Graphitization is a core step in the production process. In what equipment is it usually carried out?

Graphitization, as the core production process, is typically carried out in four types of equipment: the Acheson graphitization furnace, internal series graphitization furnace, box-type graphitization furnace, and continuous graphitization furnace. The specific analysis is as follows:

Acheson Graphitization Furnace

As a traditional mainstream piece of equipment, it utilizes the principle of resistance heating to raise the temperature to 2,800-3,000°C, making it suitable for the production of high-purity graphite. This furnace type features a simple and robust structure. However, it has drawbacks such as a long production cycle, high energy consumption (approximately 4,000-4,800 kWh/t), and low efficiency. Currently, companies like Putailai and Shanshan still widely adopt this technology and have improved energy efficiency by optimizing the ratio of resistance materials and enhancing the insulation structure.

Internal Series Graphitization Furnace

This furnace heats directly through the electrodes themselves, eliminating the need for resistance materials to generate heat. It offers advantages such as high thermal efficiency, short power-on time (only 1-2 hours during the high-temperature stage), and relatively low energy consumption (approximately 3,300-4,000 kWh/t). The furnace types include I-type, U-type, W-type, and plum-blossom-type, with the U-type being the most widely used. Carbon plants in Germany, the United States, and Japan have adopted this technology on a large scale for the production of large-sized ultra-high-power graphite electrodes. However, its maximum furnace temperature (around 2,800°C) is slightly lower than that of the Acheson furnace.

Box-Type Graphitization Furnace

This technology employs carbon or graphite plates to construct a box structure, using the material itself as the resistance heating element instead of traditional coke-based resistance materials. By optimizing the thermal field distribution, it reduces energy consumption. However, it faces challenges such as material oxidation, low thermal efficiency, and uneven temperature distribution within the furnace. Companies like Hebei Kuntian and Shanshan Co., Ltd. hold relevant patents and have improved product consistency by enhancing the box sealing and optimizing the power-on curve.

Continuous Graphitization Furnace

This furnace enables continuous material feeding, high-temperature treatment (2,500-3,000°C), and cooling discharge. It offers advantages such as high production efficiency, low energy consumption, and a high degree of automation. Temperature gradient control is achieved through resistance heating (external heating method) or self-heating of the material (internal heating method). However, the internal heating method is more complex to operate due to the self-heating and movement of the material. Companies like Kuntian and BTR are promoting the industrialization of this technology, which is expected to replace intermittent production modes in the future.

Industry Trends and Equipment Selection Recommendations

• Energy Consumption Optimization: Internal series and box-type furnaces reduce energy consumption by minimizing the use of resistance materials, while continuous furnaces further enhance efficiency through heat recovery, aligning with the demand for low-cost production under carbon neutrality goals.
• Efficiency Enhancement: Continuous furnaces enable 24-hour uninterrupted production, with a single-line capacity reaching up to 10,000 tons, more than tripling the output of traditional equipment. This makes them suitable for large-scale anode material enterprises.
• Product Quality: The Acheson furnace remains preferred for high-end graphite production due to its superior temperature uniformity, while the continuous furnace meets the stringent consistency requirements of power battery materials through precise temperature control.
• Technological Iteration: New processes such as microwave graphitization and plasma graphitization are under research and development, potentially breaking the 3,000°C temperature limit and further shortening processing times in the future.