Coal Tar Pitch Pyrolysis Condensation Behavior Research And The Development Of Cold Ramming Paste Of Carbonaceous

The processes of thermal weight loss of coal-tar pitches are studied by means of TGA. The characteristics of pyrolysis condensation of coal-tar pitches are analyzed. The character of pyrolysis condensation of medium pitch is compared with that of modified pitch. The influences of heating rate on the pyrolysis condensation of coal-tar pitches are investigated. It is found that rapid heating results in more constituents of coal - tar pitches evolving and is unfavourable to the enhancement of coking value of coal-tar pitches. The effect of atmospheres on the pyrolysis condensation of coal-tar pitches is studied. The results show that coal-tar pitches pyrolyze more easily in N2 flow, which results in increasing of thermal weight loss of coal-tar pitches.The modification effects of aromatic nitro-compounds on the binder used for cold damming paste have been comparatively studied. 2,4-dinitro toluene and meta-dinitrobenzene have been optimized as modification additives of the binder. It is shown that the addition of two kinds of additives increases markedly the coking value of binder, which increasement is as many as 4%-7%. Moreover, the additives can improve the plastic property of binders. The suitable additives content is about 5%.Through the thenno-gravimetric analysis of binders, effect of aromatic nitro-compounds on the reaction process of pyrolytic condensation of binders has been investigated. The mechanism of improving coking condensation behavior by aromatic nitro-compounds has been preliminarily explored. The nitro-groups containing in aromatic nitro-compounds have strong electron-attracting and high reactivity. This results in catalytic coking condensation of aromatic hydrocarbon molecules containing in the binders. As the amounts of nitro-groups increase, the effects of catalytic coking condensation are better.The structural compositions of aromatic nitro-compounds are similar to aromatic hydrocarbon molecules in binders. So it is beneficial to improving the application performance of binder and the quality of carbon pastes. By means of addition of two kinds of additives, the pyrolytic weight loss of green carbon body during baking has been reduced obviously. The bulk density of baking body has been effectively improved. The compressive strength of baking body has been increased by a factor of 13%-44%. The additives improve greatly the application performance of the cold damming paste.