nitric leaching question...anyone to share :x

Loaded question guys!
I was successful w/ AP & HCL+CL, but not 100% successful with AR on the first try. First time I just dumped 10 intermidiate cpus in AR Sams way, which made a huge mess. I guess I was trying to use excess poorman's AR to complete the process. I will try AR sometime later, but I think HCL+CL is easier since it worked for me. I understand that I have to leach out base metals first to make my life easier. So what I did was put 5 intel pentiums in a beaker w/ 100ml of nitric + same about of reverse osmosis water (total 200ml). Legs fell off in every 5 cpu batch after about 2.5-3 hours where I added little bit more water so I was not running things dry at near boiling temperature. 5-10% of pins I still had to removed manually. Wasn't too hard. Some fell of from me breathing. I did notice some pins floating, but most still had alot of base metal inside the tube. At this point I desided not to waste any more nitric acid (not cheap) & put those in my sulfuric cell - totally different from what I tried to do in the first place, but kind of made sense...less "mess" to deal with...rest of CPU will go into AR or HCL+CL . Had serveral amps running through for a minute on those pins which were on a copper mesh. However, I was not able to get those cpu pins to a nice tin color as I could with fiber cpu or motherboard pins or cpu lids. I did move the pins around w/ glass rod to get a better contact, but there was definitly some yellow color on the pins ( not as thick as before sulfuric cell process). Question 1: Was that brass/copper under the coating or what -(sorry no picture taken)? Did I not finish reverse plating somehow? I know I couldn't get any more amps to go through. & Question 2: goldchild mentioned that nitric or HCL should be used to removal base metals. I am using too much/wasting nitric or not using enough? If not, could put this partially spend nitric in a container & try puting more nitric on the cpus to complete the process? Let's say 100ml+100ml water. If necessary repeat again?

P.S. I'm aware that pins could also be removed in AP + it is probably cheaper? But, I'm not sure I want to remove base metals that way. Also, I think Hoke's way is HCL, then Nitric, and lastly sulfuric to remove base metals if I remember correctly. Any thoughts?

Thanks for the time explaining,
-Mike

Mike, I do not know where to begin trying to answer the post, the question seemed to discuss so many different things at once.

HCl and bleach is easier to learn on, the aqua regia process is a bit more challenging.

Base metals should be removed from the gold before dissolving it. (The CPU’s can be processed without doing this, as base metals are normally low in volume, if done properly, but you also need to have a good understanding of what happens in solution and how to deal with it).

I do not think I would jump from one process to another with the half done process (like starting to remove base metals from the material using nitric acid getting half way done, and then moving the same materials to a totally different process like the concentrated sulfuric acid cell.

Try to slow down, and get focused, it sounds like you are trying to recover and refine like you asked this question, jumping all over the place, it is hard to hit your target if you do not take good steady aim, bouncing all over the place and pulling the trigger it is going to be hard to hit your target.

Thanks for the input Butcher!
Is there any reason why I should not move it to sulfuric cell? I mean those pins are gold plated aren't they? This is what sulfuric cell is for. I guess I don't want pins in AR yet since I'm not 100% sure how to deal w/ base metals in AR yet...& possibly loosing values due to this fact. Possibly, I would be introducing small amount of nitric to sulfuric cell since i'm not incinerating. Not much base metal would be left on the ceramic...won't take much chemicals in AR. So I guess i'm spliting in two seperate processes, but not all over? :idea:
I'm not sure I want to go to AR again w/ base metals there...since I had a bunch of grey silver? precipitate, where pins would not digest all the way, which was what happened on the first try. Maybe i'll have better luck with straight nitric + HCL as oppose to poor man's AR for whole cpu. What would I do if the process was to stop again due to silver chloride covering the pins in AR? Can not be shaking the pins of silver chloride all day?

I'm also a bit dazzled by your posts variable.

Please accept my words as they are intended.

If you need help, we are all here for you. But since we are not mind readers, an effort must be made by you to explain in your posts what exactly have you done, how did you do it and what was your feed stock. Before you hit the "Submit" button open a new window and use the forum search option with keywords from your own post. In most cases, you will find a relevant answer and realize you don't even need to post your question anymore.


One thing i have noticed are the words "intermidiate cpu's" and "AR".
Is it safe to assume you put celeron (black, fiber) type cpu in AR?

