Processing Fingers with CuCl2 etching solution

[purgatory]

This is one board, it"s weight is 158 grams, dimentions are 9 inches by 7.5 inches.
Can I please know the price of this board, the guy has in bulk.

It weighs 98.5 gram. dimentions are 7 inches by 2.9 inches.

It weighs 42.5 grams. Dimmentions are 7 inches by 2.9 inches

Can you please suggest me at which price i should buy these boards at in order to recover gold?

This would be a great help in buying these beautifull boards.

Thank you

Alvi

 

[purgatory]

From what I understand, since lead was removed as solder and replaced with tin, the tin carries over from one process to another. Since some use nitric acid to remove base metal and the base metal contains tin, you get metastannic acid (hydrated tin oxide). If you remove base metal with copper(II) chloride, the tin is oxidized to just tin oxide. Either way, incineration helps to reduce the tin oxide to elemental tin which can be removed in a hcl bath.

Hoke's Acquaintance Tests:
Obtain from your supply house small samples of pure tin and pure lead. A pennyweight of each will be enough. Do not use metals of whose purity you have doubts. The metals may be in pellets, foil, grains, or any other convenient form.
First take a bit of tin about the size of the head of a pin and cover it with a few drops of hydrochloric acid, plus a couple of drops of water. Heat to boiling and watch the results. Now do the same thing with a little lead; use a clean test tube or beaker for each test.
(Note that hot hydrochloric acid dissolves tin promptly). It is slower in its action on lead. Now, let the lead-hydrochloric acid mixture cool. . . Note that a heavy precipitate of white crystals appears. This is lead chloride. Add some water to make up for evaporation, then alternately heat and cool the mixture, observing that considerable lead chloride will be held in solution by a little hot water, only to crystallize out when it cools.

You will note that the tin chloride, formed when the tin is acted on by hot hydrochloric acid, is not so markedly affected by heat.
Because of the above facts, we use hot hydrochloric acid to dis- solve solder (tin plus lead) in cases where the hot acid can reach the solder. So, if your old jewelry shows lumps of soft solder, boil it in hydrochloric acid until the solder loosens and can be scraped off. But if the solder is inside the article, the hot acid will not reach it.

From this point of view, I understood that if these telecome circuit boards containing tin and lead solder should be treated with hot concentrated hcl as a pretreatment and rinsed thoroughly, tin from the solders will be dissolved. Correct me if I'm wrong please. And after this I can treat them with nitric acid to strip the plated gold from these boards, please correct me if I understood in a wrong way.

Actually I have seen the result using nitric acid, it strips the gold plating with in minutes, this is the only reason why I'm so keen in using nitric acid as a cooper leach to strip plating.

Please correct me if I understood the process in a wrong manner.
Thank you

Alvi

 

[purgatory]

Frankly, if I was involved in processing these products by the methods being discussed, not only would I do a prewash in heated HCl, I'd also incinerate first. There's great benefit doing both.

One of the things I discovered after having problems with filtration is that a prewash with HCl and a rinse with (tap) water will generally dissolve and remove contaminants that restrict filtration. It does little to control oils, which tend to float gold, so incineration is very desirable as well, with the added benefit of reducing the volume of solids, some of which may actually absorb and retain values (activated carbon, for example). The added work is often rewarded with higher quality and shorter filtering time. I found both of them indispensable.

Harold

Harold, your post clarifies my doubts in my last post, I'm glad I understood Hoke and Geo in a possitive manner.
Even if I missunderstood please clarify me, I want to move further anad attain possitive results while having all the points in my mind which I have learnt from this forum and from Hoke's book.

Alvi

 

[Geo]

From what I understand, since lead was removed as solder and replaced with tin, the tin carries over from one process to another. Since some use nitric acid to remove base metal and the base metal contains tin, you get metastannic acid (hydrated tin oxide). If you remove base metal with copper(II) chloride, the tin is oxidized to just tin oxide. Either way, incineration helps to reduce the tin oxide to elemental tin which can be removed in a hcl bath.

From this point of view, I understood that if these telecome circuit boards containing tin and lead solder should be treated with hot concentrated hcl as a pretreatment and rinsed thoroughly, tin from the solders will be dissolved. Correct me if I'm wrong please. And after this I can treat them with nitric acid to strip the plated gold from these boards, please correct me if I understood in a wrong way.

Actually I have seen the result using nitric acid, it strips the gold plating with in minutes, this is the only reason why I'm so keen in using nitric acid as a cooper leach to strip plating.

Please correct me if I understood the process in a wrong manner.
Thank you

Alvi

I was talking about foils AFTER they were recovered from the (boards,pins,fingers,etc.) and not before. Be careful with the process as you described it. If you pretreat the boards with hcl before you move to nitric acid, the solution will form a weak AR solution and dissolve some of the gold because you can't rinse acids off with just water rinses. It is possible to pretreat the boards with hcl if you neutralize the hcl before moving to nitric acid. Perhaps treat with hot hcl wash to remove solder and then pass the boards through a dilute sodium hydroxide bath and rinse well with with water and then dissolve the copper underlay with nitric acid.

