After mixing pitch and raw materials evenly and sufficiently, they can be sent to granulation + pre-carbonization kiln. The electrical heating device will provide staged heating to help the mixed materials coated and carbonization. The complete granulation and pre carbonization system contains low-temperature section, high-temperature section, pre-carbonization section, cooling section and exhaust gas treatment system. The maximum temperature can reach 1100℃. With modular design, the granulation + pre-carbonization kiln can be combined according to actual production requirements, such as high temperature section + carbonization section + cooling section, carbonization section + cooling section, etc.