Customized graphite cathode block material is a carbon block made of high-quality anthracite, coke and graphite. Used as cathode of aluminum reduction cell. It is built at the bottom of the electrolytic cell, also known as the bottom carbon block. The characteristic customized graphite cathode block material has the dual functions of conducting electricity and forming the inner lining of the electrolytic cell. High temperature resistance of graphite cathode block is required in aluminum electrolysis production. It has the characteristics of resistance to molten salt corrosion, good conductivity, good thermal conductivity, high mechanical strength, good thermal shock resistance and strong sodium corrosion resistance, which is conducive to energy saving and improvement of cell life in aluminum electrolysis production.

Types of customized graphite cathode block material according to the quality requirements of products, selected raw materials and process conditions, China basically divides customized graphite cathode block material into three categories: ordinary graphite cathode blocks, semi graphite cathode blocks and graphite cathode blocks. Ordinary graphite cathode block material is mainly made of anthracite calcined at 1250 ~ 1350 ℃. Semi graphite cathode blocks are divided into two types according to different production processes.
One is to calcine anthracite with high-quality high-temperature electricity, or take more graphite fragments or even all graphite fragments as aggregate. The formed green products are only roasted (the roasting temperature is not more than 1200 ℃) and will not enter the graphitization furnace for heat treatment. This kind of customized graphite cathode block material is called semi graphite cathode block.
The other uses more graphitized coke as aggregate. After roasting, the raw products enter the graphitization furnace for heat treatment at the temperature of 1800 ~ 2000 ℃. This kind of carbon block is called semi graphitized carbon block. The former has higher strength and hardness, while the latter has better conductivity and integrity. Customized graphite cathode block material, with graphitized coke as raw material, its graphitization treatment temperature should reach about 2500 ℃.
The difference between semi graphite cathode block and graphite cathode block lies in the degree of ordered lattice arrangement of products, that is, the degree of graphitization. The degree of graphitization can be expressed by the resistivity of the product. The lattice of customized graphite cathode block material is basically in an orderly state, and the resistivity is less than 15 μ Ω? m； The graphitization degree of semi graphite cathode block is low or only partially graphitized, and the resistivity is 15 ~ 45 μ Ω? m。 In the process, it is shown as the heat treatment temperature. The maximum heat treatment temperature of semi graphite cathode block is about 2000 ℃, and the graphitization treatment temperature of customized graphite cathode block material is 2500 ~ 2800 ℃. Common cathode carbon block, resistivity 50 ~ 60 μ Ω? m。
Customized graphite cathode block material is the conductive material used in the cathode of aluminum electrolytic cell, which represents the development direction of aluminum electrolytic industry. With the technological progress and development of electrolytic aluminum industry, the electrolytic cell is developing towards a large capacity of more than 300kVA, and the requirements for cathode materials are higher. The main advantages of customized graphite cathode block material are to strengthen the current, improve the current efficiency, achieve the purpose of increasing production and energy saving, and make the electrolytic cell operate stably. The larger the cell type is, the more obvious the stable operation effect is, and the more obvious the improvement of current efficiency is. The unit capacity of aluminum electrolytic cell using graphitized cathode is increased by 10-15%, and the power saving per ton of aluminum is more than 600kwh. Graphitized cathode aluminum electrolytic cell is one of the materials that the state gives priority to promote and develop in the electrolytic aluminum industry because of its obvious effect of energy saving, consumption reduction and emission reduction.