# Making photo grade silver nitrate



## Danasullivan (May 6, 2010)

Hi folks, I'm new to the forum, so I hope to break the forum record for the longest, most rambling and incoherent first post! Bear with me, while I explain myself.

My company sells kits, chemicals and gear for antique photographic processes. I currently make a few precious metal compounds like Gold Chloride, Palladium Chloride and Potassium Chloroplatinite and have recently started making my own Silver Nitrate.

My question is this: How do I obtain the greatest yield without having lots of leftovers to reclaim and refine?

Today I made some Silver Nitrate and it went like this:

1.Digested 10.22 troy ounces of .999 silver using 340ml 70% HNO3 in a 4 liter flat bottomed flask on a hotplate set to 220C.
2.Reduced solution until the solution started to form a skin of crystals on the surface, then removed from heat.
3.Added 25-30 ml 70% Nitric Acid to help the Silver Nitrate crystals precipitate. Cooled in a water bath and then to about ~30F in the freezer.
4.Removed excess liquid from crystals using a Buchner funnel and flask under vacuum. Saved the mother liquid (70ml) and set aside.
5.Flushed crystals with 400ml of Acetone chilled to 0F to remove excess Nitric Acid and water.

Total yield was 481 grams of fine white crystals. Theoretical yield is 511, I believe.

How do I get the extra 30 or so grams of silver nitrate that is trapped in that mother liquid without jumping through hoops?

Should I just take the mother liquid and add it to the reaction flask the next time I make more Silver Nitrate, since it's already Nitric Acid from step 3 above? Any recommendations or hints for this silver newb? Do I take the liquid and precipitate silver chloride and then go through the process to turn it into elemental silver, or is that too much work?

Another question: Does anyone use Hydrazine Dihydrochloride as a reducing agent? When I make Potassium Chloroplatinite, I'm often left with a small amount of liquid containing platinum salts. I save up the liquid and reduce the platinum out using sodium carbonate and Hydrazine Dihydrochloride. Just a thought.

Thanks for reading my post!

-Dana


----------



## Oz (May 7, 2010)

What you are doing is less labor intensive than trying to chase every gram out since for photography purity is critical. You will save yourself much grief by just saving solutions and incorporating them into your next batch.

I can not say for sure if will affect your photographers end product (the developed picture) but I would stay away from the acetone as a drying agent. It has a high vapor pressure but even so it is just another potential contaminate.


----------



## Lou (May 7, 2010)

Dana,

When I saw your user name, I immediately thought of Bostwick and Sullivan. Why? You mentioned photography. Am I right in my presumption? If you are affiliated with that fine company, I've heard nothing but the best about you guys.

To the forum: Bostwick & Sullivan is a very good company (or so I've been told my numerous friends as well as other people on various forums dedicated to photography and amateur chemistry). 

I intend to address all of your questions in *explicit* detail sometime this weekend! Especially any questions regarding platinum, palladium, and the rest of the other platinum group! I'd also like to discuss some photochemistry if you're willing  I've been meaning to setup a dark room for pure recreation in the art and science of photography.


I'll be out of town most of this weekend, but Sunday evening I should have some thing that you may find useful.
I can help you with your hydrazine hassles--I've used it extensively until switching to switching to hydrogen about 2 years ago.

Best regards,

Louis


----------



## Juan Manuel Arcos Frank (May 10, 2010)

Dana:

My Grandfather was a photograper,my Father was a photographer too and I am the third generation of photographers in our family.In the mornings I take photos,in the afternoons I recover silver and gold.

You are doing it pretty good,I am sure that you can make it better,take a look to this patents about silver nitrate.

Kindest Regards.

Manuel


----------



## Juan Manuel Arcos Frank (May 10, 2010)

The last two.
Manuel


----------

