The white precipitate is Ag2SO4, which is poorly soluble in water, but very soluble in concentrated H2SO4. As soon as you diluted the acid, the precipitate formed. That precipitate contains most of your silver. You can either try to dissolve it into a huge amount of water, or you can put about 500 ml of distilled water and NaCl and stirr. Because the Kps (solubility product constant, Ksp (AgCl) = 1.7 x10-10) of AgCl is much smaller than that of Ag2SO4 (1.2⋅10−5), an exchange will happen as the equilibrium is displaced to form 99.99% AgCl in the precipitate. You should be able to recover your silver after that...
Great content as always! I thoroughly enjoy gaining hobbies and enjoy it even more when I can learn from others' mistakes! Thank you very much for putting your experience online!
My favorite part is when he shows his lunch. You should have said, "I add in the 50 ml of dilute acetic acid to the 100 ml of olive oil, give it a good stir, and add it to my lunch". (acetic acid is vinegar) ps. I get the feeling he is subtly flexing on us by showing off his watch.
I had to do a Google Lens search. Omega Constellation in yellow gold? Pfft. I'm not going to wear anything on my wrist that has a higher street price than my hand! Totally feel you about the lunch.
Learning more and more every day! Thank you! You know that silver bar being stamped "reetips" is a mint error. It will be rare and sought after one day. Just subscribed to tomoko's
This is a fantastic resource, thanks Sreetips, definately a thumbs up and saved to my refining playlist! Now if only there were a way to do something similar with gold... 🤔
Thank you. I’d like to develop this a little more to get a good yield. I think it can get just as good yield as nitric can. Just have to tweak it some.
That was very cool! I don't know why it smoked so much when I just tried it... but it was an amazing amount of smoke. Totally overwhelmed my ventilation. Just a word of warning to everyone else! I don't know if my silver was that dirty, or the drain cleaner was that old... but it turned black as night and smoked for 2 hours. Then it went white as snow when I added it to the distilled water after cooling down. But 2 hours of nasty bad, very dangerous smoke... be warned! Thanks again Sreetips!
Interesting method, I had not thought of this approach before, thanks for sharing. . As a chemist, regarding the precipitate: I can think of two possibilities: (1) silver sulphate is actually only moderately soluble in water. (0.83 g/100 mL at 25 deg C, and only 1.33 g/100 mL at 10 deg C), and much more so in concentrated sulphuric acid. So: one possibility is that the white precipitate is silver sulphate that crashed out of solution when you diluted the sulphuric acid. In that case, your yield can be much improved by using (a lot) more water, so that all the silver sulphate stays in solution. I think this is what was meant in your textbook by 'a considerable amount' of water. Note also that without stirring, the dense sulphuric acid solution will tend to settle in a layer on the bottom, and stirring or swirling after adding all the sulphuric acid may cause the solutions to mix and heat up suddenly. I would advice stirring while pouring the sulphuric acid into the water. (2) Another possibility I can think of is that the precipitate is lead sulphate. It is soluble in concentrated sulphuric acid, but very insoluble in water or dilute sulphuric acid so it would crash out when you dilute the concentrated acid. However, I don't think lead is a common component of silver alloys, and the candleholder doesn't seem to contain many (if any) soldered joints, so the amount of precipitate you observed seems to be too much for it to be lead sulphate. So, my money is on hypothesis nr 1. Would be interesting if you could figure out what the precipitate is and let us know.
You sure come up with some great ideas. What a sweet wee bar.I must have had at least a dozen new subs mentioning you sent them today and a bunch over the last week since your last post. Thank you very much my dear friend.
Yup. This is why the Hoke book said to dilute it in AMPLE quantity of water. Solubility in water 0.57 g/100 mL (0 °C) 0.69 g/100 mL (10 °C) 0.83 g/100 mL (25 °C) 0.96 g/100 mL (40 °C) 1.33 g/100 mL (100 °C)[2]
@@AirForce15A No... instead not enough water. the oversaturated solution when being poured into the water still resulted in a total amount of silver sulfate that was more than his 700-odd (and later 1200-odd) ml of distilled water could hold, so it precipitated out.
