Refining IC chips

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  • Refining IC chips

    Hi all, I have finally hit 5kg of IC chips and I think its about time to try my hand at refining them.

    First I want to clean all the non pm metals off them like the feet and solder etc. What do you think is the best way to do this? Looked online and I find many conflicting chemical combinations to do this. I want to dump the chips in something, come back say a few days later, rinse them and find them all clean ready for incineration.

    Okeden or someone that is familiar with this please give me some advice?

  • #2
    Hi pav,

    I'm also attempting to refine my IC chips by incineration. The method I use for removing the pins (legs) is by using a grinder on them, it takes a lot of time since you have to do it one by one but it gets the job done. I'm not too sure about using chemicals to dissolve the legs. Hope this helps mate.

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    • #3
      Cheers Ewasterecycler, a lot of the IC's are really small so a grinder is not really possible. Would be ok for the proms I have but not so much the really small flat packs. I read that Hydrchloric acid with peroxide would do the trick after a while but other people were saying thats not good as if there is any gold it could disolve that as well.

      I really want to know the chemical mix that can remove the legs and other metal but not touch the gold. Maybe just straight hydrochloric? Or Nitric? Problem with using Nitric is its very expensive for the amount I have.

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      • #4
        You're welcome mate. Hydrocloric acid and peroxide will work, if you use a 3-1 ratio of AP you shouldn't lose any gold in solution. If you use too much peroxide you will lose some, you could easily drop the gold with smb if you do though.

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        • #5
          Sweet, will start that tomorrow. There are a few of IC's that are split so while not a lot of gold would be lost I still hate seeing any spec lost.

          I am really bad with video so will take a series of pics along the journey and post them for critique.

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          • #6
            Lot of us scrappers in melbourne just use our teeth but the steel does go into the chip so after incineration you'll still have steel.
            so why not incinerate the lot and use a magnet to remove the steel from the ash?
            Buying eWaste link here

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            • #7
              When you have 5 kilos its a lot of steel and solder etc. I just want to make it as clean as possible before incineration. Throwing them all in an acid bath 1 week before I am ready to incinerate is no biggy. I have seen the end result and its a lot less pollutants to deal with when processing later down the track. After incineration and crushing, the gold sticks to some of the steel during the crushing stage. Less steel means less chance I will lose some gold.
              Last edited by Pav; 03-04-2016, 12:00 PM. Reason: **edit** after posting I still dont have a come back for the teeth quip :) damn.

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              • #8
                fair enough, I notice there's a lot of mini processes when scrapping gold bits and i've come to the conclusion that it's best to deal with things as you go.
                like gold plugs, cleaning them and sorting them saves a big job, pulling pins by type makes things go quicker and for an average accumulator of ic chips it's probably best to deal with the pins as you get them.

                so you pull 6 ic's off a board, run them straight over a bench grinder, so by the time you build up a few kg's, they are all ready to go.
                but once you got a lot, grinding would take ages to do, yeah, dissolving the pins is the only sensible way.

                so what then? burn them and pan for gold?
                Buying eWaste link here

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                • #9
                  unfortunately time is not on my side when I scrap, its a hobby and I have to deal with a 10 month old so i scrap when I can. Also, I usually scrap a heap of boards at once. My scrapping sessions will yield about 500 grams of IC's at a time. I also have read about people taking the tiny IC's off the boards and them having gold in them so I take absolutely every IC. I attached a photo of the IC's so you can see that grinding the small ones is just asking for a disaster. The small ones at the bottom of the pick are not even the smallest I have so rather than pick them out its an acid bath for them.

                  I guess I could just separate the small ones as I go, but I like the idea of clean IC's ready for burning.

                  Next step is burn them. Separate the magnetics from the mix, pan/dilute the ash as stage one gold extraction. Then chemical for the rest.

                  I will be doing the 5kg in batches and wait until all have been incinerated before using chemicals to extract the not so easy to get gold.

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                  • WEEE Ben
                    WEEE Ben commented
                    Editing a comment
                    yeah the small one's would be a pain to grind down, I see you put ic's and flat packs together, I guess they balance about the same as eachother anyway but for some reason I keep them separate.

                • #10
                  What will you use to incinerate them Pav?

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                  • WEEE Ben
                    WEEE Ben commented
                    Editing a comment
                    I was thinking about them rocket type stove set ups, something that will create high heat fast and cheap.

                  • Pav
                    Pav commented
                    Editing a comment
                    I was thinking about that a lot. I don't have a firm setup as yet but I found really decent shell from a UPS I scrapped and have a lot of grilled steel so was thinking of setting up a makeshift incinerator. Will be buying something to burn them this weekend. Will take some photos once I have them set up.

                  • WEEE Ben
                    WEEE Ben commented
                    Editing a comment
                    what about bga chips? mostly the nth bridge type with gold corners, they seem to be different

                • #11
                  G'day Pav, been away for the week so just caught up with the posts. Grinding is probably the best way of getting rid of the legs. If I cut them from the boards, as against using a heat gun, then if you cut as close as possible to the edge, you get a pretty clean chip. I use a heavy duty Stanley type blade, and it works well. You could certainly soak them in nitric acid, but as you say yourself, it is a bit costly, and I agree. I've got a small bench-grinder I got from Aldi ages ago for $10-$15 and mainly use it to test for what metal I'm dealing with. But because it is nice and small, it does work for the IC's. But you still have to use a magnet to get most of the other ferrous metal out, so I wouldn't get too concerned about leaving a bit on. Especially with the very small ones which are a pain to clean up.

                  Don't know how you are going to incinerate them, but don't use a direct flame. You need to heat the container from the bottom until they all turn whitish and become just powder which you then pan off.

                  Ben mentioned the bga chips. These need to be done separately. Think you will find that there is little or no gold in the ceramic part, it is in the fibre underneath. If you break the ceramic off on you will see what I mean.

                  Anyway, good luck with it, be keen to see your pics as you go.
                  OKEDEN SCRAP & PM's
                  http://www.okedenscrapandpms.com.au

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                  • Pav
                    Pav commented
                    Editing a comment
                    Thanks Okeden, Just bought to long hollow metal pipes for crushing. The bigger one is like the container and has a cap on the bottom, the smaller is another pipe with the cap on it, will see how it goes.

                    Thanks for the advice on the incinerating, tried doing a couple with direct flame to test and they stayed black but they did crush into powder. I will do it from below with no direct flame next time.

                    I have separated the bga chips and will process them later. Seen quite a few good vids on youtube about that.

                    So after a week of soaking in the acid, most are clean except for the prom chips, the acid did nothing to them so I will just incinerate and see what happens. Use a magnet to get rid of the meta etc.

                • #12
                  How did you go Pav? any pics of the results?
                  Buying eWaste link here

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