Fell in Love With Science Tonight - Cemented Silver 1st Time

[kadriver]

Hello:

I took the advice of the forum and studied the Hoke Book (got it downloaded pdf). I was doing the Aquaintance Experiments on page 15.

I dissolved a piece (.1 gram) of sterling silver in a test tube with 20 drops Nitric Acid. Got a little gas and fumes. Heated it and it realy took off!

I had on splash goggles, nitrile gloves, respirator and a good cross ventilation going through the garage.

I let it cool and a slush formed. So I added 20 more drops of nitric acid and reheated because the silver (sterling off a candle stick holder) was still in the slush.The slush dissapeared when heated and the metal began to dissolve some more.

I cooled it again, added 20 more drops of nitric and this time the acid completely dissolved the silver metal - I was amazed because the solution was crystal clear with slight bluish tinge.

I put a few grains of urea to neutralize, then added a few ml of distilled water to dilute.

Took a piece of heavy gauge copper wire from the garage (about 1 1/2 inches long) and formed it into a circle. Then I tied a string on it and dangled the copper in the solution.

What happened next made my jaw drop - the silver immediately began to form on the piece of copper - faster than I expected.

This may be very elementary to most of you, but to me it was a very satisfying and exillerating experience. I'm not a big chemistry type person, but I think that may change.

I can't wait to do my first small batch of gold. Thanks for listening and looking.

 

[nickvc]

It's good to do small experiments to start as it gives you a feel of what to expect when you start doing bigger volumes.
The only thing I would say is you should have used water and nitric, 50/50 mix it uses less acid and works more efficiently but keep up the good work and read till your eyes bleed so you really know what's what.

 

[qst42know]

Where's the blue?

The resulting solution should be copper nitrate which is a deep royal blue.

The copper will consume any remaining nitric so the addition of UREA is not required, and I don't know chemistry well enough to know if urea would cause problems.

Perhaps one of the chemists on the forum could comment on this?

 

[goldenchild]

Where's the blue?

The resulting solution should be copper nitrate which is a deep royal blue.

The copper will consume any remaining nitric so the addition of UREA is not required, and I don't know chemistry well enough to know if urea would cause problems.

Perhaps one of the chemists on the forum could comment on this?

I see a slight tint of green/blue. I bet the starting silver was pure so no color when dissolved in nitric.

 

[Platdigger]

I am curious about the use of the urea in this, could that have had somethin to do with the fast cementing reaction?
I will have to try this.

My experiece, at least from dilute solutions, and without the use of any urea, is that the cement silver is much brighter, but takes much longer to form.

 

[butcher]

Great job kadriver,
Some things I will comment on, I would not do this in a garage, these fume will dissolve your tools and stuff in the garage. this looks from picture like a test tube so you shoul be safe for now.
urea is not needed, lowering PH to much can cause trouble as some acid is needed as this is a displacement reaction, your solution will normally turn blue even if the silver nitrate was pure silver and nitric acid as some of the copper buss bar will dissolve replacing the silver from solution, here you lowered the acid content so either you still have silver in the liquid, or the liquid has used up all of the nitric and will not remove copper, i would try adding a little few drops nitric to the decanted solution and adding a clean piece of copper to see the reaction, that can tell you if there was silver left in solution or not.
Also I save my copper nitrate solutions you can get back some nitric from them or use it in cell projects, or other uses.

You would be better off using a copper buss bar for the copper (can be found in old electrical panels), some silver will plate to the copper but most of the pepper looking powder will shake off easily, save the buss bar for this purpose, you can melt that pepper looking silver powder back to silver metal. Another exiting thing you will love. Using the torch to watch pepper form a shinning button of silver metal.

congratulation’s you are becoming a refiner, and having fun learning, keep us posted on your experiments and the study of Hoke's book, and thanks for helping us to encourage a new forum member to read her book, as if they read it and learn we all become more informed as a group, and less time is wasted trying to explain the basic's, for the millionth time.

This is an experiment I like to show young people to get them interested in chemistry, a silver metal, turned to clear liquid, then magically forming pepper that turns back to metal under fire, I usually show the silver chloride precipitation along with it (mixing two clear liquids AgNO3 + NaCL-H2O  AgCl + NaNO3+H2O, explaining how silver can be in the clear solution AgNO3 as dissolved metal, just as they watched the salt dissolve to a clear liquid. Share this with a young man; make a friend helping him to get excited about learning.
Again Great job, I guess your hooked now, another metal refining addict to our list of members.

 

[kadriver]

Thanks for your interest and all of your inputs. I will try 50/50 water & Nitric acid.

I also did this experiment on two gold plated 925 earring posts (just the posts, <.1 gram)

To my amazement, the acid dissolved the silver and left two tiny "tubes" of gold plate.

I will get these out of the liquid and save for refining later on when I graduate to gold.

Thanks for your encouragement Butcher. You should see my lab. My wife did not complain
about the money I spent either.

I do not plan to do any more reactions in the garage. I will do everything else outside
on a big wooden table inside a large plastic tub. I got a tiny wiff of the red gas when
I took my respirator off too soon to do some writing. Smelled it all day long after that.
I won't do that again - lesson learned.

I want to do a larger batch of silver tomorrow (Sunday) about 100 grams of silver metal.
I will do it in a large pyrex coffee pot with a heavy glass lid I bought off Ebay for this purpose.
I only have one liter of Nitric Acid (minus about 20ml for experiments).

How much acid/water should I use for this batch?

I will get a copper bus bar and use that as suggested.

I can't wait to fire up my new Oxy/Acet torch and melt some silver bars.

This is really a great forum and you folks are really helpful - Thank you all.

 

[butcher]

I have read 1.4 ml 70% then diluted 50:50 would dissolve a gram of sterling if my memory is correct, I belive GSP stated it, but I could be wrong as usual, I am sure he will correct me if I am. I really do not measure so I am in the dark on this.

 

[butcher]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=39&t=534&hilit

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=37&t=7021
these may help you with the figures.

 

[kadriver]

If you are new to this forum and to refining, then get Hoke's book and READ IT.

I was reviewing my day last night before I went to sleep.

During this review I realized that I was getting ahead of myself again
(this is one of my character flaws). Something did not feel right about
my proclaimation that I was going to dissolve 100 grams of scrap silver
jewelry.

I was reviewing Hoke and there is was right in front of me on page 74: SILVER

As I read, I realized my mistake: I was getting ready to dissolve a large
quantity (for me anyway) of silver using information based on an experiment I performed
out of the GOLD REFINING SECTION of Hoke.

I am going to do some more study before I move on to bigger and better things.

By the way, what is GSP?

Thanks for listening - kadriver

 

[kadriver]

Butcher: I went to the post by GSP (know what that is now) and there was write-up of the amounts needed that has answered my question perfectly. I actually copied and pasted, then printed it out. I am building a reference library of information and I will add this to it.

Thank You
kadriver

 

[butcher]

Well a GSP is a GOLD SILVER PRO, and heck get his book too, you never can learn too much when it comes to refining, and GSP Chris has put 40 years of professional expierience in his book for you. yes most of us tend to jump the gun when we start learning to refine, you are ahead of most of us, you are studying, and realize you get ahead of yourself, take time learn that 100 ounces of silver can wait on you.