The Role of Modified Asphalt in the Preparation of Anodes

The role of modified asphalt in the pre-baked anode primarily includes the following aspects:

‌Bonding Action: Modified asphalt, acting as a binder, can tightly bond solid carbonaceous raw materials such as petcoke and asphalt coke together, forming pre-baked anode blanks with certain shapes and sizes. This bonding action not only enhances the overall strength of the pre-baked anode but also improves its electrical conductivity and corrosion resistance._

‌Carbonization Process: During the baking of pre-baked anodes, the upgrading asphalt undergoes pyrolysis and condensation reactions, gradually transforming into coke, which significantly enhances the mechanical strength and conductivity of the pre-baked anodes. The formation of coke strengthens the overall structure of the pre-baked anodes, resulting in a substantial increase in mechanical strength.‌

Fill Pores: Modified asphalt can flow and fill the gaps between solid carbonaceous raw material particles during the heating softening and subsequent coking process, making the structure of the pre-baked anode denser. This not only increases the density of the pre-baked anode but also enhances its erosion resistance and reduces the penetration of gases and electrolytes.

Enhanced Conductivity: The carbon structure formed from the coking of modified asphalt possesses excellent electrical conductivity, enabling the construction of a continuous conductive network in pre-baked anodes. This reduces resistance and improves electrolytic efficiency, which is crucial for achieving uniform current distribution and enhancing electrolytic efficiency in the aluminum electrolysis process.

Enhanced Mechanical Strength and Wear Resistance: Modified asphalt boasts superior strength and adhesive properties, effectively improving the mechanical strength and wear resistance of pre-baked anodes. This allows pre-baked anodes to withstand greater pressure and impact forces, extending their service life during the electrolytic process.

Enhanced Corrosion and Chemical Resistance: Modified asphalt boasts excellent chemical stability and corrosion resistance, effectively combating acidic and alkaline corrosion in electrolytes, thereby extending the service life of pre-baked anode blocks. This corrosion resistance ensures that the pre-baked anodes maintain good chemical stability in the electrolyte, reducing the likelihood of dissolution or corrosion.

Enhanced Heat Stability: Modified asphalt maintains excellent stability at high temperatures, resisting softening and loss. This ensures the performance stability of pre-baked anodes during the high-temperature electrolysis process, minimizing deformation or cracking.