesting things about you, when you get some idea and try something just for the sake of trying it. You should try to do this anytime you have a curiosity about some aspect of refining, because it's just plain fascinating and not many people would have so much gold and so much equipment that they would be willing to satisfy these kind of random experiments for No reason other than childlike curiosity. One of the better videos in a long time and my one and only request would be a little less time-lapse, especially when you pour nitric boils into the silver jar. Watching that thick cloud of nitrogen dioxide erupt from the silver is one of my personal guilty pleasures and it makes me a bit sag to not get to watch them all. But that's just me, I get most people probably don't care about that so Much. Good work though. 👍
Now that was beautiful, trying out the zinc was very interesting, and the results were impressive. Thanks for trying new things and sharing them with us, it's greatly appreciated.
Man that cement silver was a booger to melt. It is one of the most electrically conductive materials available and you can see how resistant it is as soon as it is sintered
I'm an electrician and older or larger electrical contactor switches have silver pads on their copper contacts, though I was always told that they used the silver because it doesn't stick when the electric arcs across the pads where if they were pure copper the contacts would basically weld together, whenever I would have to change a contactor I would hang on to the old ones and salvage the tiny bit of silver out of them, still have a couple mason jars full of those old contact pieces in my garage, the temperature probes they use on the giant furnaces in foundries have platinum wires in them also, us electricians would always argue over who got to change those out since the guy that changed it got to keep the junk one lol
Hi Sreetips, have you ever fancied setting up an electrolytic cell for gold, as well as your silver? It would be great to see you set those up side-by-side, see how they run
I would expect there is as much zinc contamination as there is copper contamination in cement Ag. Really appreciate this video - I have a kilo of zinc I've been tossing around an experiment like this with it. So, Cementing Ag for the cell it is. Maybe some PGM stuff later. Awesome Video man as always. 👌👍👍👍
@@bruceneely4859 But not zinc alloyed with gold. Just as silver cemented on copper always carries some of the copper atoms with it, so will the gold. In Streetips silver cell, you can see the copper turn the electrolyte blue. Aqueous Zinc ions are usually colorless, so you won't see them -- but they're there.
@@guygordon2780 true you can never get it perfectly pure, but the major difference is both copper and silver dissolve in nitric acid whereas Zink dissolves readily in HCL but gold dissolves very slowly in HCL, so should get the gold pretty clean, I agree with Sreetips though this is not the way to refine gold.
Inquarting will be very efficient in my new furnace. I can adapt it to use all manner of fuels, and with varied internal heights, mounts for crucibles, incineration tubes, and I can even turn it into a pizza oven! Just a simple loose brick chimney design, but with a few tweaks that allow quick and easy rearrangement to anything needed!
Good old Merrill-Crowe makes an appearance on Sreetips! For many decades, before adsorption onto activated carbon became the go-to recovery option for gold in cyanide solutions in major gold plants, using zinc shavings and now zinc dust was the method used to precipitate the zinc from the low grade cyanide gold solutions. It is still used in mines who have a very high soluble amount of silver as well as gold in solution as the carbon can easily become overwhelmed with the silver and so you start losing gold. Fascinating to see it working so well from an acid solution -good job!
The flaky texture of the zinc precipitation is very interesting. I wonder how pure this gold is. It's not the usual powder texture of the stump out precipitation, but doesn't mean it's bad either. Would a nitric acid boil before drying the gold disolved the extra zinc in there?
There’s a smaller you tube channel where this Austrian guy goes and finds rocks to crush and get gold out of…he uses Zinc a lot because he tries to avoid acids and chemicals as much as possible. Fascinating stuff.
Interesting! Zinc did not work to bad and the precipitation looked cool but so2 gas is obviously the way to go, the result you get from just adding SMB to the gold solution probably gives the best complexity to result ratio. :-) Seemed like the cement silver worked ok though, in case you dont't have any sterling silver it is perhaps better to use that to inquart the gold and use the copper to cement out the silver rather than to inquart the gold. Fun to see you experimenting with different ways of refining. Big thumbs up!
