More info requested on AP process

[Sharding757]

First of all hello everyone! As most can tell I'm new to the forum. Been doing alot of research before joining and found you guys. With the understanding that dealing with Pm recovery can be a rather tedious and a dangerous process if not done in a safe manner, I have been doing my share of reading (even though I first downloaded the hokes book and was missing many pages (the one that shows two pages per frame) but finally found one that wasnt. Took my thinker off for a tick until i realized some pages were missing. Any how, I read in hokes book and it was quoted several times to not worry about the Silver but only if worth while. I'm studying/planning on using the AP method as seen on LazerSteve's website. Hoke's Book focuses mainly on the aqua regia method. Is there more information on the AP method? Perhaps a book, something readable to gain more knowledge in this particular venue of recovery? I want to recover all I can from Computer boards and such. I have been reading the forums as well. Im mainly concerned with the gold and silver recovery for the time being as I grow in knowledge, I'm sure I'll move on and expand the process. I see talk about recovering silver and much talk about there's not enough to even bother in some cases, not to mention its insoluble if using the aqua regia method. So if using the AP method, and correct me if im wrong, The base metals including silver but not gold (unless too much h202 is added) are put "into solution". If I were to first filter out my gold from fingers and gold board etchings (board components removed for incineration later using Patnor's Guide), can I further refine the AP solution containing the other base metals? For instance precipitating Silver by chance. Many articles avoid even the mention of silver extraction from an AP, other articles mention using table salt to turn it into Silver Chloride then zinc to cement the chloride into metal but some state its done when in a nitric acid solution others when in HCl. Others state using Karo and sodium hydroxide etc. There are so many different ways but from what I've read they all would appear to be used with nitric acid and not the ap method. I'm a little confused on the subject. Again I still search the forums, but alot of times the answers dont quite fit my particular scenario. I still have to go back and re-read alot of these articles which I'm in the process of documenting in a journal for myself to help commit fundamentals to memory(ie Safety guidelines such as never pouring water into Sulfuric Acid but Acid into the water and procedures for different methods not to mention my own results when I start). Again I'm just looking for clarification on the silver process and AP solution. I have read much about the AP solution as far as gold goes but want more info. Where may I find a good E-book or something that spells out what can and can not be done with the AP solution to make sure it's what I want to go with? Im sure that depending on what you are doing, constitutes what method you use im sure. But in my beginning of learning I'd like to separate each one of the processes. It's kind of the way my brain works. Learn one process at a time and the pros and cons of each before moving to the next process, etc. Hopefully I dont get flamed too bad for this post im just looking where to find more info is all plus hinting in my text that I am doing my part before attempting any of the processes spoken of on the forums. Thanks in advance. Sam.

 

[FrugalRefiner]

Sam,

Welcome to the forum. There is so much to learn that it does get very confusing at first, but the more you read, the more the pieces of the puzzle fit together.

I want to start with your comments about the copy of Hoke's book you downloaded. The copy of Hoke's book that shows two pages per frame is a printer friendly version. All the pages should be there, but because it was laid out to be printed, trying to read it on screen will have you jumping back and forth to read them in the correct order. You'll find links in my signature line below for both the printer friendly version and a screen readable version. They both now include an introduction that I believe you would find of value. The downloads are fast, so I would encourage you to download the latest version(s).

When Hoke wrote her book, silver was quite inexpensive compared to the cost of chemicals and time required to recover it. That has certainly changed and silver is usually worth trying to recover. Acids were also much more available and less expensive in that time. The copper chloride (AP) method is a workaround to the high cost and difficulty in obtaining nitric acid. It is very effective for ewaste. In addition to the videos, Steve also has some downloadable documents on his site, including one that discusses the AP method in some detail.

Silver does not dissolve in the AP process. Silver chloride, which results when silver is exposed to HCl, is relatively insoluble. Any silver will be found as an insoluble precipitate at the bottom of your AP bucket.

Keep reading. There is much more to learn.

Dave

 

[Golddigger Greg]

First off, welcome to the forum! You have found the one place where, if you continue to study, you will find every single answer you seek.

You have to remember that Hoke's book was written at a time when silver was a rather inexpensive metal and recovering the small amounts that the typical home refiner would come by was largely outweighed by the time and expense to do so. (My understanding as to why silver is discounted by Hoke; I could be mistaken)

Also, Hoke wrote her book long before there were printed circuit boards, but the lessons spelled out are as true today as when she wrote them. The chemistry hasn't changed, the material you'll deal with has though. As the material, be it fingers, IC's, or whole boards changes so must your approach to how to best recover the metals in them. The short answer is to (1)separate the material into like categories so you don't cause yourself grief trying to recover 9 grams of gold foils from a gallon of tin-laden solution, for example. (2) Start with the safe(r), easy stuff (clean gold fingers in AP) in small experimental batches to familiarize yourself with the process and the results. (3) Keep studying the forum and use the search feature to expand your knowledge as you learn. (4) Remember that it's not a race, and your precious metals aren't going anywhere. They'll still be there when you are ready to tackle them.

I see that I was beaten to the punch! :mrgreen:

 

[Sharding757]

Thanks for the replies! Dave thanks for setting me straight on the silver. I will continue to study and learn.

 

[Pantherlikher]

Welcome to the forum.
It all looks very confusing at first and can be tough keeping things straight. That's why we take notes and reread everything.

As far as Acid Peroxide, AP, do a search on Acid Peroxide and you will find old posts on what it is and does. Silver should not even be present in an AP solution. and if it were, copper will cement it out.
Do the search and read about it a well as how to deal with the waste as well as the gold we are extracting out of it...The whole reason to use AP.

Good luck and it will make sense as time goes on.

B.S.

 

[Sharding757]

Thanks Pantherlikher, I've been reading on alot of posts and getting my E-scrap all divided up into categories depending on recovery methods etc. I did try a small test run, with some gold plated vesa boards (depopulated and solder mask removed)and gold fingers in AP. I have good foils and the black sand, which tells me gold was first absorbed into the solution then cemented out as the copper was dissolved. (probably a little too much H202, used 2:1 HCL/H202 ratio) in AP process. I've filtered the solution and have a teaspoon and a half of gold mash. So I'm happy with the results thus far as a test run. The foils and black sand were washed in water twice and the filter stashed away for incineration later during refinement. Currently the foils and sand now are settling in HCL for the moment (First HCL Wash). On this small batch which again is a test run and wanting to refine the gold further before converting the gold to auric chloride, would it be best to run a strong magnet in a ziplock bag through the gold solution as it's agitated to pick up any iron from some of the pins (which should have been processed separately) then incinerate or incinerate and then use the magnet in the dust? Obviously all this prior to using HCL/Clorox. I'm worried about losing some of the dust if it gets trapped between the iron and the magnet. Thanks Again...Still reading...Tons more to learn.