Forming method of electrode paste
In the production process of electrode paste, there are many molding methods, the main methods are molding, extrusion molding, vibration molding, and isostatic compression molding.
1. Molding method
This method is to use a vertical press, first make a mold according to the shape and size of the product, and then load a certain amount of kneaded paste or pressed powder into the mold on the workbench of the press, start the press to apply pressure to the paste or pressed powder, and maintain it for a certain period of time to form it, and then eject the pressed embryo from the mold.The molding method can be divided into one-way pressing, two-way pressing, hot pressing and cold pressing according to different processes and equipment conditions.The molding method is suitable for pressing products with small size in the three directions and little difference in size in the three directions, uniform density, dense structure and high strength, but the products are anisotropic and are mainly used in the production of electrode pastes, anode pastes and various special graphite products.
2. Extrusion molding method
The extrusion method is to use a horizontal extruder. The paste is first loaded into the material chamber of the press, and the main plunger of the press is used to apply pressure to the paste, and then pre-pressed, and then the pressure is applied so that the paste is squeezed out through the nozzle installed in front of the material chamber that is consistent with the cross-section shape and size of the product. , And then cut off with a cutter according to the required length, that is, the embryo is squeezed.The extrusion method is suitable for bars, pipes or other special-shaped products with relatively large L/D.The extrusion method can be continuously produced, with high production efficiency, simple operation and high degree of mechanization, but the bulk density and mechanical strength of the product are low, and it is anisotropic. It is mainly used for the production of graphitized electrodes, carbon electrodes and carbon blocks.
3. Vibration forming method
Vibration forming is to load the paste into a mold placed on the vibrating table of the vibration forming machine, and then place a heavy hammer on it, using the high-speed vibration of the vibrating table to make the paste achieve the purpose of compaction and forming.The vibration forming machine has a simple structure. As long as a smaller forming pressure is applied to the paste, it can produce larger-size products. It is especially suitable for the production of stubby products and some special-shaped products with little difference in size in the three directions of length, width and thickness, such as pre-baked anode, cathode, carbon block and large-size or extra-large-size carbon electrode and crucible.
4. Isostatic compression molding method
Isostatic compression molding is done in an isostatic pressure vessel. It loads the pressed powder into an elastic mold made of rubber or plastic, seals it and puts it in a high-pressure container, and uses an ultra-high-pressure pump to inject a high-pressure liquid medium (oil or water) to make the pressed powder pressed and formed.Isostatic compression molding has cold isostatic compression molding and hot isostatic compression molding.Isostatic compression molding can produce isotropic products and special-shaped products. The structure of the products is uniform, and the density and strength are particularly high.Generally used in the production of special graphite, iron is mainly used in the production of large-scale special graphite products.