It seems that the cement silver took much longer to melt? I did like that you charred the top before adding the second flame so you didn't blow the powder out of the melt dish!
You'd mentioned this.. I was curious to see it happen. This is the same process I was looking at with doing with copper, as this will eliminate everything above it... my only real issue with the zinc is that it will drop other metals from it down, decreasing purity
I think the greatest advantage from using fresh nitric acid boils is that contaminants are removed quickly, instead of remaining in the beaker until all the non-gold metals are dissolved.
It would be interesting to see the inquarted silver be cemented out and then be used in other inquartations. (Noticing along the way, the amount of loss in the process.) Thank you for the great content.
I should have pointed this out in the video: using cement silver, over and over, to inquart gold is not recommended because PGMs will follow the silver and build up in the silver.
Another nice video, Sreetips. Question: at certain steps in the refining process, you add a few ml of sulfuric acid to drop out any lead. How would you proceed if it actually dropped out some lead?
Yess!! I've been thinking about this for months and now i see you trying it! In principle it should work given the difference in reactivity of the two metals. I am very curious about the composition of the ingot and what exactly contamined it, can you do an analisis on it? 🙏🏻
neat experiment, but unfortunately zinc ions would be trapped in the gold precip during the exchange. Might be fine for a preliminary precip, but not the final.
thanks again for your fantastic video ,i would like to ask when you transferred the solution to the larger baker to participate with zinc , was the heater ( heat ) on ? ty for replaying.
They cost as much as a used car. Six years ago to rent; $1500 per week, $4500 per month. Includes a “courtesy” visit from local authorities to ensure proper use.
You are welcome. Well worth the minor contamination to observe an alternate method of precipitation (not to mention inquarting with cement silver). Thank you Sir!👍👍🤟
Just a guess, but I would venture to think it's much easier to get the gold out without having to use an excess of water to get it out. The use of ice to cool the gold bearing solution. easier to get a status check. It is easier to add smb through a larger opening. Or it could simply be personal preference. It's a good question, I wonder myself.
I can’t understand why you don’t pour all the solids in the Gold Refining Waste flask into the stockpot to recover it? It always makes me laugh when I see it in the bottom of the flask
Very cool! I wonder what you use for stirring the gold-silver melt. A carbon rod? You don't want any unnecessary contamination at this stage. Greetings from New Zealand.
A very interesting experiment. That zinc reaction looked really neat but I can see why you wouldn't use it except as a test as it sure left the gold bar at the end not as pretty as usual. 👍🏻
@streetips I've watched your explanation on why you enquart silver into gold but I do have a question! Once you are halfway through your HNO 3 boils, it is my understanding that the gold becomes more pure and less enquarted with silver. Would it be logical to deduce at some point the reaction would slow down because of gold becoming to pure? As demonstrated with your wedding band, the HNO 3 can't penetrated the gold because it is to pure?
That’s reflected in the color of the dilute Nitric solution as he progresses through (usually) 6 boils. The 1st time the solution becomes a very dark blue. By the 5th boil there is barely a tint of color. The 6th usually remains clear and and colorless, indicating that all of the silver and base metals have been removed.
The gold becomes more pure, but it is not solid like the wedding band. When its inquarted, and the silver dissolved away, it creates a honeycomb structure in the gold, tiny pores, so that the nitric can penetrate deep into the gold flakes. Multiple nitric rinses just penetrate deeper into the gold pores as the silver is dissolved. If that makes sense. Where as the wedding band is solid with no pores for the acid to enter.
I use sterling to refine gold. Cement silver is a by-product of my gold refining. I melt it, run it through the silver, harvest the pure silver crystal.
How do you ensure there is no nitric residue left in your cement silver? The forums I've seen seem to find it difficult to ensure the nitric is gone and they have a red cloud momentarily appear when the silver is melted.
"i've got some cemented silver here..." pulls out a 80kg tub of cemented silver..
