| 摘要 |
PURPOSE:To carry out the refining of rare earth metal concentrate at a low cost, by exposing powder of rare earth metal concentrate having a specific particle size to a plasma atmosphere. CONSTITUTION:Powder of rare earth metal concentrate 2 having particle size of 100-300 mesh and a rear earth metal content of about 60% is filled in the hopper 1 and the lids 1a and 9a are closed to seal the whole processing system. Ar gas is introduced from the gas source 12 into the hopper 1 by opening the valve 13. The whole processing system is filled with Ar gas by the action of the vacuum pump 14, and the atmosphere is adjusted to the pressure of about 3 Torr. The powder of the concentrate 2 is introduced continuously into the heat-resistant glass tube 6 driving the screw conveyor 4, and at the same time, radiofrequency power is supplied from the electrical source 8 to the radiofrequency induction coil 7 to generate plasma in the heat-resistant glass tube and to activate the concentrate powder 2. The powder 2 subjected to the plasma treatment is stored temporarily in a tank 9, delivered periodically to the dissolution tank 10, and dissolved with e.g. hydrochloric acid solution 11, etc. |
