Remove tin solders

[Ayham Hafez]

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.

Do you have idea about this:

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.

 

[niks neims]

Over here in eastern europe not only we buy industrial quantities of "pure" tin (including "recovered" from PCBs) for about ~15 eur/kg, we also buy tin dross/slag from PCB production (including wave solder) companies for about ~10 eur/kg...Any impurities of Pb, makes price go down considerably, though

 

[snoman701]

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

Also not worth your time if your only sales outlet is eBay. I have sold literal tons of industrial solders on eBay and while you can move it, you can't move it in the quantities required to actually make consistent money. It sells to hobbiests.

Hence the reason I ask, are there sellers selling reasonable quantities of tin, at competitive prices. 100+ lbs a week but not 40,000 lbs.

 

[kurtak]

An electrolytic cell for Tin is usually hampered by the growth of whiskers.

Yes tin whisker growth is a real problem in a cell - the whiskers grow very quickly between anode & cathode causing the cell to short out - if you don't keep a very close eye on the cell to keep the whiskers knocked down

You can (at least somewhat) over come that problem by setting up a roller that rolls over the cathode every so often to knock the whiskers down using a step motor &/or timer to turn motor on/off to operate the roller

The only way out of that is to somehow reduce it to metal by either chemical

If you have tin in solution (dissolved in HCl) you can cement the tin out with zinc - you have to get the chem WELL washed out of the tin cement - dried & melted right away (actually smelted as you will need some flux)

The tin cement will start to oxidize rather quickly (even with the chem well washed out) so you need to dry & melt it ASAP or you will need to use more flux with more tin going off in the slag

you don't need to completely dry it - just drive off enough of the water (on low heat) so you don't get a steam explosion at actual melt temps

Kurt

 

[kurtak]

Also not worth your time if your only sales outlet is eBay. I have sold literal tons of industrial solders on eBay and while you can move it, you can't move it in the quantities required to actually make consistent money. It sells to hobbiests.

Hence the reason I ask, are there sellers selling reasonable quantities of tin, at competitive prices. 100+ lbs a week but not 40,000 lbs.

I used to sell my tin to a guy that did bronze casting for $18 a pound - he would buy 30 - 30 pounds at a time

Kurt

 

[snail]

Also not worth your time if your only sales outlet is eBay. I have sold literal tons of industrial solders on eBay and while you can move it, you can't move it in the quantities required to actually make consistent money. It sells to hobbiests.

Hence the reason I ask, are there sellers selling reasonable quantities of tin, at competitive prices. 100+ lbs a week but not 40,000 lbs.

I had a Michigan company, Mayer Alloys, express interest in 300 lbs of 53% tin content Babbitt I was trying to sell. Lead tin alloys and solder appear to be their specialty. I never got as far as an offer because of distance issues.

Wound up doing a deal with a local company on XRF results. Had it cast into 30lb ingots of uniform analysis. It was a battle to get a deal, many companies would not even talk to me because of conflict metals reporting issues.

 

[goldenfrog]

Mine is a simple question. I have 159grams of gold pins from a communication board. Heatgun to remove but caked with tin solder. I soaked in hcl for a week but now all my pretty gold pins are coated with tin solder. Should I just try hcl again to remove what seems to be re-plated tin? Or does this mean my pins are not actually gold plated to begin with?

 

[Martijn]

The gold will be there, but the base metal core is more reactive than Tin (Probably iron), so it will keep cementing or plating back on it i'm afraid.
Have you tried AP on a few pins?

 

[anachronism]

Martijn is correct. Don't worry your gold is under the Tin! I remember the first time it happened to me too, I was scratching my head for days.