Lol😅
Lol😊
Only Streetips😂 " 80kg of cement silver going in "
Where can cemented silver be found/bought?
The man is a trained professional. Never question his methods 🤣
I really appreciate you incourting the gold with the cement silver. I've asked you about it and now you've done it. Thank you so much
Great experiment Chief. My son and I love learning from you. Makes home schooling fun.
That was cool to see the zinc part just for an experiment. Thanks for keeping us entertained and trying different things so it's not the same video each time.
Thanks again for listening to the community and try the crazy ideas we are trowing arround sometimes. It's one of the thing I really appreciate about this chanel. You are close to us, take the time answer all our dumb, dumber and sometime not so dumb questions.
My spouse and I wish we’d have had this in HS chemistry, to follow along and balance out formulas during the process. I find your videos very relaxing and a great time to get my Nerd on. Thanks again!
I’m really impressed by you being able to experiment with an uncommon refining process and have it come out this well. Not perfect, but hey, we learned something, so thanks!
I would like to see him do a drop with electrolysis... it's similar to the gold cell but uses a carbon anode instead of gold, and the solution fades from gold-red to clear as it pushes it out.
Like this it isn't "selective" (anything that will favor over hydrogen can be/is pushed out) but it doesn't contaminate the "drop" (plating). In fact you can keep it completely out of the solution by putting a bag around it like the silver cell. The only thing that will appear in it will be trace carbon that may have agitated loose.
(Edit: Process is called "electrowinning")
That’s exactly what he’s doing, carbon would contaminate the metals
I loved the gold cell method.
Anyone else feel like any gold that doesn’t make it into the final yield directly affects you, like it’s your gold pouring into the waste container? Very engaging, I love watching
I've watched many gold refining videos, but your methods are far more comprehensive than others. Thank You!
Thanks for trying cemented silver!
How fast the zinc reacted --> I know it can be dangerous to work with and really isn't appropriate for industrial scale for several reasons, but DAMN if that isn't one of the coolest reactions I've yet seen on this channel!! The reaction just took off!!!
Bang!
That reacted with the zinc and dropped the gold out much faster and more dramatically then I though it would.i thought it was gonna take hours.very cool
I get it wasn’t as efficient but dang it was awesome to see! The bigger flakes vs a cloud. Really enjoyed this video.
Great and beautiful work ❤
I'm very interested in seeing how to remove the zinc from the gold! Thank you for making this so understandable and interesting!!
That bucket full of cement silver made me gasp and then smile from ear to ear.
Very interesting to watch. I could tell by the color of the precipitate that gold was contaminated. I was amazed at how it looked after the melt. It looked fake. It reminded me of gold I've seen in India, dull and plastic looking.
I read a paper talking about this, and they recommended using Zn powder, bubbling N2 through the solution and fixing the pH between 2 and 4. This was a process to create ultra high purity for microelectronics.
In my experience, zinc will follow the gold no matter how many rinses, acid or water, are performed. In order to get that zinc out I’m going to have to refine it out. Including inquartation. If I tried to dissolve that bar as-is, filter and precipitate, then traces of zinc will still be present and make an ugly bar. The only way to get it out is to inquart.
I worked for a big gold refinery in Australia for a while. There we would inquart the gold with silver and a bit of copper, and wrap it in a lead parcel. This was then put in a furnace on a special dish that would absorb lead but not gold, silver or copper. Once it would come out we'd be left with a silver coloured bead. This would then be beat into an oblong shape and fed through rollers that made it into a strip, there were a couple of annealing steps along the way to assist with this shaping. These strips were then coiled around to keep the surface area but reduce the space they would take up. These were then boiled in nitric to remove the silver. All this in fact was just to do an assay on any gold the refinery received.
With that in mind, thinking about your nitric acid boiling step, if there was any desire to speed it up and improve it, then some step to increase the surface area could be done. Since you do the step pouring the molten inquarted gold into water though, I guess that's the best and quickest way to increase the surface area. If you had some kind of press though, you could flatten these flakes to increase the surface area. Doing that though, I guess would increase the risk of a boil over with the nitric steps.
