Carbon products require a variety of performance characteristics depending on their intended use. To achieve this, raw materials must be selected based on their intended use and their dosage and particle size must be carefully coordinated. The properties of each raw material must be balanced within the product to achieve the desired performance. The process of combining one or more solid raw materials with different properties and particle sizes with a binder in a specific ratio is called batching. Batching is a crucial step in the production of carbon products.
Generally speaking, batching involves three aspects: selecting the type of carbon raw materials and determining the ratio between them; determining the particle size composition of the solid carbon raw materials, that is, the ratio of particles of different sizes; and determining the type, properties, and dosage of the binder.
The performance of a carbon product is based on the fundamental properties of its primary raw materials. Therefore, when designing the batching process, raw materials should be selected based on the product's performance requirements and the characteristics of the different raw materials. Generally, the following basic principles should be considered: For products requiring higher purity, such as graphite electrodes and anode paste for aluminum electrolysis, low-ash raw materials should be used.
High-purity graphite products have higher requirements on raw materials, such as ash content below 5%; for graphite products with high strength requirements, more pitch coke should be used, and in some cases, a small amount of carbon black can be added; for products requiring good resistance to high-temperature thermal shock, petroleum coke is better than pitch coke; for products with low current density during use, such as electrode paste, anthracite, metallurgical coke or graphitized metallurgical coke can be used to reduce costs; for metallurgical furnace linings and blast furnace carbon blocks, high-ash raw materials can be used.