I-Graphite petroleum coke(GPC), njengesikhulisi sekhabhoni, iyingxenye ebalulekile embonini yokwenza insimbi. Isetshenziswa ngokuyinhloko njengesengezo sekhabhoni ngesikhathi sokukhiqizwa kwensimbi ukuze kwandiswe okuqukethwe kwekhabhoni, kuncishiswe ukungcola, futhi kuthuthukiswe ikhwalithi yonke yensimbi.