Abstract
Graphite, coke powder and charcoal powder sieved out between 100∼150 mesh were heated under the constant condition of oxygen supply, and measured their igniting points, maximum rising temperature and time of combustion. A small electric resisting furnace was arranged having a constant ratio of temperature rising, i. e. 40°C per minute, in which one gram sample previously dryed at 80°C was contained in a porcelain boat. Oxygen ejected through one milimeter diameter oliffice into the furnace under the constant pressure of 800 milimeter H2O. Igniting points are 502°C, 454°C and 95°C for coke powder, graphite and charcoal powder respectively, and they tend to become higher as increasing the mixing ratio of coke to graphite, and to lower as the charcoal is mixed to graphite. Times of combustion are 4.55 minutes for graphite, 3.70 minutes for charcoal powder and 3.35 minutes for coke powder. Coke powder has an influence of increasing the time when it is mixed to graphite but by mixing charcoal to graphite up to 70%, it becomes longer than both of each constitutional blacking. The differences between the maximum rising temperature and igniting point are 407°C for charcoal, 155°C for graphite and 100°C for coke. In this case the effects of mixing are same as that of igniting points. When each of three is mixed together, the charcoal powder has an obvious effect on igniting points and the maximum rising temperature.
