| 摘要 |
The fibres consist essentially of beta crystalline variety, are essentially rectilinear and have a mean diameter of between approximately 0.5 and approximately 4 mu m, a length of between 20 and 300 mu m and an aspect ratio higher than 20. The process for preparing them comprises the manufacture of granules based on silica, carbon black and catalyst and bringing them into contact with an atmosphere of hydrogen and nitrogen and/or ammonia. |
