| 摘要 |
PURPOSE:To provide a simple, low-cost process for the preparation of hollow pitch beads without addition of any special additives, which comprises heat melting coal or petroleum pitch having a particular softening point, spraying the pitch into a gas phase, where the pitch is contacted with a coolant. CONSTITUTION:Coal or petroleum pitch having a softening temp. of 100-320 deg.C is heat molten. The molten pitch is sprayed into the gas phase within a spray column having a height of 20m or more by employing an appropriate kind of nozzle and an appropriate application pressure according to need so as to cause the pitch to be contacted with a coolant (e.g., air), thereby obtaining hollow pitch beads. The hollow beads are useful as a bulking material for paints, a low-temp. thermal insulant, etc. Moreover, hollow carbon beads are obtd. by oxidizing these hollow pitch beads in an oxidative gas or liq., followed by calcination in a non-oxidative atmosphere at 900 deg.C or above.
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