@@brandonmccullah710 That test must be done in neutral or basic pH. An acidic solution will simply neutralize the ammonia. I usually run this test with 25% NH4OH, which tends to force the pH >7.
Well Mr. Sreetips, as far as i know, the silver sulfate is little soluble in water, just like the silver chloride (maybe a bit more soluble than the second one). So, when you took a concentrated sulfuric solution and diluted it on distilled water, part of the silver sulfate precipitaded out.
WOW WOW WOW 🤯🤯🤯 THIS HAS TO BE ONE OF THE BEST VIDEOS IVE SEEN IN QUITE A WHILE 😎👍🏼👍🏼👍🏼 Wish I had a set up like yours..... I'd definitely be doing this for myself.
Thank you sreetips. In norway its not legal to own nitric acid for privat use. I really wanted to try refining silver at home and you showed me a way. Cheers.
Thanks for showing your lunch (in addition to all the interesting chemistry as usual). One of the great things about the personality you show in these videos is that you exude personal discipline.
John, the misdeeds of a few ruin it for the many. I bought the concentrated sulfuric acid drain opener over the counter at Ace Hardware. Same with the lye. Sugar and sea salt at the grocery store.
The precipitate you're getting might very well be silver sulfate, which is soluble in sufuric acid, but poorly soluble in water. That's why it came out of solution when you diluted the acid. You can turn the solid silver sulfate into silver oxide just by mixing it thoroughly with sodium hydroxide the same way you did with the silver chloride.
Really? I had no idea. I just did a video on getting the silver chloride from the sulfate. It's uploading right now. If that's the case then a totally new video is in order. I'll do side by side refinings of some sterling flatware. One in nitric and one in sulfuric. Max yield from both is the goal. Oh well.
@@sreetips I am an amateur at best, but I immediately thought of what craoun said. My thinking was, the sulfuric was still 44 degrees c, when it hit the distilled water, the colder temperature combined with the fact it's water forced some silver out of solution.
2Ag + 2H2SO4 ---> Ag2SO4 + SO2 + 2H20 Ag2SO4 is hardly soluble in H20 at room temp. So that precipitate is going to be Ag2SO4. You need to heat to 100degC for a solubility of 1.33g /litre. You could thermally decompose the Silver Sulfate. Ag2SO4 + Heat ---> 2Ag + SO2 +O2
@@johnlintorn6768 i am searching for a source that can teach me the chemistry behind everything. It seems what you said is what I said, just exhibiting a much greater understanding of the material. are there any books on the subject that you've read that you felt helped everything 'click' together? I would like to start a dialogue with you about a few roadblocks I have hit. If you are interested and can provide contact information, it would be greatly appreciated
When you pulled out the book to show your facts is when you had me sold. Thanks for the video. im about to refine 13.8 pounds of silver plate. ill be refering to your video alot.
I didn’t use silver plated material, I did this experiment with solid sterling silver. If you use silver plated material then the yield will be very low. My guess is not even an ounce of silver from 13.8 pounds of silver plate. Plus, a lot of toxic sulfuric acid waste that must be treated prior to disposal. Hot sulfuric is very dangerous. It will burn a hole in your skin if any gets on you. One guy reported that it makes an open wound, very deep, that doesn’t heal well even after thinking all the acid was rinsed and washed away. The risk is too high to try this on silver plate. Especially if you’re new to this. Not a good place for a beginner to start.
Solubility of silver sulfate is about 1 gram per 100 ml of water, 1.3 liter could hold about 10 grams which is consistent with the resulting button. Take the white salt that crashed out of the sulfuric acid and boil it in another liter of distilled water, then test it with some chloride salt. I think you will be surprised.
1.33g per 100ml at 100C. Thanks Goran, had to look it up. I figured some of the silver got hung up in that precipitate. Plus, it too is light sensitive.
