Recycling use method of nitration acid

The invention relates to a method for preparing 1,5(1,8)-hexa-nitride by reclaiming and recycling nitric acid, which comprises: feeding 1,5(1,8)-di-phenoxyl anthraquinone into the nitric acid at a temperature of between 15 and 50 DEG C, wherein the mass ratio of materials, namely the nitric acid to sulfuric acid to the 1,5(1,8)-di-phenoxyl anthraquinone is 6.4-7.8:15-30:1; performing reaction for 6 to 8 hours at a temperature of between 30 and 65 DEG C after the feeding is over, cooling the mixture to the room temperature, filtrating the mixture, collecting mother liquor acid and filter cakes, feeding the filter cakes into cold water for pulping, filtrating the filter cakes, using water to wash the filter cakes to be neutral, and obtaining 1,5(1,8)-hexa-nitride; and taking a fixed quantity of the collected mother liquor acid, supplementing fuming sulfuric acid or introducing sulphur trioxide and concentrated sulfuric acid, restoring the mother liquor acid to the prior nitric acid, namely the ratio of the nitric acid to the sulfuric acid is 6.40-7.8:15-30, and using the mother liquor acid for next nitration. The consumption of the sulfuric acid for preparing one ton of the 1,5(1,8)-hexa-nitride by the method is less than 1,000 kilograms, and is only 20 percent of that of the prior art, so that the method greatly reduces emission of waste acid water, and has obvious environmental benefit and economic benefit.