 

[solar_plasma]

You would save yourself a lot problems, if you would clean the boards from any components by heat, then dissolve any tin solder in HCl and at last process them in CuCl2 to get the foils. If you want to know why, read more. Everyone who has spent a long time educating himself will master the stannic acid problem, but why do you want to make it harder to start than necessary?

 

[solar_plasma]

Even if you neutralize the HCl, you could still have traces of chlorides, which again would form poor man's AR and dissolve gold, like Geo already mentioned.

 

[purgatory]

Hi
How are you all doing?

Geo, you are right, I will have to neutralize hcl, your suggestion to let boards go through the Sodium Hydroxide bath will neutraliz the remaining hcl from the boards, noted down... Thank you Geo.

Solar Plasma, my plan was the same, like to depopulate the boards with my burner and cuttiing them into small pieces like gold fingers from the boards, treat (only those pieces which contain solder) with hcl to get rid of tin and as Geo suggested will let them run through the Sodium Hydroxide bath to neutralize the hcl which would be sticking with the board pieces after hcl treatment, that way all the board pieces would be very much cleaned for the further stripping process.
Basically I'm just afraid of metastannic acid, thats all.
On the other hand once I stripped the gold from mobile fone cards with hcl and hydrogen peroxide, That process took one week to finish and at the end of the stripping process i was left with alot of white colout powder which was copper chloride I presume, then I had to put some water and hcl to get it again dissolved, it was kind of a mess for me to deal with, with nitric acid I could save myself from these kind of problems. The plated gold could be stripped off with in minutes.
Maymann and Harold suggested to incinerate the foils after nitric acid treatment to get rid of any nitric and offcourse board's green colour left overs.
This is my plan and if you think I'm putting myself into a more lenthier process, kindly correct me with details, I would be so much glad to learn more and more.

Thank you Geo and Solar Plasma

Alvi

 

[purgatory]

Dont you think they would be chlorides of sodium? If I would neutralize the hcl with sodium hydroxide the only salt could be form is sodium chloride? And this is very much soluble in water.

 

[solar_plasma]

Dont you think they would be chlorides of sodium? If I would neutralize the hcl with sodium hydroxide the only salt could be form is sodium chloride? And this is very much soluble in water.

If I think anything, I will say: I think. Ofcourse it will be Na⁺ and Cl^- and if dried, NaCl. Maybe you can wash it completely off. Can you be sure? No.

HCl and HNO3 are very soluble, too. Maybe Hoke didn't know that, so she incinerated, while she just could have washed the acids quickly away. No. I think she incinerated, because it is the only way to be sure all choride, nitrate, hydronium ions, HCl gas and NOx or what else troublemakers there may be left are gone.

 

[Harold_V]

Maymann and Harold suggested to incinerate the foils after nitric acid treatment to get rid of any nitric and offcourse board's green colour left overs.
This is my plan and if you think I'm putting myself into a more lenthier process, kindly correct me with details, I would be so much glad to learn more and more.

It is my opinion that you understand perfectly that which I tried to explain. Any incineration should come after the values have been recovered (but before dissolution for final refining) where escrap is concerned, as that limits the volume of contaminants that produce toxic gasses upon incineration.

The benefits of incineration and the HCl wash will become instantly obvious, especially if you have processed similar material without these procedures.

Harold

 

[Geo]

I believe that a dilute sodium hydroxide solution will be enough to neutralize the acid that would be a problem. If we want the absolute, then it would not be enough. I also feel that we must understand and accept that there will be loses in each process. As we gain knowledge and experience, the losses get less and less. If there are time restraints, it would be the fastest way to process the boards. Any losses will be recovered in the waste stream later. I can't find a good reason that that it will not work.

 

[Barren Realms 007]

Another way you can approach this is after you depopulate the board is run through sodium hydroxide to remove the solder mask and the solder and then either AP or Poor Mans AR. But you need to be familiar with the process rather than just jump into using it.

 

[maynman1751]

Be VERY CAREFUL with sodium hydroxide, especially if it is heated. It will very rapidly 'digest' your skin and blind you if you get it in your eyes. Wear all of your protective gear when working with this very dangerous chemical.

 

[Claudie]

Mis read the post, comment not related so I deleted it.

 

[solar_plasma]

Be VERY CAREFUL with sodium hydroxide, especially if it is heated. It will very rapidly 'digest' your skin and blind you if you get it in your eyes. Wear all of your protective gear when working with this very dangerous chemical.