@@sreetips Yep, and only 0.96 grams at 40 degrees C. That precipitate is almost 100% silver sulfate., with probably a trace of copper sulfate. Copper sulfate has a much higher solubility in water, so very little of it will precipitate during the dilution step. It might be easier to just pour off the mixed metal solution and just dump it into your stock pot. You could then continue the processing with the almost pure silver sulfate precipitate.
Great work!! Your are hands down my favorite channel! I have literally tons of old misc electronics. I wanted to start processing stuff but I don't have a fume hood and I'm super freaked out with dealing with nitric acid. I have a liter if nitric but I have not used it yet due to not having a fume hood. I was thinking of building a tiny shed out in my backyard so I can turn it into a lab. The only thing is it get so cold in the winter months. I'm still a newbi but I'm trying really hard to be good so I want to make sure I have all my ducks in a row before continuing on. The other problem I'm having is because I'm not processing any old electronics so they keep piling up. I was wondering if by chance you could do a video to demonstrate an inexpensive way to get started?
The precipitate is silver sulfate. It's poorly soluble in cold water, about 8 g/100mL, goes way up in solubility to around 80 g/100mL in .10% molar sulfuric acid/water. Adding a small amount of sulfuric acid to the beaker and hearing it would have dissolved most of that white stuff.
What really made me happy was doing the experiment before hand without that pesky camera looking over my shoulder. I think this made for a better video because I knew what to expect. Many of my videos are shot in the raw; you're seeing me do it for the first time ever with out any knowledge of what to expect.
Did you ever discover what the first strange precipitate was.thank you for your teachings I have studied hard and have my own lab now and am processing my gold from my lode claim I owe it to you.listen to this man if you want to learn how but you have to put in much effort and study.
lol, so last year I played around with silver in nitric acid then winter came. I learned what happens when silver gets to cold when dissolved in nitric acid. I figured that sulfuric acid considering how hot it gets would give me a better result than it turning to silver Nitrate crystals,,,, I was wrong, lol, but it was fun and interesting figuring out how to fix it so now I’m done for the year till it’s warmer. Thanks sreetips!
Too bad you didn't weight the initial amount of metal you started from. If you aim is to recover silver, you should keep the first white precipitate... what is mainly Ag2SO4. It is possible that Ag2SO4 is quite soluble into the concentrated H2SO4 by complexation or due to the lack of water, but crashes out of solution when dilluted. Copper sulfate remains soluble and this is observed all allong your process. To me the use of NaCl to make HCl via in situ reaction with H2SO4 and precipitation of AgCl is useless... You can start immediately from demi-water washed solid Ag2SO4 to the next step. Ag2SO4 (s) + 2 NaOH (aq) --> 2 AgOH (s) + Na2SO4 (aq) 2AgOH (s) --> Ag2O + H2O (via heating) C6H12O6 + Ag2O --> 2 Ag + C6H12O7 (gluconic acid as Na gluconate) (via heat and basic NaOH media). I hope this will help you increase the yield, efficiency and reduce the wastes. PHZ (PHILOU Zrealone)
That is a good reply. I am trying to figure out a process where I can use easily available chemicals for recovering some silver plate. You say the copper sulphate remains soluble and this is observed all along your process. How is that being observed? In your method you say.... 2AgOH (s) --> Ag2O + H2O (via heating). Do you simply melt the solid with heat and the water comes off as water vapour? From reading your reaction I guess that is what the process is. I presume the silver oxide could then be added to the silver oxide he precipitated out from the rest of his solution before the conversion to silver metal so all of the silver is recovered. I am wondering if the sulphuric acid and silver reaction would work if the sulphuric acid was less concentrated? I have about 10 litres of sulphuric acid I recovered from scrap batteries and wondering if I can use it. I realised this morning I have a battery hydrometer so can measure its density and maybe give me a clue of its concentration.
