Silver Recovery From Computer Keyboard Mylars
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- Опубліковано 5 жов 2024
- In this video I attempt to recover silver from a bunch of scrap computer keyboard mylars sent to me by my friend Rick in Georgia, USA. These e-waste keyboard mylars have silver traces and contacts. How much did I recover from them? Watch and see. Please visit the Urban Gold Mining section of my web site at mdpub.com/Urban... for more information.
Chemicals used in these videos:
Nitric Acid: xelexo.net/ind...
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you'll know when you've added too much sugar when you start getting clumps of melted sugar with silver in it. The best way to release the silver is using boiling hot water rinses. room temperature water will work, eventually, when all the melted sugar dissolves. I just did this yesterday! I always boil the silver in HCL to clean it up to a nice light grey color before I melt it.
Good Morning Mike, Excellent video! Your timing is spot-on! I've had 150 mylars soaking in a bucket for 3 weeks. Hope I get an ounce of silver!! The next batch has already been cut in half. Still have 8 pounds left - been saving them for 10 years. Thumbs up! Have a wonderful 4th!! Stay safe. Jim
What a nice result, way better than I expected!
Much better than what I expected too. I was worried I had wasted a week and a bunch of nitric acid.
Excellent, that was a very worthwhile experiment and good yield. 👍
Cool vid! I bet even an office paper cutter would’ve sliced those pretty well! Almost an ox too, awesome
Nice 👍
I can’t wait to process mine. I probably have a least that many in a tote.
Cutting them up or shredding would definitely save on space and liquids.
I have a huge pile of those. Just waiting until I retire.
Didn't expect so much silver. Wow.
Neither did I.
It helps to cut the mylars into 1-2 inch wide strips. The mylars have a thin layer of plastic sheeting between the upper and lower mylar, on laptop keyboards. I was curious if the acid would melt the glue that binds the 3 together or not. It does not unless I cut them into strips. I increase my yield by about 30-40% by taking a few minutes to cut them into strips. I went even further cutting the strips into lengths of about 6 inches. I can get more in a bucket too.
I saw a video of burning the mylars but I think my neighbors would have a fit
Great video , I’m saving all my keyboard Mylars when I scrap them out and see how many I have in couple years
To get the highest profit out of processing Computer Keyboard Mylars, the smallest possible quantity of chemicals and the least amount of time spent must be taken into consideration, as well as always extracting ALL the values of any raw material. My main turnover is sales of various recyclable plastics. Every year I process tons of PET plastic; exactly what Computer Keyboard Mylars is made of. However, even after silver removal this Poly Ethylene Terephthalate would still be too contaminated for sale, so the solution is: Pyrolysis. Never burn any kind of plastic, it's illegal! The pyrolysis process emits no smoke and no toxic fumes.
Now a bit of a warning. Everyone will say that you must not pyrolyze PET, and you must sort mixed plastics intended for pyrolysis while taking great care to remove any pieces of PET. This is certainly true for amateurs, but I use an advanced pyrolyzing method. The problem is that the Terephthalate will sublimate, meaning it's one of those compounds that cannot exist in liquid form. Upon leaving the pyrolysis reactor in gaseous form it will immediately crystalize at the slightest cooling of the vapor, thus clogging the pipe leading to the condenser; inevitably resulting in a dangerous pressure increase.
One of my four pyrolysis units is built for pyrolysis of PET and PBT plastic. It's a two stage system with an insulated second chamber where the Terephthalate is converted at 700 C back to Benzene, a very useful hydrocarbon for fx. solvent extraction and numerous other uses (fx. size reduction of EPS, Expanded Poly Styrene). The raw pyrolysis oil from this process contains on average minimum 30% Benzene, which is distilled off at low temperature, and the rest is later cracked into free petrol/gasoline, diesel for my truck, and fuel oil for my metal melting furnace.
Computer Keyboard Mylars are pyrolyzed as soon as 50 kg is accumulated, separate from other PET/PBT plastic. When the process is completed the pyrolysis vessel contains beside the silver also a lot of black carbon. Despite having an unlimited supply of Nitric Acid at no cost (homemade from natural nitrates) I always use the smallest quantity of acids needed for chemical reactions, thus avoiding to spend more time than absolutely necessary when processing waste liquids for acid recovery and extraction of spent chemicals for reuse. Therefore the carbon is removed by calcination over open flame in a cast iron pan. Membrane filtered oxygen rich air is blown into the material at very low pressure via a quartz glass tube to assist conversion of carbon to CO2. Size reduction of the silver bearing material equals much less Nitric Acid to be consumed. Boiling point of silver is 2162 C so no silver is lost during the calcination.
For many years I converted silver chloride to metallic silver using glycerine (byproduct from my bio diesel production) and homemade Sodium Carbonate (instead of NaOH). No expenses for sugar or lye.
To avoid the tedious process of washing the metallic silver powder after the lye/sugar treatment, you can skip the entire conversion process and go another way. Silver chloride is different from most other chlorides, when heated it easily decomposes to metallic form and chlorine gas. Unfortunately, chlorine is a deadly gas so you need a closed stainless cylinder with an acid resistant pipe leading the chlorine gas into a beaker with ice cold water. Bobbling the chlorine gas through cold water will recover >99% of your HCl to be reused again and again. I always take care to distill off all excess acid from liquid solutions, before further reactions; not only for acid recovery but mainly to reduce the waste destined for later processing (acid recovery and extraction of chemicals for reuse).