Hi Sam!
No, I didn't use black fiber in AR. I think those have alot of iron and not that much gold in them. I removed black fiber pins with a heatgun (electicity is free for me)...and put those in sulfuric cell. Back to your other question, I used 10 of those in the picture in AR which I screwed up. But, my question was more about anyone trying the cpu pins from the picture in sulfuric acid...after those were removed with nitric acid. I tried removing those pins with mapp gas or heatgun & the pins wouldn't come out. Well, I still have same question(s) as question1 & question 2 from above - Is that a waste of good nitric since I used 100ml per 5 cpus to remove pins? Perhaps, wrong method to remove the pins. Hmm...if you suggest me to search my own posts...that tells me i'm onto something. :| By the way those 10 cpus that i screwed up in AR was from your video. My cpus never got to a point where all the metal was dissolved. I did see a bunch of grey powder which looked like silver cholide or some lead on the bottom of my beaker.

http://www.youtube.com/watch?v=tQ_R8Gr26kk&feature=channel_video_title

p.s. As you can see i'm avoiding dirty AR...don't want to mess up again since my education is becoming expensive :lol:

Mike

In my opinion, when you write down your questions as you would for posting it, it usually helps you define more accurately what is it you want to know.
Once you have defined (more or less) your quastions, we all advocate the use of the forum search prior to posting. You will come to learn that most questions you are asking, had already been asked and answered before.

Sometimes, the amount of information can be overwhelming to people who are not well versed in the terminology, i get that.
But on the other hand, the amount of information digested by reading through countless posts that sometimes seems unrelated, will really help you connect the dots further down the road.
Most of us been there at some point in the past, i know i have. Some of our forum members and moderator haven't been that fortunate to have such source (the forum)they could just type in the search and find relevent info, they had to figure it out and they humbly share their knowledge with others. We try to respect that by not asking the same questions over and over. The info is already availble.

To your questions,
It is hard to tell how much more work you could squeeze as there is not way to know how much metals had been leached.
I would simply put another batch of cpu's and see if there's any reaction. Hot solution will leach more metals then cold ones so you might want to try. Generally, heat drives reactions forward and increase solubility of salts (metals compounds).

About the stripping of chemically removed cpu pins, i'm only spaculating here, but perhaps (or mot likely?) the nitric acid damaged the integrity of the Nickel underplate and/pr the base metal it self, resulting in faulty electrical conduction through the entire structure of the pin.
Adding to this, is the regular problems of handling such small pins in a cell.

IMO, if we/you could figure out what went wrong with your AR process, it might spare you the ordeal of moving the pins around from process to process.

IMO, if we/you could figure out what went wrong with your AR process, it might spare you the ordeal of moving the pins around from process to process.

Click to expand...

Yeah Sam I think you're right.
Let me step back and abandon my nitric leach idea since I don't think it's working too well for now and I'll focus more AR (poor man's or straight nitric). I'll try changing some should we say "variables" in my equation. I don't think the heat was the issue. I was using hot water bath, so it kept the cpus somewhat warm. I'm looking at the post w/ Steve's poor man's AR and focusing on steps 9 and 10:


9. If salts form allow to cool completely and pour off dark acid through tight filter and start at step 3 above. Filter may contain gold foils or powder. Rinse any solids back into the reaction vessel. Test saturated acid for dissolved gold with stannous chloride.
10. Repeat steps 7 and 8 until all metals are dissolved.

...I think this was part of my problem. I kept everything in the same beaker...figuring that I need larger volume of acids so I ended up w/ large volume of acids. I'll try pouring off the dark acid & collect it in seperate beaker. :arrow: Thanks for quick response Sam and i'll keep you guys updated on my progress as soon as I have time for this.

-Mike

Mike your last post was much more understandable, more clear to the point, less variable,

I also believe learning to process the ceramic processors using a known method that works, following the steps as closely as you can, and also figuring out what little detail you may be doing or not doing, in your trials of the process, and learning this process until you can do it successfully, is better than jumping from one process to another with the same materials, not knowing what is going wrong with either of these processes.

Slow down take baby steps at first, get the process down first, then run with it once you get it working.

Experiment, learn, with small batch's, or less valuable materials first, you do not want to loose your best materials and gold, while trying to learn, save the best material for when you can recover it without the problem's that come with learning how to recover from a new process you are beginning to learn on.

Keep up the good work of making your posts more clear and to the point, it helps the members give you better answers to your question's, also try to give good details of what your working on, how and what you have done up to the point of your question, this also helps the member to see some small detail that may have given you the problem in your process.