@@parcydwr Hi Robert Smith, thank you. The Cu (copper sulfate - CuSO4.xH2O is blue like Cu(2+) what is dissolved ion (into water)... the dehydrated form is white and recolor blue as soon as it catches moisture from the air or liquid water). That color is observed into Sreetips video process into the collecting "recycling" drum. Copper is often joined to Silver to make harder and cheaper alloys. Silver and copper are two "precious" or "near precious" metals and they display a special property to have a high oxydation (électro-)potential... as such they oxydise their ion against glucose if hot and in presence of a base (oxydoredox potential can express in acidic (H(+)) media or basic (OH(-)) with different processes and results... In the present case copper sets a characteristic precipitate of Cu2O red (or sometimes a copper mirror) and silver a characteristic mirror or grey powder. In general aldehydes (reductible) can react to form the related acid... here gluconic acid. Ag(+) + 1e(-) --> Ag(0) (silver mirror or dust) Cu(2+) + 1e(-) --> Cu(1+) (like into Cu2O see Fehling test for sucrose/aldoses) Cu(1+) + 1e(-) --> Cu(0) HO-CH2-CHOH-CHOH-CHOH-CHOH-CH=O --> HO-CH2-CHOH-CHOH-CHOH-CHOH-C(=O)-OH (here only the aldehyd group is oxydised to a carboxylic one and it passes from +1 oxydation state to +3 oxydation state) The AgOH turns into Ag2O suspension/precipitate from "maturation" (concentration and heat of solution). Paradoxaly Ag2O is specifical as it is not wel linked to its oxygen and it will set it free upon heating to live "native" silver and pure oxygen... this happens also with Gold whose oxide is also unstable and even explosive (set O2 free explosively from heat). 2 Ag2O -heat-> 2 Ag2 + O2(g) I will reply a bit further/deeper later about the process of Sreetips soon. PHZ (PHILOU Zrealone from the Science Madness forum)
XRF would give you a definitive answer, but that white precipitate has to be either (1) a contaminant in your sulfuric acid, or (2) a salt of one of the metals from your sterling, so a silver, copper, tin, etc sulfate / oxide/ hydrate. Likely contaminants in drain cleaner sulfuric acid include a corrosion inhibitor like Rhodine 31A, which can crash out when neutralized (you might try pouring a few mL of the acid into 10 mL of water and see if you get a similar precipitate volume). Silver sulfate is a white salt that is barely soluble in neutral water (1.3g/100mL at 100C), but it's light sensitive like silver nitrate, and the missing silver's mass would show up if you can get a yield on one of those runs. Most copper sulfates are vivid blue and highly soluble. Tin, nickel, cadmium, or zinc sulfates all seem too soluble (33g/100mL, 65g/100mL, 76g/100mL, and 57g/100mL respectively). A tin or zinc oxide seems like a possibility too, depending on the sterling.
it is best to let it cool first for one main reason, pgm's can turn to sulphates and drop back out when it cools. Pgm sulphates can also precipitate upon dilution. I've experimented with this and its interesting. Pgm's will also drop out fully when adding sodium chloride. It can get complex very fast, but a great cheap way to remove base metals from a large bulk of material. Most interesting part is the copper will be attacked last if pgms are present, all noble metals seem to go up into solution first which yields some really clean pour offs early in the process. You say large amounts of waste, ehh depends on how crazy you get rinsing otherwise waste amount isn't so bad after you filter copper and other base metals off using iron, just don't forget your zinc and iron after neutralizing the acid. However you can recycle the acid if you're clever and it greatly reduces waste other than rinsing. i've found it to be a useful method as well to separate say rhodium from platinum or ruthenium from palladium.
The problem with dumping the sea salt in without dissolving in water first is that it will also force precipitation of some of the copper sulfate. Also, once the silver chloride is precipitated, you should test the blue liquid to make sure all the silver has been precipitated.
Good to see some fresh content. I believe the white precipitate was just some silver sulfate dropping out of solution after you had lowered the ph by adding water. You may need to use more acid, dilute less or simply drop the chloride out before dilution. It should redissolve in hot water tho allowing you to convert the rest.. Id be interested to see if it works with diluted sulphuric or with drain cleaner containing inhibitors as this is what the public can buy in the UK (where Nitric is hard to source).
