my first attempt to refine...

[dcurzon]

So yesterday i had my first attempt. Started out with 130gm's of .925 earrings/chains etc, including one big blob of previously melted 925 weighing approx 25gm.

i put 175ml de-ionised water into beaker, and added 175ml 70% nitric.
i added to this my silver.
All went well, started getting my reaction immediately, then 30 seconds in, the red smoke. After about 1.5hrs, reaction was completed. But i had some clear CRYSTALS at the bottom of the beaker. Not sure what they were.

Filtered the crystals/crap (couple of stones from earrings etc)out, and added my copper pipe. Left it overnight and returned in the morning. This had seemed to complete, so filtered it (keeping the silver cement, waiting for it to dry now).

I decided to pop some copper into the fluid that was filtered off, and sure enough, seems to be getting more silver out of it, so i have left that running whilst i went to work.

so far happy with how it has all gone

some questions:

1. does everything that i've done seem ok? Didnt have internet access at the time.

2. de-ionised water. couldnt get distilled, but i believe this is much the same stuff?

3. clear crystals. no idea what they were. any clues?

4. is it usual to do the copper cementation to seemingly finish, and then to be able to extract more afterwards?

5. my 25gm lump didnt break down in the nitric acid. It's still a lump, allbeit only 20gm now. Not enough acid used? what should the correct silver gm/ml formula be?

6. is there a way to work out how much silver you should have AFTER refining? my maths looks like this:
130(gm) - 20(gm) = amount of silver dissolved (my starting amount less the lump that didnt dissolve)
110(gm) x .925 = 101.75(gm) less (guessing)2% refining loss = 99.7(gms)

many thanks, sorry for all the q's

 

[Barren Realms 007]

I all of your nitric was not used up it could still dissolve your silver that you cemented out.

 

[goldsilverpro]

The crystals are likely silver nitrate which should dissolve in water (maybe, warm water). The heat from the reaction probably evaporated enough water so the solution was over saturated with silver nitrate. For this same reason, I usually add some extra water immediately after the silver is dissolved.

DI water is fine to use instead of distilled.

If you have any free nitric left in the solution, it will dissolve copper first. When all the free nitric has been used up by the copper, the silver will cement.

 

[dcurzon]

thanks for the A's

i'll dissolve my 'lump' in with my next batch, whenever that may be. I was looking to create small bars of 100gm's each.

 

[dcurzon]

so i got home last night, and checked out my '2nd cementation' of the fluid. I was quite amazed that the amount of silver that came out was about equal to how much came out first time, and very thankful that i had decided to pop some copper in just in case.

waiting for it all to dry out

 

[dcurzon]

looks like i got sloppy on the gloves. I have black silver nitrate marks on my hands so assume that some was on the outside of my beaker.

*Lesson learnt* dont take it for granted that there wont be chemicals where i dont expect them to be.

also, my disposal of the spent nitrate has left black stains. Looks like i should have waited for more silver to drop out.

*lesson learnt* patience, grasshopper

 

[Harold_V]

looks like i got sloppy on the gloves. I have black silver nitrate marks on my hands so assume that some was on the outside of my beaker.

*Lesson learnt* dont take it for granted that there wont be chemicals where i dont expect them to be.

also, my disposal of the spent nitrate has left black stains. Looks like i should have waited for more silver to drop out.

*lesson learnt* patience, grasshopper

Can you say "test"?
Testing is one of the most important functions you must learn and do.

Harold

 

[dcurzon]

Thanks Harold... to be honest, i dont think the sarcasm was really called for.

I made a partial error, i recognised my error and learned from it. I have realised that i ran before i could walk and am currently working my way through Hokes' (which is a phenomenally interesting read) so that i can gain further knowledge and more importantly, understanding. i realise that you probably read way too many novice 'ive messed up please help' type posts, and this thread is not going in that direction i hope, more like 'i messed up but heres what i have learned from it'.

 

[Harold_V]

Sorry you interpreted my comment as sarcasm. It was not intended that way, but the message is clear. All too many of you guys think you can jump in blindly and achieve your goal of processing. It simply doesn't work that way. Even after refining for more than 20 years, no solution was discarded without being tested. Your situation was brain dead simple---a test of a drop of solution with a drop of HCl, or a crystal of salt. Done. No precipitation = no silver. White formation = silver. I can't begin to understand why you, or anyone, wouldn't conduct that simple test before discarding.

I would suggest to you that you don't make an issue of this. I'm very short of patience with anyone that chooses to argue over an issue that is of their own making.

If I appear to be somewhat sensitive to your lack of testing, there's more than good reason. Some members of this board have proudly proclaimed they don't have need for stannous chloride, and likely don't feel testing of any kind is worth the effort. With an attitude like that, there's no reason I can think of to even try to help them. In all their wisdom, they, above all others, seem to know what they must know, and what isn't important. I have no way of knowing if you're one of them, or not.

So then, learn to test, and read Hoke. Otherwise you'll come to understand that you won't get much help on this forum. We're not here to hand feed people that think they are entitled---we're here to help folks that work hard but get tripped up over issues----and we do it happily (in most cases).

Harold

 

[dcurzon]

fully understood, and thankyou for filling in the picture )

i appreciate that folks as experienced as yourself and others on this forum have probably come across almost every viable problem at some stage or another and applaud the time and effort that you put in to helping others