extracting silver from galena

Hi everyone !

I guess some people here have never seen what happens when a mixture of hydrogen peroxide and nitric acid goes bang....

My really sincere advice is: never ever mix such dangerous chemicals. I worked in a company which had a process step where acidic peroxide solutions were used. And I know how people look like after accidents. Nitric acid is already very bad but adding hydrogen peroxide to it is calling for accidents. These solutions can spontanously start to boil and one drop of the liquid getting in the eyes means blindness. An experienced person may handle small amounts in a fume hood but using this for bulk treatment is a hazard. And also if you try to buy such amounts of nitric acid and or peroxide the secret services will come after you thinking you want to build explosives.

And then afterwards to have to get rid over a lot of contaminated liquid..... very expensive if you follow the regulations - shame on you if you do not.

Peter posts a lot of warnings - listen to him - he usually is right

Holger,
If you mix fairly concentrated nitric acid with hydrogen peroxide then yes, you are asking for trouble. However, if you generate nitric acid in situ as I suggested from zirconium nitrate as I suggested then the nitric acid can be very dilute and yet still dissolve both lead and lead sulphide. Its one of the technique used in oifields that suffer from lead or lead sulphide scaling. The solutions are very dilute so that all of the scale is dissolved and the waste is then pumped up to the surface. Its a cheap and effective method.

ALan