look up NurdRage on you tube, I have tried all three methodes they use to make nitric, I use the second one, I try to stay away from sulfuric as much as possible but have used the third methode in the vide to produce nitric wich does use sulfuric, which works quite well if you have the patience to do it and the equipment, also I have seen and read a few things about using a little bit of 35% hydrogen peroxide adding it to the "dirty" sulfuric and with the addition of a little bit of heat over time will clear up the acid, havent tested it myself but it is worth for research if you really need to clean the acid up for your purpose