I think sulfuric can be concentrated by boiling, but I've never tried it. I tried dilute sulfuric on some cement silver once and it did not do well. That's what struck me when I read the book. I had never tried concentrated sulfuric, only dilute and it was a bust. But as you can see, sure enough, hot concentrated sulfuric will dissolve silver. I had people who find it difficult to get nitric in mind when I did this experiment.
i just want to informally say thankyou, for your knowledge , your kind demeanor, your excellent video quality and your no-nonsense constan commitment to science. Everything I have learned I have learned from you. my girlfriend and i joke around about you all the time. WWSD
@@sreetips do you believe its a good idea to buy one of those melted down computer pin bars that are 300grams for 45 $ on ebay to practice purification?
Those bars are most likely 99.9% base metals with only .1% Au. That wouldn't even yield you your $45.00 Back you spent on it. Including the cost of chemicals you would need to refine it. :)
That white precipitate is silver sulfate ;). It tends to only wan't to dissolve in concentrated H2so4, once diluted with water the solubility goes down.
That’s silver sulfate falling out of solution. It’s solubility in cold/room temperature water is fairly low, no where near the solubility of silver nitrate. Bringing it back up to boil should bring all that back into solution, then while it’s hot is the time to do the chloride drop. If I remember correctly the solubility at 100 degrees C is about 1.5 grams per 100ml of water. Whereas in cold water it is about 0.4 or 0.5 grams per 100ml.
Back in the day, I used to work in a photographic mini lab. We were told that our depleted chemistry contained silver from all the 35mm films that had been through it. The value of that silver helped to pay for the processing of the used chemistry so it could be safely disposed of. It'd be great if you could make a video to show how much silver can be extracted from the chemistry and the process for doing it
My guess for the white precipitate on crashing with water would be silver sulfate. Sterling is usually just silver and copper and the copper sulfate is probably pushing it out of solution as the temperature drops. Hope you didn't throw it out :)
I have a fun challenge for you. High purity Bismuth! Many places that sell Bismuth seem to claim 4 or even 5 9's but if you try and grow bismuth crystals they may either never form properly or be gray and dull in luster. I tried this myself and so far it seems electrolysis is an option but it is soooo slow.
The precipitate is silver sulphate powder. Silver sulphate is insoluble in water and the dilutuon of silver sulphate and sulfuric acid in water causes the silver sulphate to precipitate out somewhat.
Start small to get the feel for it. Resist the urge to go all in with a hundred grams of karat gold. Instead start with just five grams to see how it goes.
Mr sreetips you made my day!! I have a pile of ~7Kg of scrap silver without processing because of the difficulty to find Nitric Acid around here and the online options being expensive to the extreme. But Muriatic and Sulfuric I have Gallons and Gallons and Gallons. Depending on how cold it gets today, I will start my batch. My only concern is with the quantity of silver I have and optimize the process. Possibly I need one extra waste bucket before I start to avoid surprises. THANK YOU
Be prepared to deal with that precipitate. It ties up some of the silver as silver sulfate. Insoluble in water. Plus roll the pieces of silver very thin and cut them up before putting in concentrated sulfuric. Thick pieces of silver will probably take a long time to dissolve. Don't boil sulfuric in the kitchen. You'll fill the air with the stench of sulfur!
sreetips thank you!!! Have you found what is that precipitate at the end? Did you process it somehow? I have my shop/lab for my computer sciences and metal experiments 😊
A shortcut I'm experimenting with right now is adding Spectricide stump remover (100% Potassium Nitrate) to the sulfuric acid solution and heating it. The mixture creates nitric acid in-situ and seems to dissolve the metal (copper and silver out of scrap jewelry) exactly like commercial nitric acid. So far, so good. We'll see how the potassium bisulfate follows the silver through the process and if it messes up the silver or gold. Perhaps you'd like to try this experiment with your setup.
I’ve never tried this, but if it works and everything dissolves (have to filter out solids with a micro fiber glass filter due to sulfuric with dissolve a paper filter) then the silver can be precipitated by adding hydrochloric acid (carefully because it reacts violently with sulfuric) to precipitate out the silver chloride. Then the silver chloride can be converted to pure silver with lye and sugar.
