The acid resistante depends on the Si/Al ratio of the zeolite. What kind of zeolite are you going to dissolve? Do you aprox. know its Si/Al ratio?

The zeolite is mordenite MOR with Si/Al ratio 15 and 20

HNO3 : HCl = 2 : 1

example: 5 mL HNO3 + 2.5 mL HCl

Thank you Arif. Will give it a try

For complete dissolution of silicon, you need to add a few drops of hydrofluoric acid in a closed system, then the excess amount of HF can be attached to the boron using boric acid. Microwave digestion shows good recoveries and total dissolution.

I was actually trying to avoid HF... I wish i could do it without HF

without HF, I do agree with Mr. Khanh's suggestion. You might go to the fusion with lithium metaborate and tetraborate as well

Among acids, concentrated HCl and H2SO4 are better for dissolving all of zeolites.  For this purpose, you must enter a zeolite sample in concentrated acid mixtures and heated them until the zeolite species dissolved. This method can be used for dissolving of zeolites that not digested in HF.   

Thank you all. I really appreciate your contributions