percentage of nitric acid needed ?

[aideauxa]

im new to this, im trying to read and learn as much as possible before starting gold/silver refining, and i wanted to know what was the minimum recommended percentage of nitric acid needed iv seen 98% on amazon but its like 99$ for a half liter..... i plan on making my own because its not really available to me..... so what concentration is needed to successfully achieve a working aqua regia?
thanks in advance for your help,
alex

 

[jimdoc]

You don't need 98%, 70% is just fine.

Jim

 

[Fournines]

Even 42% is just fine and cheaper than reagent grade.

 

[patnor1011]

I use 30% HNO3.

 

[aideauxa]

ok thanks for the info !!!!!!!!!!