Time:2023.08.25Browse:1
(1) Degree of graphitization: As the degree of graphitization of carbon materials increases, their activity towards gases decreases. The higher the final heat treatment temperature of carbon materials, the higher the temperature at which they begin to oxidize, so graphite products have a higher starting oxidation temperature than carbon products.
(2) Structural state: Carbon materials with loose and porous surfaces are prone to react with gases. For example, the surface dense pyrolytic graphite treated at 3200 ℃ begins to oxidize in air at a temperature of 850 ℃, while the porous and loose charcoal on the surface begins to burn at 360 ℃.
(3) Catalytic effect of impurities: Carbon materials contain impurities that have a significant impact on their gasification reaction, with varying catalytic effects. For example, iron, cobalt, nickel, copper, manganese, etc. are catalysts for the oxidation of carbon materials, while impurities such as boron, titanium, and tungsten have inhibitory effects on oxidation. Alkali metals and transition metals exhibit great catalytic effects on any gasification reaction of carbon materials.