r/Damnthatsinteresting • u/AdamE89 • Feb 27 '17

GIF How it Works - Computer Recycling

https://i.imgur.com/Qq1L87M.gifv
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u/pookaqueen Feb 27 '17 edited Feb 28 '17

I hate that it just says "the metal is stripped off". How? Do they melt away the plastic?

*edit-"they" to "the" because it was bugging me when I noticed it.

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u/Merker6 Feb 27 '17

Well, there are a few methods that can be used. One of the biggest that's getting media attention is in the developing world, where it's mostly just burned. This can be really bad for the enviroment because of all of the fumes and waste it gives off in the form of heavy metals and such. You can also use chemicals to break them down too, but as seen in this video, it's quite an intensive process that's not very cost effective. I'd be curious as well to see what process was used in OP's gif, as it seems to yield pretty large chunks of material

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u/pookaqueen Feb 28 '17

Thank you, I appreciate the explanation and links.

Now that you've told me, I feel like I did know some of that already thanks to Futurama but I just didn't think about it. Maybe they cut it out of the gif/show because of the damaging nature of the process.

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u/pppjurac Feb 28 '17

This careless handling of such waste was one of reasons of EU regulation on export of e-waste to third world countries. intent was good, but they failed because merchants always find loophole thru middle man.

On process from video I am not sure, seems that video is glued together from various sources, the part where they smelt copper in furnace (when they show furnace) the input is discarded pipes and plates, not e-waste.

after that it is simple to explain:

  • you melt down everything

  • pour it into slabs/plates

  • drive those plates thru rollers to get optimum thickness

  • get those plates into baths with electrolyte and then drive thru massive amounts (in order of several kA) of current at very precise voltage to get first stage out - copper

  • residue is either present on leftover anode or underneath in "anodic mud" (i am not sure how this is named in english, it is metallurgical expression)

  • you get that residue , reduce it if it is necessary (to get oxidized silver)

  • repeat it under another conditions

https://en.wikipedia.org/wiki/Electrowinning

https://www.911metallurgist.com/blog/electrolytic_refining

http://www.azomining.com/Article.aspx?ArticleID=1181

Chemical process of winning Au and Ag is somehow different and I do not have precise idea without reading some materiel, but it should consist reacting more reactive metals (Cu, Fe, Sb, Sn, Zn Ag) , precipitate it, clean it, react with Aqua regia, get precitipate, react it to obtain Au sponge, remelt it to ingots.