Mainstream Furnace Types and Processes for the Graphitization of Anode Materials

Currently, the main furnace types used in the graphitization process for anode materials include the Acheson graphitization furnace, the in-line graphitization furnace, the chamber-type graphitization furnace, and the continuous graphitization furnace. Among these, the Acheson graphitization furnace is the most widely used, while the in-line graphitization furnace is used to a limited extent. The chamber-type and continuous graphitization furnaces are new types developed in recent years; the chamber-type graphitization furnace has seen relatively rapid development, primarily through the retrofitting of Acheson furnaces and some new construction. Continuous graphitization furnaces are all newly built and are still in the experimental phase; their designs and processes are not yet fully mature, and it will take some time before they are widely adopted. Because there are significant differences among the various furnace types in terms of charging methods, production processes, and the use of auxiliary materials, the quality of anode materials produced by different furnace types also varies significantly.

In an Acheson furnace, carbon-based anode materials are loaded into single-chamber (single-hole crucible) crucibles, which are then placed inside the graphitization furnace with resistive material inserted between them to serve as a resistor. After insulating material is packed on both sides and the top cover, graphitization is completed by applying an electric current. In an in-series graphitization furnace, carbon-based anode materials are loaded into a multi-chamber crucible (9-chamber crucible). The crucibles are then connected end-to-end in series and placed inside the graphitization furnace. After insulating material is packed on both sides and the top cover, graphitization is completed by applying an electric current. In a box-type graphitization furnace, the carbon-based anode material is loaded directly into a large chamber pre-fitted with carbon or graphite plates. A carbon or graphite cover plate is added to serve as a resistor. After insulating material is packed on the top and both sides, graphitization is completed by applying an electric current. In a continuous graphitization furnace, the carbon-based anode material is continuously fed into the furnace chamber, where it undergoes high-temperature graphitization before being cooled and discharged.