# Waste Treatment, Unexpected Results



## raschultz62 (Nov 7, 2021)

I tried looking for a solution back through the threads, but as of yet, no luck. I am hoping that one of you fine folks can help me out.

I have been using copper to drop my silver for years with no issues. Early this summer, I had a batch of silver nitrate that I added HCI by mistake, and the very second that I realized it, it was too late to go back, so I ended up using the lye and sugar method to drop the silver. All went well except the ton of waste I ended up with, which it partially the reason for this post.

The waste, a combination of HCI, HNO3, NaOH, Table sugar and water, sat there for the summer. Well now winter is coming quick and it was time to treat it. It was sitting at a PH of between 9 and 10, and I added Sodium Bisulfate (PH Down) to bring my waste down to a PH of 7, which I did. That was 3 day's ago. Today, when i went to do a final filter, I noticed what at first what I thought was ice on the bottom of the bucket, didn't think anything about it though because it dropped below freezing here the last couple of nights. After filtering the remainder of the waste, I realized that is not ice, rather giant crystals. Not sure what I am really dealing with here. This has left me scratching my head. Since I am not used to using this method I am at somewhat at a loss as of what to do next. I need to get rid of this, but I want to make sure it is safe to do so.

So, if anyone can chime in and give me an idea as to what these crystals are I would very much appreciate it. Also, not sure this is relevant, but the solution has a yellow tint to it.

I know some people like this method, but if not for my mistake I would have never used it. Way too much waste to deal with!

I appreciate any help in advance


----------



## Marcel (Nov 7, 2021)

I like dropping silver by putting the nitric solution out in the cold.
Acids lose their power with dropping temperatures, so they "free" the bonded molecules.
You can also experiment using silver in very dilute nitric acid, heat it and boil it down until the silver gets dropped as crystals. Then add a little of water and within seconds the crystals disappear - into the solution again.
I would bet - let us say a dollar - that those crystals are pure silver.
But I am not an expert on silver. Someone else may have a better explanation.


----------



## raschultz62 (Nov 7, 2021)

Marcel said:


> I like dropping silver by putting the nitric solution out in the cold.
> Acids lose their power with dropping temperatures, so they "free" the bonded molecules.
> You can also experiment using silver in very dilute nitric acid, heat it and boil it down until the silver gets dropped as crystals. Then add a little of water and within seconds the crystals disappear - into the solution again.
> I would bet - let us say a dollar - that those crystals are pure silver.
> But I am not an expert on silver. Someone else may have a better explanation.


There was no silver left in that basic solution. If those crystals actually silver I would have hit the Jackpot!


----------



## Marcel (Nov 7, 2021)

Ok, I may have lost that dollar then :-(
I buy you a drink if we meet, ok?
Lead forms crystals but they do look like needles.
Any photo?


----------



## olawlor (Dec 7, 2021)

raschultz62 said:


> The waste, a combination of HCI, HNO3, NaOH, Table sugar and water, sat there for the summer. Well now winter is coming quick and it was time to treat it. It was sitting at a PH of between 9 and 10, and I added Sodium Bisulfate (PH Down) to bring my waste down to a PH of 7, which I did. ...
> 
> So, if anyone can chime in and give me an idea as to what these crystals are I would very much appreciate it.


Highly likely these are a mix of salts, like Na Cl and Na2 SO4 (probably as the hydrates). Unless your winter is very cold the Na NO3 is probably still in solution. You might verify the salts dissolve in hot water, but they should be treated like the rest of your solid waste from refining.


----------



## orvi (Dec 7, 2021)

sulfates arent spectacularly soluble at low temperatures. very possibly some sodium sulfate/chloride mixed salt. 
if there are chloride ions in solution, silver would drop out as powder. 
set it aside... or get it to some more water, mix it in as a solution and continue with stock-pot.

i think no big deal. sodium sulfate decahydrate (as supposed above by olawlor) form big crystals, i would bet it is Na2SO4 or something similar.


----------



## Topher_osAUrus (Dec 7, 2021)

Sugar?


----------



## orvi (Dec 8, 2021)

Topher_osAUrus said:


> Sugar?


also possibility. NaCl and glucose form nice co-crystals. if sucrose was used and enviroment was still acidic (hydrolysing sucrose to glucose and fructose), this could be it. or not  my bet is bit of everything  
need more testing, if the curiosity is the driving force. if not, it does not seem to hold any values and does not seem to involve anything toxic (from what was said to us). dissolve and dispose


----------



## Martijn (Dec 8, 2021)

If there was sugar, NaOH, and nitric acid involved: oxalic acid crystals maybe? 

Really.. it could be anything. Without chemical analysis you'll never know for sure. Dilute to dissolve and treat as waste is what I would do. I don't think it's worth analyzing and trying to recover. 

Depending on how much HCL you added to the batch of silver nitrate! : 
You should keep adding until no more white cloud forms upon HCL additions. Did you do that or just accidentally added a bit of HCL and then went for the lye / suger method?
If so, after dilution you could add a piece of copper to check for silver before treating as waste. Or test a bit with HCL. 
Should you decide to save the crystals in a jar, label it with "dangerous unknown crystals"!

Martijn.


----------

