Recover Copper from Ferric Chloride Etchant (Waste free method)

Recover Copper from Ferric Chloride Etchant (Waste free method)


WARNING: This experiment handles boiling hydrochloric acid and sulfuric acid as well as toxic quantities of ionic copper and iron. Gloves should be worn and the experiment should be performed outside or in a fume hood. Greetings fellow nerds. In this video we’re going to recover the copper in a spent solution of ferric chloride printed circuit board etchant. As well as restore the ferric chloride etchant to working chemistry. And as an added challenge we’re going to do so without producing any additional chemical waste. So here is our spent ferric chloride etchant contaminated with copper chloride. Take note of the original volume as we’ll use that as a guide for restoring it later. I have about 400mL. Now filter the solution to remove any insoluble particles like bits of circuit board dust. You can wash down the filter paper with some deionized or distilled water if you want to maximize recovery. Now I’m getting the filtrate and distilling off the water and hydrochloric acid. This step is actually optional but i’m doing it because I wanted to weigh how much ferric and copper chlorides i had. You don’t actually need to do this part and can go right to adding copper. So this is what the raw mixture of spent ferric chloride and copper chloride looks like. Black crud. Now we add copper metal. We want to completely react all the remaining ferric chloride and copper chlorides. Now if you distilled off the acid to dryness like I did and weighed the residue then ratio to use is 3 to 1. For every 3 grams of spent ferric chloride etchant add in 1 gram of copper metal. This is a rather huge excess but we’re doing it to ensure the reaction goes to completion. If you didn’t distill and don’t know the mass of the ferric chloride then that’s okay, just make a guess and add a lot of copper. You can always go back and add more if there isn’t enough. I recommend using larger pieces of copper like i am here as it will make it easier to remove the copper later. Now since i distilled out the acid i’m going to add the acid back in. Okay, now we distill the mixture again. But this time the added copper will react with the ferric chloride and copper chlorides to produce ferrous chloride and cuprous chloride. These are also known as iron (II) chloride and copper (I) chloride. We’re doing this because while iron (II) chloride is soluble in water, copper (I) chloride is not, and that gives us our means to separate the two. Keep going with the distillation until it’s almost dry. It’s hard to see from this angle but the solution is considerably lighter as the reaction goes to completion. Finally the residue should be this light color of iron (II) chloride and copper (I) chloride rather than the black brown color of the iron (III) chloride and copper (II) chlorides. If it’s not, you need to let it cool, add the acid back in, and boil again until it is. You also need to make sure there is an excess of copper metal left over. If all the copper metal reacted then there is likely still unreacted Iron (III) chloride and copper (II) chlorides. So you’ll need to add in more copper metal when repeating the distillation. Anyway. Looks like my run worked out. Turn off the heating and let it cool. You can see here the cake of light green copper (II) chloride and white copper (I) chloride. Now take the residue and at least three times its mass of water. If you don’t know the mass then don’t worry, just add enough water to equal the original starting volume. The cake is fairly solid so you’re going to have to shake it a lot to break it up. We’re trying to dissolve the green Iron (II) chloride and separate it from the insoluble copper (I) chloride. At the same time try and remove any copper metal pieces if you can. You might have to pour it out and back in several times to do so. As you shake it up, you’ll might notice a rusty color develop on the sides of the glassware. What’s happening is the air is actually oxidizing the iron (II) chloride into iron oxide, which is rust. While it certainly looks like horrible contamination, the amount is actually very tiny. So don’t worry too much about if it’s happening. Okay now once the solid residue is dissolved and it’s just a suspension of fine white particles, filter the solution. It is at this point that we are separating the copper from the iron. You can also take this opportunity to remove any remaining bits of copper metal. Be sure to wash out any remaining residues with water to ensure maximum recovery. Once everything is filtered, retrieve the residue of copper (I) chloride. And there you have it, separation of the iron from the copper. Now we need to convert the copper chloride back into the copper metal that went into it. Now it just so happens i already have a video on that goes into that process in full detail so I won’t waste your time here. You can go right to the weighing part and proceed to convert the copper chloride to copper sulfate, distill off the hydrochloric acid, and electrolyze the copper sulfate to recover the copper. The process is no different. Now we deal with the iron (II) chloride. Boil down to a volume that corresponds to the difference between how much hydrochloric acid was recovered and the original volume. Since i recovered 300 mL of hydrochloric acid, and my original volume of ferric chloride was 400 mL, i’ll need to boil down to 100 mL. My solution a bit darker than originally because I performed this part of the video a few days after the filtration. In that time air had oxidized some of the iron (II) chloride into iron (III) chloride and some iron hydroxides. This is not a problem. Anyway, once you have boiled off the appropriate amount of water, let it cool and then add the hydrochloric acid back in. Now this solution still contains mostly iron (II) chloride as well as hydrochloric acid. To convert it to iron (III) chloride, or ferric chloride. Get an aquarium pump and bubble air through it until it becomes the characteristic dark yellow of ferric chloride. What’s happening is the oxygen in the air is reacting with the iron (II) chloride and hydrochloric acid to produce iron (III) chloride, also known as ferric chloride. And there you have it. We have now recovered the copper from spent ferric chloride PCB etchant and regenerated the etchant for reuse. And we’ve done so without producing additional chemical waste. Thanks for watching.

