Pins are a Pain

[wildbill_hickup]

Boy these pins (from connectors such as ribbon wire connectors to hard, disk,cdr drives) are a pain. I had a few that I through in the small batch refered to earlier this week. All has gone fine with the AP batch except these bloody pins theyt just don't want to desolve. Everything else in the way of base metal is long gone, I don't know what those are made of(looks like copper the gold is gone) but boy are they stuborn. I've treated in AP washed in HCL rinsed with water rewashed in HCL rinsed water Retreated with a fresh batch AP rewashed in HCL let sit in HCL etc, etc, etc. Thought I finally had them this AM(A little hard to see through the AP sollution. Dumped off the sollution rinced with HCL and presto there they are. They are getting smaller but wow slowly is an understatement.

It has been 4 days since starting all other base metal gone beginning of second day, it's a little chilly in the barn between say 45F at night and 70F during the day with one night near freezing. Could that be the problem :?: Don't really have a way of warming to say room temp without moving into house. Even if I wanted to wife would shoot me :!: :!: :!:

Guess I'll have to be patient. By the way how cold can it be and still be able to work with this stuff. I'm used to working in the cold, probably will close up lab when it gets down below freezing and just collect for next year. However I am curious?

 

[lazersteve]

Wildbill,

AP works best at warmer temperatures.

The pins will dissolve better in hot HCl. Isolate them along with all the foils and boil the lot in HCl until the pins are gone.

Even better would be to keep the pins on the plastic headers when processing with AP. Next remove and rinse the plastic headers with the stripped pins. The header tends to keep the pins spaced out so the solution can reach them and it also makes removing the copper pin cores easier in the end. This also saves acid. The only down sides are the extra rinses required and the increased volume of solution required.

Steve

 

[Husker]

since the pins are just plated, and he has stripped them, wouldn't you simply need to rinse them well (to remove any residual gold dust), and toss the copper cores? Why spend the time (and AP), dissolving copper, when the values have already washed fully off? Now, if they were hollow core pins, where it might be a little harder to detect if all of the inner plating had been removed, then there might be a little more work needed. But he listed these as cable plug pins, which are pretty easy to detect when they are fully de-stripped.

Even if there was a pin or 10 that were not fully stripped, would spending several extra days, and lots of time, really be worth it, for the .01g of gold yet unrecovered?

H.

 

[wildbill_hickup]

thanks for the tip on hot acid Steve. Basicly I did what Husker suggested and manually discarded the pin cores. It took a few minutes but, I got sick of waiting. I will boil in HCL just to be sure.

Thanks guys

 

[Never_Evil]

You can try the sulfuric cell method. Keeping the pins in the plasic header will keep the maximum surface area. Since they are very thinly coated they will strip quick and and be put into either the copper mesh or into a stainless steel strainer. I think that technique is hiding in one of Steve's videos. Im still collecting pins and havent done it yet.

 

[wildbill_hickup]

Well I believe we have success .75g of dirty gold. I haven't processed in HCl+Cl yet I probably will wait till I have more. Haven't made a cell yet, trying to learn one thing at a time guess I just collect pins for awhile and stick to fingers and GP jewelery(got a whole box for a buck at the end of a yard sale). Iknow it won't yield much but it'll be good practise.

 

[P_CARROLL]

If your goiong to be dealing with pins I suggest you follow my technique.It id listed here http://goldrefiningforum.com/phpBB3/viewtopic.php?t=645&highlight=

Then more discussion here
http://goldrefiningforum.com/phpBB3/viewtopic.php?t=2578&highlight=

Good luck!!

 

[wildbill_hickup]

Thanks for the tip. I'll have to try it next batch of pins I do.