Very right, have all skin covered, especially your face or even a tiny splash will cause a permanent scar within some seconds. I've made this mistake only to use safety goggles once when I was making soap. I am lucky it only has been a tiny splash.

 

[cyrus899]

Hi good day I am new on this forum , want to know what are chemicals do I need for refining gold on board of cellphone , as the moment I have HCL, HNO3, and AGUA REGIA. I am interested to know and willing to learn. Hope you will help me guys...

 

[FrugalRefiner]

Welcome to the forum cyrus!

Everything you need to know to recover and refine precious metals can be found here on the forum. It takes a lot of study but it's incredibly rewarding!

The first rule is to be safe in everything you do. Before you jump into any of the processes you see discussed here, be sure you understand the potential hazards and do everything you can to minimize the risks. Read EVERYTHING in the Safety section of the forum, especially the Dealing with Waste topic. No amount of precious metal is worth jeopardizing your health or the health of those around you.

Follow the Guided Tour created by LazerSteve. It will provide an introduction to the forum and numerous valuable links including the General Reactions List. Be sure to follow the link to his web site as he has many outstanding videos, a collection of great reference documents, and he sells a lot of the supplies needed to get started including detailed instructional DVDs. Samuel-a also has a lot of videos, guides and tutorials at his web site Gold-N-Scrap.

Download C. M. Hoke's book. You'll find links to both screen readable and printer friendly versions in my signature line below. You'll see her book mentioned repeatedly here on the forum for good reason. It is probably the best book ever written for the beginner who wants to learn refining. It is written in layman's terms and will provide a solid foundation that will help you understand everything you read here on the forum. You'll also find a tremendous amount of information in the two Forum Handbooks compiled by aflacglobal, Forum Handbook Vol 1 and Forum Handbook Vol 2.

bmgold2 has also been putting together a useful set of links for beginners. You'll find a few links there that are duplicates of the ones I'm providing, but he has also taken the time to link to many other very good threads on specific topics of interest. His thread is here: New Member Answers.

Once you understand the basics you can start to try some small scale experiments. If there's something you don't understand or you get stuck, there will be someone here to help you.

Best of luck,
Dave

 

[cyrus899]

Welcome to the forum cyrus!

Everything you need to know to recover and refine precious metals can be found here on the forum. It takes a lot of study but it's incredibly rewarding!

The first rule is to be safe in everything you do. Before you jump into any of the processes you see discussed here, be sure you understand the potential hazards and do everything you can to minimize the risks. Read EVERYTHING in the Safety section of the forum, especially the Dealing with Waste topic. No amount of precious metal is worth jeopardizing your health or the health of those around you.

Follow the Guided Tour created by LazerSteve. It will provide an introduction to the forum and numerous valuable links including the General Reactions List. Be sure to follow the link to his web site as he has many outstanding videos, a collection of great reference documents, and he sells a lot of the supplies needed to get started including detailed instructional DVDs. Samuel-a also has a lot of videos, guides and tutorials at his web site Gold-N-Scrap.

Download C. M. Hoke's book. You'll find links to both screen readable and printer friendly versions in my signature line below. You'll see her book mentioned repeatedly here on the forum for good reason. It is probably the best book ever written for the beginner who wants to learn refining. It is written in layman's terms and will provide a solid foundation that will help you understand everything you read here on the forum. You'll also find a tremendous amount of information in the two Forum Handbooks compiled by aflacglobal, Forum Handbook Vol 1 and Forum Handbook Vol 2.

bmgold2 has also been putting together a useful set of links for beginners. You'll find a few links there that are duplicates of the ones I'm providing, but he has also taken the time to link to many other very good threads on specific topics of interest. His thread is here: New Member Answers.

Once you understand the basics you can start to try some small scale experiments. If there's something you don't understand or you get stuck, there will be someone here to help you.

Best of luck,
Dave

thanks all the information that you it will help me a lot. I already downloaded the C.M. Hooke and started reading it and still looking some videos.

 

[Claudie]

Please practice safety. Many new comers don't understand the importance of safety, and just how dangerous some of these chemicals are. NEVER work inside your home with anything. Know what the chemicals are and how they work BEFORE you use them. Sometimes you don't get a second chance. :|

 

[purgatory]

Hi Everyone
How are you all doing?

Cyrus, wellcome to the forum, wish you best of luck.

Quick question.... Respected members, can you please guide me a bit more, I need to ask like, can I use stainless Steel pan to incinerate the foils which would be recovered using Nitric? After incineration do I need to rinse these foils with water prior to boil in hcl?

I'm all prepared to process the above mentioned gold plated boards, I will run a small batch of about 500 grams of these boards. I have cut them to small pieces like gold fingers, cleaned from dirt, ready to be treated.

I will start this process by tomorrow.
Will post the details with probablly pictures.

Thank you for your supposrt and guidance.

Alvi