trouble with drop using MSB

[kjdave]

Thanks for all the great posts. I must spend 3 hrs a day just reading and trying to understand it all. Also thanks to steve for your great website and reasonable products and videos. I am 62 years young and haven't had this much fun in a long time. We should all get together and have a Party/confrence some where. I have all sound gear and video equip. to donate to the effort.
so to my question:
1) I have about 1 out of 3 of my drops using msb fail... i warm the Ac up just a little and most times it works fine with just a little msb added while i stur .... but lately i have been getting this orange liquid after i add the msb. it never clears and turns black & drops. I am working with gold boards processed in AP for the most part, My fluid tests positive with sc, befor and after the attempted drop, so i know there are values in it. the reddish orange liquid is a puzzle to me. can't find any posts that address it so here i am. any thoughts or ideas of how to proceed would be appreciated and if anyone else has adderessed this issue a link to help me along. I thought i might run the whole thing threw a graphite cell to drop out all the metals and start again. or is there a better approach? this by the way works great to clean up ap solution before reuse.

2) is there a good way to deal with spent msb liquids?

In the way of additions to the forum: Ihave found by tilting your flask and gentely bumping the bottom edge with a rubber handeled plyer causes the drop to move to the edge so siphoning can be done easer. it is similar to when you bump the side of your gold pan to move the gold to the edge of your pan.

 

[Geo]

kjdave, welcome to the forum.

did you check out the guided tour? it will get you acquainted with the chemicals and their abbreviations.the chemical you are referring to is sodium metabisulfite (SMB) by the way,also you will find there, post on how to deal with your waste after refining.

red in solution can be a couple of things, the major being iron in electronics.you said you tested and got a positive before and after adding the SMB. is this an AR solution or a hcl/Cl solution? you may have a free oxidizer thats prohibiting the drop either free nitric in the case of AR or Cl in the case of hcl/Cl. we need to know which one to give you any kind of help with this.

 

[butcher]

kjdave,
No need to use graphite and electrolysis to remove all metals from your solution, a copper buss bar would just cement values from solution, leaving the metals copper and above in the reactivity series of metals in solution, but this would only be used when you can not get the values from regular precipitation techniques, or in your stock pot.

 

[kjdave]

thanks for your reply.... for the last 4 months i have read quite a lot so when it comes to putting it down on paper i got a little convused. I did Mean SMB of course .. i love this no nonsense group, as it should be since one could kill themselves here if not carful.

Geo: i use a cell like steve's on big things but only cleaned it up once so far. my main method is HCL/CL. if you mean too much CL, i was wondering if that might not be the case (adding too much CL i guess you mean) my test was on an HCL solution. thus far i only use the nitric i made to clean up my nugets i make. i am thinking of using the great video on Utube in this post looks simple and very clearly presented.
butcher? did you mean if i use a copper anode or diode with graphite it will only drop the values? got a link or explain exactly what you are saying?

thanks for all your help.

 

[Geo]

by adding too much Cl in the form of bleach, the SMB has to fight the free Cl to precipitate the gold.

this is whats happening. the gold precipitates out molecule by molecule which sticks together. as the SO2 created by the SMB reacting with water precipitates the gold, it is almost instantly re-dissolved back into solution by the free oxidizer.chlorine gas will evaporate from solution at ambient temperature over time, so a hcl/Cl solution, if left uncovered will evaporate all the free chlorine. usually overnight is all it takes. you can speed this up by warming the solution to a steam and keep it there, it will drive the chlorine out of solution much faster.

as far as using copper to recover PM's from solution. its a matter of cementation, no other equipment is needed, just copper. the electromotive series of metals tells us that as copper is dissolved into solution, metals thats higher in the series will be pushed out. copper is not selective, it will precipitate all metals higher on the scale which includes all the PM's (silver,gold and PGM's).

 

[FrugalRefiner]

the electromotive series of metals tells us that as copper is dissolved into solution, metals thats higher in the series will be pushed out. copper is not selective, it will precipitate all metals higher on the scale which includes all the PM's (silver,gold and PGM's).

Geo, I don't want to nitpick, but copper cements out metals that are lower in the electromotive series. I keep it straight in my head by thinking the elements higher in the series are more highly reactive, i.e., they want to react and go into solution. Elements lower in the series are lower in reactivity and so they don't want to be in solution, therefore they precipitate out. Just don't want to confuse the new members.

Dave

 

[Geo]

of coarse, i was typing faster than i was thinking. thank you for pointing that out and straightening it out.

 

[kjdave]

so am i to assume that only platinum will drop gold since it is the only metal higher on the EM series?

 

[philddreamer]

so am i to assume that only platinum will drop gold since it is the only metal higher on the EM series?

No, that's incorrect! Platinum is below gold.

You need to take a look at the Reactivity Series chart so to understand the "above and below".

http://www.zephyrus.co.uk/thereactivityseries.html

I hope this helps.

Phil

 

[FrugalRefiner]

Actually, I think it gets more complicated here. Most reactivity tables aren't very complete. While most show platinum, few show any of the other PGM sisters, and I believe they can do some tricky things with changing valences. I've seen reactivity tables with gold lower than platinum and others just the opposite.

You would probably be better served by following traditional methods when it comes to separating the two.

Dave

 

[kjdave]

thanks again for all your support... i will try to get my head around what you are saying. I was secretely hoping to solve a witches brew delema i have with the cementation trick. but there no tricks just accurate science. (when the tried and true fail i gotta figure out what I did wrong not what was wrong with the system)

 

[kjdave]

ok i think i got it copper will drop out gold plat. etc since everything else is below it. where graphite is neutral and will drop everything.

 

[philddreamer]

ok i think i got it copper will drop out gold plat. etc since everything else is below it.

Bingo! 8)

All it takes is studing & searches; when you have questions, ask them, we are here to help. Your question will give us a clue if you have been studing or not. :mrgreen:

Take care & be safe!

Phil

 

[kjdave]

I would never clame to be the sharpest stick in the box but with your kind assistance i can get the job done. by the way it is working great finally. you are all to be commended for your devotion to the craft.

 

[FrugalRefiner]

ok i think i got it copper will drop out gold plat. etc since everything else is below it. where graphite is neutral and will drop everything.

Sounds like you've got the right idea with copper cementing gold and platinum (as well as silver, palladium, etc.) because of their position.

But another factor is that the element you're using to cement (copper in the example above) must be soluble in the same acidic solution in order to react. So, since silver isn't soluble in chloride solutions like AR or HCl/Cl, you can't use it to cement gold.

Graphite isn't really soluble in the mineral acids, so it can't be used to cement anything. It can be used as an inert anode and/or cathode in certain electrolytic processes.

It's really easy to get confused and mix up parts of different processes, but it can also be very dangerous. Keep studying until you really understand it all before you open your first bottle of chemicals and be safe.

Dave