Need help with nitric

[Anonymous]

First off Im sure I have my percentages off.Im using 600ml 67% nitric with 600ml water,breaking it down into 2 baths of 600 ml each and processing about 100g of pins in each bath.Also how do I dispose of the used nitric.
Johnny

 

[lazersteve]

John,

You could process them a lot cheaper than using up your good nitric by using the crockpot and HCl. AP should do the trick also. Nitric is by far the fastest way.

Assuming the pins are copper based, the amount of nitric you're using should be about right. The copper nitrate formed works great as an electrolyte for processing sterling silver to prepare it for the silver cell. Use the copper nitrate after filtering it when you are done with the pins reaction, the anode is made from the sterling silver scrap melted into a bar and the cathode is a piece of hard graphite or copper mesh (I prefer the graphite).

Dry Copper nitrate crystals can also be used to make more nitirc acid by decomposing them around 175 C and bubbling the NOx vapors through distilled water.

Steve

 

[Anonymous]

Thanks steve.I only used it because I got impatient.I tried the crockpot method a couple of months ago and it went horribly wrong(as usual).Oh yeh that charmin filter trick has done wonders for me.I don't seem to have that white powder problem anymore.Also I have tried countless time to get a hold of the gentleman with the watch cases and I think hes been out of town or something.I have a couple of very large beakers coming,and jack has been doing well using them in the crockpot with the sand,so I may try that.Thanks for everything.
Johnny