Views: 0 Author: Site Editor Publish Time: 2026-01-12 Origin: Site
Blending is an important step in the production of aluminum anodes. The process may seem simple, but different times, temperatures, negative pressures, cutter gap sizes, etc. can lead to different quality results, which have a significant impact on both the raw anodes and the finished products.
Ensure uniform mixing of different-sized aggregates to enhance density;
2. Make the binder evenly cover the surface of the dry material particles, penetrate the pores, and bind the particles together;
3. Ensure uniform distribution of the dry material and the binder, with appropriate temperature, to improve plasticity.
Principle of blending: The materials are evenly distributed in the mixing machine, achieving a dynamic equilibrium at a certain moment. Separation and mixing alternate. There are generally three types of actions:
a) Convection mixing; b) Diffusion mixing; c) Shear mixing (This process also involves material particle fragmentation.
The gap between the cutter should be controlled to prevent changes in the particle size of the formula).
2. Interaction between dry materials and asphalt: The adsorption, infiltration and capillary penetration between them ensure that the paste is mixed uniformly and reaches the required plasticity. This process is accompanied by the action of chemical bonds, which can be intuitively described as the influence of the wetting contact angle.
The angle formed by the liquid when it contacts the surface of a solid is called the contact angle, also known as the wetting angle. Based on the size of the wetting angle, the wetting condition can be determined: θ = 0° or does not exist; spreading 0° < θ < 90°; immersion 90° < θ < 180°; sticky (in the 90° industry, it is usually recognized, and there are also studies considering the artificial critical angle to be 60°)
Wetting is an important behavior at the solid-liquid interface, and the wetting angle is closely related to the nucleation of crystals in the material. a) After the thermometer is broken, the mercury is in a rolling ball state on the ground, as shown in Figure 1, and it does not wet; dew drops on the lotus leaves have a very large wetting angle, and basically do not wet. b) Water droplets on paper towels have a very small wetting angle, as shown in Figure 2, and the wettability is very good. Therefore, by artificially changing the wetting angle of the asphalt binder on the carbon surface through temperature, the asphalt's wettability can be improved. Generally, the paste temperature is controlled at 160-180℃, which not only ensures that coal tar asphalt can be fully softened and the flow is enhanced to improve the wettability, but also prevents coal tar asphalt from undergoing high-
temperature oxidation, thereby reducing the plasticity of the paste.
Mixing Temperature: Generally, medium-temperature modified asphalt is used, with a softening point ranging from 104 to 112℃. It is 50 to 60℃ higher than the softening point. Bitumen coal has better fluidity and wetting effect. If the temperature is too high, some components of bitumen coal will decompose and volatilize, causing the mixture to age (so production should be interrupted and the temperature of the mixing pot should be controlled). Usually, the dry mixing should reach 120℃, and the wet mixing should reach 170-180℃.
2. Mixing Time: Extending the mixing time is beneficial for the mixture to be more uniform. At the same time, the wet contact angle will rapidly decrease within 40 minutes, and there will be little change after that (so the wet mixing time is generally controlled at 30-40 minutes). The time for dry mixing depends on the time it takes for the dry material temperature to reach the predetermined temperature. 3. Dry Material Particle Size: The proportion of each particle size component of the dry material has a significant impact on the paste. In addition to the original formula, negative pressure will remove the powder, the cutter will crush the particles, and this also affects the factors.
