GB811734A - Improvements in or relating to processes for the production of shaped carbon articles - Google Patents

Abstract

In the production of carbon articles, a shaped article is produced from a mixture of a carbon-containing substance, e.g. coal, coke, or semi-coke, and a carbonaceous binder, e.g. tar, pitch, or synthetic resin, the article is subjected to an initial heat treatment for several days at 100-250 DEG C. to harden the binder by polymerization or condensation, and the initially-heated article is subjected to a subsequent final heat treatment to convert the article to amorphous carbon or graphite. Hardening of the binder may be facilitated by allowing access of air during the initial heating, when temperatures at the lower end of the range are used, or by including a polymerization accelerator in the binder, either admixed therewith or acting in gaseous form, e.g. chlorine, hydrogen chloride, polyvinyl chloride, chlorobenzenes, sulphur, sulphides, thiosulphates, thionyl chloride, aliphatic compounds, furfural, hydroquinone, naphthols, phenols, gallic acid, amino-, diamino-, and nitroso-compounds, cumolhydroperoxide, and benzoyl peroxide. The initial heating, which may be for up to 20 days at 120-150 DEG C., or, on average, 15 days at 150 DEG C., or 10 days at 210 DEG C., may be effected in an electrically, or superheated steam, heated chamber communicating, say through trap doors, with pre-heating and cooling chambers, through which the article passes in sequence, and the article may be embedded in powdered coke. The initially-heated articles may be converted to amorphous carbon in an annular kiln at 1000-1300 DEG C., or to graphite by direct passage of electric current in a graphitising furnace. Alternatively, the initial and final heating may be carried out continuously in an electrically, or gas heated tunnel kiln, the zone for initial heating being appropriately dimensioned in relation to the zone for final heating.