87 Comments

  1. Looks like tubestart isn't going to work for crowdfunding. So i'm checking in with other sites. I know everyone is going to say Patreon, but i'm reluctant to use them since they require i give my social security number. I keep looking for other funding sites.

  2. Have you tried GofundMe? It's what we used to crowd fund my friend while he was in the hospital for 6 months or so.

  3. NurdRage, do you know Tipeee ? Its a french crowfunding website based on tips. I dont know how they work exactly but you could take a look eventually. (https://www.tipeee.com/)

  4. Am I the only one where who is watching those videos just because he wants to learn something about chemistry and who is propably never going to perform any of those experiments himself?

  5. Anyone else thunk this guy sounds like buffalo bill?

    "It puts the lotion on the skin or it gets the hose again"

  6. NurdRage, what kind of gloves are sufficient for chemical protection for these kinds of things? Are nitrile exam gloves sufficient?

  7. Well, I'm an idiot in chemistry for sure, but this ferric chloride recovery tutorial would be pretty useful for me. I'm into electronics and etching protoboards pretty frequently. Usually I'm just buying new PCB etchant for every time my current one gets contaminated, but now it looks like there's a way of using the same solution for over and over again, and I'm definitely going to try it some day. 

    P.S.
    Uh, but why all this chemical equipment is so expensive? A heat plate, alembic and some basic glassware would cost like a brand new state of the art oscilloscope! D'oh!
    http://images.batronix.com/products/oscilloscopes/Rigol/DS1000Z/DS1104Z-S/DS1104Z-S-oblique2-l.jpg

  8. :O My lab has a large amount of left over ferric chloride etchant.  We physicists at the lab had no idea it could be recycled XD

  9. I want to see a method of doing a copper mirror on the inside of a bottle. I know the glucose reducing methods like the ones used for silver are too weak for copper but i don't have the time to explore this much further in my lab. I would like to see a series of this. To show the experimental prosses it takes to get something done. Kinda like a road to copper mirror series. It would give an insight on what a scientist goes through to reach an acceptable outcome. It could come off as pretty educational and might inspire some young chemist to do the same. Just some thoughts.

  10. I only understand about 20% of things you talk about, but for whatever reason I still find your videos extremely interesting 😐

  11. Hey NurdRage. I've been watching your videos for a while now and I've been thinking that you should set up a patreon account for your channel. It will help cover for the cost of any lab equipment (I'm no chemist so I don't exaclty know what you may need/want) and also allow for you to maintain a steady revenue from what you do.

