| 摘要 |
PURPOSE:To perform uniform pulverization of the titled calcined powder without absorbing the moisture, CO2 etc. in the ambient atmosphere, by jetting into the grinding chamber, of calcined powder for Y(La)-Ba-Cu-O-based superconducting ceramics having rhombic texture together with a supersonic oxidative gas stream of specific composition. CONSTITUTION:Calcined powder of composition MBa2Cu3O7-x (M is Y or La) having rhombic texture is coarsely ground and introduced into a raw material hopper 2. The resulting powder is then jetted into a grinding chamber 6 together with a supersonic oxidative gas stream with the CO2 content of <=0.001wt.% and dew point of <=-70 deg.C, containing >=20vol.% of O2 which is introduced through a gas feed main pipe 4, to effect pulverization into fine powder with an average size <=2mum through such collisions as between the raw powder and said gas, among powder and between the powder and the wall of said chamber, then recovering through a cyclone 7. Thus, the release of the Ba in the calcined powder can be prevented and a superconductor with narrow critical temperature range can be obtained. |
