Remove tin solders

[Ayham Hafez]

Why there is many people works hard to prepare new recipes to remove tin solders while we can just use HCl, I mean is there any disadvantage of using just HCl?

 

[GoIdman]

Why there is many people works hard to prepare new recipes to remove tin solders while we can just use HCl, I mean is there any disadvantage of using just HCl?

I think because some people (including me) want to reclaim the solder itself since it can be sold for cash. As interesting as it is, Tin price per ton is 24000 USD (https://www.lme.com/en/metals/non-ferrous/lme-tin#Summary) so if you reclaim the solder and sell it for just the half of that money to the scrapyard you already made a pretty good deal.
My approach is always mechanical+heat first, chemicals for last instance.

Pete.

 

[Ayham Hafez]

I think because some people (including me) want to reclaim the solder itself since it can be sold for cash. As interesting as it is, Tin price per ton is 24000 USD (https://www.lme.com/en/metals/non-ferrous/lme-tin#Summary) so if you reclaim the solder and sell it for just the half of that money to the scrapyard you already made a pretty good deal.
My approach is always mechanical+heat first, chemicals for last instance.

Pete.

Yes in your case, but I saw many YouTubers just make new recipes to get rid off tin.

What is your last chemical step yo recover tin, do you use HCl then electrolysis method to get tin crystals?

 

[GoIdman]

Yes in your case, but I saw many YouTubers just make new recipes to get rid off tin.

What is your last chemical step yo recover tin, do you use HCl then electrolysis method to get tin crystals?

I just reclaim solder from boards by using heat and a shaking rotating drum. I sell the solder as is, I don`t purify it or do any chemical refining process.

Pete

 

[Thirmo21]

I just reclaim solder from boards by using heat and a shaking rotating drum. I sell the solder as is, I don`t purify it or do any chemical refining process.

PeteView attachment 60668

Thats great method, i also use it.
But i have prtoblem with seperating mlccs, small resistors and similiar small devices from tin as they get mixed together.
Do you have any way to seperate those?

Btw. When i see people on youtube depopulating pcbs with heat gun, drill or air hammer it makes me cringe.

 

[tsfarley]

I just reclaim solder from boards by using heat and a shaking rotating drum. I sell the solder as is, I don`t purify it or do any chemical refining process.

PeteView attachment 60668

Pete, Can you provide details or point me to a thread that gives more info on "heat and shaking, rotating drum"?. I can't visualize that setup. thanks in advance!

 

[GoIdman]

Pete, Can you provide details or point me to a thread that gives more info on "heat and shaking, rotating drum"?. I can't visualize that setup. thanks in advance!

The simpliest setup that i used(it is under reconstruction), is from an old washing machine converted, to be used with either a propane torch and heatgun as well, but you have to control the heat, because it can easaly overheat and burn the PCB's, which will emanate, bad smell and poisonous gases, you can only experiment until you get it right. I dont think there is a universal design, i made mine according to a chinese design, you'll find that on google. Its very simple diy project if you are handyman and have the necessary tools as well.
You can also buy one but it is expensive. I work with small batches so its enough for me.

https://www.gominerecycling.com/e-waste-recycling-machine/pcb-dismantling-machine.html
Something similar but much smaller.

 

[rickbb]

Thats great method, i also use it.
But i have prtoblem with seperating mlccs, small resistors and similiar small devices from tin as they get mixed together.
Do you have any way to seperate those?

Btw. When i see people on youtube depopulating pcbs with heat gun, drill or air hammer it makes me cringe.

Hey now, I use a heat gun and putty knife. But I'm just a hobbyist with small quantities. lol

 

[Shark]

There is short video in the link that will give a basic idea of what he talking about. Not near as big as Goldman is talking about though.

First Small Batch...I'm Hooked!

 

[tsfarley]

Thanks Goldman
that helps alot, I've been mulling over how to get myself out of the clipping components task....
I'll search Google too for some more ideas.
I tested holding a board with tongs over my outdoor deck propane heater, which worked like a charm, I just tapped it on cardboard on the floor and everything fell out. most of the solder fell also. but the smell was bad, so I stopped that idea.
I did find out 1 heater got up to 275F and a second one I had got to 750F measuring with an Atkins thermometer.
I'll give your suggestions a try.

 

[GoIdman]

My first design used a drum from a washing maschine with front loading (see picture 1). My second design will use a drum from a top loading machine (see piture 2).

The photos are just for illustration (downloaded).

Pete

 

[manorman]

Used cheap rotisserie oven, fabricate wire cage, components and solder fall off.

 

[snoman701]

Where are you selling your solder for anything more than hard lead? In what kind of quantity?

 

[Ayham Hafez]

I did an experiment that shortcut tin solder removing before use AR.

I processed 5 kg of mobile circuit boards in one big bucket, soak them in HCL for 1 hour, after that I added nitric acid to make AR, after reaction finished, I filtered the solution very smoothly, so there is no metastannic in the solution, at the end I precipitated gold very well.


But now am a bit confused about the chemical reaction, for first 1 hour, tin chloride should be made by soaking the Pcb's with tin in HCl, next when added nitric acid, gold dissolved but since tin chloride is already in the solution it should be precipitated immediately, but that not happened, again I got same gold amount that usually I get from same quantity.

 

[Darkthirty]

Where are you selling your solder for anything more than hard lead? In what kind of quantity?

Current spot Sn @ 11.19 usd/lb is 2.92 x Cu @ 3.82 Seems to be worthy of investigation.

 

[snoman701]

Current spot Sn @ 11.19 usd/lb is 2.92 x Cu @ 3.82 Seems to be worthy of investigation.

But Cu is sold on a competitive market. Tin / lead solder sells for less than $1/lb at the scrap yard.

That's why I asked if anyone has experience selling it for a competitive price.

 

[Darkthirty]

I did an experiment that shortcut tin solder removing before use AR.

I processed 5 kg of mobile circuit boards in one big bucket, soak them in HCL for 1 hour, after that I added nitric acid to make AR, after reaction finished, I filtered the solution very smoothly, so there is no metastannic in the solution, at the end I precipitated gold very well.


But now am a bit confused about the chemical reaction, for first 1 hour, tin chloride should be made by soaking the Pcb's with tin in HCl, next when added nitric acid, gold dissolved but since tin chloride is already in the solution it should be precipitated immediately, but that not happened, again I got same gold amount that usually I get from same quantity.

Where did the tin go? Is it still in solution?

 

[Darkthirty]

But Cu is sold on a competitive market. Tin / lead solder sells for less than $1/lb at the scrap yard.

That's why I asked if anyone has experience selling it for a competitive price.

tin ingot is selling for 25.00 lb on ebay. edit Not worth your time if your only sales option is a scrapyard

 

[Ayham Hafez]

Where did the tin go? Is it still in solution?

Yes it should be, this is why I ask.

 

[Yggdrasil]

Yes it should be, this is why I ask.

The only way out of that is to somehow reduce it to metal by either chemical or electrolytical way.
Study Tin mining to see how they do it.
An electrolytic cell for Tin is usually hampered by the growth of whiskers.