In the refinery in Australia we would receive gold from a variety of sources. We'd get prospector nuggets, things that people had found with metal detectors, these were always interesting shapes. We would also get a lot of Indian jewellery that was of high purity. We would also get nuggets from the mines, samples that they had extracted chemically then melted into nuggets of alloy that were of unknown purity at that stage. We'd also get various gold bars and coins from mints around the world, Indian tola bars, South African krugerrand's and so on. All were treated to the same initial step, weighed when they first came on site, then a small piece taken and an assay ran, and then the whole lot was added to the gold refineries main purifying process. The storage room was incredible, it was a room full of pallets of stacked 14kg gold bars.
I enjoyed working there, but it did get repetitive. It was officially a lab analyst job, but it felt more like I was a blacksmith, using a big hammer to pound the little beads into a perfect shape to be flattened and coiled up.
All the garbage was collected and reduced with high heat into a black crud. This was also assayed to see how much gold was in it. If the gold was above a certain amount, we extracted it, if it was below that but above a secondary limit...it was sent to Africa on a ship to be extracted! If it was below this secondary limit, it was just binned as normal garbage. Periodically the paint on the walls from certain places was also removed and treated to a similar process as the garbage.
I tried rolling Inquarted gold once. After a half hour I have up and just poured it in water. Rather let the chemicals do all the work.
@@sreetips Ah! haha! Sheesh. Yeah, the gold refinery had these special rollers, we'd roll them through it twice, then anneal them, and roll them again. I guess the difference with the refinery is that they wanted to get the gold at that stage to 4 nines or higher in purity for the sake of the assay.
Even though the zinc was not the best method it was great to watch.
Enjoy the different ways you refine gold, silver and PBMs. Goooood evening from central Florida! Hope everyone has a great night!
Goooood evening!
Yes Mr Sreetips. Plus, for poor rookie refiners like me, I can use selective separation by using Zn or Al. Being Al something that pops out everywhere in my house. If we run out of SMB or any other reason.
First, diluted NH3 boil
However as alternative you can use pure HCl with highly concentrated H2O2, no Nitric (it is needed extra care here because it is very likely not all Au will go in solution in the first boil).
Add small pieces of clean Zn or Al until everything drops.
You go selectively separating the metallic salt, first with HCl, clean, HCl with low concentration H2O2.
If Ag is present, after the first round of separation with HCl only, use in. 1:1 proportion high concentration HCl with NH4Cl, it will dissolve everything up to Ag.
There are intricacies and further refining is needed to achieve better purification and it there are PGMs present.
Just is just an abridged overview of this option if we lack of NH3 and SMB, or we want to save either or.
There is also another alternative that involves boil in H2SO4 and a follow up boil in H2SO4 + H2O2 (I used this method this week to recover gold from sundry integrated electronic components). Not talking to much because it is dangerous and most refining communities have banned either the topic or the topic and the person who raised the topic.
Points to consider: volume of waste generated, level of certainty that you do have all Au and up recovered.
At the very end when, supposedly, you have only Au (and PGMs) in solution, one boil with a bit of Nitric is recommended to ensure the leftover salt (please noticed I use salt very loosely to refer to precious metals in cement or powder state. Some of them are salt, other are not even close, just to make annotations easier when making annotations of the experiment in execution) is pure gold
Neither zinc nor aluminum are recommended for gold refining. They produce compounds that make the refining troublesome.
@@sreetips if we are within a controlled stage of the process, it should not:
Au + HNO3 + 4Cl -> AuCl4 + NO2 + 2H2O
And then we filter and add Zinc:
AuCl4 + Zn -> Au + Zn(2+ ionized) + 4Cl
Again filter, boil the pure Au with water a couple of times, then boil the pure Au with HCl.
There should not get outside this scenario.
We might want to evaluate the scenario of we have any known contamination during either equation. For the first equation, if there is Ag on the left side alone or alloyed, the right side is completely different.
