Carbon anode for aluminum electrolysis refers to the carbon electrode connected with the positive electrode of the power supply in the aluminum reduction cell, which is an important part of the aluminum reduction cell. It includes carbon anode body and metal anode conductor. In the early development of aluminum industry, several thousand amperes of small pre baked anode were used, which was suitable for the production level of carbon industry at that time. In order to enlarge the anode size and improve the current intensity, in the early 1920s, referring to the continuous self baking electrode type of ferroalloy furnace at that time, the continuous self baking anode was installed on the aluminum reduction cell, and the side inserted rod type was adopted. In the 1940s, in order to simplify the anode operation and improve the degree of mechanization, the self baking anode with inserted rod was developed. In the 1950s, prebaked anode was widely used due to the improvement of carbon electrode quality and the success of vibration molding to manufacture large size prebaked anode carbon block. In the late 1980s, the current capacity of the latest prebaked anode aluminum reduction cell has reached more than 280-300ka.
The daily average consumption of Carbon anode for aluminum electrolysis is about 2cm in the process of aluminum electrolysis. It is necessary to add new anode paste (self baking anode) to the electrolytic cell regularly or replace new anode block (prebaked anode) regularly to keep the normal operation of the electrolytic cell.
The basic requirements of carbon anode for aluminum electrolysis production are: resistance to molten salt erosion, lower resistance, higher purity and better mechanical strength. The quality and working condition of carbon anode have great influence on the current efficiency, energy consumption and material consumption of aluminum electrolysis.
Under normal operation of aluminum reduction cell, ohmic voltage drop of carbon anode is 300-600mv, accounting for 10% - 15% of cell voltage. Net consumption per ton of aluminum carbon anode is 400-500kg (calculated by residual electrode recovery). The working quality of anode can be improved by improving the quality of raw materials, production formula and process, anode structure and anode working system
