A/P or Nitric Acid??

[nebiconezer]

hello, pretty new to this and have been reading a ton on the forum. this place is great!! thanks to all who share.
I have been reading on how to remove gold plate from boards. I have a supply of boards that are pretty much fully plated front and back from some satellite equipment.
so I read here how to depopulate with a heat gun. a bit slow but works great...then I put them in an HCL bath...again seemed to work well removing any tin/lead left.
I then placed them in a 3:1 mix of HCL and H2O2...few bubbles and few hours later the process seems to be working but super duper slow...have I done something wrong?

also just wondering what the difference between the A/P method and just soaking them in straight Nitric Acid is??

thanks all

 

[FrugalRefiner]

I then placed them in a 3:1 mix of HCL and H2O2...few bubbles and few hours later the process seems to be working but super duper slow...have I done something wrong?

also just wondering what the difference between the A/P method and just soaking them in straight Nitric Acid is??

thanks all

You probably haven't done anything wrong with your A/P. It's a slow process. Think in terms of days, weeks, or months, depending on weather, agitation/aeration, feedstock, etc.

Both A/P and nitric can be used to dissolve base metals from gold plated materials. A/P is slow, but inexpensive and reusable if your base metal is primarily copper. Nitric is faster, but more expensive and considerably more difficult to recycle.

Dave

 

[nebiconezer]

ok great, thanks....so I wait.....not good at that.....hmmm

 

[Anonymous]

Don't use 3:1 on the AP mate.

You only need a small amount of peroxide to begin the process properly.

 

[niteliteone]

Don't forget to use a fish tank air pump with an air stone in the bottom of your AP tank.
AP requires oxygen to do its job quickly. For my tank, it turned a week long process to less than 2 days 8)

 

[sharkhook]

On Low Noise Block boards or LNB, (the receiver piece from the satellite dish) my first batch took about 5 days. The second batch with a small aquarium pump took 2 days. I only used a couple of ounces of peroxide for 8 cups of Hydrochloric, and it did both batch's. Those small pumps are cheap and worth every penny. Not very much of this is quick, if your in a big hurry, expect to loose material, or create headache's that will slow you down even more in the next several steps.

EDIT: It is an LNB not a LBN as originally stated.

 

[nebiconezer]

On LBN boards, (the receiver piece from the satellite dish) my first batch took about 5 days. The second batch with a small aquarium pump took 2 days. I only used a couple of ounces of peroxide for 8 cups of Hydrochloric, and it did both batch's. Those small pumps are cheap and worth every penny. Not very much of this is quick, if your in a big hurry, expect to loose material, or create headache's that will slow you down even more in the next several steps.

ok great info, the boards i have are from that exact thing. scrap out the aluminum and get these great looking plated boards. i'll get an air pump for the next batch.

any idea of the yield on this type of board?

 

[nebiconezer]

Don't use 3:1 on the AP mate.

You only need a small amount of peroxide to begin the process properly.

so like 6:1 or 10:1

or just pour a little in?

 

[sharkhook]

No I don't, I mixed the foils with others from some fingers and other boards I did. Some of them looked good, and some seemed to turn almost to dust for the flake sizes. I still have the flakes and will be going to further processing with them when it warms up a bit more. Finish your first batch without the pump, then the next one use the pump, you will be really surprised just how much it helps. And it will help to clean up your AP so you can reuse it again.

Read this, there others so look for more posts on "Reuse AP" and related terms.

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=39&t=11840

 

[FrugalRefiner]

No I don't, I mixed the foils with others from some fingers and other boards I did. Some of them looked good, and some seemed to turn almost to dust for the flake sizes.

Keep in mind that not all plating is the same thickness. Fingers are designed for multiple insertion/removal cycles. The plating is relatively thick to stand up to the physical abrasion. Other areas of a board may be plated for other reasons that may not require as heavy a plating. When plating turns to dust, it's a good indication the plating was thin. When it comes off as intact foils, it was probably thicker.

Dave

 

[sharkhook]

No I don't, I mixed the foils with others from some fingers and other boards I did. Some of them looked good, and some seemed to turn almost to dust for the flake sizes.

Keep in mind that not all plating is the same thickness. Fingers are designed for multiple insertion/removal cycles. The plating is relatively thick to stand up to the physical abrasion. Other areas of a board may be plated for other reasons that may not require as heavy a plating. When plating turns to dust, it's a good indication the plating was thin. When it comes off as intact foils, it was probably thicker.

Dave

You are very right about the thickness. Even LNB boards from the same companies such as Dish vary in thickness of the plating. I assume they use different manufacturers or they may have changed over the years as needed. I had one that I believe was not even gold. It looked almost a white color, closer to silver. In AP, that silver one was the first one deplated, it only took about 10 hours to come completely off. the rest took around 24 hours. I also think this will cause me grief when refining the gold, but I didn't know that at the time. A prime example of leaping before learning.

EDIT: Corrected the LBN to LNB.