Contrary to the vast majority of metal nitrates which decomposes on heating to metal oxides only (varying from somewhat complicated, to outright very difficult to reduce to metallic form), silver nitrate is also different. It readily decomposes to metallic silver, oxygen, and NO2. This fact is beneficial.
All liquid nitric solutions should first and foremost be distilled to recover any unreacted Nitric Acid. Processing Computer Keyboard Mylars gives a solution of silver nitrate with almost no contamination, ideal for extraction of even more values. First comes distilled water, then weak Nitric (mix of water and Nitric), and finally azeotropic Nitric Acid. The residue consists of crystalized silver nitrate. It can be directly converted to relative pure metallic silver. Running it through a silver cell will purify it to five nines.
Heating dry crystalized silver nitrate yields metallic Silver, Oxygen, and NOx gasses. NO is best oxidized under slight pressure at near 400 C; luckily it's not created in this step. However, NO2 is created, and it'll oxidize already at 250 C. As the two other components needed (heat and Oxygen) is present most of the NO2 will oxidize to NO3 and NO4. Place the silver nitrate in a closed stainless cylinder with an acid resistant pipe leading the NOx gasses to a beaker with water. Heat the cylinder and you'll not only get silver metal, but at the same time recover most of your Nitric Acid. There will be a 10 to 20% loss due to the fact that a portion of the NOx gasses will convert to NO during the absorption in water.
A bit more advanced equipment will be able to recover 100% of your expensive Nitric Acid for reuse in an eternal circle.
Wow i was expecting about half of that well done
Very good video. I'm doing it now myself
I'm 12 seconds in and I am going to guess that you averaged 100mg per mylar so in the area of 14-15gm just for them. I have done far too many of these things and I am soooooooooo sick of them. Unless I get them for free I won't touch them.
Edit: OK. I made it to the end and I think I am just as shocked as you are. That's double what I was expecting and the only way I can think that may have happened is that these were from OLD keyboards. Modern ones from the 2000's never seem to have anywhere near that. Nice haul there.
Oh yeah, it must be at least a kilo on there😂
Great video. You should try bleach next time. I use it to remove silver from xray films. Just rinse the mylars in a separate bucket, and after the bleach bucket settles you can siphon the bleach back into jugs for reuse later. Because youre not using nitric, you can use tap water to rinse silver in the bottom of your buckets....then use lye and sugar to convert as usual.
Great suggestion!
On your vac pump, you have the liquid separator with a ball. What is it called, and where did you find it. I have already destroyed a pump. Thank you for all the videos that you put out, I have learned so much from you. I live in Okeechobee not too far from you.
Float valve. If the reservoir fills with liquid, the ball floats up and blocks the inlet to protect the pump.
Corn syrup is dextrose and sometimes high fructose, not glucose like cane sugar.
What will you do with the copper chloride solution?
this result Double the Expected, nice ...
It's a lot more than I was expecting too. Maybe older mylars used more silver? I could tell some of them were from very old keyboards. They were also almost all from full size keyboards with the numeric keypad.
Mike wow nice amount! Every video now reminds me of another thing I haven't gotten back to. I burned a couple hundred milars one winter... and left the ashes in a bucket. Still need cut some petrified wood myself. And it's a good time to get melting metal with the furnace. Busy life, for people that have this kind of.... fun 😂
I don't know how you fit in the travel, but keep the good stuff coming!
Você não precisa desperdiçar ácido muriático pra isso. Basta por sal de cosinha. AgNO3 + NaCl = AgCl + NaNO3. O nitrato de sódio resultante é extremamente solúvel em água, bastando fazer uma filtragem simples.
Good Video, lots of great comments below. At about 18:00 when you added HCl to the Nitric solution, didn't you just create a weak Aqua Regia solution? Can't this solution be kept for later use to dissolve gold?
Maybe. That would be pretty weak though. Might be useful for leaching low levels of gold out of e-waste.
When you started I was expecting about 10 to 15 grams!!
sent from a friend called rick from georgia! 😂
A paper cutter would have been great for that. The old school kind
Good idea!
@@omegageek64 If I would have know that much silver would come from them. Well lets put it this way we had about 2 or 3 thousand keyboards at one time. Every computer from every school in the district. Thousands of them
The few times that I have tried to process keyboard mylars I have run into them wanting to stick together thereby keeping portions from getting contact with the acid. Any suggestions, recommendations or comments? Thank you!
How much nitric acid did you have to use total to dissolve that silver?
I used 400 ml, but probably could have used a lot less if I had shredded the Mylars and didn't need so much water to cover them. I wanted about a 5% solution of acid covering them.
@@omegageek64 Thanks! Still trying to learn the ropes here, and this information is extremely helpful-
I especially found your video on the topic of deNOxing incredibly, incredibly helpful. I had never seen anyone compile all the information and techniques in one video before! You’re a lifesaver!
why didn't you use copper to cement the silver out
I think the lye and sugar method produces purer silver.
@@omegageek64 yes it does. but it also creats a lot of waist. you can purify your silver by running it through a silver cell. just an idea. you can also get silver off xray film.
Did you weigh the mylar?
No. Probably should have now that you mention it.
U can melt silver chloride
Rock may have metals too...
I do mine sort of the same. Plating out on copper is easier. ua-cam.com/video/twOHe0nhTZE/v-deo.html
Can't you just use normal house bleach
That might work for precipitating the silver chloride. Haven't tried it. I will try it in the future. Thanks for the idea.
BE SMART !
mix your nitric & distilled water together before pouring it in to the bucket.
Corn syrup is dextrose and sometimes high fructose, not glucose like cane sugar.
What will you do with the copper chloride solution?