  12. C10H15N, tell me da easy way to make it.. as soon as possible, n da lab order ..Is it the science company as the right way to order the chemicals? Step by step.. email me: [email protected] gmail.com

  13. It would be cool, you tried electrolysis of different organic compounds (mainly carboxylic acids or amines). Surprisingly little is known about such a reactions.

  14. what is a good reasonably priced hotplate a begging chemist could use. i don't want to break the bank but i i want it to get hot enough it will be useful. also i hear a lot of danger about hot plates is it really an easy thing to catch it on fire? i don't want this obviously ha ha.

  15. hey NR I was just looking at some info on the Journal of Chemical Education on Sulfamic acid (http://pubs.acs.org/doi/pdf/10.1021/ed020p189).  Seeing that they reference that it is used to make nitrous oxide, I naturally went to your page to see it.  You haven't done it yet, so consider this my request.

  16. What do you think would happen if you drunk liquid nitrogen because the whatever frost effect would stop it from touching you cause it's hotter on the inside of your body

  17. Would you mind if I took the information in this video and made it into an assignment for my students? I'd be showing them your video afterwards.

  18. NurdRage is a gold plated anode good? because gold is the only non reactive metal I have on hand and I could do some electroplating to make a nice anode.

  19. If you dont mind asking, may i know where did you get the voice changer i find it so awesome :3? Also love your channel bro its cool 👌🏼

  20. @NurdRage Hey I have a very peculiar question. If you boil off urine. What is left at the bottom of the container? 

    Also- You should do a video on the old method of deriving saltpeter from urine. 
    It may seem disgusting but in the name of science all must be tested.

  21. Are you a girl because The sweater sleeve is one that I cannot imagine a guy wearing and your skin is smooth and shiny like a girls

  22. This is a terrific video. Thank you so much for producing it. I have encountered three additional ferric chloride solutions I would like to recover, but as they are not pure, I am not sure how this process would work with them. The first is ferric chloride that has had citric acid added to make what is called the Edinburgh Etch which uses four parts ferric chloride and one part citric acid solution (1 liter hot water mixed with 300ml citric acid powder).
    The other two solutions are both straight ferric chloride, and the Edinburgh Etch solution that have been neutralized with baking soda in a misguided attempt to render them harmless. Any suggestions how to process these solutions would be greatly appreciated. I believe solving to this could help keep hundreds of gallons of waste from being illegally dumped into land fills and sewers. There is a large group of people etching art in addition to those making circuit boards and I believe many would benefit. Thank you again for all of your great videos!

  23. shame i live in Texas and i cant buy any glassware because it will label me as a meth cook and get my house raided in the middle of the night. science!

  24. If you were using Ferric Chloride to dissolve Iron, Steel or Stainless Steel, what would be needed to recover / rejuvenate the spent etchant? I suspect just more HCL acid and then oxides again? Follow up – what happens to carbon, nickel and Chromium if etching Stainless Steel? Super practical reasons for asking – many thanks!

  25. I read that Ferric Chloride can be made to etch faster by addition of Citric Acid to make a solution called 'Edinburgh Etch'.

    I'm very curious to know if you've heard of this technique and if you could possibly talk about the mechanism of action and efficacy?

    Love your channel btw, wish there was a subscriber level in patreon that would get us in more direct contact with you for this sort of discussion.

    Be well

  26. is more convenient and easy, to recover copper and ferric chloride,at same time, making an electrolitic cell with diaphragm, in one compartiment. 50%hydrocloric acid and in the other the waste ferric chloride,,,,electrodes made from graphite and a thin foil of cooper.,current density about 10 amp/inch2,,,,remember 96500 coulomb=1 mol of copper.=63 grs

  27. 2:50 I think it was meant light green Iron 2 Chloride, not light green copper 2 chloride, easy mistake damn chloride tongue twisters

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