For every other scenario I did not achieve any scenario where pure Au is extracted.
Also, I did not calculated the scenarios having PGM. There are ionizations I do not remember the expression (like with ionized Zn above which results in minus 2 electrons when exchanging places with Au).
@@sreetips well, just to make sure, gold i AR is gold(III) with the formula AuCl4- , however the - sign should be upper-script like the Z2+ and my phone does not have the feature.
Also, when Zn is added to goldIII), a redox reaction takes place. Zn acts as a reducing agent and reduces gold(III) ions to metallic gold as per the formula above.
@@sreetips just for reference, the formula for adding SMB to gold(III) is:
AuCl4- + 3Na2S2O5 + H2O -> Au + 3NaHSO4 + 4HCl
We have somewhat similar scenario if no contamination is present.
Wow! Always shows us something new. Thanks! 👍
I still highly recommend pouring into coin molds over bar molds, the coins just look better in a big pile, one of these days im gonna come across a nice wooden chest to drop em all in so i can do my blackbeard impression 😂
I like to use zinc instead of stump out because its way less fumes. It also depends on what I'm doing. I don't have a nice set up or fume hood so unfortunately everything I do is backyard buggie! Lol.
I'm going to build a tiny work shed because it gets so cold in New England that is hurts my reactions and things take so much longer because any heat used needs to be done super super slow so no glass or beaker gets broke. I love your channel Sir! You are #1 in Professional Gold Refinement Sir! Thank you so much for all you do! God Bless you & the Wife!🙏
Another great video! Can I just give one small critique. That extra light you've added is great and all but it's way too warm. Videos go looking from a nice pro garage lab setup to looking like someone refining gold in their living room. Not a big deal but I think a nice bright cool light would make a huge difference. Just my two cents anyway.
I wanted to mention a few days back how interesting it was that you added a watch in the background to see elapses wall-clock time on some of the sped-up clips. Nice touch !
I absolutely love learning new things.
This is one of the coolest precipitations I’ve seen on this channel! So freakin cool! I like the way you experiment, Sreetips. Keep it up! Keep playing and learning! This is awesome. 🙂😎👍
The way it sloughs off the zinc strip was BEAUTIFUL!
It builds up then falls off and more builds up etc...
I had no idea you could use zinc to precipitate gold!
How does that chemistry work i wonder? How many different ways to precipitate gold?
Reactivity series of metals
Fascinating!
That was a fun new video. Great job keeping the content fresh and interesting!
This was a great experiment. I'd never seen gold cement out on zinc before.
Love your videos Sreetips, they are very intriguing.
Happy Veterans Day, thank you for your service!
Thank you!
The contamination makes the bar look like galvanized gold!
Great video, Thanks for sharing!
This is the method that many prospectors use to precipitate gold from AR although it carries the risk of also dropping out other metals if not removed first.
An enjoyable experiment for sure. Zinc is highly reactive vs other metals. I enjoyed it. thanks for the content to learn and grow from.
You did that exactly the way I hoped you would every step of the way. Nothing at all to even be mad about. It was very very cool to see how that would work to try using zinc to cement gold, and I woulda been Kinda upset if you refined a third time because the curiosity in me needed to know if that would be at all a viable method of getting gold out of solution. I wonder if some sort of equation could get that process to work without any contimation. Like if you used the exact amount of zinc required and not a speck more, would the final Product be threw mines fine? I dunno but damn was that cool to see and especially how the zinc was replaced by gold so efficiently that the shape or the zinc sheet was still there only it was actually gold flakes that took its place. Overall this is one of the best and most interesting things about you, when you get some idea and try something just for the sake of trying it. You should try to do this anytime you have a curiosity about some aspect of refining, because it's just plain fascinating and not many people would have so much gold and so much equipment that they would be willing to satisfy these kind of random experiments for No reason other than childlike curiosity. One of the better videos in a long time and my one and only request would be a little less time-lapse, especially when you pour nitric boils into the silver jar. Watching that thick cloud of nitrogen dioxide erupt from the silver is one of my personal guilty pleasures and it makes me a bit sag to not get to watch them all. But that's just me, I get most people probably don't care about that so Much. Good work though. 👍
First 👍's up sreetips thank you for sharing 😊
These close up shots that you’ve been doing lately are great to see what’s going on in the beaker.
