How much nitric is needed to dissolve 1 gram of BM ?

[razvanflorin]

Hey ! I Would need an information how much Nitric Acid is needed to dissolve 1 gram of BM (CuZn) ?

Thanks in advance !

 

[nickvc]

GSP has posted this many times, maybe not for all metals but I know it takes twice as much nitric to dissolve copper than silver.
Try a search with GSP as the author you should find what you want.

 

[kurtak]

GSP has posted this many times, maybe not for all metals but I know it takes twice as much nitric to dissolve copper than silver.
Try a search with GSP as the author you should find what you want.

Actually it more like 3.5 - 4 time more to dissolve copper then nitric - a gallon of nitric (68 percent) will dissolve around 7 or 8 lbs of silver but only about 2 lbs of copper

Kurt

 

[4metals]

Those numbers (that Chris and others posted) are for the stoichiometric reaction, where every molecule behaves and reacts proportionally. In the real world temperature and concentration effect different off gassing rates which can effect efficiency. In practice you will always digest less than the stoichiometric proportion calculated on paper.

 

[goldsilverpro]

I always assume the worst case ( meaning the most nitric used) would be when dissolving in an open container. I have never given stoichiometric values for nitric or for aqua regia. All my numbers are based on actual usage from my 1000's of experiences doing this, in which I usually used an open top container.

At worst case, 4.2 ml of 67 percent nitric diluted with 4.2 ml of water (distilled water, if silver is involved) should dissolve about 1 gram of, say, a 70Cu/30Zn alloy.

If you cover the beaker with a watch glass during the dissolving, it could somewhat improve this.

If you're able to totally recycle the off gases back into the system, it will, at best case, only take about 1/2 of the worst case above. This 1/2 would be the stoichiometric amount.

 

[4metals]

Ideally in a digestion setup a reflux reaction would give the best life to your acid as it recycles a good fraction of the off gassing NOx. I only see this in larger operations although it is attainable on a small scale as well.

 

[Topher_osAUrus]

Ideally in a digestion setup a reflux reaction would give the best life to your acid as it recycles a good fraction of the off gassing NOx. I only see this in larger operations although it is attainable on a small scale as well.

Do you have any pictures of the "larger operations" reflux setup?

I love it when you post pictures 4metals.
Its like christmas.

 

[kurtak]

Just to add to what 4metals & GSP posted here is something I posted a while back :arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=22286&p=233294&hilit=electrolyte#p233294

Kurt