How to get 98% nitrict acid from dilute solution

[Chimical_Ali]

Can somone tell me the easy/ low cost method of getting 98% HNO3 from 60-70% HNO3 solution.?

[Greippi]

The most obvious solution to concentrate it that I can think of would be: Dilute the acid with a base to make some sort of nitrate salt. Then distill that with concentrated sulphuric acid.