CHEMICAL CLEANING OF ULTRADISPERSED DIAMONDS WITH HYDROGEN-PEROXIDE

Ultradispersed diamonds (UDs) are made by the detonation of certain ex plosives and can be purified from nondiamond carbon by the use of aque ous hydrogen peroxide with added bases, salts, or acids. The UD is mos t effectively purified in the presence of small amounts of nitric acid . Studies have been made on the extent of UD purification in relation to treatment time, HNO3 concentration, and H2O2 consumption. Measureme nts have been made on the rate constants for the oxidation of nondiamo nd carbon at 150-260 degrees; the apparent activation energy is E appr oximate to 2.6-2.9 kJ/mole.