1. Ammonium nitrate and other amine compounds are used to decompose and destroy the structure of graphite and organic carbon black adsorbed on the surface of nano-diamond at 180℃ ~ 200℃, reduce the surface temperature of nano-diamond, and at the same time, graphite oxide and organic carbon black can achieve purification of nano-diamond.
2. Non-diamond carbon is used to react with sulfuric acid and nitric acid at 280℃ to generate carbon dioxide gas and water-soluble substances to separate non-diamond carbon and purify synthetic diamond
3. According to the different density of graphite and flake alloy catalyst and diamond, water washing can remove a large number of unconverted graphite, because diamond is hydrophobic, easy to float, so special attention should be paid to the loss of diamond
4. Perchloric acid is a strong oxidant, after heating can make graphite slowly all oxidized, the metal catalyst has been removed and a large number of graphite materials placed in a beater, pour perchloric acid, sometimes add a small amount of potassium chromate as a catalyst, and then heating the solution began to react, as the reaction proceeds, the color of the solution from black gray - green with - brown orange red, when the solution is orange red, After all the graphite has been removed, it can be removed from the electric heating plate, cooled to room temperature, poured out the upper liquid, and washed until neutral and then dried.