I think your unknown white precipitate (11:00) is Lead Sulphate, Strangely enough Lead Sulphate is extremely insoluble in water which is why you use sulphuric acid to protect from lead contamination, but lead sulphate is fairly soluble in concentrated sulphuric acid. I had a bunch of PbSO4 contamination forming crappy suspensions and gels in a batch of copper sulphate i'd bought.
I've seen other youtubers "purify" silver plated items through electrolysis. Their final products look like they have a large amount of copper impurities. However, I think that might be a good starting point for using this process with a lot less volume and a lot less waste. I think it might be a good idea for another one of your videos to follow up on the video you did last year on refining silver plated items.
I've got a tube full of silver plated stuff. I'm saving it for when silver gets up around $100. But I could break some out and do a video on it with these chemicals. Good idea.
The low solubility of your silver sulfate is being aggravated by the common ion effect. There is quite a bit of unreacted sulfuric acid and copper II sulfate in your solution. H2SO4 and CuSO4 are much more soluble than Ag2SO4. The water becomes so saturated with sulfate ions that it can't solvate any more. This pushes the solubility equilibrium of silver sulfate far to the left and crashes out Ag2SO4. The precipitate is very pure silver sulfate, which you might be able to take directly to silver oxide with NaOH. If that works, you might consider crashing out all the sulfate by adding an excess of sulfuric acid, filtering, then going straight to the lye step.
White precipitate when you dissolved silver in sulfuric acid is silver sulfate, it is slightly soluble in water. Silver hydrogen sulfate was soluble in sulfuric acid but when you diluted, equilibrium shifts and almost insoluble silver sulfate is formed so you technically discarded most of the silver.
@@jameseves9209 Nothing. Simply do not use sulfuric acid. Use nitric acid and precipitate silver with copper metal. You can recycle both copper metal and nitric acid from Cu(NO3)2 byproduct with sulfuric acid and aluminum metal. Also, this way of getting silver from silver chloride is not very efficient. It's much better to put sodium hydroxide with silver solution to precipitate silver hydroxide which turns to oxide and then pure silver, when heated. But here you cannot do it because raw silver contains base metals like copper so hydroxide will be contaminated so best way is definitely precipitating Ag with Cu from AgNO3/Cu(NO3)2 mixture when you dissolve raw silver in nitric acid
Typically I make a salad dressing from Acetic Acid, Sodium Chloride, Piperine and Oleic Acid. Use a 3:1 Ratio of Oleic to Acetic Acid, then Sodium Chloride and Piperine to taste. Yummy.
I believe the Silver is on the bottom at when you poured the silver nitrate and copper nitrate into distilled water. Since it's more heavy weight than copper and water. When molecule weight is higher than 100. The molecules as Silver of 107 are heavy weighting. Copper will just float in the water. The ending result gets blue color as only copper. But as copper and silver in nearly same is like the same as green and blue. But silver in bottom make only copper look blueish, when copper is green with Silver. But both can make either what they represent. So green solution has more likely copper and silver. But both can be sometimes either blue or green. But what Silver acts as color is gray. As in the second solution with the mixer. You don't know it before you pour copper and silver which is used as alloy together. There is actual strange difference in the color blue and green. Both don't make yellow color. But they make their dark green and dark black blue which in logic can't make yellow. But as soon it either is blue or green dark. Having only darker colors. You should try as well to find out easiest way for copper refining. Many people would be interested in 100% output refining. You nearly where there. So best solution is really to take out the water of blue into other compartment. As silver lies in the bottom. What you had when you first dissolved with sulfuric acid was platina and in the bottom as very darkish collection. Might as well be titanium or other metals as gold. But palladium is clearly short the same molecule weight. Since nature make palladium first as halving to Silver. If there is no escape of energy palladium stays in the mountain. It is short lived. The molecule weight represents important information. I believe you know much. But you might not know everything yet?
