HETEROGENEOUS LIQUID-PHASE CRYSTALLISATION OF DIAMOND

摘要

The present invention relates to a principle for the heterogeneous liquid- phase crystallisation of diamond, wherein said crystallisation is carried ou t on the heterogeneous surface of a catalyst. This surface is characterised in that, during the high-temperature dehydrogenation process of heavy hydrocarbons containing bitumen-tar and asphaltenes, the catalyst performs a chemisorption of hydrogen under an atomic form. The catalyst surface submitt ed to the chemisorption exhibits a characteristic which is essential for the crystallisation of diamond in that only the growth of crystalline carbon- diamond is possible. This invention also relates to a method for implementin g this principle with a yield in excess of 3,000 carats of diamond crystals having various fractions of between 100 and 1000 microns. During the experiments, the largest diamond crystal obtained had dimensions of 3.5 x 3. 5 mm, while the production of diamond crystals with maximal dimensions was not contemplated as a goal.