Thank you Sir for another great show.
It's amazing how much cement silver you have in that one bucket. Have you ever checked the purity of the cemented silver?
I wondered about the purity too!
It’s about 98% to 99%, the rest is copper.
Now that was beautiful, trying out the zinc was very interesting, and the results were impressive. Thanks for trying new things and sharing them with us, it's greatly appreciated.
I think "that looks really cool" is one of the best reasons for doing an experiment.
Agree!
Man that cement silver was a booger to melt. It is one of the most electrically conductive materials available and you can see how resistant it is as soon as it is sintered
Pardon my ignorance, what does electrical conductivity has to do with being melted with a torch?
I'm an electrician and older or larger electrical contactor switches have silver pads on their copper contacts, though I was always told that they used the silver because it doesn't stick when the electric arcs across the pads where if they were pure copper the contacts would basically weld together, whenever I would have to change a contactor I would hang on to the old ones and salvage the tiny bit of silver out of them, still have a couple mason jars full of those old contact pieces in my garage, the temperature probes they use on the giant furnaces in foundries have platinum wires in them also, us electricians would always argue over who got to change those out since the guy that changed it got to keep the junk one lol
God Bless You!
Hi Sreetips, have you ever fancied setting up an electrolytic cell for gold, as well as your silver? It would be great to see you set those up side-by-side, see how they run
Yes, I posted an electrolytic gold refining cell video last spring.
I would expect there is as much zinc contamination as there is copper contamination in cement Ag. Really appreciate this video - I have a kilo of zinc I've been tossing around an experiment like this with it. So, Cementing Ag for the cell it is. Maybe some PGM stuff later.
Awesome Video man as always. 👌👍👍👍
zinc dissolves completely in HCL so the rinses should have washed the gold completely clean
@@bruceneely4859 But not zinc alloyed with gold. Just as silver cemented on copper always carries some of the copper atoms with it, so will the gold. In Streetips silver cell, you can see the copper turn the electrolyte blue. Aqueous Zinc ions are usually colorless, so you won't see them -- but they're there.
@@guygordon2780 true you can never get it perfectly pure, but the major difference is both copper and silver dissolve in nitric acid whereas Zink dissolves readily in HCL but gold dissolves very slowly in HCL, so should get the gold pretty clean, I agree with Sreetips though this is not the way to refine gold.
Inquarting will be very efficient in my new furnace. I can adapt it to use all manner of fuels, and with varied internal heights, mounts for crucibles, incineration tubes, and I can even turn it into a pizza oven!
Just a simple loose brick chimney design, but with a few tweaks that allow quick and easy rearrangement to anything needed!
love your videos and how transparent and entertaining they are
You have incredible skills 👍 Thank you for sharing with us. Nice Work. God Bless 🙏
Zinc is a "dirty" metal. It is hard to keep it from contaminating a sample. Great video!
The zinc precipitation was really exciting to watch i was expecting a boil over when u put extra zinc in, another fascinating video 👍
*23:45** I should have been paying attention... what gas was produced?*
Probably hydrogen
@@sreetips Thank you. And thank you for your videos.
If it works so well could you use zinc for inquartation instead of silver or copper
Good question
Not recommended. It’s so reactive that it would cause the gold to crumble.
It is amazing 👏 cing all the different reactions that u do with the gold. Fantastic job 👏 👍 👌
Good old Merrill-Crowe makes an appearance on Sreetips! For many decades, before adsorption onto activated carbon became the go-to recovery option for gold in cyanide solutions in major gold plants, using zinc shavings and now zinc dust was the method used to precipitate the zinc from the low grade cyanide gold solutions. It is still used in mines who have a very high soluble amount of silver as well as gold in solution as the carbon can easily become overwhelmed with the silver and so you start losing gold. Fascinating to see it working so well from an acid solution -good job!
