| 摘要 |
1,145,351. Ground coke. MARATHON OIL CO. 4 March, 1966 [4 March, 1965], No. 9670/66. Heading C1A. [Also in Division B2] Finely divided carbon is produced by comminuting coke in an inert O 2 -free atmosphere, e.g. steam, N 2 , H 2 , He or Ar, to a weight average particle size of not over 2À5Á, and is immediately protected from oxidation, e.g. by coating. The coke may be fluid petroleum or delayed coke, preferably containing not more than 7% volatiles. Comminution may be effected in a fluid energy mill, e.g. using steam at a nozzle pressure of 100-500 p.s.i.g., to give a size distribution with at least 90% less than 5Á, at least 50% less than 1À5Á and at least 10% less than 0À5Á. The coating agent may be solid or liquid and should melt or evaporate during compounding of the carbon into plastics and rubber formulations; examples are zinc stearate, stearic acid, and primary amines. It may be added to the classifier of the mill in amounts of 0À1 to 1À0% by wt. of the carbon. (Examples of unsuitable grinding atmospheres are O 3 , NH 3 , HCl and N oxides.) |
