METHOD OF PRODUCING SYNTHETIC DIAMONDS AND APPARATUS FOR REALISING SAID METHOD Russian patent published in 2013 - IPC C01B31/06 C30B29/04 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical and jewellery industry. Diamonds are synthesised in a high-frequency induction crucible furnace with frequency range of 60-100 kHz. A ceramic crucible 1 is fitted with a ceramic grid 2 with holes with diameter of 0.3-0.5 mm, lying at a height of 20 mm from its bottom, and a ceramic pipe 3 with inner diameter of 15-20 mm for feeding a mixture of methane and carbon dioxide with specific volume rate of 60-70 h^-1. Sodium carbonate and potassium carbonate are fed into the crucible 1, said carbonates being mixed in equimolecular ratio and heat treated at 400-450°C for 2 hours. Diamond synthesis is carried out in one day at temperature of 700-900°C in a melt of said salts in the presence of a catalyst - powdered iron with granule size of 3-5 mm in amount of 5-10% of the molten mass. Gas supply is cut at the end of the process. The molten salts, along with the catalyst and diamonds, are poured into moulds. The cooled down ingots are fed into a reactor - crystalliser 5. After dissolving the sodium carbonate and potassium carbonate, the suspension of catalyst and diamonds is fed onto a filter 6.The obtained filtrate is used in the reactor-crystalliser 5, and the diamond crystals are separated from the catalyst by a magnet.

EFFECT: invention simplifies the process, increases efficiency of the process and excludes toxic and explosive substances.