The flaky texture of the zinc precipitation is very interesting. I wonder how pure this gold is. It's not the usual powder texture of the stump out precipitation, but doesn't mean it's bad either. Would a nitric acid boil before drying the gold disolved the extra zinc in there?
Possibly
Just What I needed to wind down the evening, thank you Sir!
It would be interesting to see an analysis of the zinc precipitated gold.
Always fun to go out of norm to see different effects! Expanding experience and knowledge contributes to a better informed operation!
Always love your videos brother
There’s a smaller you tube channel where this Austrian guy goes and finds rocks to crush and get gold out of…he uses Zinc a lot because he tries to avoid acids and chemicals as much as possible. Fascinating stuff.
Name ?
Interesting! Zinc did not work to bad and the precipitation looked cool but so2 gas is obviously the way to go, the
result you get from just adding SMB to the gold solution probably gives the best complexity to result ratio. :-) Seemed
like the cement silver worked ok though, in case you dont't have any sterling silver it is perhaps better to use that to inquart the
gold and use the copper to cement out the silver rather than to inquart the gold.
Fun to see you experimenting with different ways of refining.
Big thumbs up!
It seems that the cement silver took much longer to melt? I did like that you charred the top before adding the second flame so you didn't blow the powder out of the melt dish!
I dont know why and this is probably weird af, but my favorite part of these videos is when Mr Sreetips says "sodium metabisulfate" lol
You'd mentioned this.. I was curious to see it happen. This is the same process I was looking at with doing with copper, as this will eliminate everything above it... my only real issue with the zinc is that it will drop other metals from it down, decreasing purity
Thank you sir, could watch you work everyday.
It was fun to watch gold come out of solution on zinc like silver comes out of solution on copper. Fun experiment.
I think the greatest advantage from using fresh nitric acid boils is that contaminants are removed quickly, instead of remaining in the beaker until all the non-gold metals are dissolved.
Agree
That was amazing. Thank you.
It was cool to see it with the zinc to bad it contaminated it. Great video your getting better and better!
As much metal as you melt you need a small forge.
It would be interesting to see the inquarted silver be cemented out and then be used in other inquartations. (Noticing along the way, the amount of loss in the process.) Thank you for the great content.
I should have pointed this out in the video: using cement silver, over and over, to inquart gold is not recommended because PGMs will follow the silver and build up in the silver.
@@sreetips Good to know. Thank you.
@@sreetips Does that pose a problem for future gold refinings or for the eventual silver refining?
PGMs built up in the silver could cause problems in the silver cell.
@@sreetips Thank you!
Just keep adding zinc and hydrocloric and it get it all out oh you did your awesome screetips i love you man
Another nice video, Sreetips. Question: at certain steps in the refining process, you add a few ml of sulfuric acid to drop out any lead. How would you proceed if it actually dropped out some lead?
He adds the Sulfuric acid in the step right before a filtration. The lead precipitate will be caught in the filter.
So any lead sulphate won't redesolve in the aqua regia?
Filter it out before precipitating the gold
Your work is always impress ☺☺
Great video! ❤ the process.
Incredible work brother
Yess!! I've been thinking about this for months and now i see you trying it! In principle it should work given the difference in reactivity of the two metals. I am very curious about the composition of the ingot and what exactly contamined it, can you do an analisis on it? 🙏🏻
I just saw the short you uploaded, it looks like you already dissolved it 😂
Zinc
neat experiment, but unfortunately zinc ions would be trapped in the gold precip during the exchange. Might be fine for a preliminary precip, but not the final.
thanks again for your fantastic video ,i would like to ask when you transferred the solution to the larger baker to participate with zinc , was the heater ( heat ) on ?
ty for replaying.
