METHOD FOR SYNTHESIZING DIAMOND PARTICLES

摘要

PURPOSE:To continuously obtain diamond particles uniform in particle diameter with a simple device at high yield and at low cost by injecting gaseous powder incorporating diamond particles to thermal plasma jetted as a plasma jet and quenching the thermal plasma. CONSTITUTION:A DC plasma torch having a cathode 1 and an anode 2 is used and voltage is impressed between both electrodes 1, 2 while allowing discharge gas to flow and DC arc discharge is generated and arc plasma of >=5000 deg.C is generated and also a gaseous raw material consisting of H2 and CH4 which have fed to an arc plasma generating part from a discharge gas pipeline 5 provided on the anode 2 is heated and activated and jetted as high-velocity plasma jet 3. Then gaseous powder 4 incorporating fine diamond particles to be nucleus is injected to this jetted thermal plasma 3 through a powder filter 15 and allowed to collide against it and quenched and diamond is grown in a vapor phase on the surfaces of the fine diamond particles. Then diamond particles having been regulated to required size are sized with a size classifier 9 via a pump 8 and recovered in a powder collector 10.