Sciencemadness Discussion Board

separation of lead from tin in ppm level

kumarsriit - 3-1-2011 at 02:24

I have pure tin (99.9%). I want to electrolytically refine it to 99.999%. Main aim is to remove Pb(which is in ppm quantity) from the pure tin(99.9).Also want to remove Bismuth from 99.9% tin.
Any suggestions how to do this.

plante1999 - 3-1-2011 at 05:34

generaly the lead and the bismuth is more chemicaly resistan than the tin

you can rafine it electrochemicaly.

kumarsriit - 7-1-2011 at 02:46

how to separate tin and lead at ppm level

kmno4 - 7-1-2011 at 05:30

Quote: Originally posted by kumarsriit  
I have pure tin (99.9%). I want to electrolytically refine it to 99.999%. Main aim is to remove Pb(which is in ppm quantity) from the pure tin(99.9).Also want to remove Bismuth from 99.9% tin.
Any suggestions how to do this.

I know that by electrolysis (Sn anode/cathode, SnSO4 sol.) easily you can get 99,995% Sn. Possibly, repeated (few times) process can give you higher Sn content.
If you want to remove ppm Pb, the only "simple" method I know is zone melting.

I have just found free article about zone melting and tin:
Code:
http://www.informaworld.com/smpp/ftinterface~content=a762701496~fulltext=713240930~frm=content



[Edited on 7-1-2011 by kmno4]

blogfast25 - 7-1-2011 at 10:31

Quote: Originally posted by kmno4  
I know that by electrolysis (Sn anode/cathode, SnSO4 sol.) easily you can get 99,995% Sn. Possibly, repeated (few times) process can give you higher Sn content.
If you want to remove ppm Pb, the only "simple" method I know is zone melting.



You say ‘easily’ but I think that’s true only as in ‘theoretically easily’. When I electrolysed a solution of SnCl2 (12 V, 4 A) I got quick formation of what you could call a ‘tin tree’ but while the tin in there may well be highly pure it’s more like tin sponge, with loads of electrolyte locked into it. To properly obtain solid tin metal specific conditions of voltage and current densities are required, or so I believe. If you have any information/experience with those conditions I’m all ear.

Interesting stuff about zone refining… Good luck with rotating to 3000 rpm though!

[Edited on 7-1-2011 by blogfast25]

kmno4 - 7-1-2011 at 12:31

The method I gave is normal practical procedure. Exact formula you can find in Karakin and Angelov (page 435). There is also variant with SnCl2 but in this case Sn is obtained as thick powder.


[Edited on 7-1-2011 by kmno4]

blogfast25 - 8-1-2011 at 12:58

Karakin and Angelov (page 435): if you have those conditions at hand could you post a summary here?

purifying tin

kumarsriit - 23-1-2011 at 23:35

Is "karaklin,angelov" name of the book. If it is what is the complete name of the book. Also can give the condition (composition, current etc) to get 99.999% tin by electrolysis in stannous sulphate-sulphuric acid system.
Thanks

kmno4 - 24-1-2011 at 02:53

Ю.В. Карякин, И. Ангелов - "Чистые химические вещества"
(in Russian of course). You can find it freely available in DJVU format, however it seems to me that I have seen also PDF version of this book.

kumarsriit - 24-1-2011 at 18:13

@Kmno4
The russian language book you mentioned in djvu format has 402 pages. how to get the process u mentioned in page 435. Is there english version of this book available. please respond.
thanks

kmno4 - 24-1-2011 at 22:12

I gave page number from another edition of this work.
You have to search a word "oлово" = tin in Russian and possibly it is on page 295. In another case - use index and search "oлово". Unfortunately I know nothing about English edition.
The most possibly it is not translated at all.
Very pity, because I know only few words in Russian language. :mad:
However, translation of this particular preparation is not very difficult.

@KMno4

kumarsriit - 7-2-2011 at 20:38

can you please get the russian translation of that particular page mentioned in earlier post regarding tin refining. It not be necessary in chaste english. at least paste the translation of brief summary of process.

Mixell - 8-2-2011 at 05:46

Just post the link here, and I will translate the text (from Russian of-course).