No
You really deserve to have one XRF instrument to substantiate your experiments with quality purity tests.
They cost as much as a used car. Six years ago to rent; $1500 per week, $4500 per month. Includes a “courtesy” visit from local authorities to ensure proper use.
@@sreetips I know, but you deserve it , nevertheless 😁
I only wish that I could afford one.
You are welcome. Well worth the minor contamination to observe an alternate method of precipitation (not to mention inquarting with cement silver). Thank you Sir!👍👍🤟
Great content as always! Is there a reason you don’t precipitate with smb directly in the vacuum flask?
Just a guess, but I would venture to think it's much easier to get the gold out without having to use an excess of water to get it out. The use of ice to cool the gold bearing solution. easier to get a status check. It is easier to add smb through a larger opening. Or it could simply be personal preference. It's a good question, I wonder myself.
The conical shape of the flask makes it difficult to retrieve the precipitated gold.
I can’t understand why you don’t pour all the solids in the Gold Refining Waste flask into the stockpot to recover it? It always makes me laugh when I see it in the bottom of the flask
You’ll see why in my next video
If I found a bag full of that brown gold dust I'd think its dirt or soil and throw it away...
Wow that's awesome 💯
Man those time lapses are so cool
Does the zinc dissolve completely
Yes
All you videos are informative. When you have the silver in liquid how or can you get pure silver back as a metal
Watch his silver electrolyte cell refining process videos.
I add clean copper to the silver nitrate and cement the silver out on the copper.
Very cool! I wonder what you use for stirring the gold-silver melt. A carbon rod? You don't want any unnecessary contamination at this stage. Greetings from New Zealand.
Hello New Zealand it’s a graphite rod
A very interesting experiment. That zinc reaction looked really neat but I can see why you wouldn't use it except as a test as it sure left the gold bar at the end not as pretty as usual. 👍🏻
And it’s hard to get it all out.
That was fascinating !!
It was pretty amazing to watch the gold precipitation with zinc, who or what gave you the idea to do it this way over the SMB?
Curiosity.
@streetips I've watched your explanation on why you enquart silver into gold but I do have a question! Once you are halfway through your HNO 3 boils, it is my understanding that the gold becomes more pure and less enquarted with silver. Would it be logical to deduce at some point the reaction would slow down because of gold becoming to pure? As demonstrated with your wedding band, the HNO 3 can't penetrated the gold because it is to pure?
That’s reflected in the color of the dilute Nitric solution as he progresses through (usually) 6 boils. The 1st time the solution becomes a very dark blue. By the 5th boil there is barely a tint of color. The 6th usually remains clear and and colorless, indicating that all of the silver and base metals have been removed.
The gold becomes more pure, but it is not solid like the wedding band. When its inquarted, and the silver dissolved away, it creates a honeycomb structure in the gold, tiny pores, so that the nitric can penetrate deep into the gold flakes. Multiple nitric rinses just penetrate deeper into the gold pores as the silver is dissolved. If that makes sense. Where as the wedding band is solid with no pores for the acid to enter.
Fascinatingly awesome sreetips 😮 can one purchase cement silver or do you have to make it yourself? I'd defintly would buy some
I use sterling to refine gold. Cement silver is a by-product of my gold refining. I melt it, run it through the silver, harvest the pure silver crystal.
I’m not selling any silver, I’m buying.
How do you ensure there is no nitric residue left in your cement silver? The forums I've seen seem to find it difficult to ensure the nitric is gone and they have a red cloud momentarily appear when the silver is melted.
First, I heat the silver nitrate with undissolved sterling silver to consume excess nitric. I still get a little red gas from time to time.
I'm sure you've probably said it in a video before but would the reaction be much slower or would it not happen at all without adding the heat?
I didn’t add any heat for the zinc reaction.
@@sreetips I meant with the acid baths if the heat is just a way of speeding up the reaction or if it won't react at all without the heat
I see, hot acid will dissolve metals much faster than cold acid.
Such a cool process to draw the gold out of the solution . 👌👍